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Module on Plants

INTEGRATION OF FRESHWATER BIODIVERSITY INTO AFRICA’S

DEVELOPMENT PROCESS:

MOBILIZATION OF INFORMATION AND DEMONSTRATION SITES

Demonstration Project in the Gambia River Basin

By

Dr. Fatimata Niang Diop

September 2010

Training of Trainers

Module

On

The monitoring

of flora and

aquatic

vegetation

Module on Plants

INTEGRATION OF FRESHWATER BIODIVERSITY INTO AFRICA’S

DEVELOPMENT PROCESS:

MOBILIZATION OF INFORMATION AND DEMONSTRATION SITES

Demonstration Project in the Gambia River Basin

Training of Trainers Module

On

The monitoring of flora and aquatic

vegetation

Wetlands International Afrique

Rue 111, Zone B, Villa No 39B BP 25581 DAKAR-FANN

TEL. : (+221) 33 869 16 81 FAX : (221) 33 825 12 92

EMAIL : [email protected]

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TABLE OF CONTENTS Introduction ........................................................................................................................................................................ 4

Course 1. An Introduction to the monitoring plan ........................................................................................................ 10

1.1. Why monitor flora and vegetation .................................................................................................................... 10

1.2. The role of plant communities in the monitoring of ecosystems ....................................................................... 10

Course 2. General information on aquatic plants ......................................................................................................... 12

2.1. The ecology of aquatic plants ............................................................................................................................ 12

2.2. The morphology and biology of aquatic plants ................................................................................................. 13

2.3. Structure of a plant formation ........................................................................................................................... 14

2.3. Principle types of aquatic plants ........................................................................................................................ 14

Course 3. PRINCIPLE AQUATIC ECOSYSTEMS AND STUDY SITES ................................................................................... 16

Course 4. TERMINOLOGY AND THE IDENTIFICATION OF AQUATIC PLANTS ................................................................. 20

4.1. Terminology..................................................................................................................................................... 20

3.2. Illustrations of select aquatic plants ............................................................................................................. 22

Course 5. METHODS FOR MONITORING FLORA AND AQUATIC VEGETATION .............................................................. 28

5.1. Preparatory phase ............................................................................................................................................. 28

5.2. Materials ............................................................................................................................................................ 28

5.3. Collection methods: techniques of transection and phytosociological data collection ..................................... 29

5.4. Data analysis ...................................................................................................................................................... 36

REFERENCES ...................................................................................................................................................................... 42

ANNEXES ........................................................................................................................................................................... 43

Annex 1. Data collection sheet...................................................................................................................................... 43

Annex 2 : List of freshwater flora in the Gambia River basin ........................................................................................ 45

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INTRODUCTION

As part of the implementation of the project “Integration of Freshwater Biodiversity into Africa’s

Development Process: Mobilization of Information and Demonstration Sites” Wetlands

International has implemented a number of programs to ensure effective consideration and the use

of data relevant to biodiversity in the decision-making and implementation of development projects

across the continent. The first phase focusing on the regional evaluation of the conservation status

of freshwater biodiversity has indicated that many freshwater species are severely endangered. In

addition, the management of water resources must take into account the requirements (needs) of

freshwater species. This approach is at the heart of the concept of environmental flows, which aim

to ensure that there is enough water to meet environmental, economic and social needs. After the

first phase, the second phase targets a case study in the Gambia River basin for a better assessment

of biodiversity in development projects. Within this framework, a monitoring plan with regard to

the construction of the Sambagalou dam was developed, and should allow for the documentation of

potential changes in the habitats. This can be the case thanks to careful monitoring of species and

habitat dynamics that should enable the identification of potential negative changes and as such that

adequate measures are taken. Different taxonomic groups will be monitored. In the framework of

this document, we will focus on the development of a method for monitoring aquatic plants. They

are typically studied through various methods. The study of flora and aquatic vegetation is generally

based on phytosociological methods relying on the use of transects and phytosociological data

collection. Phytosociology, or the science of plant groupings, allows the description and

understanding of vegetation, the organization in space and time, both on the quantitative and

qualitative levels of the plant species they constitute (Rameau, 1987). Phytosociology is based on

the assumption that plant species, or even better plant associations, are considered the best

integrating factors of all those ecological factors responsible for the distribution of vegetation

(Beguin et al., 1979). Vegetation is considered to reflect site conditions (Beguin et al. 1979;

Rameau, 1987). The use of transects enables the description of the vegetation distribution. These

phytosociological data will allow for the collection of quantitative data. The use of records

necessitates a directed sampling that requires a few basic practices and precautions (Guinochet,

1955).

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GOALS AND OBJECTIVES OF

THE MODULE

This module is designed for the state’s

technical services, NGOs and the local

communities of the Gambia River Basin to

implement in a practical manner a preliminary

plan for the monitoring of freshwater

biodiversity in the Gambia River Basin. It

offers a precise and operational methodology

to monitor the status and dynamics of

freshwater plants. The creation of this type of

course involves choices that must be justified

on the field and eventually adjusted.

Ultimately, this course will enable a:

‐ General understanding of concepts

related to plant ecology

‐ Recognition of the most common

aquatic plants of the Gambia River

Basin

‐ Grasp a method of studying and

monitoring flora and aquatic

vegetation

Photo1 : Wetlands workshop (Simenti, 2009)

Photo 2 : The Gambia River (Wetlands, 2009)

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CONTENT OF THE MODULE

It contains different chapters detailed

throughout the courses.

Course 1 gives an introduction to the

monitoring plan.

Course 2 contains general information on

aquatic plants.

Course 3 gives the definitions of some terms

commonly encountered in the analysis of

flora and aquatic vegetation. It also provides

illustrations of some aquatic plants so as to

facilitate their recognition.

Course 4 is a brief summary of the flora and

vegetation in the Gambia River basin and of

the sites where monitoring should be done.

Course 5 describes the method to be used for

monitoring the flora and aquatic vegetation in

the Gambia River basin. This course also

focuses on the analysis of collected data.

Photo 3 : The Gambia River (Wetlands, 2009)

Photo 4 : Visit to the Sambagalou site (Wetlands, 2009)

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ORGANIZATION OF THE COURSE

Courses 1, 2 and 3 will consist of explanations related to the monitoring plan and aquatic

ecosystems, with a focus on flora and aquatic vegetation, but also on the greater ecosystems of

the Gambia River basin. Concerning the latter, a description will be given of the major types of

vegetation in the aquatic ecosystems of the Gambia River Basin, and of present sites where

monitoring should be done by emphasizing the current list of plants that are present there. The

procedure is to first listen to the views of participants on certain issues pertinent to the relevant

chapters. Then, the facilitator will compile and present through slides the main points of the

chapters. At the end of the course, a hard copy should be given to participants.

The required duration of courses 1, 2 and 3 is 9 hours, or more precisely 3 hours for each.

For course 4 the objective is to share with participants some concepts commonly encountered in

the realm of aquatic plant study. Thus, the facilitator must show images of some common aquatic

plants encountered in the Gambia River Basin. The course will last 3 hours.

Course 5 is the most important course so the facilitator will insist as much as possible on the

various points of this course. Clear explanations should be provided, discussion with the

participants and questions should be asked to check their level of understanding. This course will

last 12 hours (2hx6 or 3hx4).

At the end of the training and before the actual collection of data, it is important to organize a

field mission to test the operational capabilities of the methodology and, if needed, to make the

necessary adjustments.

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TRAINING NEEDS

Human Resources:

- 1 facilitator (specialist who will do the training)

- People in charge of the conservation of ecosystems in the countries sharing the

Gambia River Basin

Materials needed

- Room (to host the training)

- Training documents (in a PowerPoint format)

- Copies of the complete training document

- Video projector

- Flip chart and markers

- Notebooks, pens, pencils and erasers

Financial resources

- Facilitators per diem

- Participants per diem

- Other expenses related to the organization

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EXPECTED RESULTS

The main expected outcomes in developing this module are the training of technicians

and the establishment of a method for monitoring flora and aquatic

vegetation. Ultimately, the participants in this training will have a much clearer

understanding of the flora and aquatic vegetation. They will also master a method for

monitoring the flora and aquatic vegetation that they will be able to share with the

technicians who will be in charge of monitoring.

Wetlands International will be the recipient of a methodology for the monitoring of flora

and aquatic vegetation.

Photo 5 : Visit to the Sambagalou site (Wetlands, 2009)

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COURSE 1. INTRODUCTION TO THE MONITORING PLAN

1.1. WHY MONITOR FLORA AND VEGETATION

The Gambia River basin is characterized by a diversity of habitats (estuaries, marshes, swamps,

mudflats, etc.), which host a very large number of species. With the erection of the Sambagalou

dam, Wetlands International Africa with the support of the IUCN Species Survival Commission has

developed a plan for monitoring the biodiversity of freshwater ecosystems in the Gambia River

basin. This monitoring would enable documentation of the changes that might occur with the

implementation of the dam, which is certain to cause profound changes in the ecosystem. These

changes can be seen particularly throughout plant communities, via regular data collection of their

species and respective habitats. In the case of plant communities, those known as "key species" are

essential to maintaining one or more communities. A key species can thus be considered a species

whose loss or disappearance can cause a major change in the ecosystem. For example, among plant

species, those which provide food for animal species are key species. The importance of key species

is proven by the role they play in the maintenance of a given community and not by the size of their

population in numbers. Their loss leads to major changes in the actual functioning of the ecosystem.

In conservation biology, one uses the term bio-indicator for species whose presence or the

fluctuation of whose population reflect changes in the environment or in communities of other

species. These species can act as biological indicators or bio-indicators and enable one to determine

the state of the ecosystem.

The species’ population status must be checked in the field at regular intervals because potential

negative changes within their populations or environment may be revealed. As such it would enable

an immediate respond and the application of adequate measures.

1.2. ROLE OF PLANT COMMUNITIES IN THE MONITORING OF ECOSYSTEMS

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Aquatic plants are vital for both men and animals. They also play an important ecological role

through the ecological processes of oxygenation and water purification and also in maintaining

balance in the ecosystem. An ecosystem is a dynamic unit composed of, among other things,

various species that not only interact with each other, but also with the environment. These species

play an important role in maintaining the balance of habitats. Among these species, those known as

"key species" are essential to the survival of one or more other species through the action they

perform for the maintenance of these species. With regard to plant communities, species that

provide, for example food for certain animal species are key species. Other species are used for

shelter, nesting and spawning grounds for many animal species. Their loss causes major changes in

the functioning of the ecosystem.

Moreover, in conservation biology, one uses the term bio-indicator for species, which are those

whose presence or the fluctuation of whose population reflects changes in the environment or in

communities of other species. For example, the proliferation of some algae indicates the existence

of organic pollution.

Photo 6: Aquatic plant community (ISE, 2009)

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COURSE 2. GENERAL INFORMATION ON AQUATIC PLANTS

2.1. PLANT ECOLOGY OF AQUATIC ENVIRONMENTS

The vegetation of aquatic environments is organized into plant groups within which species cohabit

under favorable conditions; the predominant environmental factors are not the same for all of the

collective species; the plant community is more or less a result of a kind of juxtaposition of a group

of species each being tied to the variation of certain ecological factors. These factors, such as the

permanence and depth of water, and its chemical characteristics (especially pH and salinity) can be

considered essential due to their influence on the vegetation; in that they themselves are the result of

an interplay of many edaphic, climate and even biological elements, the differentiation of

vegetation is integrated in a complex manner, and specifies the variation of those factors essential to

the general ecology. Let us briefly consider some aspects of the vegetation in differing

habitats. Slightly brackish waters are mainly located in the littoral-dependent lagoons, behind the

mangroves; submerged groups in Najas or Potamogeton are found in open waters while at their

periphery, meadows of Diplachne or Paspalum vaginatum undergo a more or less prolonged

seasonal flooding. Freshwater with relatively important loads of salt generally correspond to

eutrophic environments, given their chemical balance. If the depth is sufficient, the Ceratophyllum

constitute a floating group, the Nyrnphaea create a shallow beltcloser to the surface, that itself is

encircled by a Typha zone. Various types of vegetation can occupy these margins that are slightly

but consistently (or almost) flooded, such as Cyperus papyrus or Cladium. If the annual change in

water level is higher, you will be able to find « bourgoutières » (Echinochloa stagnina) that can

spontaneously switch to rice fields. The vegetation of these shallow groups may have variants,

which float through and tend to colonize deeper waters. The meadows of Bourgoo rise with the

water level, forming a loose tangle of floating stems more or less anchored to the ground, with

many edge species, belonging to the papyrus or typhaie for example, who elongate rods that float

above the deeper waters, and extend their group at the expense of the Nymphaea zone. In some

cases, the floating vegetation of these margins can development significantly; fragments can break

off or tear, while the floating stems intertwined with roots form a dense thatch, coherent enough that

debris will remain hooked to it, such that seeds can germinate there. It is therefore a veritable

substrate, composed of living vegetation, which propagates itself; plants, rooted on themselves just

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below the surface, have in fact an ecology of shallow peripheral zone, though permanently flooded.

Thus, when marginal environments occupy considerable areas, it is to the detriment of deep-water

plant groups whose species are eliminated when the surface is no longer free. For numerous

reasons, including their impact on the biology of deep water or sedimentation; edge environments

often play a major role in the dynamics of aquatic biological communities.

Waters minimally loaded with salt, more or less acid, and that can be described as oligotrophic, can

for instance accommodate special species of Najas, or Nymphaea if the depth is not too great. On

the margins whose levels do not fluctuate much, one can find Pycreus mundtii, which may extend

over the water in rafts. Rock pools, temporary or not, have rich and varied vegetation. One can

mention fugitive ponds of bowe, small bladderworts and Eriocaulon, ponds with variable levels, but

which are permanent or almost, of wild rice, savannah ponds fed during the dry season with seeps,

rich in Cyperaceae. The vegetation of flowing waters is perhaps less rich and less diverse than calm

waters, whether stagnant or not, permanent or not. Only the Podostemaceae can be found in

waterfalls on the heavily beaten rocks, or in sharp flowing streams, mostly the substrate will define

the presence (or possibility) either Utricularia rigida or Bolbitis heudelotii, or also Eriocaulon

latifolium or Crinum natans. The streams in Rotala or Limnophila for example, have a more calm

current, and the flow is definitely slow if the surface waters contain floating species such as

Ceratopleris, Pistia or Azolla.

2.2. MORPHOLOGY AND BIOLOGY OF AQUATIC PLANTS

In this work, we place the focus on "higher plants", meaning ferns and flowering plants. These are

chlorophyll containing organizations, hence capable of assimilating carbon dioxide to produce

oxygen; their various parts being differentiated by specialized organs on the one hand, and specific

tissues on the other, among which one can mention sap conduits (vessels among them).

Among ferns (Figure 1), leaves and roots are attached to a stem that is relatively short. They do not

flower but produce fruiting structures (on the leaves or directly on the stem) that contain spores.

After release, spores develop into tiny and ephemeral plants that contain microscopic sexual organs;

after fertilization, they produce young ferns.

Flowering plants are typically composed of roots, leaves, stems and flowers. The flowers are the

location of the plant’s sexual reproduction: one can find stamens that produce pollen (male organs)

and a pistil, which contains ovules (female organ). Some plants have bisexual flowers, in others the

male and female flowers are separate. The pollen is dispersed, and will fertilize the female organs:

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each fertilized egg becomes a seed, and the pistil a fruit. The seeds will later develop into young

plants.

Figure 1: Illustrations of a few ferns

2.3. STRUCTURE OF A PLANT FORMATION

A plant formation has a structure that gives it its particular physiognomy. It’s thus, that the aerial

parts of plants are usually arranged in an orderly manner. This order is the manifestation of a

structure in space. The vertical structure or stratification of the vegetation: the leaves of different

plant species are often arranged in several stages that are more or less individualized. Four

vegetation strata are eventually encountered: a tree layer, composed of the tops of tall trees, a lower

shrub layer composed of leaves of shrubs, a herb layer at no more than 50 cm above the ground, and

finally a moss layer in which one can find high bryophytes barely measuring a few centimeters.,

The number of strata however varies from one plant community to another.

2.3. PRINCIPLE TYPES OF AQUATIC PLANTS

Aquatic plants are plants adapted to life in water. Among these plants, one finds mostly microscopic

plants or phytoplankton as opposed to macrophytes or large plants visible to the naked eye. These

aquatic plants are found in marine and fresh water environments, whether in stagnant waters (lakes,

small ponds, ponds, marshes) or flowing water (rivers, streams, channels). This course will only

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tackle freshwater plants. It’s agreed that one should distinguish different types of aquatic plants by

their water requirements, but the concept of an aquatic plant is difficult to define. One can find

plants that must be submerged without exception and those that subsist on a few short weeks of

seasonal flooding, and everything in between. Aquatic plants however, can be divided into two

main groups: hydrophytes and helophytes (Figure 2). The hydrophytes are plants that have their

entire vegetative body in water, or on the water surface. One can distinguish three groups among

them:

The free floating hydrophytes: water lettuce (Pistia stratiotes) and water hyacinth

(Eichhornia crassipes)

The fixed hydrophytes with floating leaves: these are plants whose leaf blades float on the

water surface. During flowering, the flowers emerge from the water and are carried by a

stalk that can reach 20 cm in height. Example: Nymphaea lotus.

The emergent plants or helophytes in contrast, have part of their vegetative and reproductive

body in the air while developing a root system in a waterlogged muddy substrate. Example

Typha australis.

Moreover, there are plants on dry land that are likely to survive to temporary flooding. These are

called accidental or occasional aquatic plants.

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Figure 2: Main types of aquatic plants

COURSE 3. PRICIPLE AQUATIC ECOSYSTEMS AND STUDY SITES

Based on the three main reaches (Gambian, Guinean and Senegalese), one finds in the Gambia

River basin a relatively diverse set of ecosystems consisting primarily of gallery forests and the

classified forests of Guinea, the Niokolo Koba / Badiar complex, and the freshwater marshes and

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flood plains of the Gambia. These ecosystems are characterized by the presence of numerous plant

species.

The Gambian part of the river is located in the estuarine zone. The upper part of the estuary is

influenced by the freshwater marshes that as such form floodplains. These floodplains are

characterized by the presence of gallery forests and various meadows where you can find species

such as Anodelphia afzeliana, Vetivera nigritana, Eragrostris atrovirens, Panicum sp. with the

extensive settlements of Paspalum, Setaria and Andropogon on the edges of floodplains. In this

Gambian reach, three sites in freshwater ecosystems have been identified, but it was proposed to

integrate other ecosystems of brackish to saline water due to the probable influence them by the

dam. Thus, the sites that will be monitored are:

• « Lower-River ecological site »: nursery area for fish and the first Ramsar site in Gambia.

• « Central-River region » : reserve area (Manatee)

• « Upper-River ecology »: mountainous region irrigated by water from the Fouta Djallon.

• « Baobalon Wetland Reserve »

Photo 7: The Gambia River (IUCN, 2005)

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In the Guinean reach, one can find the Niokolo-Badiar, the Ndama forest, the forests of the

Gambia-Kabela and the Bakoun forest, and the Bafing basin. In Guinea, the selected sites are:

• Site in Thiéwiré in the Lébékéré Commune Rurale de Developpement (CRD);

• Site in Parabanta in the Balaki Commune Rurale de Developpement (CRD);

• Site in Kounsi in the Balaki Commune Rural de Developpement (CRD)

• Site in the District of Pakaya in the Commune Urbaine de Mali, the host site

The Senegalese portion of the basin is marked by extensive wetlands that are seasonally flooded

by rainwater and covered by grasslands and aquatic or semi aquatic formations. In this reach, the

main sites to monitor are located within the Niokolo Koba National Park. Niokolo Koba National

Park is transected by the Gambia River from southeast to northwest and is joined by two major

tributaries: the Koulountou and Niokolo Koba. To these surface waters, one can add the numerous

temporary and permanent ponds and creeks. The sites are located in Bara, the Gue of Damantan, to

the confluence points of Gambia-Niokolo and Gambia- Niériko, the ponds of Simenti, Kountadala,

Wouring, Oudassi, Banthantity, Padan and the site of Sambagalou.

Figure 3: Map of the National Park of Niokolo Koba (OMVG, 2005)

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At these sites, the main vegetation types are forest galleries and swampy grasslands. Gallery forests

located along the rivers are characterized by a relatively diverse flora with species such as Borassus

aethiopum and many epiphytes and lianas. Grasslands, located in swampy depressions and ponds,

contain a diversity of aquatic and semi aquatic plants. One can find there semi-aquatic herbaceous

species such as Vetivera nigritana, Rytachne triaristata, Commelina difusa and Melastromastrum

capitatum.

The wetlands (lakes and ponds) are found in the area going from Simenti to Gouloumbou. These are

areas usually flooded during the rainy season. They are overwhelmed by aquatic vegetation that

sometimes form extensive swampy meadows. During the dry season, these wetlands gradually

regress to form ponds in the lower areas. These areas are home to a relatively diverse flora with

species such as Arundinella nepalensis, Eichhornia natans, Eriochrysis brachypogon, Nymphoides

indica, Oryza barthii, Ottelia ulvifolia, Potamogeton nodosus and Vetivera nigritana. Other species

such as Sacciolepis, Echinochloa, Setaria, Leersia, Panicum Acroceras can also be found there. In

the Simenti pond, two semi-aquatic woody species Mimosa pigra and Mytragina inermis form

almost impenetrable thickets with Mytragina inermis occupying the edges of the pond, Mimosa

pigra closer to the center and Vetivera nigritana make up the vast meadows. Aeschynomene

afraspera, Aeschynomene crassicaulis, Echinochloa colona, Heliotropium indicum, Ipomea

aquatica, Ludwigia adcendens, Stylosanthes erecta and Vetivera nigritana are also found inside

these ponds. In the Kountadala pond, Mimosa pigra forms almost pure settlements and occupies

about 90% of the pond’s area (ISE 2009). Other aquatic species including Aeschynomene afraspera,

Aeschynomene crassicaulis, Heliotropium indicum, and Ludwigia adscendens can be found inside

the pond.

Photo 8: The Gambia River (IUCN, 2005)

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COURSE 4. TERMINOLOGY AND IDENTIFICATION OF AQUATIC PLANTS

4.1. TERMINOLOGY

o Helophytes: These are plants that grow at the water’s edge, and are rooted deep

within. Their base is submerged while the assimilative organs are at least partially borne

above the water. Examples: common reed (Phragmites australis), cattail (Typha sp.)

o Hydrophytes: These are aquatic plants

o Macrophytes: Aquatic plants visible to the naked eye -in contrast to phytoplankton

o Phytoplankton: Composed of microscopic plants floating in water. Examples: various algae

o Flora: The flora of a given region is the list of plant species found in this region. This

catalog may considerably differ from one geographical location to another, yet both can be

subject to the same environmental conditions.

o Vegetation: The structure of plant settlements

o Plant formations: Plant formations refer to the structure of plant colonies. They are often

described by the recovery percentages of the various types that compose them (herbaceous,

woody...).

o Biological types: Describe various shapes and plant structure based on their adaptation

strategy in the environment in which they live. Trees, shrubs, bushes, perennials, annuals,

rosette plants, plants with bulbs or rhizomes, and aquatic plants are all of different biological

types.

o Phytosociological table: A raw table containing data as they were collected in the field. The

summary table includes all data on a specific type of vegetation and is arranged so as to

highlight the associated characteristic species, differential species, companion species and

ecological groups.

o Plant groups: Refer to combinations of plant species found in a place without prejudice as

to their status. There are two types of schematic approaches to describe the plant

communities.

o Plant associations: These are categories of plant groups having common floral and

sociological characters. The concept of association is based on the idea that plant species do

not cluster randomly, but follow affinities in relation to the environmental

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conditions. Phytosociology or sociology of plants, is the science which classifies

associations (just like systematics is the classification of species).

BRAUN-BLANQUET, 1928: « The plant association is a more or less stable plant

community, in balance with the surrounding environment, characterized by a specific floral

composition in which certain elements are nearly exclusive, and species characteristics

reveal with their presence a particular and autonomous ecology ». In an association, one can

then find stateless species, or companions, and species characteristics, indicative of the

environment.

o Ecological groups: These are groups of species posing the same requirements on the

environment. Monitoring the species representation of a particular group or several groups

enables one to have an indication of changes related to the environmental conditions

(example: increase of species after fertilization).

o Vegetation dynamics: This is the study of vegetation changes over time. It goes through

very short periods such as seasonal changes during much longer periods that date back

further in the vegetation’s history.

o Species Characteristics: Species more or less localized in an association, which allow for

floristic characterization; whether they are exclusive, regional or local, common or rare.

o Companions: Species present in the collected data, but not particularly related to a specific

association.

o Recovery: Vertical projection surface of the plant’s aerial projections (crown, tower), or

vegetation (canopy) on the ground, or a proportion or percentage of this surface in relation

to the total area being surveyed.

o Abundance: The total number of individuals of each species in the complete sample.

o Recovery: The area occupied by individuals of a species. It is estimated using the projection

on the ground of the leafy ground cover.

o Density: The number of individuals belonging to a species per area unit.

o Relative density: The density of a species compared to the density of all species.

o Dominance: The area occupied (using recovery) by a species in a colony, per unit area.

o Relative dominance: Area occupied by a species, using recovery, compared to the area

occupied by all species.

o Frequency: Distribution of a species in a colony, i.e., the percentage of quadrants in the

sample, where one can find individuals of a species.

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o Relative frequency: The distribution of a species compared to the distribution of all species

in the sample.

o Value of Importance (VI): This is an index composed of the relative density, relative

dominance and relative frequency, which locates the structural role of a species in a colony.

The value of importance is also used to for comparison among colonies in terms of species

composition and settlement structure.

Value of Importance = relative density + relative dominance + relative frequency

3.2. ILLUSTRATIONS OF SELECT AQUATIC PLANTS

The plants should be properly identified by species. When you are in the field, you must always

have a manual for plant identification and the preliminary list of species in the study area. In order

to facilitate this identification in the field, a few illustrations are provided here to represent species

that are frequently encountered. Even the most seasoned experts make identification errors. If you

have any doubts whatsoever, take a specimen that can be identified later.

Photo 9 : Pistia straiotes

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Family: Araceae

Genus: Pistia

Species: stratiotes

Description: Grass rosette freely floating on the surface resembling lettuce leaves. Finely

branched roots are immersed in water. Almond green leaves are hairy, sessile and broadly oval.

Minute inflorescence

Ecology: Permanently or impermanently calm waters, eutrophic environments. The plant can

completely cover water ponds and thus become harmful.

hidden between the leaves

Family: Nympheaceae

Genus: Nymphaea

Species: lotus

Description: Rooted fleshy herb; rosette

leaves floating in limbo; white flowers

held by a long pedicel. The fruit ripens

under water and contains many seeds.

Ecology: Shiny calm waters that may

eventually dry out for a short period (muddy

ponds, eutrophic)

Photo 10 : Nymphaea lotus

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Family: Typhaceae

Genus: Typha

Species: domingensis

Description: Robust herbs with long linear

leaves, thickly erected, brown ears; Small

flowers densely crowded.

Ecology: Permanent waters somewhat shallow

sometimes slightly brackish: ponds. Lakes, large

stretches of water. The plant can be used in

herbal floating rafts for deep waters.

Photo 11 : View of pond covered with water lilies (Nymphaea lotus)

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Family: Pontederiaceae

Genus: Eichhornia

Species: crassipes

Common name: Water Hyacinth

Description: rosette grass floating freely in the water surface: finely branched roots rose mallow, plunge into the water. Leaves with swollen petioles and oval limbs, rough. Wide flowers 2 to 3 cm.

Ecology: American species that tends to become naturalized in certain regions of Africa. It spreads in tropical countries where it is often harmful. It forms dense floating populations. It is sometimes grown as an ornamental plant.

Photo 13: View of pond covered with water lilies surrounded by Typha australis (Nymphaea lotus)

Photo 12 : Typha australis (ISE, 2008)

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Family: Ceratophyllaceae

Genus: Ceratophyllum

Species: demersum

Description: Brittle branched herbs, rootless and submerged, floating freely. Vertical leaves, forked, denticulate at the apex. Spiny fruit about 5 mm long, containing a single seed,

Habitat: Calm waters, deep and permanent. The plant does not support dewatering.

Family: Potamogetonaceae

Genus: Potamogeton

Species: sp

Description: Leafy stems, submerged, sometimes very long, flexible. Submerged membranous leaves, translucent.

Habitat: Deep permanent waters, lakes, calm streams.

Family: Poaceae

Genus: Vetivera

Species: Nigritana

Common Name: Vetiver

Description: Powerful grass with strong tufts;

upright stems reaching up to 3 m. Leaves with very

long lamina that can reach up to 1 m.

Ecology: Flood zones

Photo 15 : Ceratophyllum demersum

Photo 16 : Potamogeton sp

Photo 17 : Vetivera nigritana

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Family: Salviniaceae

Genus: Salvinia

Species: sp

Aquatic fern native of Brazil floating freely on

the surface of the water. Horizontal stems with

opposite leaves, emerging covered with hair.

It has a strong ability to duplicate and is

capable of covering all the water. That was the

case in the Senegal River.

Photo 18 : Mimosa pigra

Photo 19 : Salvinia sp

Family: Mimosaceae

Genus: Mimosa

Species: pigra

Description: Shrub more or less scandent,

very thorny and bushy, with erect stems, with

leaves sensitive closing when touched.

Habitat: Species forming impenetrable

thickets along rivers and along areas of

lowland flooding

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COURSE 5. METHODS FOR MONITORING FLORA AND AQUATIC VEGETATION

5.1. PREPARATORY PHASE

In the framework of a large scale study such as the basin scale, it is often necessary to collect all

available information on the subject (vegetation maps, topographic, geologic, and soil maps,

floristic data, etc.). Thus, it is important to answer a number of questions including:

What is the general floristic knowledge of the site?

What is the biological and ecological knowledge about species that we want to monitor?

Is monitoring already being undertaken?

What are the technical and scientific skills required?

Are there any constraints such as accessibility?

The answers to these questions help determine the feasibility of the method and the monitoring

frequency that should be considered. It is very easy to make a decision on the necessity of setting up

monitoring, or even undertake a baseline study, however, the on-going data collection over time, in

addition to their interpretation and exploitation of results are often abandoned! Hence, it is

important to only initiate useful monitoring, feasible (in terms of ability, time and resources devoted

to it) and exploitable.

In addition, preliminary field surveys will be useful to gain an overview of the sites but also to test

the operational capability of the method. The transect method has been proposed to monitor the

flora and vegetation; this method will probably be adjusted in the field.

5.2. MATERIALS

To complete the study of flora and vegetation, various materials will be needed:

o a compass to orient transects

o GPS

o Camera

o a rope to establish transects

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o machetes to clear transects without disturbing the vegetation structure or destroying certain

species

o The flora of the Gambia, Guinea, Senegal and neighboring regions

o a notepad and pencil to record data.

5.3. COLLECTION METHOD: TRANSECT TECHNIQUE AND PHYTOSOCIOLOGICAL

DATA COLLECTION

Phytosociological methods are generally used for the study of aquatic plant communities. The

transect method combined with Braun Blanquet’s phytosociological data collection will be used to

collect quantitative data. While undertaking the study of flora and vegetation, it is also important to

study some ecological factors that will facilitate a better understand of the monitoring results.

5.3.1. TRANSECTS

Transects enable the measurement of changes from one community to another due to environmental

gradients such as moisture. These environmental gradients create vegetation gradients whose

monitoring will provide useful data on various environmental changes. They permit the

visualization of succession of vegetation and thus propose clues as to the influence of certain

ecological factors.

How to make a transect?

To make a transect, one should stretch a wire or ribbon fixed at both ends by two unmovable stakes

driven into the ground. The main species that appear will be carefully identified along that line.

With regard to the monitoring, one needs simply to return to the same location at regular intervals,

each time stretching the tape between the two stakes remaining in the ground, and write down the

plants that are in contact with the line.

Transects facilitate analysis of the vegetation monitoring along one or several gradients such

as moisture, topography, the study of soils or even human activities, going, for example, from

the dewatered to the flooded area.

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Size of transects

The width of any transect depends on the type of community found along the gradient that is being

studied. The size must be adapted to the type of vegetation.

Transects at least 5m in width will be used when the dominant community type consists of large

trees and shrubs, whereas transects measuring 1m will be used when grass dominates.

The length of transect will depend on the site where the monitoring is done. A transect extending

from a small community to another may measure a few meters, while another associated with a

bank or an elevated gradient may be much longer. Sometimes, depending on the type of vegetation,

the transect will have two widths, or even more, along the same gradient.

How to decide the number of transects?

The objectives of the monitoring program and the extent of the area covered call for the

establishment of a large number of transects. This number will depend on the sample stations and

other considerations that may be decided in the field.

How to choose the arrangement of transects and their placement?

Transects cross the moisture gradient and can start with the dewatered area and stretch toward the

flooded area, unless a barrier or a natural barrier determines the points of departure and

termination. The transect’s reference base should be placed at a convenient and easily recognizable

demarcation. From that point, the transect can be extended in both directions: up to the water

(preferably in the area of the submerged vegetation) and in the opposite direction crossing the

different types of vegetation until the transect is in a vegetated area where the gradient is no longer

apparent.

5.3.2. PHYTOSOCIOLOGICAL DATA COLLECTION

Phytosociology is the description of plant associations. It analyzes plant associations and their

dynamics. The phytosociological data collection enables the determination of the floristic

composition of the groups. A comparison of phytosociological data collection undertaken initially

permits the intake of information on the evolution of flora and vegetation. Such phytosociological

or phytoecological data will be carried out using the Braun-Blanquet system.

Data collection

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Three conditions are required for data collection:

1) Appropriate dimensions -to contain a sample of species representative of the

community

2) Habitat uniformity -the collected data will not overflow in two different habitats

3) Homogeneity of the vegetation

Identification and location of collected data

It is important to geo-reference the location and position on a map of the collected data. Moreover

in the field, marking will allow one to easily find them for the next visits. In fact, one needs to

materialize in the field an angle, or the center of the collected data with a strong stake while

considering the danger it may cause.

Data collected will be distributed in a systematic manner following steps that may be decided on the

field.

Attributes of collected data

The vegetation data should also be completed by specific guidance enabling its identification and

location in space and time. These parameters are mainly:

Station Number

Number of data

Date

Name of data

Geographic coordinates

Type of plant formation

Dominant plant species

Topography

Particularity of the station

etc.

(see monitoring form)

Size of the data or minimum area:

The search for the minimum phytosociological area meets the first condition. The concept of

minimum area is designed as the area in which almost all species of the plant community are

represented. A classical approach is based on the « method of nested surfaces » (Figure 1).

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Calculating the minimum area

In a homogeneous sector, it is defined as a square 1m2 with 4 poles and a rope. Count the number

of species present in this square. Double its size (1m x 2m = 2m2) and count the number of new

species. One doubles again this square (2m x 2m = 4m2) then (4m x 2m = 8m2) and so on. Trace the

curve area / species (abscissa = increasing area; ordinate = number of species).

The minimum area is the area corresponding to the inflection point of the curve.

Figure 4: System of nested surfaces to determine the minimum area

Each plot numbered from 1 contains the surface area of the previous plot. Thus, odd plots are

square and rectangular plots are pairs (from [18]). In bringing the cumulative number of species,

depending on the area in meters squared, one obtains the graph in Figure 2.

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Figure 5: Curve area / species for the search of the minimum area

Data collection

The statement contains three categories of information: Geographic: date, location, coordinates (by GPS eventually), altitude, slope, exposure...

Environmental: lithology, drainage, moisture, humus, soil pH, biotic factors (browsing by

game, defoliation, etc.), microclimate

Specifics or flora: List of plant species, eventually depending on the stratification of

individuals with quantitative indications of abundance, recovery, biomass, or simply

qualitative, presence.

The list of plants: all species present in the statements will be listed. And those that are not

identified in the field will be collected and later identified using herbarium.

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The abundance-dominance of each species will be assessed using the Braun-Blanquet

scale. The index of abundance-dominance of a given species is an overall estimate of the

density (number of individuals, or abundance) and the recovery rate (vertical projection of

the aerial parts, or dominance) of individuals of this species in the sample area. The

abundance-dominance concept is the one most commonly used in phytosociology. Braun-

Blanquet created the coefficient of abundance-dominance, which combines the concepts of

abundance and dominance. Abundance expresses the number of individuals who constitute

the population of the species present in the statement. Dominance is the recovery of all

individuals of a given species, as the vertical projection of their aerial vegetative parts on the

ground. The coefficient of abundance-dominance is estimated visually. It is therefore not a

real measure. Its estimate is subject to some subjectivity, which is however negligible in the

overall phytosociological analysis.

Coefficient of abundance-dominance

Among the data collected, the coefficient of abundance - dominance is typically established in the phytosociological data collection. The following scale is that most commonly adopted:

5: recovery of more than 75% of the quadrant

4: recovery between 50 and 75%

3: recovery of between 25 and 50%

2: recovery between 5 and 25%

1: less than 5% recovery

+: Very few individuals with very low recovery

r: rare

The recovery: it is estimated both from the abundance (relative number of individuals of a

species compared to the total number of individuals identified in the plot or quadrant) and

dominance (covered area i.e. the projection on the ground of foliage cover of all individuals

of the species). It is expressed through the coefficient of abundance-dominance determined

by the Braun-Blanquet scale. These coefficients vary according to the recovery.

Procedure to assign a coefficient of abundance

• Does the species cover more than 50%?

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• If more than 75%, coefficient 5

• If less than 75%, coefficient 4

• Does the species cover less than 50%?

• If more than 25%, coefficient 3

• If less than 25%, coefficient 2

• Does the species cover less than 5%?

• If many individuals, coefficient 1

• If a few individuals, coefficient +

• Is the species rare (unique individual, very low recovery)?

• Coefficient r.

Other attributes of species

Vitality, phenology and biological types

Various notations can be added as a subscript or superscript, to the coefficient of abundance-

dominance.

Thus, one can distinguish three classes of vitality [5, 22, 24]:

• Low vitality, never flowers or fruits °°

• Medium Vitality °

• Strong vitality •

Other notations can describe the phenological state (leaf-leafless, barren-flowered-fruited) of each

species. These seasonal aspects require revisiting the same sites in order to undertake further data

collection. Raunkiaer biological types, which are the subject of a separate description, can be

associated with each species for the establishment of a biological spectra.

Sociability of species

This value, on a scale of 1 to 5 according to [5], indicates the degree of spatial dispersion of

individuals. It can be added to the coefficient of abundance-dominance, by separating it from the

latter by a hyphen:

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5: Almost pure population, important

4: Many small colonies or forming a broad belt

3: Population forming small groups or cushions

2: Dense aggregates or groups

1: Solitary growth

5.4. DATA ANALYSIS

Manual sorting technique of phytosociological tables

The traditional technique of manually sorting collected data is still widely used. It consists of

moving columns (collected data) and rows (species) of a phytosociological table so as to bring the

records that are most alike and to group the species according to their sociological affinities.

One uses a raw table which is a double entry table. The columns correspond to data collected

randomly and the lines correspond to the species listed in the order they appear in the first

collected data. One then adds species from the subsequent data collection, which do not appear in

the first and so on, until all collected data and all species are listed. In the box at the intersection of

a row and a column, one indicates the abundance-dominance and sociability of the species from the

collected data. If the species is not present in the collected data, the box remains empty.

In the raw table, collected data and species identified are ranked. The table method aims to change

the order of data collected and species so as to consolidate them in the most logical manner

possible. For that, the raw table will be converted into an attendance table. In this attendance table,

one ranks the species according to their decreasing degree of attendance (the number of data

collected in which they can be found).

On this attendance table, one needs to search for the groups of species that generally flock together

in some collected data and are at the same time generally absent from the others. These species are

classified as differential species. One looks therefore to isolate subsets of collected data that share

subsets of differential species.

The most frequent species (relative frequency superior to 90%) or the most rare (relative

frequency inferior to 10%), which only play a minor role in this process are temporarily ignored

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(working on a differential table without these species may facilitate comparisons when the

number of species on the raw table is very large).

One then seeks to bring together species that are simultaneously present in some collected data and

simultaneously absent in others, by neglecting isolated presence: at the same time, one locates the

species that exclude themselves (which are almost never present together in the collected

data). This search for correlated species is used to group collected data that share these groups of

species.

A permutation of rows and columns can reconcile species and collected data by successive

approximations. By including constant and accidental species in the edited differential table, one

elaborates a table in which subsets of collected data are individualized hierarchically, and

arranged along a gradient of flora composition. This table is then divided into a number of tables,

each consisting of a homogeneous group of collected data that correspond to the tables of different

groupings.

A group consists of one or more species living in homogeneous stationary conditions.

The characteristic species are the dominant species.

Companion species: these are species that are less abundant or less numerous. The accidental are those that are not in their environment in the ecological sense.

In the analysis, it is important to test the homogeneity of phytosociological tables, for example using

the coefficient of variation. A table is considered homogeneous when the coefficient of variation is

between 10 and 25%. In each phytosociological table, it is important to note the number of

collected data, recovery, the number of species per record, the frequency of each species, the class

frequency. Frequency classes are defined as follows:

‐ Species present in 0-20% of collected data: Class I

‐ Species present in 20-40% of collected data: Class II

‐ Species present in 40-60% of collected data: class III

‐ Species present in 60-80% of collected data: Class IV

‐ Species present in 80 to 100% collected data: Class V

Example of summary tables of collected data

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If one performs a number of complete floristic data collection on surfaces at least equal to the

minimum area, they can be compared conveniently by transcribing them in a double entry table,

where each row is assigned to a species and each column to collected data. Species are descriptors;

columns are objects and indications at the intersection of row and column descriptions. A table

composed of data collected in the order they were entered in the field is a raw table, qualitative,

semi-quantitative or quantitative, based on the following attributes: presence, abundance-

dominance, number of individuals, biomass, etc. Table 1 gives an example of a raw table from a

series of collected data.

Table 1: Raw floristic table

Raw table Record number

01 02 03 04 05 06 07 08 09 10 11 12

Species

Sp1 5 4 3 2 5 3 4 5 5 3 3 5

Sp2 1 2 3 3 2 2 + 1 4 2 3

Sp3 + 2 1 3 3 2 3 3 3 + 1

Sp4 2 3 2 1 2

Sp5 3

Sp6 3 3 1 1 1 3 1 + +

Sp7 3 4 3 2

Sp8 3 3 4 2

Sp9 3 2 2 2

Sp10 2 3

Sp11 1

Sp12 2

Sp13 1

Sp14 2

Sp15 1

These records are tabulated in the order they were entered in the field

Lines: species. Columns: collected data. Numbers: Braun-Blanquet coefficients of abundance-

dominance

One may revise the raw table to elaborate other tables. For example, by substituting the values of

the coefficients of abundance-dominance with a simple indication of presence (1) and absence (0)

species, one obtains Table 2. This obviously results in a loss of information. Nevertheless, one can

consider that the mere presence of a species structure distances it from the collected data. Specific

quantitative treatment can be applied to the tables based on presence-absence.

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Reading of the tables can be done vertically and horizontally. Vertically, we can check whether the

species present are related or associated. In other words: Are the species together by

chance? Otherwise, can we identify groups of species related by their ecological

requirements? Horizontally, quantitative (abundance-dominance) and qualitative (presence /

absence) differences between collected data occur. Despite the floristic homogeneity being sought

and eventually tested, environmental heterogeneity and biotic interactions lead to differences in

collected data. Our task is to highlight similarities between collected data and gather those who are

alike, or separate the most dissimilar.

Table 2 Table of floristic presence-absence

Table of presence‐absence Record number

01 02 03 04 05 06 07 08 09 10 11 12 FR

Species

Sp1 1 1 1 1 1 1 1 1 1 1 1 1 12

Sp2 1 1 1 1 1 1 1 1 1 1 1 11

Sp3 1 1 1 1 1 1 1 1 1 1 1 11

Sp6 0 1 1 1 1 1 1 1 1 1 0 9

Sp4 0 0 0 0 0 1 1 1 1 1 0 0 5

Sp7 0 1 1 1 0 1 0 0 0 0 0 0 4

Sp8 0 0 0 0 0 0 0 1 1 1 1 4

Sp9 0 0 0 1 1 1 1 0 0 0 0 0 4

Sp 10 0 0 0 0 0 0 1 1 0 0 0 0 2

Sp5 0 0 0 0 0 0 2 3 0 0 0 0 1

Sp11 0 0 0 0 0 0 0 0 0 0 0 1 1

Sp12 0 0 0 0 0 0 0 0 0 1 0 0 1

Sp13 0 0 0 0 0 0 0 1 1 0 0 0 1

Sp14 0 0 1 0 0 0 0 0 0 0 0 0 1

Sp15 0 0 0 0 0 0 0 1 0 0 0 0 1

Number of species

2 5 6 6 5 7 7 8 6 7 4 5 15

The coefficients in Table 1 have been replaced by the values of presence (1) and absence (0) of

species.

Last column: absolute frequency of species (Fr). The species are arranged by decreasing

frequency. Last line: number of species per collected data. Last number (bold): total number of

species recorded (observed species richness, S). The average number of species per collected data

is 5.7 with a variance of 2.6.

Four changes have been applied in Table 1 to elaborate Table 2:

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1. The coefficients in Table 1 were replaced by 1 and the empty cells with 0.

The result is a table on the presence-absence.

2. A column was added at the end of the table. It contains the frequency values (or presence) of

different species (Fr). The frequency of a species is the number of times a species is present in

a table (absolute frequency) or compared to the total number of records in the table (relative

frequency).

3. Species have been rearranged by decreasing frequency. This manipulation of the table permits

the underlining of the frequent species, also known as common species, and less frequent

species, known as rare species. In Table 2, six species are represented only once. They are

unique species.

4. An additional line at the bottom of the table shows the number of species per collected

data. Thus, species richness (or flora) varies between 2 and 8 and amounts to 15 for the entire

table. It is easy to calculate an average wealth per collected data (S = 5.7) and variance (s2 =

2.6). The emergence of new species, from left to right of the table, enables to draw a cumulative

curve of species that tends to become asymptotic as the number of collected data increases

(sampling effort).

The cumulative curve of species can be used for several functions:

1) Indicate whether the sampling effort is sufficient (the curve reaches the top) or should be

continued (the slope is still too high) to optimize sampling

2) Compare species richness of communities subject to different sampling efforts

3) Improve knowledge of the total richness of the community, one of the components of biodiversity.

Thus, in our case, the cumulative numbers of species are, successively: 2, 5, 6, 7, 7, 8, 9, 11, 13, 14,

14, 15.

5.3.3. OTHER ENVIRONMENTAL FACTORS TO CONSIDER

It is important to take into account the hydrological parameters and some soil factors of the

environment and analyze them. For that, it is important to integrate into the team a hydrogeologist

who can assist with the collection and analysis of the data. The hydrological parameters are:

o The water level

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o pH

o Temperature

o Dissolved oxygen

o Conductivity

o Presence of other chemicals such as nitrates, phosphates and potassium.

The soil parameters must also be written down on the basis of soil samples that will be taken at

different points at the sampling station. These samples will be analyzed in the laboratory and

various parameters will be considered:

pH

Electrical conductivity

Total nitrogen

Assimilable phosphorus

Exchangeable bases

Cation Exchange Capacity

Degree of saturation

Organic Carbon

Organic matter

Ionic Balance

Granular measuring

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BIBLIOGRAPHICAL REFERENCES

Arbonnier M. 2000. Arbres, arbustes et lianes des zones sèches d’Afrique de l’Ouest. CIRAD-

MNHN-UICN, 542 p.

BERGHEN V. 1982. Initiation á l’étude de la végétation. Jardin Botanique national de Belgique.

263 P.

Durand JR. & Lévêque C.1980. Flore et Faune aquatiques de l'Afrique Sahelo-soudanienne.

ORSTOM Paris, 389 P.

Emms, C. and Barnett, L.K. 2006. Gambian biodiversity: A provisional checklist of all species

recorded within The Gambia, West Africa, part three: fungi and plants, 4th version.

Francois Gillet. 2000- La phytosociologie synusiale intégrée- Guide méthodologique. Laboratoire d'écologie végétale et de phytosociologie, Institut de Botanique, Université de Neuchatel (Suisse).

Thiam A. 1984. Contribution á l’étude phytoécologique de la zone de décrus du lac de Guiers

(Sénégal). Thèse de troisième cycle, Institut des Sciences de l’Environnement, faculté des Sciences

et Techniques, Université Cheikh Anta Diop de Dakar. 105 P.

Thiam, A. 1998. Flore et végétation aquatiques et des zones inondables du delta du fleuve Sénégal

et le lac de Guiers, AAU reorts 39: 245-257.

Wetlands International Afrique. 2009. Plan préliminaire pour le suivi de la biodiversité des eaux douces du bassin du fleuve Gambie. Rapport d‘étude du projet « Freshwater Biodiversity » Wetlands International Afrique. 2009. Biodiversité des eaux douces du bassin du fleuve Gambie. Rapport d‘étude du projet « Freshwater Biodiversity » Jean-Michel Noël Walter. 2006. Méthode d’étude de la végétation. Université Louis Pasteur,

Institut de Botanique-Strasbourg.

White, F. 1986. La végétation de l’Afrique, ORSTOM – UNESCO, 384p.

www.google.fr

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ANNEXES

ANNEX 1. DATA COLLECTION SHEET Station…………………………………………………………………………………………………………………………………………

Data collection number……………………………………………………………………………………………………………..

Date…………………………………………………………………………………………………………………………………………………

Name………………………………………………………………………………………………………………………………………………

Geographical coordinates………………………………………………………………………………………………………

Altitude………. ……………………………………………………………………………………………………………………………….

Topography (slope, terrain)………………………………………………………………………………………………………….

Exposition………………………………………………………………………………………………………………………………………

Substrate………………………………………………………………………………………………………………………………………

Soil characteristics……………………………………………………………………………………………………………………

Biotic factors……………………………………………………………………………………………………………………………

Recovery (%)……………………………………………………………………………………………………………………......

Species Abundance-dominance

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ANNEX 2: LIST OF FRESHWATER FLORA IN THE GAMBIA RIVER BASIN

Genre Espèce Famille

1 Abildgaardia wallichiana Cyperaceae

2 Acacia seyal Mimosaceae

3 Acacia nilotica Subsp adstringens Mimosaceae

4 Acroceras amplectens Poaceae

5 Acroceras zizanioides Poaceae

6 Adenostemma perrottetii Asteraceae

7 Aeschynomene afraspera Fabaceae

8 Aeschynomene crassicaulis Fabaceae

9 Aeschynomene elaphroxylon Fabaceae

10 Aeschynomene indica Fabaceae

11 Aeschynomene nilotica Fabaceae

12 Aeschynomene pfundii Fabaceae

13 Aeschynomene schimperi Fabaceae

14 Aeschynomene sensitiva Fabaceae

15 Aeschynomene tambacoundensis Fabaceae

16 Aeschynomene uniflora Fabaceae

17 Ageratum conyzoides Asteraceae

18 Albizia ferruginea Mimosaceae

19 Aldrovanda vesiculosa Droseraceae

20 Alloteropsis paniculata Poaceae

21 Althernanthera sessilis Amaranthaceae

22 Ammannia auriculata Lythraceae

23 Ammannia baccifera Lythraceae

24 Ammannia prieureana Lythraceae

25 Ammannia senegalensis Lythraceae

26 Ancistrophyllum secundiflorum Arecaceae

27 Andropogon africanus Poaceae

28 Andropogon tenuiberbis Poaceae

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29 Aneilema mortonii Commelinaceae

30 Aneilema paludosum Subsp. paludosum Commelinaceae

31 Anosporum pectinatus Cyperaceae

32 Anubias heterophylla Araceae

33 Aponogeton subconjugatus Aponogetonaceae

34 Aponogeton vallisnerioides Aponogetonaceae

35 Arundinella nepalensis Poaceae

36 Ascolepis brasiliensis Cyperaceae

37 Asystasia gangetica Acanthaceae

38 Avicennia germinans Avicenniaceae

39 Azolla africana Azollaceae

40 Bacopa crenata Scrophulariaceae

41 Bacopa decumbens Scrophulariaceae

42 Bacopa floribunda Scrophulariaceae

43 Bergia ammannioides Elatinaceae

44 Bergia aquatica Elatinaceae

45 Bergia capensis Elatinaceae

46 Blumea viscosa Asteraceae

47 Blumea guineensis Asteraceae

48 Blyxa senegalensis Hydrocharitaceae

49 Bolbitis heudelotii Lomariopsidaceae

50 Bolboschoenus grandispicus Cyperaceae

51 Bolboschoenus maritimus Cyperaceae

52 Borassus aethiopum Arecaceae

53 Brachiaria jubata Poaceae

54 Brachiaria mutica Poaceae

55 Buchnera bowalensis Scrophulariaceae

56 Buchnera capitata Scrophulariaceae

57 Burnatia enneandra Alismataceae

58 Butomopsis = Tenagocharis latifolia Limnocharitaceae

59 Calamus deerratus Arecaceae

60 Caldesia oligococca Alismataceae

61 Caldesia reniformis Alismataceae

62 Canthium cornellia Rubiaceae

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63 Caperonia fistulosa fistulosa Euphorbiaceae

64 Caperonia senegalensis Euphorbiaceae

65 Caperonia serrata Euphorbiaceae

66 Carapa procera Meliaceae

67 Cassia mimosoides Caesalpiniaceae

68 Cassia obtusifolia Caesalpiniaceae

69 Celosia argentea Amaranthaceae

70 Centella asiatica Apiaceae

71 Ceratophyllum demersum Ceratophyllaceae

72 Ceratophyllum submersum Ceratophyllaceae

73 Ceratopteris cornuta Parkeriaceae

74 Chara aspera Characeae

75 Chara fibrosa Characeae

76 Chara zeylanica Characeae

77 Chloris robusta Poaceae

78 Chlorophora regia Moraceae

79 Chlorophytum gallabatense Lilliaceae

80 Cladium mariscus Cyperaceae

81 Coelorhachis afraurita Poaceae

82 Coldenia procumbens Boraginaceae

83 Commelina congeesta Commelinaceae

84 Commelina diffusa Commelinaceae

85 Commelina macrospatha Commelinaceae

86 Commelina erecta Commelinaceae

87 Crateva religiosa Capparaceae

88 Crateva adansonii Capparidaceae

89 Cressa cetica Convolvulaceace

90 Crinum distichum Amaryllidaceae

91 Crinum glaucum Amaryllidaceae

92 Crinum purpurascens Amaryllidaceae

93 Crinum zeylanicum Amaryllidaceae

94 Crinum natans Amaryllidaceae

95 Cyanotis lanata Amaryllidaceae

96 Cyclosorus gongylodis Thelypteridaceae

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97 Cyclosorus striatus Thelypteridaceae

98 Cynodon dactylon Poaceae

99 Cynometra vogelii Caesalpiniaceae

100 Cyperus alopecuroides Cyperaceae

101 Cyperus articulatus Cyperaceae

102 Cyperus auricomus Cyperaceae

103 Cyperus congensis Cyperaceae

104 Cyperus denudatus Cyperaceae

105 Cyperus difformis L. Cyperaceae

106 Cyperus digitatus Cyperaceae

107 Cyperus dives Cyperaceae

108 Cyperus esculentus Cyperaceae

109 Cyperus exaltatus Cyperaceae

110 Cyperus haspan Cyperaceae

111 Cyperus imbricatus Cyperaceae

112 Cyperus iria Cyperaceae

113 Cyperus laevigatus Cyperaceae

114 Cyperus latericus Cyperaceae

115 Cyperus latifolius Cyperaceae

116 Cyperus longus Cyperaceae

117 Cyperus maculatus Cyperaceae

118 Cyperus meeboldii Cyperaceae

119 Cyperus michelianus Cyperaceae

120 Cyperus pectinatus Cyperaceae

121 Cyperus podocarpus Cyperaceae

122 Cyperus pulchellus Cyperaceae

123 Cyperus pustulatus Cyperaceae

124 Cyperus reduncus Cyperaceae

125 Cyperus remotispicatus Cyperaceae

126 Cyperus rotondus Cyperaceae

127 Cyperus submicrolepis Cyperaceae

128 Cyperus procerus Cyperaceae

129 Cyperus tenuispica Cyperaceae

130 Cyrtosperma senegalense Araceae

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131 Dalbergia ecastaphyllum Fabaceae

132 Dialium guineense Caesalpiniaceae

133 Digitaria acuminatissima Poaceae

134 Digitaria patagiata Poaceae

135 Diplacrum africanum Cyperaceae

136 Dopatrium senegalense Scrophulariaceae

137 Dopatrium macranthum Scrophulariaceae

138 Drepanocarpus lunatus Caesalpiniaceae

139 Echinochloa colona Poaceae

140 Echinochloa crus-pavonis Poaceae

141 Echinochloa obtusiflora Poaceae

142 Echinochloa stagnina Poaceae

143 Echinocloa callopus Poaceae

144 Echinocloa pyramidalis Poaceae

145 Eclipta prostrata Asteraceae

146 Eichhornia crassipes Pontederiaceae

147 Eichhornia natans Pontederiaceae

148 Elaeis guineensis Arecaceae

149 Eleocharis acutangula Cyperaceae

150 Eleocharis atropurpurea Cyperaceae

151 Eleocharis complanata Cyperaceae

152 Eleocharis decoriglumis Cyperaceae

153 Eleocharis deightonii Cyperaceae

154 Eleocharis dulcis. Cyperaceae

155 Eleocharis mutata Cyperaceae

156 Eleocharis naumanniana Cyperaceae

157 Eleocharis nupeensis Cyperaceae

158 Eleocharis setifolia Cyperaceae

159 Eleocharis variegata Cyperaceae

160 Elymandra gossweileri Poaceae

161 Elytrophorus spicatus Poaceae

162 Entada mannii Mimosaceae

163 Enydra fluctuans Asteraceae

164 Eragrostis atrovirens Poaceae

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165 Eragrostis barteri Poaceae

166 Eragrostis gangetica Poaceae

167 Eragrostis japonica Poaceae

168 Eragrostis plurigluma Poaceae

169 Eriocaulon afzelianum Eriocaulaceae

170 Eriocaulon bongense Eriocaulaceae

171 Eriocaulon cinereum Eriocaulaceae

172 Eriocaulon fulvum Eriocaulaceae

173 Eriocaulon irregulare Eriocaulaceae

174 Eriocaulon longense Eriocaulaceae

175 Eriocaulon meiklei Eriocaulaceae

176 Eriocaulon nigericum Eriocaulaceae

177 Eriocaulon setaceum Eriocaulaceae

178 Eriochloa fatmensis Poaceae

179 Erythrophleum suaveolens Caesalpiniaceae

180 Evolvolus alsinoides Convolvulaceae

181 Ficus acutifolia Moraceae

182 Ficus asperifolia Moraceae

183 Ficus capreaefolia Moraceae

184 Ficus congensis Moraceae

185 Ficus trichopoda Moraceae

186 Ficus vallis-choudae Moraceae

187 Fimbristylis alboviridis Cyperaceae

188 Fimbristylis bisumbellata Cyperaceae

189 Fimbristylis dichotoma Cyperaceae

190 Fimbristylis miliacea Cyperaceae

191 Fimbristylis tomentosa Cyperaceae

192 Floscopa africana Commelinaceae

193 Floscopa aquatica Commelinaceae

194 Floscopa axillaris Commelinaceae

195 Floscopa flavida Commelinaceae

196 Floscopa glomerata Commelinaceae

197 Fuirena stricta Cyperaceae

198 Fuirena umbellata Cyperaceae

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199 Genlisea africana Lentibulariaceae

200 Glinus lotoides Aïzoaceae

201 Grangea maderaspatana Asteraceae

202 Hallea stipulosa Rubiaceae

203 Heliotropium baclei Boraginaceae

204 Heliotropium indicum Boraginaceae

205 Heliotropium ovalifolium Boraginaceae

206 Hemarthria altissima Poaceae

207 Heteranthera callifolia Pontederiaceae

208 Heteranthoecia guineensis Poaceae

209 Heterotis rotundifolia Melastomataceae

210 Hydrocotyle bonariensis Hydrocotylaceae

211 Hydrolea floribunda Hydrophyllaceae

212 Hydrolea glabra Hydrophyllaceae

213 Hydrolea macrosepala Hydrophyllaceae

214 Hygrophila abyssinica Acanthaceae

215 Hygrophila auriculata Acanthaceae

216 Hygrophila barbata . Acanthaceae

217 Hygrophila brevituba Acanthaceae

218 Hygrophila laevis Acanthaceae

219 Hygrophila micrantha Acanthaceae

220 Hygrophila niokoloensis Acanthaceae

221 Hygrophila odora Acanthaceae

222 Hygrophila senegalensis Acanthaceae

223 Hygrophila africana Acanthaceae

224 Hyparrhenia glabriuscula Poaceae

225 Impatiens irvingii Balsaminaceae

226 Indigofera macrophylla Fabaceae

227 Indigofera nigritana Fabaceae

228 Ipomoea aquatica Convolvulaceae

229 Ipomoea setifera Convolvulaceae

230 Isachne kiyalaensis Poaceae

231 Ischaemum rugosum Poaceae

232 Ixora brachypoda Rubiaceae

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233 Khaya senegalensis Meliaceae

234 Kyllinga pumila Cyperaceae

235 Lasiomorpha senegalensis Araceae

236 Laurembergia tetrandra Haloragidaceae

237 Ledermanniella abbayesii Podostemaceae

238 Ledermanniella pygmaea Podostemaceae

239 Leersia drepanothrix Poaceae

240 Leersia hexandra Poaceae

241 Lemna aequinoctialis Lemnaceae

242 Leptochloa caerulescens Poaceae

243 Lightfootia hirsuta Campanulaceae

244 Limnophila barteri Scrophulariaceae

245 Limnophila dasyantha Scrophulariaceae

246 Limnophyton angolense Alismataceae

247 Limnophyton fluitans Alismataceae

248 Limnophyton obtusifolium Alismataceae

249 Lindernia debilis Scrophulariaceae

250 Lindernia diffusa Scrophulariaceae

251 Lindernia oliveriana Scrophulariaceae

252 Lindernia senegalensis Scrophulariaceae

253 Lipocarpha chinensis Cyperaceae

254 Lipocarpha kernii Cyperaceae

255 Lipocarpha filiformis Cyperaceae

256 Lipocarpha sphacelata Cyperaceae

257 Lobelia senegalensis Campanulaceae

258 Loudetia phragmitoides Poaceae

259 Loudetiopsis ambiens Poaceae

260 Ludwigia adscendens Onagraceae

261 Ludwigia decurrens Onagraceae

262 Ludwigia erecta Onagraceae

263 Ludwigia hyssopifolia Onagraceae

264 Ludwigia leptocarpa Onagraceae

265 Ludwigia octovalvis brevisepala Onagraceae

266 Ludwigia perennis Onagraceae

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267 Ludwigia senegalensis Onagraceae

268 Ludwigia stenorraphe Onagraceae

269 Ludwigia affinis Onagraceae

270 Ludwigia pulvinaris Onagraceae

271 Ludwigia pulvinaris

272 Machearium lunatum Fabaceae

273 Mariscus luridus Cyperaceae

274 Mariscus squarrosus Cyperaceae

275 Marsilea berhautii Marsileaceae

276 Marsilea crenulata Marsileaceae

277 Marsilea diffusa Marsileaceae

278 Marsilea gymnocarpa Marsileaceae

279 Marsilea minuta Marsileaceae

280 Marsilea nubica Marsileaceae

281 Marsilea polycarpa Marsileaceae

282 Marsilea subterranea Marsileaceae

283 Marsilea tricopoda Marsileaceae

284 Melastomastrum capitatum Melastomataceae

285 Melochia corchorifolia Sterculiaceae

286 Mesanthemum radicans Eriocaulaceae

287 Mimosa pellita Mimosaceae

288 Mimosa pigra Mimosaceae

289 Mimosa aspera Mimosaceae

290 Mitragyna inermis Rubiaceae

291 Mitragyna stipulosa Rubiaceae

292 Monochoria brevipetiolata Pontederiaceae

293 Morelia senegalensis Rubiaceae

294 Murdannia simplex Commelinaceae

295 Murdannia tenuissima Commelinaceae

296 Najas graminea Hydrocharitaceae

297 Najas marina Hydrocharitaceae

298 Nelsonia canescens Acanthaceae

299 Neptunia oleracea Mimosaceae

300 Nesaea radicans Lythraceae

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301 Nymphaea guineensis Nymphaeaceae

302 Nymphaea heudelotii Nymphaeaceae

303 Nymphaea lotus Nymphaeaceae

304 Nymphaea micrantha Nymphaeaceae

305 Nymphaea nouchali var. caerulea Nymphaeaceae

306 Nymphoides ezannoi Menyanthaceae

307 Nymphoides guineensis Menyanthaceae

308 Nymphoides indica Menyanthaceae

309 Oldenlandia capensis Rubiaceae

310 Oldenlandia goreensis Rubiaceae

311 Oldenlandia lancifolia Rubiaceae

312 Oryza barthii Poaceae

313 Oryza brachyantha Poaceae

314 Oryza glaberrima Poaceae

315 Oryza longistaminata Poaceae

316 Oryza punctata Poaceae

317 Oryza sativa Poaceae

318 Ottelia ulvifolia Hydrocharitaceae

319 Oxycarium cubense Cyperaceae

320 Pandanus candelabrum Pandanacea

321 Panicum anabaptistum Poaceae

322 Panicum brazzavillense Poaceae

323 Panicum fluviicola Poaceae

324 Panicum calocarpum Poaceae

325 Panicum hymeniochilum Poaceae

326 Panicum laetum Poaceae

327 Panicum parvifolium Poaceae

328 Panicum repens Poaceae

329 Panicum subalbidum Poaceae

330 Panicum walense Poaceae

331 Paratheria prostrata . Poaceae

332 Paspalidium geminatum Poaceae

333 Paspalum conjugatum Poaceae

334 Paspalum scrobiculatum Poaceae

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335 Paspalum vaginatum Poaceae

336 Pauridiantha afzelii Rubiaceae

337 Pavetta corymbosa Rubiaceae

338 Penaclethra macrophylla Mimosaceae

339 Pentodon pentandrus Rubiaceae

340 Phacelurus gabonensis Poaceae

341 Phoenix reclinata Arecaceae

342 Phragmites australis Poaceae

343 Phragmites karka Poaceae

344 Phragmites mauritianus Poaceae

345 Phyla nodiflora Verbenaceae

346 Phyllanthus reticulatus Euphorbiaceae

347 Physalis angulata Solanaceae

348 Phytolacca dodecandra Phytolaccaceae

349 Piper capense Piperaceae

350 Piper guineense Piperaceae

351 Pistia stratiotes Araceae

352 Polycarpon prostratum Caryophyllaceae

353 Polygonum acuminatum Polygonaceae

354 Polygonum lanigeratum Polygonaceae

355 Polygonum limbatum Polygonaceae

356 Polygonum pulchrum Polygonaceae

357 Polygonum salicifolium Polygonaceae

358 Polygonum senegalense Polygonaceae

359 Polygonum strigosum Polygonaceae

360 Portulaca oleracea Portulacaceae

361 Potamogeton nodosus Potamogetonaceae

362 Potamogeton octandrus Potamogetonaceae

363 Potamogeton schweinfurthii Potamogetonaceae

364 Pothomorphe umbellata Piperaceae

365 Pterocarpus santalinoides Fabaceae

366 Pulicaria crispa Asteraceae

367 Pycreus capillifolius Cyperaceae

368 Pycreus flavescens Cyperaceae

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369 Pycreus intactus Cyperaceae

370 Pycreus intermedius Cyperaceae

371 Pycreus lanceolatus Cyperaceae

372 Pycreus macrostachyos Cyperaceae

373 Pycreus mundtii Cyperaceae

374 Pycreus nitidus Cyperaceae

375 Pycreus polystachyos Cyperaceae

376 Ranalisma humile . Alismataceae

377 Raphia palma-pinus Arecaceae

378 Raphia sudanica Arecaceae

379 Rhamphicarpa fistulosa Scrophulariaceae

380 Rhizophora harrisonii Rhizophoraceae

381 Rhizophora mangle Rhizophoraceae

382 Rhizophora racemosa Rhizophoraceae

383 Rhynchospora brevirostris Cyperaceae

384 Rhynchospora corymbosa Cyperaceae

385 Rhynchospora eximia Cyperaceae

386 Rhynchospora gracillima Cyperaceae

387 Rhynchospora holoschoenoides Cyperaceae

388 Rhynchospora triflora Cyperaceae

389 Rhytachne gracilis Poaceae

390 Rhytachne rottboellioides Poaceae

391 Rhytachne triaristata Poaceae

392 Rhytachne megastachya Poaceae

393 Rorippa nasturtium-aquaticum Cruciferae

394 Rotala elatinoides Lythraceae

395 Rotala gossweileri Lythraceae

396 Rotala stagnina Lythraceae

397 Rotala tenella Lythraceae

398 Rotala welwitschii Lythraceae

399 Rothmannia langiflora Rubiaceae

400 Rotula aquatica Lythraceae

401 Rytigynia senegalensis Rubiaceae

402 Saccharum spontaneum subsp aegyptiacum Poaceae

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403 Sacciolepis africana Poaceae

404 Sacciolepis chevalieri Poaceae

405 Sacciolepis ciliocincta Poaceae

406 Sacciolepis cymbiandra Poaceae

407 Sacciolepis micrococca Poaceae

408 Sacciolepis indica Poaceae

409 Sagittaria guayanensis lappula Alismataceae

410 Salacia senegalensis Hippocrateaceae

411 Salix chevalieri Salicaceae

412 Salvinia nymphellula Salviniaceae

413 Sarcocephalus latifolius Rubiaceae

414 Sarcocephalus pobeguinii Rubiaceae

415 Saxicolella flabellata Podostemaceae

416 Schoenoplectus articulatus Cyperaceae

417 Schoenoplectus corymbosus Cyperaceae

418 Schoenoplectus junceus Cyperaceae

419 Schoenoplectus lateriflorus Cyperaceae

420 Schoenoplectus litoralis Cyperaceae

421 Schoenoplectus roylei . Cyperaceae

422 Schoenoplectus senegalensis Cyperaceae

423 Schoenoplectus subulatus Cyperaceae

424 Scilla sudanica Lilliaceae

425 Scleria gracillima Cyperaceae

426 Scleria lacustris Cyperaceae

427 Scleria mikawana Cyperaceae

428 Scleria racemosa Cyperaceae

429 Scleria rehmannii Cyperaceae

430 Scoparia dulcis Scrophulariaceae

431 Sesbania bispinosa Fabaceae

432 Sesbania leptocarpa Fabaceae

433 Sesbania pachycarpa Fabaceae

434 Sesbania rostrata Fabaceae

435 Sesbania sericea Fabaceae

436 Sesbania sesban Fabaceae

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437 Setaria sphacelata Poaceae

438 Simirestis paniculata Celastraceae

439 Sorghastrum stipoides Poaceae

440 Sorghum arundinaceum Poaceae

441 Spermacoce bambusicola Rubiaceae

442 Spermacoce hepperana Rubiaceae

443 Spermacoce ocymoides Rubiaceae

444 Spermacoce quadrisulcata Rubiaceae

445 Spermacoce verticillata Rubiaceae

446 Sphaeranthus senegalensis Asteraceae

447 Sphenoclea dalziellii Sphenocleaceae

448 Sphenoclea zeylanica Sphenocleaceae

449 Spirodela polyrrhiza Lemnaceae

450 Stachytarpheta indica Verbenaceae

451 Stylochiton hypogaeus Araceae

452 Syzygium guineense var. macrocarpum Myrtaceae

453 Tetraceara alnifolia Dilleniaceae

454 Tetraceara djalonica Dilleniaceae

455 Tetraceara leiocarpa Dilleniaceae

456 Tetraceara potatoria Dilleniaceae

457 Thalia welwitschii Marantaceae

458 Thalia geniculata Marantaceae

459 Torenia thouarsii Scrophulariaceae

460 Trapa natans Trapaceae

461 Treculia africana Moraceae

462 Typha capensis Typhaceae

463 Typha domingensis Typhaceae

464 Typha elephantina Typhaceae

465 Uapaca togoensis Euphorbiaceae

466 Urena lobata Malvaceae

467 Utricularia foliosa Lentibulariaceae

468 Utricularia gibba Lentibulariaceae

469 Utricularia inflexa var. stellaris Lentibulariaceae

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470 Utricularia micropetala Lentibulariaceae

471 Utricularia pubescens Lentibulariaceae

472 Utricularia reflexa Lentibulariaceae

473 Utricularia rigida Lentibulariaceae

474 Utricularia spiralis Lentibulariaceae

475 Utricularia striatula Lentibulariaceae

476 Utricularia subulata Lentibulariaceae

477 Utricularia benjaminiana Lentibulariaceae

478 Utricularia stellaris Lentibulariaceae

479 Vallisneria spiralis var. densesrrulata Hydrocharitaceae

480 Vernonia colorata Asteraceae

481 Vetiveria fulvibarbis Poaceae

482 Vetiveria nigritana Poaceae

483 Vigna luteola Fabaceae

484 Vigna longifolia Fabaceae

485 Vossia cuspidata Poaceae

486 Websteria confervoides Cyperaceae

487 Wiesneria schweinfurthii Alismataceae

488 Wolffia arrhiza Lemnaceae

489 Wolffiella welwitschii Lemnaceae

490 Xyris anceps Xyridaceae

491 Xyris barteri Xyridaceae

492 Xyris capensis Xyridaceae

493 Xyris straminea Xyridaceae

494 Ziziphus spina-christi var. microphylla Rhamnaceae

The monitoring of flora and aquatic vegetation · module on plants page 1 integration of freshwater...

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