The Petawawa

Research Forest

A Unique Forest ResourceA Unique Forest Resource

Ressources naturellesCanada

Service canadiendes forêts

Natural ResourcesCanada

Canadian ForestService

A Unique Forest Resource

The Petawawa

Research Forest

©Her Majesty the Queen in Right of Canada, 1998

ISBN 0-662-26479-7

Cat. no. Fo42-234/1-1998E

Editing/Production: Catherine Carmody

Design and Layout: Danielle Monette

All photographs are from the Petawawa Research Forest archives.

Cette publication est disponible en français sous le titre

La Forêt expérimentale de Petawawa : Une ressource forestière unique.

Printed on alkalinepermanent paperPRINTED IN CANADA

Printed onrecycled paper

The Petawawa Research Forest (PRF) of the Canadian

Forest Service (CFS), Natural Resources Canada, offers a

research potential unequaled in most of Canada. The knowl-

edge from over 75 years of forest science research awaits

the interested researcher.

The various forest communities of the PRF are natural

sites for the study of ecosystem resilience and the effects

of disturbance and stress. Data from biomass studies are

available. Wildlife, large and small, is abundant in the forest

and in the lakes and streams of the PRF. Protected water-

sheds and watercourse basins are ideal for conservation

studies. Both natural and managed stands can be used to

gain greater insight into non-timber values and the depen-

dence of local communities on traditional uses of the forest.

We are not able to describe in detail here the many

attributes that set the PRF apart and make it a unique

research site. Nor are we able to do any more than allude

to the important contributions that it can make to research

into the criteria and indicators of sustainable forest manage-

ment. We can only give an overview of the PRF’s research

potential. There is much more that can be discovered through

exploring the more detailed material available at the site —

the documented site, stand, and silvicultural histories, the

broad range of detailed research undertakings, and the well-

described and managed stands and plantations.

We encourage the use of the PRF by the CFS Science

and Technology Networks, their scientific partners, and the

research community at large. We also welcome and are solic-

iting independent third-party use of the forest with industry,

colleges and universities, governments and municipalities,

aboriginal communities, and environmental associations.

Memoranda-of-understanding are currently being negoti-

ated to establish active collaboration between the PRF and

a range of CFS and non-CFS partners.

3

Content sHistory of the Petawawa Research Forest 6A Wealth of Research Opportunity 8

Forest Management Practices 8Genetics 10Fire Management and Ecology 12Headquarters Silvicultural Area 14Untapped Research Areas 14Other Sites 14

Access to the Petawawa Research Forest 16Appendices 17

The Forest Environment 17The Forest Resource 17Scientific Names of Trees Mentioned in Text 18

The Petawawa Forest Experiment

Station was established in 1918 when mili-

tary authorities asked the Forestry Branch

of the federal Department of the Inte-

rior to protect and manage the forest

of the Petawawa Military Reserve. The

government also saw it as an oppor-

tunity to initiate a research program

and to demonstrate applied silvicul-

ture that would advance the scientific

foundations of forest man-

agement in Canada and

abroad. During the summer

of 1918, a small tent camp

was set up on the shores of

Corry Lake, at the northern

boundary of the Petawawa

Military Reserve. The first

forest inventory was begun

and the first Canadian per-

manent sample plot estab-

lished. This marked the

History ofthe PetawawaResearch Forest

7beginning of research at the Petawawa Research Forest (PRF), the oldest

continuously operated forest research centre in Canada. The 10 000-ha research

area encompasses the northern portion of the Petawawa Military Reserve through

formal agreement with the landowner, the Department of National Defence.

For more than 75 years the Station, later known as the Petawawa National

Forestry Institute (PNFI), was at the forefront of forestry research in Canada. It pio-

neered systematic study in silviculture, forest ecology, fire research, and tree breeding

and genetics. Its contributions in these areas exceeded those of any other research

centre in the country. Its forest estate was continuously monitored and managed

during this time. More than 2000 experimental plots and sites were established and

the Station became internationally recognized as Canada’s preeminent research

forest.

Although in 1996 a decision was

made by the Government of Canada

to transfer the research programs being

undertaken at PNFI to other Canadian

Forest Service (CFS) centres across

the country, the Petawawa Research

Forest has been maintained. Its objec-

tive is to protect, preserve, and pro-

mote the forest’s historical and scientific

legacy. It serves as facility for scientific

research by the CFS Science and

Technology (S&T) Networks

and for cooperating scientists

and partners from other agen-

cies. The PRF also aims to edu-

cate technical personnel and

the interested public through

field demonstrations of forest

management principles and

methods.

The Petawawa Research

Forest endeavors to protect,

preserve, and promote the

historical and scientific

legacy of the forest.

The decades-long program of researchat the Petawawa Research Forest (PRF) hasresulted in a wealth of forest data. The gener-al forest and environmental data, along withinformation from years of field investigations,provide a solid foundation for future researchand forest management undertakings.

In recent times the forests of the PRF havebeen sites for experimentation in tree biotech-nology and genetics, forest practices, and firemanagement and ecology; for investigationsinto forest meteorology and forest productsenhancement and procurement; and for thetesting and development of new technologiessuch as digital remote sensing. Much researchfocused on the red and white pine stands ofthe PRF, which flourish on the rich sandy loamsof the area. Years of historical data are avail-able from which trend lines can be divined,and periodic growth relations and stand dynam-ics can be seen for a range of values and

treatments.

In the non-research portions of the forest,modern forest management methods and har-vesting practices have been done routinely. Thus,the bulk of the forest is healthy and vigorous.

The potential of the scientific informationavailable at the PRF for retrospective researchand the establishment of new studies is evident.The PRF offers significant opportunities forscientific validation of Canada’s approach tonational and international forest policy andsustainable forest management. In the follow-ing sections, the major areas for research oppor-tunity at the PRF are explored.

Forest ManagementPractices

The more than 400 silviculture PSPs atthe PRF continue to be a prime source of infor-mation on long-term productivity of forestland. They are found throughout the treat-ment areas and in the Headquarters Silvicul-tural Area (described on page 14) established totest and provide examples of high-yield silvi-cultural practices on an operating scale. Theyawait new and innovative thinking to revealstill further information on forest responseto management activity.

Many plantations at the PRF were estab-lished on former farm sites, others on natural

A Wealthof ResearchOpportunity

Modest undertakings marked the beginnings of one of the longest standing forest

management research programs in North America. Canada’s oldest surviving per-

manent sample plot (PSP) is located at the PRF. It, and several others, were estab-

lished in 1918 in a stand of mixed pines, shade-intolerant hardwoods, and spruce

and were the starting point for what is today perhaps the finest forest resource

archive in the country.

In the early years, silviculture research at the PRF focused on such concerns as

securing the regeneration of eastern white pine and red pine, controlling white pine

weevil (Pissodes strobi) by shade manipulation, and managing shade-tolerant hard-

woods on a sustained yield basis. The stands used in many of these undertakings

remain today, as do many of the earliest pine treatment blocks.

sites following scarification or fire. They containa range of pines, spruces, larches, poplars, alders,and willows. The majority of these plantationsremain “undisturbed”, although some havereceived thinning or other tending treatmentsas part of planned experimentation.

The natural stands at the PRF usually aroseafter fire and are generally composed of semi-mature to mature pine and pine mixedwoods,spruce, and shade-tolerant and -intolerant

hardwoods. The shade-intolerant hard-woods are reserved for silvicultural experi-mentation. Numerous examples of spacings,commercial thinnings, intermediate harvestcuts, and other forms of silvicultural treatmentcan be found throughout the area.

Forest Management PracticesResearch Profile

Area: >600 ha

No. of treatment areas: 37

No. of PSPs: 400

Principal species: Pines, spruces,larches, birches, maples, and poplars

Soil types: Moderately deep to deep.Fine sands to loamy tills

Access: Mainly roadside

Data availability: Excellent

Ongoing since: 1920s

9

During the 1930s the silviculture program expanded beyond the remeasurement of

PSPs. Seeding research and the effects of intermediate and harvest cuttings on regen-

eration commenced, and forest ecology studies were initiated, including those in

silvics, site classification, and succession. Research on growth and yield, silvicultural

practices for managing and reproducing pine, and site classification began in the late

1940s. By the 1950s, studies on soil moisture, light, temperature, and nutrition were

undertaken. The program began an inexorable swing towards understanding the

relationships between site and growth phenomena and forest management practice.

The silviculture program continued its “traditional” research until 1980s, when sil-

viculture was integrated with research on fire, remote sensing, forest management,

pest management, modeling, and strategic resource analysis to become part of

a new, interdisciplinary thrust — forest management systems research. Here silvi-

culture research found its true niche in the broader context of forest health and

productivity.

Of particular interest in today’s contextof sustainable forest management is the process-oriented research carried out at various sites,including the seedling experiments at CartierLake and the Meridian Road Silviculture Area.The former was established to evaluate soil sur-face conditions, soil fertility, and weed compe-tition and to measure reforestation success withlocal pine and spruce species. The latter wasset up to determine whether commercial thin-ning, shelterwood cuts, and site preparationpromoted the sustainability and productivityof white and red pine stands. These and otherplot layouts and blocks, with treatments inplace and baseline data collected, are ideal sitesfor new compatible studies. Treatment blocks

are usually 1–2 ha to facilitate multidisci-plinary studies.

Soils across the trial areas range from fine,well-drained sands to moist, loamy tills. Forthe most part they are deep (>2 m), althoughsome shallower soils over bedrock occur. Withthe large number of treatment areas, the varioussoil–forest type combinations are difficult todescribe briefly. Two examples are fresh, till-derived loamy sand podzols over bedrock onshade-tolerant hardwood sites and drier, well-drained, fine, slightly acidic sands on pine sites.

The PRF’s research in forest managementpractices encompasses a broad range of treat-ments and has produced a wealth of data fromthe long-documented histories of the trial areas.Opportunities that await today’s researchersinclude exploring the effects of forest practiceson the growth and development of softwood,hardwood, and mixedwood stands of the GreatLakes–St. Lawrence Forest Region; adding tobaseline data on forest health, productivity, andbiodiversity; and studying pest resistance, frostresistance, and the effects of competition ondirect seedings.

Genetics

More than 800 000 trees have beenplanted in experiments, arboreta, and seedorchards at the PRF; more than 30 plantation

At the PRF, a rich legacy in knowledge has been left by an impressive line of pioneer-

ing and forward-thinking scientists and researchers in the field of genetics.

Some plantations for the study of tree genetics existed at the PRF in the 1920s;

however, concentrated genetics research began in the mid-1930s with a program to

identify species and hybrids that demonstrated fast growth, cold hardiness, resistance

to disease and insects, and ease of propagation from seed or cuttings.

The focus in the 1950s was provenance trials and breeding research on hard pines,

spruces, and larches, and in the 1960s tree breeding and genetics. Genecological

studies began with the advent of advanced computing capabilities. Seed studies

11

Tree Breeding and GeneticsResearch Profile

Area: 200 ha

No. of plantation areas: 30

No. of experimental plots: 318

Principal species: Pines, spruces,larches

Soil types: Mainly deep. Fine-grained sands to loamy tills

Access: Mainly roadside

Data availability: Excellent for latertrials. Spotty availability for earliertrials

Ongoing since: 1920s

Tree Genetics ExperimentalPlots by Species

Species No. of plots

Jack pine 58

Red pine 25

Scots pine 22

White pine 4

Other pine speciesand hybrids 9

White spruce 52

Norway spruce 41

Black spruce 15

Red spruce 3

Other spruce speciesand hybrids 35

Larch species 34

Fir species 4

Hardwoods—poplar,birches, maple, alder 16

The 318 forest biodiversity andtree genetics plantation experimentslocated at the PRF have been categorizedby species. Of these, spruces are the subject of46% of the experiments, pines 37%, larches11%, firs 1%, and hardwood species 5%. Jackpine, red pine, white spruce, and black spruceare the prominent native species across the rangeof experiments. Key non-native species inves-tigated are Norway spruce and various larches.The source of most materials was Ontario butmany were obtained from other locations inNorth America and overseas, principally

became a prominent feature of the tree breeding activities, and the National Tree

Seed Centre was established.

In the 1980s the program’s emphasis changed to population genetics and biotech-

nology. Molecular genetics was introduced in the mid-1980s. In 1992 the program

was reorganized as the National Forest Genetics Resources Centre and reportedly

housed the world’s largest collection of conifer and genomic DNA.

areas contain over 300 tree genetics experiments.The range of experimentation and treatmentat the PRF is broad and includes replicatedprogeny and provenance trials, hybridizationexperiments leading to second and third gen-eration advancements, and observation anddemonstration plantations. Studies exist on thetransfer of seed sources for planting, the effectsof climate change, early growth and yield pre-diction, and breeding to enhance growth per-formance and resistance to pests. Many of theexperiments and investigations are a compo-nent in a series of replicated trials in easternCanada, the northern United States, and else-where. Thus, directly related sources of dataare also potentially accessible.

continental Europe, includingeastern Europe and Scandinavia.

Intra-genus hybridization is promi-nent in the experimentation.

Most trial sites are located adjacent toall-weather roads providing ready access through-out the growing season. Soils are almost alwaysdeep and range from fine-grained sands formany of the pine trials to loamy tills for manyof the spruce, larch, and hardwood trials. Thesites are generally well-protected and except forplanned treatments afford relatively undisturbedhistories, even for the earliest plantations.

A key component of the genetics trials atthe PRF has been the management of pedigreerecords and documentation of measurementdata; this permits researchers to draw validconclusions based on the performance of knownsource material. Most data are computerizedin standard formats, allowing ready accessand transfer.

The data and plantations resulting fromthe PRF’s tree breeding and genetics activitiesare a good basis for further research into thesustainable management of forests, the conser-vation and management of genetic diversity,the health, vitality, and rates of biological pro-duction in forest ecosystems, and a host oftree breeding topics.

Fire Managementand Ecology

More than 100 experimental burns havebeen carried out in a variety of site and standconditions at the PRF. Trials have been con-ducted in the following cover types: matureand immature jack pine, mature and immaturepoplar, white pine–red pine mixtures, spruce–fir–poplar–birch mixedwoods, and red oak.Most recorded trials have been concerned with

fire behavior and fuel type. Some research onjack pine regeneration and poplar suckeringresponses to fire has been done. Other researchhas been aimed at competition control, forestfloor manipulation, and tree growth response.In some cases, the areas treated have been sub-ject to periodic burning by wildfire as far backas the mid-1800s. Records are available forprescribed burns conducted since the 1960s.The 11 trial blocks range in size from abouta hectare to more than 20 ha. Typically, smallertreatment plots and controls were establishedwithin each block.

Jack pine and the red and white pinemixtures are located on fine-grained sand thatoriginated as deltaic or valley-fill sedimentsThe deposits are from 10 to 30 m deep. Soilsare generally humoferric podzols with surfaceorganic covers of 2–5 cm and poorly developedmineral soil horizons. The red oak treatmentarea is the only one that varies significantly. It

Fire Management andEcology Research Profile

Area: 100 ha

No. of blocks: 11

No. of experimental burns: 100

Principal species: Red pine, easternwhite pine, poplar, balsam fir, redoak

Soil types: Mainly fine-grained,deep sands. Some shallow glacialtills with bedrock outcrops

Access: Mainly roadside

Data availability: Excellent for latertrials. Reports available for earliertrials

Ongoing since: 1930s

12

The data from six decades of fire research at the PRF are monumental testimony to

the efforts of some of Canada’s finest and most knowledgeable forest fire researchers.

Fire research at the PRF site originated with fire control and management activi-

ties in 1917. In the 1930s fire research began, making major advances during the

next several decades. The focus turned to fire management through fire behavior

research and then through fire ecology studies. One of the PRF’s earliest innova-

tions was the Canadian Forest Fire Weather Index System. The PRF also contributed

to the Canadian Fire Danger Rating System, which has been widely adopted across

Canada and which has been emulated in a number of countries. By the 1980s, the

program had become more comprehensive, embracing fire management systems

and decision support systems research for fire management agencies.

is located on a ridge top with rocky outcrops.The soil is typically a gravelly glacial till, thinnear outcroppings and deeper in bedrockdepressions.

Trial sites are located adjacent to all-weather roads and are easily accessible. More-over, because of the seclusion of the PRF, theblocks are generally free from undue humandisturbance and have retained their scientificintegrity over the years. They are excellent can-didates for the study of disturbance and stress,ecosystem and species diversity, and the conser-vation of soil and water resources.

The potential at the PRF for the advance-ment of knowledge on fire management andecology is enormous. For decades its forestshave been the site of fire behavior, control andecology trials. Thus researchers can examinenature’s efforts to deal with the physical andbiological changes caused by fire research. Inaddition, they can study the effects of fire onthe various soil types, soil micro-flora and micro-fauna, vegetation, and surface soil layers; changeswrought by multiple burnings; and the resultsof further burnings or forest managementtreatments.

14HeadquartersSilvicultural Area

The Headquarters Silvicultural Area, 371 ha,was established in 1952 as a working model ofdiverse forest management objectives and methods.Regularly updated results have been used for edu-cation and visual demonstration. It comprises52 separate stands, many having received multipletreatments. Most have been thinned and a fewhave received other treatments, such as strip thin-ning, overstory removal, herbicide application,and prescribed burning.

Stands in the Headquarters SilviculturalArea range in size from 0.5 to 25 ha. Some arethe result of natural development, whereas othershave been planted. Many of the natural pine, larch,and shade- tolerant hardwood stands are approach-ing maturity at about 110–120 years of age; others,mostly mixed spruce, fir, and hardwood, are some-what younger and in the 80–90-year range. Agroup of 10 red pine plantations of about 60 yearsold and a number of younger planted and naturalstands of poplar, white spruce, fir, and pine,30–40 years old, can also be found.

Untapped ResearchAreas

The PRF covers over 8500 ha. A largepart of it, about 3000 ha, presents an untappedresearch area. This reserve, maintained but notused for research, is fully mapped and has beeninventoried as recently as 1980. Some tractshave been managed principally for their forestvalues; others have served as demonstrationsites. Still others—ecological reserves—havebeen set aside as representative of various sitesand cover types of the Great Lakes–St. LawrenceForest Region. All tracts have unique value

and are candidates for research, especiallyresearch in support of the criteria and indi-cators of sustainable forest management.

The first ecological reserves or naturalareas were set aside in 1948. Additional reserveswere established on a periodic basis until 1964.Today there are 12 such areas covering justover 107 ha, and representing a range of coverand site types typical of the forest region. Theywere established to monitor successional behav-iors following disturbance. Some have beenused as control blocks for nearby treatmentsand for monitoring pest problems.

The areas of the ecological reserves rangefrom 2 to 40 ha. Two are islands in CartierLake. All of the areas, except the islands andan eastern white-cedar area located in the farnorthwest corner of the PRF, are readily acces-sible by road. PSPs are located on a numberof them. Remeasurement frequency has beenvariable but some have been well-monitoredwith remeasurements at 10-year intervals. Soilsrange from deep swampy mucks for the east-ern white-cedar site to dry, shallow glacial tillsfor the white pine–shade-tolerant hardwoodstype to deep loamy tills for the hemlock–shade-tolerant hardwoods and deep, moist, fineoutwash sands for shade-intolerant mixedwoods.Stands are generally even-aged to slightly uneven-aged and are at or greater than 100 years of age.Some individual trees (pines, shade-toleranthardwoods) may reach 200 years old.

Other Sites

A host of lesser trials and/or collaborativeexperimentation has been carried out at thePRF. These trials have left their own legacy ofdata and research results. The sites offer anopportunity for conducting new or continuingresearch, remeasuring the PSPs or semi-PSPs,and serving as forest science “classrooms”.

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Remote sensingUsing MEIS II technology, researchers

combined high resolution imagery with stan-dard aerial photography and ground truthingto develop detailed descriptions of nearly600 individual trees covering 19 species. Thedatabase and imagery, together with access tolocated plots, provide an excellent teaching/learning opportunity.

Soil condition and treeresponse monitoring

A study undertaken by Laval Universitymonitored long-term trends in soil condition,tree response, and litter decomposition follow-ing intensive silvicultural treatments in a whitespruce–eastern white pine plantation.

Forest ecosystem classificationFifty-four forest ecosystem classification

plots representative of normal forest conditionsin the Great Lakes–St. Lawrence Forest Regionwere established in various PRF cover typesbetween 1987 and 1994. Plot measurementsincluded tree cover, vegetation community,and soil conditions. Plots are identified andsample points marked on the ground.

Soils and physiographySystematic soil sampling and analysis were

undertaken in the late 1930s at PRF. Soil pitswere dug and physical classifications done atover 200 sites in the early 1950s. The pits wereoften associated with PSPs and the data are read-ily available today at the PRF. Surficial geology,land type and contour were studied, mapped,and documented in 1960s. The area is remark-ably well-documented with respect to soil, sur-face, and vegetation and serves as an excellentclassroom for both starter and advancedtraining.

Forest health monitoringFour long-term plots are monitored

on the PRF as part of the CFS’s Forest HealthMonitoring Network. Two of the plots are partof the national Acid Rain Early Warning Sys-tem (ARNEWS) and are monitored for changesin a variety of tree, vegetation, and soil attrib-utes. Plots are located in various stand typesand have been monitored since 1985.

15

The Petawawa ResearchForest offers researchers:

Site security, access, tenure,and protection.

Reliable site, stand, and silvicul-tural histories extending backover 75 years.

Accessible, well-organizeddatabases.

Detailed physiographic andsoil information.

A range of native and exoticspecies in experimental plotsand plantations.

Uninterrupted meteorologicalrecord of the research forest col-lected to Environment Canadastandards since the 1930s.

A range of research activity may be con-ducted on the PRF. Approval to conduct anactivity can be obtained from the Forest Man-ager provided it is consistent with the long-term goals for the stand or area that is to bethe subject of treatment. Areas of a non-archivalor non-historical interest and those with nopast research that is to be maintained will bethe least subject to restrictions on activity.

Data from past research and PSP mea-surements are currently being organized bythe staff of the PRF to ensure availability andaccessibility. Wherever possible, data will becomputer-accessible. Data arising from newtreatments, or from the manipulation of exist-ing data, will be owned by the researcher onthe understanding that new information anddata will be deposited as part of the PRF dataarchive.

Serviced, but limited, facilities are availableon-site. Use of the facilities, PRF equipment,

laboratories, and office space, road construction/maintenance, and assistance by local staff maybe made available on a cost-recovery basis. Theterms of the agreement for such usage willbe negotiated by PRF staff.

The PRF is located adjacent to Trans-Canada Highway 17, approximately 200 kmwest of Ottawa and 180 km east of North Bay.The bulk of the land area lies west of the high-way. The area is serviced by a network of all-weather roads reaching to the far corners ofthe forest.

Reasonably priced accommodation andmeals may be obtained in such nearby centersas Chalk River and Deep River (5 and 16 kmto the west, respectively) and by special arrange-ment with Canadian Forces Base Petawawa,25 km to the east. On-site transportation forCFS staff is, at present, negotiable with thepossibility of access to a limited number ofgovernment vehicles. It will be necessary fornon-CFS collaborators to make their ownground transportation arrangements.

Authorization to undertake research

on the PRF may be obtained from the

Forest Manager of the PRF. Direct

your request as follows:

The Forest ManagerPetawawa Research ForestCanadian Forest ServiceNatural Resources CanadaP.O. Box 2000Chalk River, ONK0J 1J0Telephone: (613) 589-2880Fax: (613) 589-2275e-mail: sdeon@intranet.ca

Access tothe PetawawaResearch Forest

17Climate

The climate is continental. Mean annual pre-cipitation is about 800 mm with about 230 mmof that in the form of snow. January is the coldestmonth with a mean temperature of –12.4oCand July is the warmest with a mean tempera-ture of 19.1oC. The mean annual temperatureis 4.4oC. The lowest recorded temperature is–40.6oC and the highest 38.9oC. The mini-mum frost-free period is about 100 days andthe average growing season is 136 days. Treediameter growth starts about 20 May and ismostly completed by mid-August. Prevailingwinds are from the northwest.

The Forest Resource

The Petawawa Research Forest (PRF) islocated in the L.4c Middle Ottawa Section of

The ForestEnvironment

Geology and Soils

Geologically the Petawawa ResearchForest lies on the southern edge of the Precam-brian Shield with the bedrock consisting ofgranites and gneisses, some of which are aboutone billion years old. The topography has beenstrongly influenced by glaciation and post-glacial outwashing.

There are three main types of terrain.To the east near the Ottawa River there areextensive sand plains of mostly deltaic origin.To the west are imposing hills, shallow sandysoils, and many bedrock outcrops. The balanceof the area consists primarily of gently rollinghills with moderately deep loamy sand con-taining numerous boulders, often of great size.Elevations vary from 140 to more than 280 mabove sea level.

The glacial material is usually sandy,mostly water-washed sands of various origins,and washed and basal tills varying in texturefrom fine sandy loams to loamy sands. In manyplaces a thin layer of wind-carried sand orsilt covers the surface and there are occasionalpatches of lacustrine and alluvial silt and claynear the lakes and streams. Swamps and bogswith organic soils exist; their nature and vege-tation depends on whether they occur on till oroutwash subsoils and whether there is any mov-ing water in them. Soils are podzols or podzolicin nature. Nearly 85% of the area is coveredby bedrock or glacial till, about 10% occupiedby windblown and ponded sands and outwash,and the balance by peat and muck soils.

Summary of Forest CoverTypes*

Type Area (ha)

Pine 395

Spruce 319

Aspen–birch–spruce 631

Aspen–birch–pine 1618

Pine–aspen–birch 1338

Pine–oak 1103

Cedar–ash–spruce 202

Other mixedwoods 334

Maple–birch 131

Oak 1083

Aspen 419

Birch 493

Other hardwoods 35

Total 8101

* 1979 data

the Great Lakes–St. LawrenceForest Region. Until 1840 the forest

supported magnificent stands of red pineand white pine. However for the next 30 yearsthe demand of the British market for squarepine timber and ship masts led to highly selec-tive cutting of the best trees. By 1870 mostof the original pine stands had been logged.The remainder of the accessible pine standswere logged by the turn of the century. Manyof the current, pine-dominated stands origi-nated following fire in cutover stands in thelate 1800s. Other areas of forest cover devel-oped, naturally or through artificial regenera-tion, on abandoned farmland.

The PRF is now a predominately mixedmature forest characterized by white pine, redpine, trembling aspen, and white birch. Redoak dominates many poor dry soils, particu-larly on upper slopes and rocky hilltops, whilejack pine occurs in nearly pure stands on drysandy flats. The current composition by spe-cies is white pine 32%, trembling aspen 23%,red pine 15%, oak 11%, maple 5%, whitespruce 5%, white birch 4%, other conifers 4%,and other hardwoods 1%.

About 85% of the area is covered with for-ests. Slightly over 8% is covered by water, whilethe remaining 6% is non-forested. About 17%of the forested area is all-aged, while another69% is more than 95 years of age and is con-sidered mature. The total growing stock of theforest is 1.5 million m3, with an estimated meanannual increment of all cover types of 2.1 to2.8 m3/ha. Growth rates of up to 7 m3/ha haveoccurred in some fully stocked pine stands andmaximum values of up to 10.5 m3/ha have beenmeasured on certain sample plots.

There are a total of about 610 ha of plan-tations in the research forest. The first planta-tion was established in 1922 when 24 ha wereplanted primarily with white spruce and redpine. Another 300 ha were planted in the 1930s.During this period more than 60% of the plan-tations were red pine; 20% mixtures of redpine, white pine, and white spruce; 8% whitespruce; and 10% white pine. Beginning in the1950s the Tree Breeding Project involved exten-sive tree planting. In 1962 the practice of plant-ing about 4 ha/year began in order to provideplantations of varying age classes for futuresilvicultural research.

Scientific Names of TreesMentioned in Text

Alder species (Alnus spp.)

Ash species (Fraxinus spp.)

Balsam fir (Abies balsamea)

Black spruce (Picea mariana)

Eastern white-cedar(Thuja occidentalis)

Eastern white pine (Pinus strobus)

Eastern hemlock (Tsuga canadensis)

Jack pine (Pinus banksiana)

Larch species (Larix spp.)

Poplar species (Populus spp.)

Norway spruce (Picea abies)

Red spruce (Picea rubens)

Red oak (Quercus rubra)

Red pine (Pinus resinosa)

Red maple (Acer rubrum)

Scots pine (Pinus sylvestris)

Trembling aspen(Populus tremuloides)

White birch (Betula papyrifera)

White spruce (Picea glauca)

Willow species (Salix spp.)

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19

P h o t o g r a p h C a p t i o n s

Cover: Experimental plots (tree genetics).

Title page: See page 10.

Page 4. Detail of photo on page 20.

Page 6 (Top to bottom). SecondBritish Empire Forestry Conference,held at the PRF, 1923. Twin white pines,examples of the large old trees found atthe PRF when it was established. Sum-mer field camp at Corry Lake, 1918.

Page 7. Permanent Sample Plot 1 in 1950when the stand was about 72 years old.

Page 9. Numbering trees on a perma-nent sample plot, 1919.

Page 10. Tree breeding arboretumconsisting mainly of exotic species.

Page 13. Experimental crown fire inred pine plantation.

Page 16. Main PRF entrance, Trans-Canada Highway (17).

Pages 19 & 20. Stand of mixed redand white pine.

N

Lake Huron

AlgonquinPark

Lake Ontario

Lake Erie

TORONTO

BUFFALO

SYRACUSE

ALBANY

MONTREALOTTAWA

PEMBROKE

HUNTSVILLE

NORTH BAY

ROCHESTER

RENFREW

NAPANEE

BROCKVILLE

NIAGARA FALLS

ONTARIO

QUEBEC

NEW YORK

PRF

401

41

87

90

81

2911

400

QEW

15

1760

17

417

The PRF is located adjacent to

Trans-Canada Highway 17, approxi-

mately 200 km west of Ottawa and

180 km east of North Bay. The bulk of

the land area lies west of the highway.

The area is serviced by a network of

all-weather roads reaching to the far

corners of the forest.