Beyond the stand: Reviewing landscape fragmentation dynamics on biodiversity … · 2019-07-02 ·...
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Biodiversity and ecosystem service outcomes Beyond the stand: Reviewing landscape fragmentation dynamics on biodiversity and ecosystem services in Southeast Asia M. Lo¹ ([email protected]) & Y. Laumonier¹² Background & purpose Agriculture and forest fragmented landscapes alter the composition and configuration of habitat elements which affect biodiversity and distribution of ecosystem services (ES). Agricultural practices in Southeast (SE) Asia range from traditional agroforestry to large agro- industrial plantations that form distinct fragmentation processes and patterns. Reviews on fragmentation studies are geographically bias towards temperate regions. Furthermore, few specifically focus on SE Asia despite the alarming rates of habitat and biodiversity loss occurring. A deeper analysis of the existing evidence on fragmentation in forest and agriculture landscapes in SE Asia is needed. Research objectives 1. To identify and describe the type of studies found on landscape fragmentation in SE Asia. 2. To examine the methods implemented to measure fragmentation across different types of forest and agriculture landscapes 3. To synthesise reported effects of landscape fragmentation on biodiversity and the distribution of ES 4. To explore the implications of our findings and identify key areas of research that are needed to understand the different dimensions of landscape measures, Systematic literature review process 1 st stage: Scope for search terms consisting of four components: i) Landscape: Industrial oil palm/smallholder ii) Landscape measures iii) Biodiversity and ES Outcomes) iv) Location: SE Asia 2 nd stage: Systematic literature search, screening, and quality appraisal 3 rd stage: Categorisation and extraction of data 4 th stage: Synthesis and recommendations o Patch-level studies dominated in industrial oil palm context, which were typically characterised as having clear distinct habitat boundaries and simple matrix cover o In permanent agroforestry systems we found a mixture of landscape and patch-level approaches. o For swidden agroforestry, 3/5 studies measured fragmentation at the landscape scale o Applicability of concepts: Mosaic concept for agroforestry landscapes Island biogeographic and meta-population theory for industrial/homogeneous landscapes Overview of studies (Total: 30 studies) Figure 2. Distribution of studies by county, landscape, group, and sub-group. Industrial oil palm Overall, smaller fragments that were more isolated in industrial oil palm plantations sig. reduce biodiversity - particularly of conservational concern. Riparian reserve width bordering oil palm plantations had no effect on dung beetles (n=1), but a positive determinant for bird species richness (n=1). Strong negative edge effects from oil palm altered vegetation structure in forests (n=2). Small forest fragments have little impact on boosting soil fauna in oil palm (n=2) Contiguous forest and forest fragments had no sig. impact on oil palm productivity (n=1) Smallholder swidden agroforestry We found that studies reported positive effects between fragmentation and species richness, but we observed a lack of studies that specifically assessed the conservational value and status of species. Configuration in swidden systems influenced water flow across landscape (n=1). Patch size of secondary forests significantly influenced the rate of biomass carbon recovery above ground to old growth forests (n=1). In swidden plots, abundance, avifauna diversity, and species composition were all positively influenced by neighbouring intact forest habitats. (n=1) Smallholder permanent agroforestry Despite missing two key landscape measures (forest patch size and landscape composition), studies reported positive benefits of forests for biodiversity and ecosystem services in agricultural habitats. Crops grown near agroforests experienced greater pollination stability (n=3) Agroforests sig. boosted soil fauna in oil palm smallholdings (n=1) Figure 1: Stages of the systematic literature search Landscape metrics 0 2 4 6 8 10 Area of forest fragments Area of forest cover around habitat patch(es) No. of studies 0 2 4 6 8 10 12 Distance between habitat patches Least Cost Path Corridor analysis Circuit theory Degree of buffering/fragmentation No. of studies Heterogeneity and composition landscape measures (n=2) Figure 6: No. of studies measuring landscape composition/diversity Figure 3: No. of studies found for forest patch size/forest amount around habitat patch Figure 4: No. of studies found for isolation and connectivity by type of metric. Figure 5: Sampling approach to measuring edge effects Credit: CIFOR ¹Center for International Forestry Research (CIFOR), Bogor, Indonesia ²Centre de coopération international en recherche agronomique pour le développement (CIRAD), Montpellier, France Outlook: Moving beyond the question of good or bad fragmentation How to better assess landscape fragmentation in different types of forest- agriculture landscapes? 1. The landscape context - level of human pressure and heterogeneity of habitats 2. The suitability of habitats , the range of tolerance to different habitats, and the dispersal ability of organisms 3. Accounting for lag time effects of fragmentation, particularly for flora. Greater research is needed on how fragmentation contributes to the recovery of habitats could help support conservation efforts on landscape restoration. o Malaysia led in the no. of studies carried out in industrial oil plantations, none in Indonesia; Little research on fragmentation in smallholder landscapes. o Strong taxonomic bias towards avifauna and soil fauna; Paucity of studies on ES.
Transcript of Beyond the stand: Reviewing landscape fragmentation dynamics on biodiversity … · 2019-07-02 ·...
Biodiversity and ecosystem service outcomes
Beyond the stand: Reviewing landscape fragmentation dynamics on biodiversity and ecosystem services in Southeast Asia
M. Lo¹ ([email protected]) & Y. Laumonier¹²
Background & purpose
Agriculture and forest fragmented landscapes alter the composition and configuration of habitat elements which affect biodiversity and distribution of ecosystem services (ES).
Agricultural practices in Southeast (SE) Asia range from traditional agroforestry to large agro-industrial plantations that form distinct fragmentation processes and patterns.
Reviews on fragmentation studies are geographically bias towards temperate regions. Furthermore, few specifically focus on SE Asia despite the alarming rates of habitat and biodiversity loss occurring.
A deeper analysis of the existing evidence on fragmentation in forest and agriculture landscapes in SE Asia is needed.
Research objectives
1. To identify and describe the type of studies found on landscape fragmentation in SE Asia.
2. To examine the methods implemented to measure fragmentation across different types of forest and agriculture landscapes
3. To synthesise reported effects of landscape fragmentation on biodiversity and the distribution of ES
4. To explore the implications of our findings and identify key areas of research that are needed to understand the different dimensions of landscape measures,
Systematic literature review process
1st stage: Scope for search terms consisting of four components:
i) Landscape: Industrial oil palm/smallholder ii) Landscape measures iii) Biodiversity and ES Outcomes) iv) Location: SE Asia
2nd stage: Systematic literature search, screening, and quality appraisal
3rd stage: Categorisation and extraction of data
4th stage: Synthesis and recommendations
o Patch-level studies dominated in industrial oil palm context, which were typically characterised as having clear distinct habitat boundaries and simple matrix cover
o In permanent agroforestry systems we found a mixture of landscape and patch-level approaches.
o For swidden agroforestry, 3/5 studies measured fragmentation at the landscape scale
o Applicability of concepts: Mosaic concept for agroforestry landscapesIsland biogeographic and meta-population theory for industrial/homogeneous landscapes
Overview of studies (Total: 30 studies)
Figure 2. Distribution of studies by county, landscape, group, and sub-group.
Industrial oil palm
Overall, smaller fragments that were more isolated in industrial oil palm plantations sig. reduce biodiversity - particularly of conservational concern.
Riparian reserve width bordering oilpalm plantations had no effect ondung beetles (n=1), but a positivedeterminant for bird speciesrichness (n=1).
Strong negative edge effects from oilpalm altered vegetation structure inforests (n=2).
Small forest fragments have littleimpact on boosting soil fauna in oilpalm (n=2)
Contiguous forest and forestfragments had no sig. impact on oilpalm productivity (n=1)
Smallholder swidden agroforestry
We found that studies reported positive effects betweenfragmentation and species richness, but we observed alack of studies that specifically assessed theconservational value and status of species.
Configuration in swidden systems influenced water flow acrosslandscape (n=1). Patch size of secondary forests significantly influencedthe rate of biomass carbon recovery above ground to old growth forests(n=1).In swidden plots, abundance, avifauna diversity, and speciescomposition were all positively influenced by neighbouring intact foresthabitats. (n=1)
Smallholder permanent agroforestry
Despite missing two key landscape measures (forest patchsize and landscape composition), studies reported positivebenefits of forests for biodiversity and ecosystem servicesin agricultural habitats.
Crops grown near agroforests experienced greater pollination stability(n=3)Agroforests sig. boosted soil fauna in oil palm smallholdings (n=1)
Figure 1: Stages of the systematic literature search
Landscape metrics
0 2 4 6 8 10
Area of forest fragments
Area of forest cover around
habitat patch(es)
No. of studies
0 2 4 6 8 10 12
Distance between habitatpatches
Least Cost Path
Corridor analysis
Circuit theory
Degree ofbuffering/fragmentation
No. of studies
Heterogeneity and composition landscape measures (n=2)
Figure 6: No. of studies measuring landscape composition/diversity
Figure 3: No. of studies found for forest patch size/forest amount around habitat patch
Figure 4: No. of studies found for isolation and connectivity by type of metric.
Figure 5: Sampling approach to measuring edge effects
Credit: CIFOR
¹Center for International Forestry Research (CIFOR), Bogor, Indonesia²Centre de coopération international en recherche agronomique pour le développement (CIRAD), Montpellier, France
Outlook: Moving beyond the question of good or bad fragmentation
How to better assess landscape fragmentation in different types of forest-
agriculture landscapes?
1. The landscape context - level of human pressure and heterogeneity of habitats
2. The suitability of habitats , the range of tolerance to different habitats, and the dispersal ability of organisms
3. Accounting for lag time effects of fragmentation, particularly for flora. Greater research is needed on how fragmentation contributes to the recovery of habitats could help support conservation efforts on landscape restoration.
o Malaysia led in the no. of studies carried out in industrial oil plantations, none in Indonesia; Little research on fragmentation in smallholder landscapes.
o Strong taxonomic bias towards avifauna and soil fauna; Paucity of studies on ES.
