Table a1 Listing of impact, scale (temporal and spatial), location, assessment method, number of populations and genetic diversity, or fitness consequences from individual reviewed studies
Species | Impact | Time since impact began | Material collected | Location | Marker type | Number of populations | Response | Comments | Reference | ||
|---|---|---|---|---|---|---|---|---|---|---|---|
Diversity | Inbreeding | Gene flow | |||||||||
Anacardium excelsum | Fragmentation | Seeds | Northwestern Costa Rica | Reproductive traits: pollination success, initial and mature seed set | 11 fragments varying in size (0.3 ha to >500 ha and isolation (<500 m, 0.5–2 km, >2 km) | Pollination success and initial seed set positively correlated with fragment size. Mature seed set variable, but not correlated with fragment size | |||||
Carapa guianensis | Logging | 6 years | Seeds | Costa Rica | Allozymes: Six polymorphic loci, 10 monomorphic loci | Three unlogged populations located in a 1510 ha reserve (>15 trees/ha) | H=0.12–0.13 | tm=0.967 | FST=0.046; Nm=4.10 | No differentiation between logged and unlogged forests: High gene flow due to seed dispersal | |
Six logged populations separated by up to 70 km | H=0.11–0.12 | tm=0.986 | |||||||||
C. guianensis | Logging | 10 years | Leaves from adults and saplings | Costa Rica | Microsatellites: Three loci | One continuous population located in a 1510 ha reserve | HE=0.26–0.87 (adults); HE=0.12–0.82 (saplings); HO=0.22–0.86 (adults); HO=0.13–0.84 (saplings) | Low allelic richness in the isolated logged population: Restriction of gene flow | |||
Two logged populations located 40 and 44 km from reserve (11 and 15 trees/ha) | HE=0.36–0.86 (adults); HE=0.27–0.89 (saplings); HO=0.35–0.83 (adults); HO=0.31–0.93 (saplings) | No impact on heterozygosity | |||||||||
C. procera | Logging | 10 years | Seeds | French Guiana | Isozymes: 10 loci | Seven unlogged plots within a 300 ha silvicultural trial population | tm=0.85 | Lower outcrossing in logged plots | |||
Nine logged plots within a 300 ha silvicultural trial population | tm=0.63 | ||||||||||
Caryocar brasiliense | Fragmentation | 60 years | Leaves from adults and seeds | Brazil | Microsatellites: 10 loci | Five continuous populations with a total sample area of 20.2 km2 | HE=0.855–0.882; HO=0.709–0.800 | f=0.092–0.172 | RST=0.29 | No observed response due to sampling of adults present prior to fragmentation | |
Five fragmented populations with a total area of 211.3 km2 | HE=0.751–0.889; HO=0.697–0.719 | f=0.044–0.172 | |||||||||
Cedrela odorata | Logging/habitat destruction | Seeds | Mesoamerica Mexico-Panamá | Quantitative traits; height, diameter, number of shoots after shoot borer attack (summation of 18 measurements) | 17 grasslands and home orchards, five primary or secondary forests. Trees classified as i. isolated mother tree (no other conspecifics at <500 m), ii. semiisolated (other trees ⩾100 m), iii. trees in clusters or associated with >2 trees in radius <100 m | Reduction in growth of progeny from isolated trees compared to continuous population trees | |||||
Dinizia excelsa | Fragmentation | 15–20 years | Leaves from adults and seeds | Brazil | Microsatellites: Five loci 80 alleles | Two continuous populations | 17–28 alleles per locus | Gene flow over as much as 3.2 km | Extensive gene flow due to alien pollinator | ||
Remnants in three ranches | 15–37 alleles per locus | ||||||||||
D. excelsa | Fragmentation | 15–20 years | Leaves from adults and seeds | Brazil | Microsatellites: Five loci 78 alleles | Two continuous populations Remnants in three ranches | 9–37 alleles per locus 7–28 alleles per locus | Self-fertilisation rate=10% Self-fertilisation rate=14% | Mean pollen dispersal distance=212 m Mean pollen dispersal distance=1509 m | Slight increase in self-fertilisation in remnants, but high pollen dispersal due to alien pollinator | |
Enterolobium cyclocarpum | Fragmentation | Seeds | Northwestern Costa Rica | Allozymes: 12 polymorphic loci | One fragmented population: 9.8 ha core area; 227 ha sampled in a 1600 ha ranch | Estimates of pollen flow >60% | Trees receive pollen from many donors in a large network of reproductively active individuals | ||||
E. cyclocarpum | Fragmentation | Seeds | Costa Rica | Isozymes: Five polymorphic loci | Populations and isolated trees sampled across the region | tm=1.000; rp=0.189 tm=0.999; rp=0.104 | Similar outcrossing rates between remnants and continuous forest: No restriction of gene flow | ||||
E. cyclocarpum | Fragmentation | Seeds | Costa Rica | Quantitative traits; progeny vigor and fruit set | Comparison of pasture trees (⩾500 m from conspecifics) and continuous forest trees in forest patches of 10 ha | Flowers in continuous forests more likely to have pollen deposited on stigmas than flowers from trees in pastures (52.1 vs 32.3%, respectively). Trees from continuous forests six times more likely to set fruit and produce more seed per fruit than trees in pastures. Progeny from trees in continuous forests more vigorous than progeny from trees in pasture, based on 12 of 16 indicators of plant vigour | |||||
Gliricidia sepium | Fragmentation | Leaves and seeds from all individuals | Southern Guatemala | SSRs: One locus Six alleles | One fragmented population with an area of 0.16 km2 | 1.8% of pollen transfer occurred over distances >75 m | Small proportion of long-distance gene flow | ||||
Pachira quinata | Fragmentation | Seeds | Northwestern Costa Rica | Allozymes: Seven polymorphic loci | 15 trees from continuous forests | HE=0.398 | rp=0.470; tm=0.915 | Restricted gene flow to isolated trees | |||
15 isolated trees sampled across the region | HE=0.400 | rp=0.740; tm=0.777 | |||||||||
P. quinata | Fragmentation | Seeds | Northwestern Costa Rica | Reproductive traits: seed and fruit set | 15 trees from each of continuous forests and isolated trees (>500 m) in fields | Fruit set higher in trees in mature forest (6%) than in trees separated by 500 m from conspecifics (3%). Seed production per fruit and total fruit production not affected by fragmentation | |||||
P. quinata | Fragmentation | Seeds | Northwestern Costa Rica, southern Honduras | Reproductive trait: fruit set | Trees in continuous forest, forest fragment and in pastures | Fruit production (number of capsules) not affected by degree of disturbance/fragmentation | |||||
P. quinata | Fragmentation | Seeds | Honduras – Colombia | Quantitative traits: seed and fruit set, germination, height and diameter growth | Test for outbreeding depression by controlled pollinations. Pollen sourced at different distances from mother trees (0 m, 50 m, 250 m, 700 m, 3 km, 8 km, 20 km, 70 km, 300 km, 1800 km) | 1800 km crosses showed reduced seed set equal to selfing. No other variables affected by pollination distance | |||||
Pentaclethra macroloba | Fragmentation | 40 years | Leaves from adults and seedlings | Costa Rica | Allozymes: Five polymorphic loci, Nine monomorphic loci | Seven stands of continuous forest in an 1800 ha reserve | H=0.035–0.064 (adults); H=0.035–0.048 (seedlings) | FST=0.038 (adults) and 0.019 (seedlings) | Reduced gene flow due to spatial separation | ||
11 fragmented populations up to 70 km from reserve | H=0.050–0.135 | FST=0.219 | |||||||||
Pinus oocarpa var. oocarpa | Logging, deforestation | 20 years | Seeds | Honduras | Quantitative traits: germination, mortality, no. of cotyledons, seedling height and diameter, no. of buds, survival, length, and no. of leaves | Seeds collected from trees in three different population densities (190, 102, 7 trees/ha) | With decreased density of adult tree, observed: reduced seed set, seed weight, germination and late emergency, increased no. of cotyledons and chlorophyll deficiencies, reduced seedling height | ||||
Pithecellobium elegans | Fragmentation | 15 years | Leaves from adults and seeds | Costa Rica | SSRs: Five loci 42 alleles | 28 trees within a 0.32 km2 fragment | 5–14 alleles per locus | Average gene flow distance=142 m | Long-distance gene flow | ||
P. elegans | Fragmentation | 40 years | Leaves from adults and seeds | Costa Rica | Allozymes: Six polymorphic loci, eight monomorphic loci | Two continuous populations in a 1500 ha reserve | H=0.14 and 0.14; Re=1.25 and 1.29 | FST=0.101; Nm=0.70 | Restricted gene flow to isolated trees | ||
Six fragmented populations separated by up to 75 km | H=0.12–0.15; Re=1.17–1.30 | ||||||||||
P. elegans | Fragmentation | 40 years | Seeds | Costa Rica | Reproductive traits: fruit and seed set | Two continuous populations in a 1500 ha reserve. Six fragmented populations separated by up to 75 km | Lower seed set or failure to set fruit in fragments – low % of trees flowering accentuated by isolation by fragmentation | ||||
Samanea saman | Fragmentation | Seeds | Northwestern Costa Rica | Isozymes: Six polymorphic loci | One continuous population in a 7550 ha reserve | Mean HE=0.190 | Effective self-fertilisation rate=0.010; Inbreeding coefficient=0.005 | Higher self-fertilisation and inbreeding in isolated trees | |||
17 isolated trees along a 100 km distribution | Mean HE=0.230 | Effective self-fertilisation rate=0.088; Inbreeding coefficient=0.044 | |||||||||
S. saman | Fragmentation | Seeds | Northeastern Costa Rica | Reproductive traits; pollen deposition. Seed production: no. of bruchid-damaged seeds, no. of aborted seeds, no. of undamaged seeds, total no. of seeds developed | 27 isolated trees >500 m from nearest conspecific and surrounded by agricultural fields, pastures, or small remnant forest patches and 24 trees in continuous populations of ⩾10 trees/ha. surrounded by undisturbed forest | Higher probability of flowers in continuous forest to produce mature fruit (2.1%) compared with isolated trees (0.4%). Seed predation by bruchids higher in continuous forest, so number of viable seeds similar for continuous and fragmented conditions. Seeds produced by trees from continuous populations more likely to germinate and produce greater leaf area and biomass as seedlings than seed from isolated trees | |||||
Spondias mombin | Fragmentation | Seeds | Quantitative traits: fruit production, seed germination, seedling height growth | Three conti- nuous forest populations (old, 1° successional, 2°), one large fragment (4 ha), six small fragments (0.5–1 ha) | Small fragment populations showed significant reductions in germination rate (>35%) and fruit production relative to large fragment and continuous forest populations | ||||||
Swietenia humilis | Fragmentation | 40 years | Leaves | Southern Honduras | Microsatellites: 10 loci 112 alleles | 68 ha plot in 500 ha continuous population | 54 low-frequency alleles; HO=0.481; HE=0.526; | FIS=0.217 | RST=0.032; Nm=8.9 | Loss of rare alleles; high levels of genetic variation in fragments | |
One fragmented population separated by up to 1.4 km | 25–46 low-frequency alleles; HO=0.472–0.490; HE=0.509–0.543 | FIS=0.178–0.208 | |||||||||
S. humilis | Fragmentation | 40 years | Seeds | Southern Honduras | Microsatellites: Four loci | 68 ha plot in 500 ha continuous population | 64% of pollen from <600 m | Extensive gene flow | |||
One fragmented population separated by up to 1.4 km | Pollen flow from >4.5 km | ||||||||||
S. humilis | Fragmentation | Seeds | Honduras – Costa Rica | Quantitative traits: seed and fruit set, germination, height and diameter growth | Test for outbreeding depression by controlled pollinations. Pollen sourced at different distances from mother trees (0 m, 1 km, 6 km, 35 km, 120 km) | No fitness variables affected by pollination distance, except for selfing with 0% fruit set | |||||
S. humilis | Fragmentation | Seeds | Northwestern Costa Rica, southern Honduras | Reproductive trait: fruit set | Trees in continuous forest, forest fragment and in pastures | Fruit production (number of capsules) higher in more disturbed/fragmented environments | |||||
Swietenia macrophylla | Logging | Leaves from adults | Mexico to Panama | 102 polymorphic RAPD bands | Four unlogged populations (0.8–2.0 trees/ha) 15 logged populations across a spatial scale of 1500 km (0.1–2.5 trees/ha) | Genetic diversity was on average lower in populations with a history of logging and disturbance compared to more intact populations | |||||
S. macrophylla | Logging | 100 years | Leaves from adults and saplings | Northwestern Costa Rica | Microsatellites: Five loci 21 alleles | Four unlogged sites, disturbed typically by fire | Na=3.00–4.00; Ne=2.22–2.70; HO=0.45–0.58; HE=0.47–0.54 | FST=0.0631 | No differentiation between unlogged and logged sites | ||
One logged site | Na=2.80; Ne=2.24; HO=0.49; HE=0.51 | ||||||||||
S. macrophylla | Logging | Leaves from adults and seeds | Mexico to Panama | Microsatellites: Seven loci | Three unlogged populations Five logged populations across a spatial scale of 1500 km | HO=0.533–0.578; HE=0.618–0.681 HO=0.470–0.672; HE=0.593–0.799 | Increased inbreeding within Central American populations compared to those from South America (Lemes et al, 2003) | ||||
S. macrophylla | Logging | Seeds | Mesoamerica Mexico–Panamá | Quantitative traits; growth form, height, diameter, no. of shoots after shoot borer attack | 17 grasslands and home orchards, five forest primary or secondary forest trees | Reduction in growth of progeny from isolated trees compared to trees in continuous populations | |||||
Symphonia globulifera | Fragmentation | 10–30 years | Leaves from adults, saplings and seedlings | Southern Costa Rica | Microsatellites: Three loci 55 alleles | 3.2 ha plot of continuous forest in 235 ha reserve | s=0.098 | Increased selfing in isolated trees Genetic bottleneck through reproductive dominance | |||
38.5 ha fragmented population | s=0.261 | ||||||||||
S. globulifera | Fragmentation | 10–30 years | Leaves from adults, saplings and seedlings | Southern Costa Rica | Microsatellites: Three loci | 4.2 ha plot of continuous forest in 235 ha reserve | HO=0.73 (seedlings), 0.73 (saplings), 0.77 (adults) | RST=0.005 | Inbreeding in seedlings resulting in genetic differentiation among remnant forests | ||
38.5 ha fragmented population | HO=0.61 (seedlings), 0.74 (saplings), 0.81 (adults) | RST=0.210 | |||||||||
