Mammal trap efficiency during the fragmentation by flooding of a neotropical rain forest in French Guiana

2000 ◽  
Vol 16 (6) ◽  
pp. 841-851 ◽  
Author(s):  
CHRISTINE FOURNIER-CHAMBRILLON ◽  
PASCAL FOURNIER ◽  
JEAN-MICHEL GAILLARD ◽  
CHRISTOPHE GENTY ◽  
ERIC HANSEN ◽  
...  
Keyword(s):  
Species Richness ◽  
Rain Forest ◽  
French Guiana ◽  
Habitat Modification ◽  
Water Inflow ◽  
Wet Season ◽  
Lowland Rain Forest ◽  
Factors Affecting ◽  
Trap Efficiency ◽  
Trophic Resources

During the flooding of primary lowland rain forest by the filling of a hydroelectric reservoir in French Guiana, live-trapping was conducted on 175 subsequently formed islands. Different factors affecting the mammal trap efficiency were analysed. The main results show the real complexity of the sampling problem and the influence of the habitat disturbance due to the flooding. The location and/or the type of traps influenced captures of Dasypus novemcinctus, Proechimys spp., Metachirus nudicaudatus and Philander opossum in relation to their foraging and/or locomotion behaviour, and to to their size. The conformation of the islands (height and size) had no influence on the number of captures, nor on the species richness. The number of captures increased with the number of trapnights during the first water inflow and the level stretch. The best trapping success was observed during the wet season, when the strong habitat modification and the forest fragmentation became more significant. It resulted from the reduction of available land area and trophic resources. One year after the beginning of the water inflow, the decrease of the number of captures with the increasing number of trapnights reflected a real decrease of the number of mammals on the islands. The species richness increased with the number of trapnights in all periods, and was also the highest during the wet season.

Diversity and vertical distribution of epiphytic liverworts in lowland rain forest and lowland cloud forest of French Guiana

2013 ◽  
Vol 35 (4) ◽  
pp. 243-254 ◽  
Author(s):  
Christine Gehrig-Downie ◽  
André Obregon ◽  
Jörg Bendix ◽  
Robbert Gradstein
Keyword(s):  
Vertical Distribution ◽  
Rain Forest ◽  
French Guiana ◽  
Cloud Forest ◽  
Lowland Rain Forest

Comparing composition and diversity of parasitoid wasps and plants in an Amazonian rain-forest mosaic

2006 ◽  
Vol 22 (2) ◽  
pp. 167-176 ◽  
Author(s):  
Ilari E. Sääksjärvi ◽  
Kalle Ruokolainen ◽  
Hanna Tuomisto ◽  
Samuli Haataja ◽  
Paul V. A. Fine ◽  
...  
Keyword(s):  
Species Richness ◽  
Species Composition ◽  
Plant Species ◽  
Rain Forest ◽  
Parasitoid Wasp ◽  
Parasitoid Wasps ◽  
Lowland Rain Forest ◽  
Wasp Species ◽  
Weak Support ◽  
Forest Mosaic

Local species richness and between-site similarity in species composition of parasitoid wasps (Hymenoptera: Ichneumonidae; Pimplinae and Rhyssinae) were correlated with those of four plant groups (pteridophytes, Melastomataceae, Burseraceae and Arecaceae) in a western Amazonian lowland rain forest mosaic. The mosaic structure of the forest was related to variation in soils within the non-inundated terrain. Significant matrix correlation between patterns in parasitoid wasp species composition and plant species composition was found. Most of the overall correlation was due to idiobiont parasitoids of weakly concealed hosts, which attack host larvae and pupae in exposed situations, with two of the four ecologically defined parasitoid groups showing no correlation at all. A positive correlation between the number of plant species and the number of Pimplinae and Rhyssinae species at a site was found when the latter was corrected for collecting effort. Consequently, the degree of floristic difference between sites may be indicative of the difference in species composition of ichneumonids, and the species richness of plants may serve as a predictor of the species richness of parasitoid wasps. Although these results were obtained in a mosaic including structurally and floristically clearly different types of rain forest, the correlation coefficients were relatively low, and the present results lend only weak support to the idea of using plant distributions as indicators of animal distributions.

Bat communities and deforestation in French Guiana

1996 ◽  
Vol 74 (11) ◽  
pp. 1974-1982 ◽  
Author(s):  
André Brosset ◽  
Pierre Charles-Dominique ◽  
Anya Cockle ◽  
Jean-François Cosson ◽  
Didier Masson
Keyword(s):  
Species Richness ◽  
Rare Species ◽  
Rain Forest ◽  
French Guiana ◽  
Primary Forest ◽  
Close Attention ◽  
Forest Corridors ◽  
Long Time ◽  
Fruiting Plant ◽  
The Impact

The impact of deforestation on the composition and dynamics of bat communities received close attention during a 15-year survey of the bats of French Guiana. Overall, deforestation lowers species richness: 48 of the 75 bat species from primary forest, mainly mature-forest phyllostomids, were not found in large areas that had been deforested for a long time. The 27 "rare" species, each represented by fewer than 6 of 8031 captures, had been apparently virtually eliminated from deforested areas. These altered habitats had been repopulated by a few opportunistic frugivorous phyllostomid species and by species belonging to the widespread insectivorous families Vespertilionidae and Molossidae. Habitats altered by humans harbor over four times as many individual bats as primary rain forest. This rise in both frugivorous and insectivorous bat populations in areas of degraded vegetation appears linked to the abundance of bat-dispersed pioneer' fruiting plant species available to phyllostomids and the multiplication of roosting sites for vespertilionids and molossids in human habitats. The species richness of local bat communities is positively influenced by the presence of forest corridors or the immediate proximity of a forest block.

Diversity and vertical distribution of epiphytic macrolichens in lowland rain forest and lowland cloud forest of French Guiana

2010 ◽  
Vol 10 (6) ◽  
pp. 1111-1118 ◽  
Author(s):  
Felix Normann ◽  
Patrick Weigelt ◽  
Christine Gehrig-Downie ◽  
S. Robbert Gradstein ◽  
Harrie J.M. Sipman ◽  
...  
Keyword(s):  
Vertical Distribution ◽  
Rain Forest ◽  
French Guiana ◽  
Cloud Forest ◽  
Lowland Rain Forest

Factors affecting frog species richness in the Solomon Islands

2017 ◽  
Vol 23 (4) ◽  
pp. 387 ◽  
Author(s):  
Patrick Pikacha ◽  
Clare Morrison ◽  
Chris Filardi ◽  
Luke Leung
Keyword(s):  
Species Richness ◽  
Solomon Islands ◽  
Climate Change Impacts ◽  
Habitat Modification ◽  
Amphibian Conservation ◽  
Montane Forests ◽  
Factors Affecting ◽  
The North ◽  
Frog Species ◽  
Richness Patterns

Studies across large oceanic archipelagos often provide an opportunity for testing different processes driving patterns of species richness. Frogs are among the most abundant vertebrates in the Solomon Islands but little is known of the factors influencing their richness patterns. This study used modelling to determine important ecological and biogeographic factors affecting the species richness of frogs at multiple locations on major islands across the archipelago. Between March 2009 and August 2012, 16 frog species were recorded along 109 transects placed in coastal, lowland, ridge and montane forests across 13 islands. Mean species richness was higher in the North Solomon Islands arc (6.2 species) and decreased eastwards towards the New Georgia islands (4.7 species), and Malaita (3.2 species). A plausible explanation is that the North Solomon Islands arc is closest to New Guinea, a major centre of dispersal in the south-west Pacific. Coastal (4.6 species) and freshwater (4.8 species) forests had lower predicted species richness than lowland, ridge, and montane forest types (all with 6.2 species). In addition, more frogs were predicted in areas with thin leaf litter (6.2 species), dense shrub cover (7.7 species), and moist soils (7.7 species), which are characteristic of undisturbed forests. These results suggest that frog conservation activities in the Solomon Islands should target islands in the west with intact lowland, ridge, and montane forests. Specific knowledge of this nature is vital for amphibian conservation on tropical islands experiencing extensive habitat loss, habitat modification and widespread predicted climate change impacts.

Edge effects on litterfall mass and nutrient concentrations in forest fragments in central Amazonia

2000 ◽  
Vol 16 (6) ◽  
pp. 853-863 ◽  
Author(s):  
NIGEL C. SIZER ◽  
EDMUND V. J. TANNER ◽  
ISOLDE D. KOSSMANN FERRAZ
Keyword(s):  
Rain Forest ◽  
Forest Edge ◽  
Dry Season ◽  
Nutrient Concentrations ◽  
Forest Fragments ◽  
Forest Edges ◽  
Forest Fragment ◽  
Wet Season ◽  
Lowland Rain Forest ◽  
Central Amazonia

Forest edges bordering on pasture were created by cutting and burning the surrounding Amazonian lowland rain forest in the dry season (June) of 1990. Litterfall was measured for 3.5 y along transects 10, 50, 100 and 250-m into the forest from the forest edge. Litterfall along the 10-m transects increased by up to 2.5 times that on spatial controls (250-m transects) in the dry season in which the edge was created. In the second dry season after edge creation litterfall at 10-m was lower than on controls, after which it returned to control rates in the second wet season, 1.5 y after edge creation. Litterfall 50-m into the forest was less affected; there was a smaller rise in the dry season in which the edge was cut, and no significant effects after that. At 100-m there was no effect of edge creation on litterfall. Phosphorus concentrations in litterfall were elevated along 10-m transects, 10–12 wk after edge creation, possibly because of reduced retranslocation prior to abscission. The changes in litterfall described here are inextricably linked to the biomass collapse, which occurs near forest-fragment edges in the same area.

Ants accelerate litter decomposition in a Costa Rican lowland tropical rain forest

2012 ◽  
Vol 28 (5) ◽  
pp. 437-443 ◽  
Author(s):  
Terrence P. McGlynn ◽  
Evan K. Poirson
Keyword(s):  
Mass Loss ◽  
Leaf Litter ◽  
Litter Decomposition ◽  
Rain Forest ◽  
Costa Rican ◽  
Tropical Rain Forests ◽  
Rain Forests ◽  
Food Web Structure ◽  
Litter Bags ◽  
Lowland Rain Forest

Abstract:The decomposition of leaf litter is governed, in part, by litter invertebrates. In tropical rain forests, ants are dominant predators in the leaf litter and may alter litter decomposition through the action of a top-down control of food web structure. The role of ants in litter decomposition was investigated in a Costa Rican lowland rain forest with two experiments. In a mesocosm experiment, we manipulated ant presence in 50 ambient leaf-litter mesocosms. In a litterbag gradient experiment, Cecropia obtusifolia litter was used to measure decomposition rate constants across gradients in nutrients, ant density and richness, with 27 separate litterbag treatments for total arthropod exclusion or partial arthropod exclusion. After 2 mo, mass loss in mesocosms containing ants was 30.9%, significantly greater than the 23.5% mass loss in mesocosms without ants. In the litter bags with all arthropods excluded, decomposition was best accounted by the carbon: phosphorus content of soil (r2 = 0.41). In litter bags permitting smaller arthropods but excluding ants, decomposition was best explained by the local biomass of ants in the vicinity of the litter bags (r2 = 0.50). Once the microarthropod prey of ants are permitted to enter litterbags, the biomass of ants near the litterbags overtakes soil chemistry as the regulator of decomposition. In concert, these results support a working hypothesis that litter-dwelling ants are responsible for accelerating litter decomposition in lowland tropical rain forests.

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