Web Spiders in Temperate and Tropical Forests: Relative Abundance and Environmental Correlates

Abstract String sequence analysis revealed that silk spinning behavior of adult female Embioptera varies from species-specific to individualistic. This analysis included 26 species from ten taxonomic families with a total of 115 individuals. Spin-steps, 28 possible positions of the front feet during spinning, were scored from hour-long DVD recordings produced in the laboratory. Entire transcripts of hundreds to thousands of spin-steps per individual were compared by computing Levenshtein edit distances between all possible pairs of subsequences, with lengths ranging from 5 to 25—intraspecific similarity scores were then computed. Silk gallery characteristics and architecture, body size, climatic variables, and phylogenetic relationships were tested as possible drivers of intraspecific similarity in spinning behavior. Significant differences in intraspecific similarity aligned most strongly with climatic variables such that those species living in regions with high temperature seasonality, low annual precipitation, and high annual temperatures displayed more species-stereotypical spinning sequences than those from other regions, such as tropical forests. Phylogenetic signal was significant but weakly so, suggesting that environmental drivers play a stronger role in shaping the evolution of silk spinning. Body size also appears to play a role in that those of similar size are more like each other, even if not related.

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Hunting patterns in tropical forests adjoining the Hkakaborazi National Park, north Myanmar

Oryx ◽

10.1017/s0030605305000724 ◽

2005 ◽

Vol 39 (3) ◽

pp. 292-300 ◽

Cited By ~ 33

Author(s):

Madhu Rao ◽

Than Myint ◽

Than Zaw ◽

Saw Htun

Keyword(s):

Tropical Forests ◽

Relative Abundance ◽

National Park ◽

Wildlife Conservation ◽

Legal Framework ◽

Camera Trap ◽

Policy Recommendations ◽

Major Threat ◽

Wildlife Populations ◽

Capture Rates

Hunting for subsistence and trade constitute a major threat to wildlife populations within and outside protected areas in Myanmar. We examined hunting patterns in a forested landscape adjoining the Hkakaborazi National Park in north Myanmar with the aim of generating recommendations to manage hunting. The results described here focus on two issues: the significance of proximity to settlements and markets for prey abundance, and the influence of relative abundance and intrinsic preference on prey offtake. We used strip transect and camera trap surveys to generate relative abundance indices and overall encounter/capture rates for commonly hunted species at four sites that differed in their proximity to settlements and large trading towns. Questionnaires were used to obtain meal records and information on hunting. Encounter and capture rates for hunted species appear to be inversely related to proximity to villages as well as to large, commercial towns. Hunting is indiscriminate, with offtake determined largely by relative abundance rather than intrinsic preference or legislation. Specific management and policy recommendations include the need to monitor the impacts of hunting on vulnerable species, the demarcation of no-take areas, and modification of the legal framework for wildlife conservation.

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Density and diversity of lianas along a chronosequence in a central Panamanian lowland forest

Journal of Tropical Ecology ◽

10.1017/s0266467400001231 ◽

2000 ◽

Vol 16 (1) ◽

pp. 1-19 ◽

Cited By ~ 213

Author(s):

Saara J. Dewalt ◽

Stefan A. Schnitzer ◽

Julie S. Denslow

Keyword(s):

Tropical Forest ◽

Tropical Forests ◽

Relative Abundance ◽

Light Availability ◽

Basal Area ◽

Stand Age ◽

Old Growth ◽

Lowland Forest ◽

Abundance And Diversity

The abundance and diversity of lianas were examined along a tropical forest chronosequence at the Barro Colorado Nature Monument, Panama. Lianas ≥0.5 cm diameter were sampled along transects in two replicated stands in secondary (20, 40, 70 and 100 y after abandonment) and old-growth (>500 y) forests. Ordination of stands based on relative abundance, but not presence-absence, showed a significant separation of stands by age. Lianas were significantly more abundant and diverse (Fisher's α) in younger forests (20 and 40 y) than in older forests (70 and 100 y, and old-growth). The decline in liana abundance with stand age was offset by increased mean basal area per individual, resulting in a relatively constant total basal area and estimated biomass across stand age. The proportions of tendril climbers decreased and stem twiners increased over stand age. Decline in liana abundance and changes in liana composition may be related to changes in support and light availability. Although lianas are recognized as playing an important role in the early secondary sucession of many tropical forests, these results have shown that their important contribution to total basal area and biomass can continue as the forest matures, even as the numbers of established lianas declines.

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Vertical stratification in bat assemblages of the Atlantic Forest of south-eastern Brazil

Journal of Tropical Ecology ◽

10.1017/s026646741700027x ◽

2017 ◽

Vol 33 (5) ◽

pp. 299-308 ◽

Cited By ~ 7

Author(s):

Renato Gregorin ◽

Enrico Bernard ◽

Karina Weiser Lobão ◽

Luciany Ferreira Oliveira ◽

Felipe Santana Machado ◽

...

Keyword(s):

Tropical Forests ◽

Atlantic Forest ◽

Relative Abundance ◽

Resource Partitioning ◽

Three Dimensional ◽

Vertical Stratification ◽

Forest Canopies ◽

Eastern Brazil ◽

Forest Strata ◽

Artibeus Lituratus

Abstract:Tropical forests are three-dimensional spaces with species and resources heterogeneously distributed. The vertical stratification of tropical forest biotas has been observed for several organisms and regions, but, surprisingly, the vertical structuring of large areas of important tropical forests, such as Brazil's Atlantic Forest, remains poorly studied. Here, we addressed the use of different Atlantic Forest strata by bats, comparing ensemble composition and relative abundance between the understorey and the canopy. A total of 618 bats belonging to 31 species and four families were recorded, including 11 species of frugivores and seven species of gleaning insectivores, the two trophic guilds predominantly represented in our sampling. Fifteen species were captured exclusively in the canopy, and six exclusively in the understorey, and many of those species were represented by a low number of captures (<5). The bat species composition, richness and relative abundance between canopy and understorey strata varied.Chiroderma villosumwas exclusively captured in the canopy,Artibeus lituratuswas netted predominantly in the canopy andCarollia perspicillataandDesmodus rotunduswere mostly captured in the understorey. Although processes such as resource partitioning between species and ecomorphological constraints may explain the differential use of forest strata, this remains little understood because of the scarcity of data for the Atlantic forest canopies.

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