Category Archives: Volume 16 No. 2 (1994) (Special Issue on Tropical Ecology)

Collecting beetles on Leyte Island, Philippines


Author(s): Wolfgang Schawaller and Juergen Trautner

Abstract

Beetles belonging to 67 families were collected during a 3-week survey on coleoptera inhabiting forest floor, aquatic and semi-aquatic habitats, and lower stratum vegetation in the island of Leyte, Philippines. Highest number of species was found in the primary forests around Mount Pangasugan.

Keywords : Coleoptera, Leyte, Philippines

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A new record of the microbat Hipposideros obscurus (mania malia: Hipposideridae) (Peters, 1861) from Leyte, Philippines


Author(s):Peter Widmann, Paciencia P. Milan and Josef Margraf

Abstract

The microbat Hipposideros obscurus is recorded for the first time in Leyte. Measurements and information on prey are presented.

Keywords : Bats, biogeography, feeding ecology, Hipposideridae, Philippines

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Composition of the arthropod fauna of sweetpotato fields on Leyte Island, Philippines – sampling by pitfall traps and colour pans


Author(s): Robert Spatz and Werner Koch

Abstract

The development of arthropod communities on three low input, shifting cultivation sweetpotato fields located in very distinct environments was monitored. Aim of the study was to identify if and how the composition of arthropod communities on cropland areas is influenced by the surrounding vegetation. Sampling of the arthropods was done by use of colour pans and pitfall traps. The prey was keyed to family or genus, assigned to trophic guilds, and further subdivided into “operational” species (based merely upon morphological criteria). Several indices describing ecological diversity were computed and used to compare the three communities. Results suggests that the arthropod communities on each of the fields developed into a mostly site-independent, but crop-specific fauna. An influence of the surrounding vegetation can be suspected only for predatory arthropods.

Keywords : Sweetpotato, pests, agroecology, diversity

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Bat survey in Alto Peak area, Leyte, Philippines


Author: Peter Widmann

Abstract

A 40 net nights bat survey in Alto Peak, Leyte, Philippines yielded 52 specimens representing eight species. Habitat requirements of these species are discussed.

Keywords : Bats, community structure, conservation, Philippines

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Bryophytes of river valleys and kaingin areas of Mount Pangasugan, Leyte, Philippines


Author: Celsa A. Quimio

Abstract

Fifty one bryophyte species were collected from June to December 1991. In the undisturbed river valleys, the number of species varied from 7 to 26 while in the kaingin farms (slash and burn farming) the species number varied from 2 to 13. These data give evidence that kaingin farming is changing environmental conditions unfavorably for at least 50% of the species observed. The bryophytes’ role within the ecosystem for the retention of water, the disintegration of rocks and the stabilization of substrata making them suitable for seed plant colonization is thus reduced significantly.

Keywords : Bryophytes, kaingin, Mt. Pangasugan

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Species diversity and distribution of pteridophytes in mount Pangasugan


Author(s): Beatriz S. Belonias and Lite M. BaƱoc

Abstract

A total of 93 species of pteridophytes belonging to 24 families and 55 genera were found in Mt. Pangasugan at elevations of 5-400 m above sea level (ASL). These comprise 22 families of ferns with 52 genera and 84 species, and 3 families of fern-allies with 3 genera and 9 species. Only 83 species were identified.
The families Polypodiaceae and Aspidiaceae are the most diverse in terms of number of genera and species. Species diversity was low (11 to 24 species) at 5-40 m ASL, increased up to 40 species at 81-100 in ASL but gradually declined to as low as 15 at 101-340 m ASL.
Majority of the pteridophytes collected are terrestrial (66.7%). The aquatic species comprise only 4.3%; the epiphytes, 16.1% and the petrophytes, 12.9%.
Selaginella engleri and Tectaria denticulata are the most widely adapted across different elevations followed by Angiopteris paliniformis and Microsorium punctatum and then by Lygodium japonicum. However, Selaginella engleri was best adapted at lower elevations while Tectaria denticulata favored higher elevations.
Herbarium specimens of the pteridophyte collections are presently kept and maintained at the ViSCA Herbarium, Dept. of Plant Breeding and Agricultural Botany, ViSCA, Baybay, Leyte, Philippines.

Keywords : Pteridophytes, ferns, fern-allies, species, herbarium

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Case studies on the occupation and cultivation of the forest lands of Leyte, Philippines


Author(s): Buenaventura B. Dargantes and Werner Koch

Abstract

The loss of the forests of Leyte is mainly attributed to the conversion of timberlands into kaingin, commercial agricultural use and non-timber plantations. Poverty and marginalization have led small-scale farmers and other rural residents into the cultivation of forest lands. Increasing participation in a market-oriented economy has spurred the encroachment of commercial agriculture into the forest zone. Available data also show that policy factors such as settlement projects, agricultural and forestry development projects and road construction have facilitated these conversions. This report attempts to portray through illustrative case studies conducted within Leyte the interplay of these factors as they contribute to forest loss.

Keywords : Forest, forest loss, shifting cultivation, forest fanning, social forestry

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Allelopathic effect of botanical extracts on selected fungal pathogens and test plants


Author(s): Lualhati M. Noriel, Erlinda A. Vasquez, Carlito V. Ranchez, Glenn 0. Sopsop and Flora Mia Y. Duatin

Abstract

The alellopathic effects of aqeous extracts of botanicals namely: Cassia alata L., Mikania cordata B.L. Robinson, Dioscorea hispida D. daemona Roxb., Tinospora rumphii L., Stachytarpheta jamaicensis (L) Vahl, Piper belle L., and Peperomia pellucida HBK. against selected fungal pathogens and test plants were studied.
Growth response of the test fungi to the extracts include inhibition of spore germination, and mycelial growth, and reduction in the number and size of lesion. On the other hand, the allelopathic extracts caused inhibited germination of seed/tubers and reduction in root and shoot growth of the different test plants.

Keywords : Allelopathy, botanicals, herbicidal, fungicidal and growth inhibition

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