Noor Farikhah Haneda

Consequences of tropical land use for multitrophic biodiversity and ecosystem functioning

Our knowledge about land-use impacts on biodiversity and ecosystem functioning is mostly limited to single trophic levels, leaving us uncertain about whole-community biodiversity-ecosystem functioning relationships. We analyse consequences of the globally important land-use transformation from tropical forests to oil palm plantations. Species diversity, density and biomass of invertebrate communities suffer at least 45% decreases from rainforest to oil palm. Combining metabolic and food-web theory, we calculate annual energy fluxes to model impacts of land-use intensification on multitrophic ecosystem functioning. We demonstrate a 51% reduction in energy fluxes from forest to oil palm communities. Species loss clearly explains variation in energy fluxes; however, this relationship depends on land-use systems and functional feeding guilds, whereby predators are the most heavily affected. Biodiversity decline from forest to oil palm is thus accompanied by even stronger reductions in functionality, threatening to severely limit the functional resilience of communities to cope with future global changes.

Species richness and biomass explain spatial turnover in ecosystem functioning across tropical and temperate ecosystems

Predicting ecosystem functioning at large spatial scales rests on our ability to scale up from local plots to landscapes, but this is highly contingent on our understanding of how functioning varies through space. Such an understanding has been hampered by a strong experimental focus of biodiversity–ecosystem functioning research restricted to small spatial scales. To address this limitation, we investigate the drivers of spatial variation in multitrophic energy flux—a measure of ecosystem functioning in complex communities—at the landscape scale. We use a structural equation modelling framework based on distance matrices to test how spatial and environmental distances drive variation in community energy flux via four mechanisms: species composition, species richness, niche complementarity and biomass. We found that in both a tropical and a temperate study region, geographical and environmental distance indirectly influence species richness and biomass, with clear evidence that these are the dominant mechanisms explaining variability in community energy flux over spatial and environmental gradients. Our results reveal that species composition and trait variability may become redundant in predicting ecosystem functioning at the landscape scale. Instead, we demonstrate that species richness and total biomass may best predict rates of ecosystem functioning at larger spatial scales.

Direct and cascading impacts of tropical land-use change on multi-trophic biodiversity

The conversion of tropical rainforest to agricultural systems such as oil palm alters biodiversity across a large range of interacting taxa and trophic levels. Yet, it remains unclear how direct and cascading effects of land-use change simultaneously drive ecological shifts. Combining data from a multi-taxon research initiative in Sumatra, Indonesia, we show that direct and cascading land-use effects alter biomass and species richness of taxa across trophic levels ranging from microorganisms to birds. Tropical land use resulted in increases in biomass and species richness via bottom-up cascading effects, but reductions via direct effects. When considering direct and cascading effects together, land use was found to reduce biomass and species richness, with increasing magnitude at higher trophic levels. Our analyses disentangle the multifaceted effects of land-use change on tropical ecosystems, revealing that biotic interactions on broad taxonomic scales influence the ecological outcome of anthropogenic perturbations to natural ecosystems.Direct and cascading land-use effects alter biomass and species richness of taxa across trophic levels ranging from microorganisms to birds in a multi-taxon research initiative in Sumatra, Indonesia.

Applying generalised allometric regressions to predict live body mass of tropical and temperate arthropods

1. The ecological implications of body size extend from the biology of individual organisms to ecosystem–level processes. Measuring body mass for high numbers of invertebrates can be logistically challenging, making length-mass regressions useful for predicting body mass with minimal effort. However, standardised sets of scaling relationships covering a large range in body length, taxonomic groups, and multiple geographical regions are scarce. 2. We collected 6293 arthropods from 19 higher-level taxa in both temperate and tropical locations to compile a comprehensive set of linear models relating live body mass to a range of predictor variables. For each individual, we measured live weight (hereafter, body mass), body length and width, and conducted linear regressions to predict body mass using body length, body width, taxonomic group and geographic region. Additionally, we quantified prediction error when using parameters from arthropods of a different geographic region. 3. Incorporating body width into taxon- and region-specific length-mass regressions yielded the highest prediction accuracy for body mass. Using regression parameters from a different geographic location increased prediction error, causing over- or underestimation of body mass depending on geographical origin and whether body width was included. 4. We present a comprehensive range of parameters for predicting arthropod body mass and provide guidance for selecting optimal scaling relationships. Given the importance of body mass for functional invertebrate ecology and a paucity of adequate regressions to predict arthropod body mass from different geographical regions, our study provides a long-needed resource for quantifying live body mass in invertebrate ecology research.

Pemanfaatan Etnobotani dari Hutan Tropis Bengkulu sebagai Pestisida

Sumatra Island in Indonesia has a high potency of plants diversities. Traditional people have a local wisdom, like using plants extract for pest control which considered as an alternative technique that practical, economical, and environmentally safe. The aim of this study was to do inventory on pest control plants widely used by traditional people in the island. In order to analys the pest control efectivity of the plants, analysis on bioactivities of crude extracts on pest Spodoptera litura was done in invitro scale. The research was carried out in Rejang Lebong District, Bengkulu. Bioactivities test was done in Laboratory of Forest Protection, Palembang Forestry Research Institute. The results revealed as much as 25 species plants potential as biopesticide. Among these plants, 5 species used as fish poison, 17 species used as pesticide, 7 species used as rat poison, and 1 species used as nematode poison. Traditional people in Rejang Lebong District have a long history using these plants regularly to control some pests. Sitawar (Costus speciosus), puar kilat (Globba sp.), and legundi (Vitex trifolia) extracts affected mortalities and inhibitor S. litura development significantly.

KEANEKARAGAMAN ARTHROPODA TANAH DI HUTAN PENDIDIKAN GUNUNG WALAT (Diversity of Soil Arthropods in Gunung Walat Education Forest)

This paper reviews potential causes of amphibian population declines in Indonesia in relation to global amphibian declines. At least six factors were identified: over-harvesting, loss of forest and wetland habitats, pollution, disease, introduction of exotic species and deformities. The conservation of Indonesian amphibian faces many challenges, among other the low perception and knowledge about amphibian among general public, also low number and low quality of local herpetologist . Key word: global amphibian declines; amphibian; frog; Indonesia