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Sakchoowong W.,Forest and Plant Conservation Research Office | Hasin S.,Kasetsart University | Pachey N.,Forest and Plant Conservation Research Office | Amornsak W.,Kasetsart University | And 3 more authors.
Asian Myrmecology | Year: 2015

In tropical rainforests, variability in the distribution of soil and litter arthropods is usually explained at regional scales by altitude, soil nutrients, and disturbance regimes. However, the influence of these factors on insect assemblages at the micro-habitat scale has rarely been studied. We investigated whether the species identity of decomposing leaves in tropical forest affected the composition of ant assemblages around them. Ants were extracted from litter below three common tree species, Parashorea stellata (Dipterocarpaceae), Intsia palembanica (Fabaceae) and Shorea gratissima (Dipterocarpaceae) in a 24 ha lowland rainforest plot in southern Thailand. A total of 2,257 individual ants, representing 71 species in 38 genera of 6 subfamilies were collected in the dry and wet seasons during 2010. Ant species richness was never significantly different among litter samples under the crown cover of three tree species. Ant species richness was higher in the wet season than the dry season. Our results demonstrate that ant assemblages are seasonally heterogeneous. Leaf mass and litter mass did not relate to the presence of ant diversity. Soil humidity was the only important factor influencing ant diversity in this study. Future studies should consider the importance of soil moisture related to litter ant diversity. © Watana Sakchoowong, Sasitorn Hasin, Nongphanga Pachey, Weerawan Amornsak, Sarayudh Bunyavejchewin, Pitoon Kongnoo and Yves Basset.

Basset Y.,Smithsonian Tropical Research Institute | Eastwood R.,Harvard University | Sam L.,The New Guinea Binatang Research Center | Lohman D.J.,Harvard University | And 8 more authors.
Insect Conservation and Diversity | Year: 2013

1.Standardised transect counts of butterflies in old-growth rainforests in different biogeographical regions are lacking. Such data are needed to mitigate the influence of methodological and environmental factors within and between sites and, ultimately, to discriminate between long-term trends and short-term stochastic changes in abundance and community composition. 2.We compared butterfly assemblages using standardised Pollard Walks in the understory of closed-canopy lowland tropical rainforests across three biogeographical regions: Barro Colorado Island (BCI), Panama; Khao Chong (KHC), Thailand; and Wanang (WAN), Papua New Guinea. 3.The length and duration of transects, their spatial autocorrelation, and number of surveys per year represented important methodological factors that strongly influenced estimates of butterfly abundance. Of these, the effect of spatial autocorrelation was most difficult to mitigate across study sites. 4.Butterfly abundance and faunal composition were best explained by air temperature, elevation, rainfall, wind velocity, and human disturbance at BCI and KHC. In the absence of weather data at WAN, duration of transects and number of forest gaps accounted for most of the explained variance, which was rather low in all cases (<33%). 5.Adequate monitoring of the abundance of common butterflies was achieved at the 50ha BCI plot, with three observers walking each of 10 transects of 500m for 30min each, during each of four surveys per year. These data may be standardised further after removing outliers of temperature and rainfall. Practical procedures are suggested to implement global monitoring of rainforest butterflies with Pollard Walks. © 2012 The Royal Entomological Society.

Peay K.G.,University of California at Berkeley | Kennedy P.G.,Lewis And Clark College | Davies S.J.,Harvard University | Tan S.,Sarawak Forestry Corporation | And 2 more authors.
New Phytologist | Year: 2010

Relatively little is known about diversity or structure of tropical ectomycorrhizal communities or their roles in tropical ecosystem dynamics. In this study, we present one of the largest molecular studies to date of an ectomycorrhizal community in lowland dipterocarp rainforest. We sampled roots from two 0.4 ha sites located across an ecotone within a 52 ha forest dynamics plot. Our plots contained > 500 tree species and > 40 species of ectomycorrhizal host plants. Fungi were identified by sequencing ribosomal RNA genes. The community was dominated by the Russulales (30 species), Boletales (17), Agaricales (18), Thelephorales (13) and Cantharellales (12). Total species richness appeared comparable to molecular studies of temperate forests. Community structure changed across the ecotone, although it was not possible to separate the role of environmental factors vs host plant preferences. Phylogenetic analyses were consistent with a model of community assembly where habitat associations are influenced by evolutionary conservatism of functional traits within ectomycorrhizal lineages. Because changes in the ectomycorrhizal fungal community parallel those of the tree community at this site, this study demonstrates the potential link between the distribution of tropical tree diversity and the distribution of tropical ectomycorrhizal diversity in relation to local-scale edaphic variation. © 2009 New Phytologist.

Harrison R.D.,CAS Kunming Institute of Botany | Harrison R.D.,World Agroforestry Center | Tan S.,Center for Tropical Forest Science | Plotkin J.B.,University of Pennsylvania | And 5 more authors.
Ecology Letters | Year: 2013

Hunting affects a considerably greater area of the tropical forest biome than deforestation and logging combined. Often even large remote protected areas are depleted of a substantial proportion of their vertebrate fauna. However, understanding of the long-term ecological consequences of defaunation in tropical forests remains poor. Using tree census data from a large-scale plot monitored over a 15-year period since the approximate onset of intense hunting, we provide a comprehensive assessment of the immediate consequences of defaunation for a tropical tree community. Our data strongly suggest that over-hunting has engendered pervasive changes in tree population spatial structure and dynamics, leading to a consistent decline in local tree diversity over time. However, we do not find any support for suggestions that over-hunting reduces above-ground biomass or biomass accumulation rate in this forest. To maintain critical ecosystem processes in tropical forests increased efforts are required to protect and restore wildlife populations. © 2013 Blackwell Publishing Ltd/CNRS.

News Article | October 23, 2015
Site: www.nature.com

The sun has been pale for months here in Sumatra and the skies are grey all day — choked with pollution from the massive fires that rage across the Indonesian island. Since the late 1990s, the haze caused by these annual fires has posed a significant threat to the health of Sumatra’s rural communities. This year’s haze is especially bad and has affected major cities, both here and abroad; consequently, the fires have again made headlines around the world. Many of these news stories blame the big palm-oil companies for the fires. Slash-and-burn techniques remain the cheapest way to clear forest for new plantations. But scientific evidence suggests that this simple narrative is not absolutely true. A number of surveys have found that the bulk of these fires are started outside the official oil-palm concessions. Small-scale farmers seem to be more to blame. The haze in Indonesia is not just an environmental issue; it is a complex socio-economic problem that is driven partly by conflict over land ownership between palm-oil companies and rural communities — a struggle that the companies usually win. Besides holding financial and legal power, these companies also have science on their side. High-quality research at state-funded centres has found ways to increase the production of palm oil, such as the manipulation of the gene SHELL and ways to weed out oil-palm clones with reduced yields. These technologies have been developed by the Malaysian Palm Oil Board, and the big companies in the region can pay to license and use them. But such technologies are out of the reach of smallholders and the rural population. Yet smallholders produce a large proportion of the crops, mainly through conventional farming practices. Some 80% of Indonesian rubber, for example, is made by small-scale farmers who do not have access to the research products and whose welfare has not improved. What has science done to empower these people? The problems of Indonesian farmers might seem low on the list of global priorities. But as the nations of the world prepare to discuss a treaty on climate change in Paris next month, the fires that fuel the Sumatran haze offer a perfect example of how the relationship between science and industry must shift if we value sustainable development. Scientists need the private sector to provide funding and a ‘tunnel’ for commercialization; the private sector needs scientists to develop products. This alliance, together with support from the government, is called the triple helix — a concept that has driven the world’s economy since the Industrial Revolution. But is this concept still relevant? Although some parts of the world have achieved a stable economy driven by scientific advancement, around half of the world’s population still lives in poverty. The people of these regions also face environmental threats, such as deforestation and its extended impact, on a daily basis. Those who are most vulnerable benefit from science the least. There are scientists who want to transfer their knowledge to these people, but this has proved difficult. The failure of an experiment in the Solomon Islands to help indigenous people to exploit their local environment as ‘ecosystem services’ was attributed to a culture gap between scientists and local people. This claimed divide is often presented as a barrier to the transfer of science and technology. Scientists must try harder to bridge this gap. Science is a fuel for economic development, but its influence must extend beyond the triple helix. That model simply uses science to exploit natural resources for economic gain. Given the need to mitigate the harmful environmental effects of this conversion, the model is no longer enough. Mitigation must be the responsibility of everyone on the planet, not just scientists, businessmen and policymakers. Indigenous and local people should also be involved, especially those who call carbon sinks, such as tropical forests, home. There are already examples of science reaching out. The residents of the Wanang Conservation Area in Papua New Guinea, for instance, have offered 1,000 hectares of their 10,000-hectare protected forest for research conducted by institutions such as the Smithsonian Tropical Research Institute’s Center for Tropical Forest Science. In this zone, scientists and indigenous people collaborate to investigate the response of trees to climate change. Local people are trained then employed as field research assistants and have received compensation for the lease of their forest. Meanwhile, a project supported by the US Agency for International Development is training local people in West Kalimantan, Indonesia, to be plant parataxonomists. The project was initiated by Campbell Webb, a plant evolutionary biologist and bioinformaticist at the Arnold Arboretum of Harvard University who is based in West Kalimantan. It is teaching local people to collect plant data in Gunung Palung National Park, an area of high biodiversity that faces the threat of deforestation. The Paris talks should discuss the need for such initiatives to be copied and scaled up. For decades, the relationship between science, industry and government has been celebrated by all involved as a good thing. But not everybody benefits. Science might be able to pin the blame for the southeast Asia haze on Indonesian smallholders, but it has not yet given them — or others in their position — a way to help prevent it.

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