Xishuangbanna Forest Fragmentation Project

Forest conversion to other land use types, especially agricultural monocultures, represents the most significant threat to local and regional biodiversity due to increased extinction risk, considerable modification of habitat characteristics and creation of new ecological boundaries. Forest conversion in southeast Asia is especially extensive and have placed regional biodiversity under extreme pressure. 

In Xishuangbanna County, Yunnan Province, primary forest area has decreased substantially as a result of conversion to rubber plantation, and to a lesser degree, tea plantation. The rate of change is extremely rapid, with most land conversion occurring in the last 20 years. There is an urgent need to understand the effects of fragmentation pattern in Xishuangbanna on biodiversity and to devise appropriate conservation actions to protect remaining biodiversity pools.

We have established a permanent forest fragment plot network encompassing 50 plots in the Menglun area, including both large forest reserves and small forest fragments embedded within a rubber plantation matrix. We have finished tree inventories, soil measurements and stand structure measurements in these plots. We have several projects currently running that explore plant and animal diversity across the forest fragments and adjacent plantations. These fall both under our own research group and also under collaborating research groups. These are described in detail below.  We intend to maintain regular monitoring of the forest community over time to follow the development of longer-term fragmentation effects. These permanent plots provide an excellent opportunity to assess the effects of forest fragmentation on multiple aspects of biodiversity, and we encourage other scientists to get involved with new projects.

In addition, we are studying fragmentation effects on animals and plants at larger scales within Xishuangbanna County, in order to assess fragment x environment effects at larger scales, and also to assess how biodiversity responses to fragmentation change based on the introduced matrix species (rubber versus tea). More details below.

This project is coordinated by Ferry Slik (University Brunei Darussalam) and Kyle Tomlinson.


The Spatial Distribution of Forest Fragments: Consequences for Tree Conservation

The non-random distribution patterns of forest fragments, with remaining forest fragments mostly located in less productive areas, can have a profound effect on which tree species will disappear from a landscape. We aim to study this possible impact with the objective of informing local authorities and tree species conservation agencies in the tropics in general how to best preserve biodiversity within production landscapes.

People involved: Liu JiaJia (PhD candidate), Ferry Slik, Kyle Tomlinson

Impact of forest fragmentation on understory herbs and microclimate

As part of the group doing research in forest fragment plots in Xishuangbanna, Southwest China, my concern deals primarily in understanding how microclimate condition and understory herb species will respond to forest fragmentation. Microclimate (i.e. temperature and humidity) varies considerably over time and under different weather condition, and the heterogeneity of forest fragments might influence this variation. Herbs, due to their relative short life span, react faster to environmental change than trees. Therefore, herb dispersal and germination might be limited during forest fragmentation and might result in patches of particular herb composition and structure. Seasonal variation (i.e. wet and dry season) and environmental effects (i.e. fragment size, forest type, canopy structure, elevation, aspect, and slope) will be considered in this study. Knowing the processes involved in herb and microclimate dynamics will help in creating viable restoration and conservation strategies in a changing forest landscape.

People involved: Bonnie Pasion (MSc candidate), Ferry Slik, Kyle Tomlinson

Impacts of fragmentation on tree dispersal syndromes

Seed dispersal is an important aspect of community assembly studies. Species vary in dispersal strategies which may result in different distribution patterns along environmental gradients. Therefore it is important to study how fragmentation affects these natural patterns which have developed and are probably adapted to continuous forests.

In this study, we examine the change in seed traits of old (>5cm dbh) and young (<2cm dbh) trees across a fragment size gradient (50 plots; 0.1 to 13500 ha) in the tropical forests of Xishuangbanna, China. We use three seed dispersal traits (dispersal type, dispersal agent and dispersal unit size) to determine how these are affected by fragment size, topography, soil type, and distance to the forest edge.

People involved: Huang Guohualing (MSc candidate), Ferry Slik, Kyle Tomlinson

Litter arthropods and conservation of tropical forest fragments

Arthropod communities and functional groups reflect the degree of fragmentation on the landscapes. However, research on the biodiversity of tropical fragmentation has mainly focused on changes in bird, mammal and plant diversity, or single taxa groups of arthropods. 

In this study, we collect leaf-litter arthropods from fragments as well as rubber plantations, and categorise them into different functional groups to investigate conservation value of forest fragments in Xishuangbanna County.

People involved: Mika Yasuda (Postdoc), Ferry Slik, Kyle Tomlinson

Community analysis of litter ants in forest fragments and rubber plantations using metabarcoding.

Ants are important as pollinators, seed dispersers, decomposers, predators, invasive species and indicators of habitat change. However, there are few studies on the comparison of species composition and diversity of leaf-litter ants between forest fragments and rubber plantations in Xishuangbanna. It is therefore crucial to have diversity estimates of ant species between forests and rubber plantations in order to assess the impact of rubber plantation on local ecosystem functions  Here we apply novel, metabarcoding, techniques to study the ant species composition in these two habitat types

People involved:
Ms Shen Xianhui (MSc candidate), Yann Surget-Groba (Ecological Evolution Group)
Ferry Slik, Kyle Tomlinson

How land use changes in Xishuangbanna affect arthropod communities

Forest conversion to other land use types, especially agricultural monocultures, represents the most significant threat to local and regional biodiversity due to increased extinction risk, considerable modification of habitat characteristics and creation of new ecological boundaries. However, it is still largely unknown if and how land use changes in Xishuangbanna affect arthropod communities. Conversion of natural forests to monoculture plantations changes the biophysical conditions required for arthropod growth, reproduction and survival. These changes have negative consequences on arthropod diversity and composition and result in increased extinction risk.

Traditional methods of measuring and assessing arthropod community composition and diversity are time consuming and require high expertise.  Metabarcoding represents a powerful tool for biodiversity conservation and ecosystem management at the organismal to community level because it is more comprehensive, faster, reliable, and less dependent on taxonomic expertise. It is a fast biodiversity monitoring approach that integrates DNA taxonomy and high throughput DNA sequencing. This project takes advantage of robust, established arthropod sampling methodologies in addition to implementing recent high-throughput technologies using short DNA sequences to distinguish and assign taxonomies to individual arthropod species. Emerging technologies including DNA extraction, PCR amplification and pyrosequencing will be used to prepare samples, extract, amplify, and purify DNA, and post quality control of sequences. In order to cluster the sequences into Operational Taxonomic Units (OTUs), we will apply existing experimentally validated methods.

People involved:
Kingsly Beng (PhD candidate), Ferry Slik, Kyle Tomlinson,
Alice Hughes (Centre for Integrative Conservation, XTBG)







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