Assessing factors influencing the spatial distribution of species diversity in ground dwelling ant assemblages in lowland, wet forest of southwest Sri Lanka

Tropical forests of the world are fast disappearing and there is a race to understand patterns of species distribution in space and time. Studying species distributions can provide better frameworks for conservation of these ecologically important patches of floral and faunal diversity. The island of Sri Lanka is a well known harbour of unique and highly threatened biodiversity. Tropical lowland forest is remnant in the south-west of the island now mainly existing in small patches. While most are small disturbed fragments, Sinharaja Forest Reserve represents one of the largest remaining patches of this important ecosystem. As a UNESCO World Heritage Site and a Man and Biosphere Reserve, it has a dual role as a conservation area and a historically important resource forest. While the distribution of vegetation diversity has been well documented, analyses of invertebrate species distributions are lacking. This thesis investigated a key arthropod group, ground dwelling ants, in relation to environmental gradients within the forest. Cumulative results demonstrate the high diversity of the forest patch. In an area representing less than half the reserve, over 173 ground dwelling ant species were found in distinct assemblages throughout the forest. Since the forest is located upon a series of parallel ridges, ant species distribution was first analysed in terms of this small elevation change. Species richness declined over a vertical incline from 430 m to 660 m, highlighting a possible small-scale, mountain mass effect. This section of the reserve is also characterised by a patch of once-logged forest (30 years previously). A study was undertaken to investigate whether there were residual effects of selective logging on the reserve.Significant differences between species assemblages in once-logged forest and unlogged forest add to growing evidence that selectively logged forests continue to remain distinct from unlogged forest even after decades of regeneration. Ant distribution was then analysed for their relationship with habitat heterogeneity and tree species distribution. Long-term research on tree species in the SFR has demonstrated a close relationship to habitat complexity. Ant species appear to respond more to the structural heterogeneity of the vegetation than to actual topographic variation within the forest. From a conservation perspective, maintaining the integrity of this highly diverse forest is imperative. The impact of anthropogenic land uses surrounding the forest was investigated in terms of ant assemblages along the forest edges. Significant differences were found between assemblages within the edges bordered by different matrix types. Even relatively large forest remnants can be affected by the surrounding matrix land uses and encouraging the growth of structurally similar vegetation and maintaining low disturbance along the borders should attenuate the effect of the edge. Overall, the highly heterogeneous distribution of ant assemblages within the SFR demonstrates the potential for other small patches to be harbours of further species diversity. Future research should be undertaken to assess the diversity and distribution of ant species within this region and encourage the protection of this remnant diversity

A brief overview of the Western Ghats – Sri Lanka biodiversity hotspot

The Western Ghats of India and Sri Lanka biodiversity hotspot is often regarded as one unit because of shared biogeographical history. However, recent studies suggest that certain faunal components, particularly in the wet zones are distinct. This article looks at the existing information on species richness and endemicity of taxa in both regions. Data are available on some taxa but not on others, and many taxa have not received equal attention in both regions. The natural ecosystems of this hotspot are under threat and urgent conservation action is needed, especially in augmenting the protected area network. There is also the need for increasing the level of scientific collaboration in biodiversity studies between the two countries

Many eyes on the ground: citizen science is an effective early detection tool for biosecurity

Early detection of target non-indigenous species is one of the most important determinants of a successful eradication campaign. For early detection to be successful, and provide the highest probability of achieving eradication, intense surveillance is often required that can involve significant resources. Volunteer based monitoring or “citizen science” is one potential tool to address this problem. This study differs from standard citizen science projects because the participants are personnel or contractors of a company working on Barrow Island, Western Australia. We show that personnel can contribute successfully to a surveillance program aimed at detecting a broad taxonomic range of non-indigenous vertebrate and invertebrate species. Using data collected over a five year surveillance period on Barrow Island, we show that eighteen of the nineteen (95%) non-indigenous invertebrate species new to the island were detected by personnel working on the island, and that the number of detections made by these workers was significantly related to the number of personnel on the island at any one time. Most personnel detections (91%) were made inside buildings where the majority of active surveillance tools could not be implemented. For vertebrates, 4 NIS species detections (100% of detections) were made in the built environment by personnel. Although reporting of suspect non-indigenous species is voluntary, personnel are required to attend inductions and toolboxes where reporting of suspect biosecurity risk material is encouraged. These results demonstrate the value of industry led ‘citizen science’ programs, resulting in sustained stewardship and conservation of areas with high environmental value

The database of the PREDICTS (Projecting Responses of Ecological Diversity In Changing Terrestrial Systems) project

The PREDICTS project—Projecting Responses of Ecological Diversity In Changing Terrestrial Systems (www.predicts.org.uk)—has collated from published studies a large, reasonably representative database of comparable samples of biodiversity from multiple sites that differ in the nature or intensity of human impacts relating to land use. We have used this evidence base to develop global and regional statistical models of how local biodiversity responds to these measures. We describe and make freely available this 2016 release of the database, containing more than 3.2 million records sampled at over 26,000 locations and representing over 47,000 species. We outline how the database can help in answering a range of questions in ecology and conservation biology. To our knowledge, this is the largest and most geographically and taxonomically representative database of spatial comparisons of biodiversity that has been collated to date; it will be useful to researchers and international efforts wishing to model and understand the global status of biodiversity