Assessment of the bioindicator values of flying insects at a higher taxonomic level for different logging schemes in the lowland tropical rain forests of Deramakot, Sabah, Malaysia

The importance of the ecosystem services of, and the biological values of tropical forests are increasingly recognized amid drastically changing landscapes in the tropics. There is an urgent demand for establishing an appropriate environmental assessment method to keep healthy ecosystem functions and biodiversity along with sustainable forest use based on ecological principles. In this study, we tried to assess logging disturbance using several flying insect groups with their abundance in managed lowland tropical rain forests, Deramakot Forest Reserve (DFR), Sabah, Malaysia, with consideration of seasonal changes. We used a bait trap system to collect flying insects in several strata from the ground to a canopy in four seasons (periods) throughout a year in five forests with different logging histories/intensities. All the studied insects at a lower taxonomic level fluctuated seasonally in their abundance, while the family composition which took into account the relative abundance of families of trapped insects was relatively constant across the plots and the seasons. Although, effects of logging on the abundance of flying insects were distinct at an intensively logged plot, there was no clear difference among undisturbed plot and the moderately disturbed plots harvested by reduced-impact logging (RIL). The abundance of flying insects at higher taxonomic level has a potential of indicating logging disturbance

Soup to tree: the phylogeny of beetles inferred by mitochondrial metagenomics of a Bornean rainforest sample

In spite of the growth of molecular ecology, systematics and next-generation sequencing, the discovery and analysis of diversity is not currently integrated with building the tree-of-life. Tropical arthropod ecologists are well placed to accelerate this process if all specimens obtained via masstrapping, many of which will be new species, could be incorporated routinely in phylogeny reconstruction. Here we test a shotgun sequencing approach, whereby mitochondrial genomes are assembled from complex ecological mixtures via mitochondrial metagenomics, and demonstrate how the approach overcomes many of the taxonomic impediments to the study of biodiversity. DNA from ~500 beetle specimens, originating from a single rainforest canopy fogging sample from Borneo, was pooled and shotgun sequenced, followed by de novo assembly of complete and partial mitogenomes for 175 species. The phylogenetic tree obtained from this local sample was highly similar to that from existing mitogenomes selected for global coverage of major lineages of Coleoptera. When all sequences were combined, only minor topological changes are induced against this reference set, indicating an increasingly stable estimate of coleopteran phylogeny, whilst the ecological sample expands the tip-level representation of several lineages. Robust trees generated from ecological samples now enable an evolutionary framework for ecology. Meanwhile, the inclusion of uncharacterized samples in the tree-of-life rapidly expands taxon and biogeographic representation of lineages without morphological identification. Mitogenomes from shotgun sequencing of unsorted environmental samples and their associated metadata, placed robustly into the phylogenetic tree, constitute novel DNA ‘superbarcodes’ for testing hypotheses regarding global patterns of diversity

Impacts of habitat fragmentation on genetic diversity in a tropical forest butterfly on Borneo

Many areas of rain forest now exist as habitat fragments, and understanding the impacts of fragmentation is important for determining the viability of populations within forest remnants. We investigated impacts of forest fragmentation on genetic diversity in the butterfly Mycalesis orseis (Satyrinae) in Sabah (Malaysian Borneo). We investigated mtDNA diversity in 90 individuals from ten forest sites typical of the sizes of forest remnants that currently exist in the region. Nucleotide diversity declined with increasing isolation of remnants, but there was no effect of remnant size or population size, and haplotype diversity was similar among sites. Thus, approximately 50 y after forest fragmentation, few changes in genetic diversity were apparent and remnants apparently supported genetically viable populations of this butterfly. Many studies have shown that responses of species to habitat fragmentation usually follow a time delay, and so we developed a Monte Carlo simulation model to investigate changes in genetic diversity over time in small remnants. Model output indicated a substantial time delay (> 100 y) between fragmentation and genetic erosion, suggesting that, in the smallest study remnants, an increased risk of extinction from reduced genetic diversity is likely in the longer term

Selective-logging and oil palm: multitaxon impacts, biodiversity indicators, and trade-offs for conservation planning

Strong global demand for tropical timber and agricultural products has driven large-scale logging and subsequent conversion of tropical forests. Given that the majority of tropical landscapes have been or will likely be logged, the protection of biodiversity within tropical forests thus depends on whether species can persist in these economically exploited lands, and if species cannot persist, whether we can protect enough primary forest from logging and conversion. However, our knowledge of the impact of logging and conversion on biodiversity is limited to a few taxa, often sampled in different locations with complex land-use histories, hampering attempts to plan cost-effective conservation strategies and to draw conclusions across taxa. Spanning a land-use gradient of primary forest, once- and twice-logged forests, and oil palm plantations, we used traditional sampling and DNA metabarcoding to compile an extensive data set in Sabah, Malaysian Borneo for nine vertebrate and invertebrate taxa to quantify the biological impacts of logging and oil palm, develop cost-effective methods of protecting biodiversity, and examine whether there is congruence in response among taxa. Logged forests retained high species richness, including, on average, 70% of species found in primary forest. In contrast, conversion to oil palm dramatically reduces species richness, with significantly fewer primary-forest species than found on logged forest transects for seven taxa. Using a systematic conservation planning analysis, we show that efficient protection of primary-forest species is achieved with land portfolios that include a large proportion of logged-forest plots. Protecting logged forests is thus a cost-effective method of protecting an ecologically and taxonomically diverse range of species, particularly when conservation budgets are limited. Six indicator groups (birds, leaf-litter ants, beetles, aerial hymenopterans, flies, and true bugs) proved to be consistently good predictors of the response of the other taxa to logging and oil palm. Our results confidently establish the high conservation value of logged forests and the low value of oil palm. Cross-taxon congruence in responses to disturbance also suggests that the practice of focusing on key indicator taxa yields important information of general biodiversity in studies of logging and oil palm

Coefficient shifts in geographical ecology: an empirical evaluation of spatial and non-spatial regression

Copyright © 2009 The Authors. Copyright © ECOGRAPHY 2009.A major focus of geographical ecology and macro ecology is to understand the causes of spatially structured ecological patterns. However, achieving this understanding can be complicated when using multiple regressions, because the relative importance of explanatory variables, as measured by regression coefficients, can shift depending on whether spatially explicit or non-spatial modelling is used. However, the extent to which coefficients may shift and why shifts occur are unclear. Here, we analyze the relationship between environmental predictors and the geographical distribution of species richness, body size, range size and abundance in 97 multi-factorial data sets. Our goal was to compare standardized partial regression coefficients of non-spatial ordinary least squares regressions (i.e. models fitted using ordinary least squares without taking autocorrelation into account; “OLS models” hereafter) and eight spatial methods to evaluate the frequency of coefficient shifts and identify characteristics of data that might predict when shifts are likely. We generated three metrics of coefficient shifts and eight characteristics of the data sets as predictors of shifts. Typical of ecological data, spatial autocorrelation in the residuals of OLS models was found in most data sets. The spatial models varied in the extent to which they minimized residual spatial autocorrelation. Patterns of coefficient shifts also varied among methods and datasets, although the magnitudes of shifts tended to be small in all cases. We were unable to identify strong predictors of shifts, including the levels of autocorrelation in either explanatory variables or model residuals. Thus, changes in coefficients between spatial and non-spatial methods depend on the method used and are largely idiosyncratic, making it difficult to predict when or why shifts occur. We conclude that the ecological importance of regression coefficients cannot be evaluated with confidence irrespective of whether spatially explicit modelling is used or not. Researchers may have little choice but to be more explicit about the uncertainty of models and more cautious in their interpretation

Comparison of biodiversity between plantation and natural forests in Sabah using moths as indicators

The Malaysian state of Sabah, in northern Borneo, started massive monoculture forest plantations of fast-growing introduced tree species in the mid-1970's to replace part of the harvested tropical rain forest. Many people, particularly conservationists in the West, are very much against this sort of reforestation as they fear it would spell a permanent loss to the Bornean rain forest biodiversity. This project was carried out at the more established forest plantations of Sabah Softwoods Sdn. Bhd. in Brumas from 1991 to 1993, where fast-growing exotics namely Acacia mangium, Eucalyptus deglupta, Gmelina arborea, Paraserianthes (=Albizia) falcataria, Pinus caribaea, were studied to assess their biodiversity and these plantations were compared with the natural regenerating logged-over secondary forest in Brumas, as well as the primary forest in Danum Valley, by using light-trapped macromoths as indicators. The method of light-trapping as a reliable means of capturing moths was supported by canopy knockdown in the form of mist-blowing. Results obtained showed that for the year-long (January-December 1991) light-trap samples, the biodiversity values, as represented by Williams alpha (higher the value, higher the diversity), were unexpectedly high in the various plantation forests. Their alpha values ranged from the lowest in Acacia mangium with 208.14+-9.22, to the highest in Eucalyptus deglupta with 330.85+-16.37 which was even higher than the natural secondary forest with 314.53+-11.99, and certainly not inferior to the published values (300 to 350) from undisturbed Bornean forest of similar altitudes (below 500m). For the shorter month-long subsidiary samples (October/November 1992, January/February 1993), the alpha values of the samples from the lowland primary forest in Danum were not necessarily higher when compared with the similarly sampled disturbed forest habitats in Brumas, but despite its small samples, Danum produced some 33 species of macromoths which were never collected out of the 1680 species obtained from Brumas in the entire project. The main reason behind the surprisingly good diversity measures (as indicated by moths) in these forest plantations was the presence of an understorey of varying diversity under the canopy. It would appear that with the fast-growing introduced trees acting as light-demanding pioneers, many plant species ranging from herbs, shrubs, to saplings of native tree species, managed to germinate and grow more or less efficiently in the understorey. Eucalyptus deglupta had a more diverse understorey both in terms of plant species and architecture, which in turn supported a more diverse moth fauna. These findings are encouraging in terms of biodiversity conservation, as plantation forestry seems to be the only way forward for many developing countries like Malaysia.</p

Comparison of biodiversity between plantation and natural forests in Sabah using moths as indicators

The Malaysian state of Sabah, in northern Borneo, started massive monoculture forest plantations of fast-growing introduced tree species in the mid-1970's to replace part of the harvested tropical rain forest. Many people, particularly conservationists in the West, are very much against this sort of reforestation as they fear it would spell a permanent loss to the Bornean rain forest biodiversity. This project was carried out at the more established forest plantations of Sabah Softwoods Sdn. Bhd. in Brumas from 1991 to 1993, where fast-growing exotics namely Acacia mangium, Eucalyptus deglupta, Gmelina arborea, Paraserianthes (=Albizia) falcataria, Pinus caribaea, were studied to assess their biodiversity and these plantations were compared with the natural regenerating logged-over secondary forest in Brumas, as well as the primary forest in Danum Valley, by using light-trapped macromoths as indicators. The method of light-trapping as a reliable means of capturing moths was supported by canopy knockdown in the form of mist-blowing. Results obtained showed that for the year-long (January-December 1991) light-trap samples, the biodiversity values, as represented by Williams alpha (higher the value, higher the diversity), were unexpectedly high in the various plantation forests. Their alpha values ranged from the lowest in Acacia mangium with 208.14+-9.22, to the highest in Eucalyptus deglupta with 330.85+-16.37 which was even higher than the natural secondary forest with 314.53+-11.99, and certainly not inferior to the published values (300 to 350) from undisturbed Bornean forest of similar altitudes (below 500m). For the shorter month-long subsidiary samples (October/November 1992, January/February 1993), the alpha values of the samples from the lowland primary forest in Danum were not necessarily higher when compared with the similarly sampled disturbed forest habitats in Brumas, but despite its small samples, Danum produced some 33 species of macromoths which were never collected out of the 1680 species obtained from Brumas in the entire project. The main reason behind the surprisingly good diversity measures (as indicated by moths) in these forest plantations was the presence of an understorey of varying diversity under the canopy. It would appear that with the fast-growing introduced trees acting as light-demanding pioneers, many plant species ranging from herbs, shrubs, to saplings of native tree species, managed to germinate and grow more or less efficiently in the understorey. Eucalyptus deglupta had a more diverse understorey both in terms of plant species and architecture, which in turn supported a more diverse moth fauna. These findings are encouraging in terms of biodiversity conservation, as plantation forestry seems to be the only way forward for many developing countries like Malaysia.</p

Assessment of higher insect taxa as bioindicators for different logging-disturbance regimes in lowland tropical rain forest in Sabah, Malaysia

One of the serious environmental problems since the 1980s has been the conflict between the high rate of deforestation and maintenance of healthy ecosystem services and biological values in tropical forests. There is an urgent demand for setting up an appropriate environmental assessment to keep healthy ecosystem functions and biodiversity along with sustainable forest use based on ecology. In this study, we tried to assess logging-disturbance effects on the abundances of several flying insect groups (higher-taxon approach) in lowland tropical rain forest (Deramakot Forest Reserve, Sabah, Malaysia), while considering seasonal changes and vertical forest stratification. The season was the most important factor affecting the abundances of all the insect groups. Effects of logging disturbance were prominent in the understorey but obscure in the canopy. Changes in physical conditions caused by logging—possibly an increased evaporation due to solar radiation—may have decreased the abundance of desiccation-sensitive insects, especially in the understorey. There are also two probable reasons for the difference between events in the understorey and those in the canopy: (1) noise effects of various physical, environmental factors may have obscured insect responses to logging disturbance in the canopy; (2) higher spatio-temporal variation in quality and quantity of living food resources—such as leaves, flowers and fruits—provided in the canopy may have affected the abundance of their consumer insects independently of logging disturbance. Thus, this study suggests that the abundance of some insect groups at higher-taxon level, especially in the understorey, can be used as bioindicators for assessing effects of logging disturbance on the forest ecosystem