Indicators Of Forest Disturbance Research Articles

Diversity Of Epiphytic ferns in the cross river national park, Akamkpa, Nigeria as indicators of forest disturbance

Diversity Of Epiphytic ferns in the cross river national park, Akamkpa, Nigeria as indicators of forest disturbance

Species density diverges after forest fragmentation in lianescent Machaerium Pers. (Fabaceae) in Central Amazonia

Liana density is positively associated with forest fragmentation. The process of colonization by lianas is often reported without considering species composition, and consequent changes in liana species composition is relatively unexplored. To understand the compositional change associated with disturbance, we inventoried lianas in permanent plots of the Biological Dynamics of Forest Fragments Project (BDFFP), north of Manaus, Central Amazonia, Brazil. This analysis was focused exclusively on species of the diverse genus Machaerium Pers. (Fabaceae). All lianas with DBH ≥ 2 cm were marked, measured, collected, and identified to the species level in 34 1-ha plots, distributed in continuous and fragmented forests. Density data were analyzed at three hierarchical taxonomic levels: the whole liana community, the genus Machaerium, and each species within Machaerium. At both the generic and species levels, we calculated absolute and relative density. Density (absolute and relative) was evaluated using two indicators of forest disturbance: (1) continuous versus fragmented forest, and (2) plot proximity to forest edge. We employed Generalized Linear Mixed Model with Template Model Builder for analyses. As expected, whole community liana density was positively related to forest disturbance. However, absolute density of the genus Machaerium was not affected by edge or by forest fragmentation, and consequently relative density of the genus Machaerium was reduced. Among the eight species of Machaerium, we found distinct patterns of response to disturbance. Absolute densities of M. hoehneanum and M. aureiflorum were positively affected by forest disturbance, similar to the pattern of the whole liana community, while absolute densities for M. macrophyllum and M. ferox were negatively affected. Absolute densities of the other four species (M. madeirense, M. leiophyllum, M. multifoliolatum, and M. quinata) were not affected by fragmentation indicators. The relative density of six of the eight Machaerium species was negatively affected by forest fragmentation. The variation of responses in closely related species of lianas suggests that liana species are neither uniformly nor always positively affected by forest fragmentation.

Monitoring Mangrove Forest Degradation and Regeneration: Landsat Time Series Analysis of Moisture and Vegetation Indices at Rabigh Lagoon, Red Sea

Rabigh Lagoon, located on the eastern coast of the Red Sea, is an ecologically rich zone in Saudi Arabia, providing habitat to Avicennia marina mangrove trees. The environmental quality of the lagoon has been decaying since the 1990s mainly from sedimentation, road construction, and camel grazing. However, because of remedial measures, the mangrove communities have shown some degree of restoration. This study aims to monitor mangrove health of Rabigh Lagoon during the time it was under stress from road construction and after the road was demolished. For this purpose, time series of EVI (Enhanced Vegetation Index), MSAVI (Modified, Soil-Adjusted Vegetation Index), NDVI (Normalized Difference Vegetation Index), and NDMI (Normalized Difference Moisture Index) have been used as a proxy to plant biomass and indicator of forest disturbance and recovery. Long-term trend patterns, through linear, least square regression, were estimated using 30 m annual Landsat surface-reflectance-derived indices from 1986 to 2019. The outcome of this study showed (1) a positive trend over most of the study region during the evaluation period; (2) most trend slopes were gradual and weakly positive, implying subtle changes as opposed to abrupt changes; (3) all four indices divided the times series into three phases: degraded mangroves, slow recovery, and regenerated mangroves; (4) MSAVI performed best in capturing various trend patterns related to the greenness of vegetation; and (5) NDMI better identified forest disturbance and recovery in terms of water stress. Validating observed patterns using only the regression slope proved to be a challenge. Therefore, water quality parameters such as salinity, pH/dissolved oxygen should also be investigated to explain the calculated trends.

Using the U‐net convolutional network to map forest types and disturbance in the Atlantic rainforest with very high resolution images

AbstractMapping forest types and tree species at regional scales to provide information for ecologists and forest managers is a new challenge for the remote sensing community. Here, we assess the potential of a U‐net convolutional network, a recent deep learning algorithm, to identify and segment (1) natural forests and eucalyptus plantations, and (2) an indicator of forest disturbance, the tree species Cecropia hololeuca, in very high resolution images (0.3 m) from the WorldView‐3 satellite in the Brazilian Atlantic rainforest region. The networks for forest types and Cecropia trees were trained with 7611 and 1568 red‐green‐blue (RGB) images, respectively, and their dense labeled masks. Eighty per cent of the images were used for training and 20% for validation. The U‐net network segmented forest types with an overall accuracy >95% and an intersection over union (IoU) of 0.96. For C. hololeuca, the overall accuracy was 97% and the IoU was 0.86. The predictions were produced over a 1600 km2 region using WorldView‐3 RGB bands pan‐sharpened at 0.3 m. Natural and eucalyptus forests compose 79 and 21% of the region's total forest cover (82 250 ha). Cecropia crowns covered 1% of the natural forest canopy. An index to describe the level of disturbance of the natural forest fragments based on the spatial distribution of Cecropia trees was developed. Our work demonstrates how a deep learning algorithm can support applications such as vegetation, tree species distributions and disturbance mapping on a regional scale.

Cultural and ecological insights into sacred groves: managing timber resources for improved grove conservation

This mixed methods study investigated cultural and ecological aspects of five sacred groves within the Kodagu district, South India. Sacred groves are community-managed forests that are protected due to spiritual reasons and can provide habitat for rare species in human-dominated landscapes; however, they are globally threatened due to land use pressures, cultural changes and resource extraction. Within the study region, sacred groves are not only being encroached but are also losing quality, leading to a reduction of rare and threatened species. Interviews with 43 residents documented perceptions of grove quality, grove histories and related beliefs. Ecological indicators of forest disturbance and detailed demographic data of the threatened valuable timber tree Dysoxylum malabaricum as a model species were recorded. Results found degrees of forest disturbance, congruent with residents' perception that grove protection is weakening, and an ongoing local cultural association with these sacred spaces. Management of the sacred groves could be improved through regular interaction between the Forest Department and local temple committees. Additionally, implementing silvicultural management of rare timber species could synergistically serve ecological and cultural conservation goals.

Diversity patterns of ground beetles and understory vegetation in mature, secondary, and plantation forest regions of temperate northern China.

Plantation and secondary forests form increasingly important components of the global forest cover, but our current knowledge about their potential contribution to biodiversity conservation is limited. We surveyed understory plant and carabid species assemblages at three distinct regions in temperate northeastern China, dominated by mature forest (Changbaishan Nature Reserve, sampled in 2011 and 2012), secondary forest (Dongling Mountain, sampled in 2011 and 2012), and forest plantation habitats (Bashang Plateau, sampled in 2006 and 2007), respectively. The α-diversity of both taxonomic groups was highest in plantation forests of the Bashang Plateau. Beetle α-diversity was lowest, but plant and beetle species turnover peaked in the secondary forests of Dongling Mountain, while habitats in the Changbaishan Nature Reserve showed the lowest turnover rates for both taxa. Changbaishan Nature Reserve harbored the highest proportion of forest specialists. Our results suggest that in temperate regions of northern China, the protected larch plantation forest established over extensive areas might play a considerable role in maintaining a high biodiversity in relation to understory herbaceous plant species and carabid assemblages, which can be seen as indicators of forest disturbance. The high proportion of phytophagous carabids and the rarity of forest specialists reflect the relatively homogenous, immature status of the forest ecosystems on the Bashang Plateau. China's last remaining large old-growth forests like the ones on Changbaishan represent stable, mature ecosystems which require particular conservation attention.

Diversity and abundance of orchid bees (Hymenoptera: Apidae, Euglossini) in a tropical rainforest succession

Euglossine bee males are easily lured to chemical baits imitating natural fragrances gathered by bees, providing a widely applied measure for estimating the diversity and abundance of euglossines. In here, I report the composition of euglossine bees in three lowland rainforest habitats of Peru, a primary old forest, a reforested and managed forest, and a very disturbed forest. A total of 2,072 males of euglossine were collected, belonging to 33 species and four genera. Although a comparable diversity relative to other studies from the Amazonian region was found, no significant differences among the sampled areas were detected. Perhaps, the short time and low intensity surveys here used (< 3 months) were not good enough indicators of forest disturbance without additional data. Compared to other major studies on the euglossine bee fauna, Loreto is most similar to the species assemblage reported from lowland rainforest in Brazil (Manaus), central Peru (Panguana) and southern Peru (Tambopata).

Use of modern tree‐fall patterns as a guideline for interpreting prostrate trees at a pre–Last Glacial Maximum paleoforest site, upper North Island, New Zealand

Wind throw, as evidenced by a tree bole with an attached root plate, is an indicator of forest disturbance, and can often be used as direct evidence of surface winds during a single storm event. We assess tree‐fall patterns resulting from the 1982 Cyclone Bernie event in the North Island, New Zealand, and apply these findings to interpretation of a pre–Last Glacial Maximum (LGM) tree‐fall site to determine if the subfossil tree‐fall pattern could have been caused by a single extropical cyclone. There is insufficient evidence to recommend that a single extropical storm event could have caused the forest destruction observed at our pre‐LGM tree‐fall site, and therefore multiple possibilities for enhanced wind flow that could have caused tree throw are possible.

Main disturbance factors in north-west Russian forests: Structure and databases

The official statistics of the Ministry of Natural Resources of the Russian Federation record areas of forest degradation as a key indicator of forest disturbance. The forest degradation area of the north-western part of Russia varies from 14,000 to 28,000 ha per year, the main disturbance factors in forests of the Russian Federation being fires, insect outbreaks and strong wind. These factors caused degradation of forests up to 21,000, 3000 and 300 ha per year in 2001–2003, respectively. There is a need for further development and correction of the databases on forest degradation by the Ministry of Natural Resources of the Russian Federation, particularly with respect to forest degradation resulting from insect outbreaks. Data on degradation areas after forest fires and storms can be verified and corrected to bring them to a representative level. Official statistics on areas of fires and number of fires can be used for initial disturbance assessment. This paper describes the new database structure for insect outbreaks using various sources of information, including official statistics, published data, special forest pathology assessment reports, data from local subdivisions of the forest service and the reports of local experts. The database developed demonstrates the enhanced importance of insect outbreaks. The taxonomic structure of insect pest outbreaks is different to the official statistics and the list of species is longer; the frequency and scale of outbreaks are also much higher. It should be possible to create databases for other important forest disturbance agents such as diseases and air pollution in a similar way.

Vegetation diversity and vertical structure as indicators of forest disturbance

Plant species composition and vertical structure of oak-mixed Atlantic woodlands differing on disturbance regime were studied in the Basque Country, northern Spain. Four different disturbance groups were considered depending on the time since last thinning and the presence/absence of grazers. Plant species cover varied among disturbance groups for 17 out of the total 47 species present in the study area. In general, disturbance by clear-cutting favoured the cover of Betula alba, Castanea sativa and Quercus robur. The shrub species most affected by disturbance were heathers. Among these, the most drastic effect was found for Calluna vulgaris, Daboecia cantabrica and Erica vagans which disappeared in those woodlands subjected to grazing. Several nemoral species, such as Vaccinium myrtillus, Blechnum spicant and Lamiastrum galeobdolon, were absent in these same grazed forests. By contrast, generalist species, such as Ruscus aculeatus, Geranium robertianum and Veronica officinalis, were mostly present in the grazed woodlands. Diversity was measured as Species Richness as well as with the Shannon’s and Simpson’s indices. Plant species richness did not vary with disturbance treatment, however, it was highest for trees and shrubs at those woodlands in an advanced stage of regeneration, and for herbs in the lowest and highest disturbance groups. Besides, only the third vertical layer (2.5–10 m) was affected by disturbance treatment. Simpson’s was the best index to explain the observed differences in the structure of woodlands subjected to unalike levels of disturbance. Species diversity was highest in woodlands with lowest disturbance or in an advanced state of regeneration. Woodlands with lowest disturbance had the highest diversity of trees and those woodlands in an advanced state of regeneration showed the highest diversity of shrub species. Regarding vertical structure, diversity was mostly affected in the intermediate layer (2.5–10 m), with highest values found in woodlands at the lowest disturbance group, i.e. at least 100 years of no disturbance. Two indices of evenness, i.e. Pielou’s and Simpson’s were also calculated in this study. Results here presented suggest that plant species composition, percent cover of individual plant species, and the Simpson’s diversity index (applied considering the different growth-forms and vertical layers) are suitable and complementary indices to evaluate disturbance at the studied woodlands.

Vegetation diversity and vertical structure as indicators of forest disturbance

Plant species composition and vertical structure of oak-mixed Atlantic woodlands differing on disturbance regime were studied in the Basque Country, northern Spain. Four different disturbance groups were considered depending on the time since last thinning and the presence/absence of grazers. Plant species cover varied among disturbance groups for 17 out of the total 47 species present in the study area. In general, disturbance by clear-cutting favoured the cover of Betula alba, Castanea sativa and Quercus robur. The shrub species most affected by disturbance were heathers. Among these, the most drastic effect was found for Calluna vulgaris, Daboecia cantabrica and Erica vagans which disappeared in those woodlands subjected to grazing. Several nemoral species, such as Vaccinium myrtillus, Blechnum spicant and Lamiastrum galeobdolon, were absent in these same grazed forests. By contrast, generalist species, such as Ruscus aculeatus, Geranium robertianum and Veronica officinalis, were mostly present in the grazed woodlands. Diversity was measured as Species Richness as well as with the Shannon’s and Simpson’s indices. Plant species richness did not vary with disturbance treatment, however, it was highest for trees and shrubs at those woodlands in an advanced stage of regeneration, and for herbs in the lowest and highest disturbance groups. Besides, only the third vertical layer (2.5–10 m) was affected by disturbance treatment. Simpson’s was the best index to explain the observed differences in the structure of woodlands subjected to unalike levels of disturbance. Species diversity was highest in woodlands with lowest disturbance or in an advanced state of regeneration. Woodlands with lowest disturbance had the highest diversity of trees and those woodlands in an advanced state of regeneration showed the highest diversity of shrub species. Regarding vertical structure, diversity was mostly affected in the intermediate layer (2.5–10 m), with highest values found in woodlands at the lowest disturbance group, i.e. at least 100 years of no disturbance. Two indices of evenness, i.e. Pielou’s and Simpson’s were also calculated in this study. Results here presented suggest that plant species composition, percent cover of individual plant species, and the Simpson’s diversity index (applied considering the different growth-forms and vertical layers) are suitable and complementary indices to evaluate disturbance at the studied woodlands.

Effects of two silvicultural practices on ground beetles (Coleoptera: Carabidae) in a northern hardwood forest, Quebec, Canada

The impact of selective cutting (6 and 8 years after treatment) and strip clear-cutting (12 and 13 years after treatment) on abundance and diversity of carabid beetles was evaluated in a northern hardwood forest of Quebec, Canada. A total of 1078 individuals belonging to 14 species were captured with pitfall traps from June to September 1996 during 2568 day-trap. Abundance of Synuchus impunctatus Say was significantly higher in clear-cut compared with uncut control strips. There were no within-species differences between selectively cut and uncut plots. None of these two silvicultural systems had any significant impacts on species diversity and richness 6–13 years after treatment. Although we observed an effect of strip clear-cutting on the abundance of S. impunctatus in this northern hardwood forest, the discrepancy between the response of carabids to forest disturbance in this study compared with other studies in different ecological regions suggests that the same carabid beetle species cannot be used as an indicator of forest disturbance over a large region. Our results suggest the use of carabid beetles as a disturbance indicator at the ecological-type scale (relatively similar soil and forest type) in a given region.

A Comparison of the Phyllostomid Bat Assemblages in Undisturbed Neotropical Forest and in Forest Fragments of a Slash‐and‐Burn Farming Mosaic in Petén, Guatemala1

ABSTRACTUsing mist nets, we compared phyllostomid bat ensembles of continuous mature forest in Tikal National Park, Guatemala, and of forest fragments in the nearby farming landscape. Of 20 species captured, 13 were shared between treatments, 4 were unique to continuous forest, and 3 were unique to forest fragments. Dominance–diversity curves were similar for the two treatments except that Sturnira lilium comprised 43 percent of captures in the forest fragments, resulting in greater dominance there. Capture rates (and presumably relative abundance) differed significantly between continuous forest and forest fragments, both in terms of species and feeding guilds. Sturnia lilium and Dermanura sp. were captured significantly more often in forest fragments than in continuous forest, whereas Artibeus jamaicensis, A. lituratus, and Centurio senex were taken significantly more often in continuous forest. Large frugivores accounted for a higher proportion of total captures in continuous forest than in forest fragments, whereas small frugivores showed the opposite pattern. By their abundances, Carollia perspicillata and S. lilium are indicators of forest disturbance. The relative abundances of large frugivores, which feed on large fruits of mature forest trees, and small frugivores, which feed on small‐fruited plants occurring in early succession, are an indicator of forest disturbance. Other groups, such as large insect‐ and vertebrate‐eating bats, because of their low capture rates, are impractical as indicators for rapid assessment of forest disturbance based on mist netting, but may prove especially vulnerable to forest fragmentation.

A Comparison of the Phyllostomid Bat Assemblages in Undisturbed Neotropical Forest and in Forest Fragments of a Slash-and-Burn Farming Mosaic in Petén, Guatemala1

Using mist nets, we compared phyllostomid bat ensembles of continuous mature forest in Tikal National Park, Guatemala, and of forest fragments in the nearby farming landscape. Of 20 species captured, 13 were shared between treatments, 4 were unique to continuous forest, and 3 were unique to forest fragments. Dominance–diversity curves were similar for the two treatments except that Sturnira lilium comprised 43 percent of captures in the forest fragments, resulting in greater dominance there. Capture rates (and presumably relative abundance) differed significantly between continuous forest and forest fragments, both in terms of species and feeding guilds. Sturnia lilium and Dermanura sp. were captured significantly more often in forest fragments than in continuous forest, whereas Artibeus jamaicensis, A. lituratus, and Centurio senex were taken significantly more often in continuous forest. Large frugivores accounted for a higher proportion of total captures in continuous forest than in forest fragments, whereas small frugivores showed the opposite pattern. By their abundances, Carollia perspicillata and S. lilium are indicators of forest disturbance. The relative abundances of large frugivores, which feed on large fruits of mature forest trees, and small frugivores, which feed on small-fruited plants occurring in early succession, are an indicator of forest disturbance. Other groups, such as large insect- and vertebrate-eating bats, because of their low capture rates, are impractical as indicators for rapid assessment of forest disturbance based on mist netting, but may prove especially vulnerable to forest fragmentation.

Measuring disturbance in tropical forests: a critique of the use of species–abundance models and indicator measures in general

Recent papers have considered the merits or otherwise of using species-abundance models to detect disturbance in tropical forests (Hill et al. 1995; Hamer et al. 1997; Nummelin 1998; Hill & Hamer 1988). The purpose of this paper is to argue: (1) that there are simpler, more reliable ways of assessing forest disturbance; and (2) that the use of species-abundance models to assess whether a forest is disturbed or not ignores the different types, degrees and scales of disturbance that exist, each of which potentially have a different impact on forest biodiversity. Tropical forest biodiversity is undeniably threatened. Although estimates on the number of species in tropical forests vary greatly, there is a widespread assumption that at least half the world's species are concentrated in only 7% of the terrestrial land mass (e.g. Stork 1988; Myers 1990; Bibby et al. 1992; World Conservation Monitoring Centre 1992). As Hill et al. (1995), Hamer et al. (1997) and many others point out, tropical forest species are threatened by logging and forest clearance for a range of purposes, from the establishment of small farms as part of the practice of shifting cultivation to the large scale clearance of forest for pasture and plantation crops of exotic timber tree species, rubber, oil palm, and many other crops. Shifting cultivation and logging have been practiced in tropical forests for thousands of years, but the area partially or wholly cleared for these purposes has increased dramatically during the twentieth century (Phillips 1997). Thus, many authors rightly argue that there is an urgent need for more research on the impact of forest disturbance on biodiversity (e.g. Phillips 1997; Watt et al. 1997). In fact Hill & Hamer (1998) justify the development of methods of assessing whether or not a forest is disturbed as a precursor to the measurement of the impact of forest disturbance on tropical forest communities. Hill et al. (1995) first suggested that species-abundance models could be used to indicate forest disturbance after finding that butterfly data from an unlogged area of forest on Buru, Indonesia, fitted a log-normal distribution, whereas the data for an area of logged forest did not. Nummelin (1998) tested the applicability of species-abundance models as indicators of disturbance by studying ladybirds (Coccinellidae), tortoise beetles (Cassidinae), dung beetles and plants in forest near Kibale, Uganda. Nummelin found that the species-abundance distributions fitted a log-normal distribution irrespective of whether they came from logged or unlogged forest. In a more recent paper on Indonesian butterflies (and therefore not available to Nummelin at the time of preparing his paper), Hamer et al. (1997) again showed that speciesabundance data collected in Sumba, Indonesia, were affected by forest disturbance, although in this case only the butterflies in the most disturbed of three disturbed forest sites sampled showed a log-normal distribution. Hill & Hamer (1998) respond to Nummelin by listing a number of requirements that should be met for assessing the usefulness of species-abundance models as indicators of forest disturbance. The purpose of this paper is not primarily to prolong the discussion on the usefulness of species-abundance models as indicators of disturbance. However, it is worth noting that the restrictions in the use of species-abundance models described by Hill & Hamer imply that this technique cannot be regarded as an easy 'instantaneous indicator of forest disturbance' (Hamer et al. 1997), but at best must be applied cautiously. In addition, although Hill et al. (1995) found that the presence of a log-normal distribution distinguished disturbed from undisturbed forest, data from only one of the three disturbed forest sites sampled by Hamer et al. (1997) showed a log-normal distribution. A more important point, however, is that it is surely unnecessary to sample butterflies to assess whether or not a forest has been disturbed. It is, of course, possible to detect extreme disturbance in the form of complete deforestation, both from the ground and from satellite (e.g. INPE 1997). Less severe disturbance in the form of selective logging may also be assessed through the presence of logging roads and trails; the soil compaction caused by the removal of logs resulting in poor growth of vegetation over long periods of time (e.g. Pinard, Howlett & Davidson 1996; Guariguata & Dupuy 1997; Whitman, Brokaw & Hagan 1997). For example, Nummelin (1998) noted that '1520 years after logging, logged areas were still easily recognizable due to the large gaps in the canopy' and

Ecological and biogeographical effects of forest disturbance on tropical butterflies of Sumba, Indonesia

ABSTRACT. Butterfly assemblages within lowland monsoon forest were compared at four sites on Sumba, Indonesia that differed in terms of protection and exhibited associated differences in levels of human disturbance. A numerical method employing principal components analysis was devised for describing forest structure at each site. The first principal component (PRIN1) grouped attributes tending towards dense forest with closely‐spaced trees, a closed canopy and a poorly developed field layer, with trees that tended to be large with the point of inversion in the upper half of the trunk. The highest values for PRIN1 were recorded within protected forest, and PRIN1 values were considered to be a useful index of forest disturbance at each site. Species diversity of butterflies was highest in unprotected secondary forest, but was not affected by lower levels of disturbance. Those species occurring at highest density in secondary forest generally had wide geographical distributions, whereas those species occurring at highest density in undisturbed primary forest had restricted ranges of distribution, in most cases with a separate subspecies on Sumba. Overall, an index of biogeographical distinctiveness decreased with increasing disturbance, and this supports the hypothesis that the most characteristic species of undisturbed climax forest have the smallest geographical ranges of distribution. Species abundance data for butterflies fitted a log‐normal distribution at all but the most disturbed site. These results indicate that the pattern of proportional abundance of tropical butterfly species may be used as an ‘instantaneous’ indicator of forest disturbance, and that changes in the structure of tropical forests in S.E. Asia resulting from human disturbance, even within partially‐protected forest, may result in the presence of butterfly assemblages of higher species diversity but of lower biogeographical distinctiveness, and therefore of lower value in terms of the conservation of global biodiversity.

Effects of Selective Logging on Tropical Forest Butterflies on Buru, Indonesia

1. The butterfly fauna of lowland monsoon forest on Buru, Indonesia was compared in unlogged forest and forest that had been selectively logged 5 years previously. 2. Seven variables relating to vegetation structure were measured in each habitat. Tree density and percentage cover of vegetation in the canopy and understorey were significantly higher, and vegetation cover 2 m above the ground was significantly lower, in unlogged forest. There were no differences between sites in the mean heights or girths of trees, but the ranges of both heights and girths were lower in logged forest. Percentage cover of vegetation at ground level was similar at the two sites. 3. Species richness, abundance and evenness of butterflies and an index of taxonomic distinctiveness were all significantly higher in unlogged forest. Two endemic species and a further four species with distributions restricted to Maluku Province were recorded only in unlogged forest. 4. Species abundance data for butterflies at both sites fitted a log-series distribution. Data for unlogged forest also fitted a log-normal distribution, whereas those for logged forest did not. This indicated the presence of a more complex butterfly community in unlogged forest. 5. These results indicate that the distributional pattern of species abundance of tropical butterflies may be used as an indicator of forest disturbance, and that selective logging of tropical forests in SE Asia may be associated with a significant decrease in biodiversity of butterflies, at least during the first 5 years of forest regeneration.