Changes in Alpine Butterfly Communities during the Last 40 Years

Our work aims to assess how butterfly communities in the Italian Maritime Alps changed over the past 40 years, in parallel with altitudinal shifts occurring in plant communities. In 2019, we sampled butterflies at 7 grassland sites, between 1300–1900 m, previously investigated in 2009 and 1978, by semi-quantitative linear transects. Fine-scale temperature and precipitation data elaborated by optimal interpolation techniques were used to quantify climate changes. The changes in the vegetation cover and main habitat alterations were assessed by inspection of aerial photographs (1978–2018/1978–2006–2015). The vegetation structure showed a marked decrease of grassland habitats and an increase of woods (1978–2009). Plant physiognomy has remained stable in recent years (2009–2019) with some local exceptions due to geomorphic disturbance. We observed butterfly ‘species substitution’ indicating a general loss in the more specialised and a general gain in more tolerant elements. We did not observe any decrease in species richness, but rather a change in guild compositions, with (i) an overall increased abundance in some widespread and common lowland species and (ii) the disappearance (or strong decrease) of some alpine (high elevation) species, so that ‘resilience’ could be just delusive. Changes in butterfly community composition were consistent with predicted impacts of local warming.

Abandonment of cultural landscapes: butterfly communities track the advance of forest over grasslands

Rural landscapes in Europe have suffered considerable land-use change in the last 50 years, with agricultural intensification in western regions and land abandonment in eastern and southern regions. The negative impacts of agricultural intensification on butterflies and other insects in western Europe have been well studied. However, less is known about the impacts of abandonment on mountain and humid areas of eastern and southern Europe, where landscapes have remained more natural. We sampled butterfly communities in the Picos de Europa National Park (Spain), a region which is undergoing a process of rural abandonment. 19 hay meadows with different periods of abandonment were studied (long-term 18 years or mid-term abandoned, 3–7 years) and compared to meadows continuously managed in a traditional way. We examined how local meadow characteristics and landscape variables affected butterfly community response to abandonment. Butterfly communities were affected by abandonment, with an overall increase in the density of individuals in the long term. Community composition appears to undergo major change over time, with a species turnover of around 50% in the first few years of abandonment, rising to around 70% after 18 years of abandonment. There was a tendency for species with higher preference for closed habitats to increase their densities as time since abandonment proceeded. Landscape variables had a major impact on butterfly communities, stronger than the effect of meadow management. Community preference for closed habitats was associated with higher forest cover in the surroundings of the meadows, but heterogeneous landscapes (in their composition or configuration) mitigated this effect. Implications for insect conservation Our findings suggest that we should ensure that communities have time to react to the diverse stressors imposed by global change. Facilitating survival to all kinds of functional and taxonomic groups implies promoting landscape heterogeneity and connectivity.

Butterfly communities (Insecta: Lepidoptera) at two recreational areas in Sungai Petani, Kedah, Peninsular Malaysia

Basri NIA, Zakaria N. 2021. Butterfly communities (Insecta: Lepidoptera) at two recreational areas in Sungai Petani, Kedah, Peninsular Malaysia. Biodiversitas 22: 5039-5047. The knowledge on the butterfly diversity, especially in various habitats in Kedah is still poor. A study was conducted to determine and compare the diversity of butterflies at two recreational areas in Sungai Petani, Kedah, namely Bukit H and Taman Jubli Perak. This study was carried out starting from January 2021 until March 2021 with a total of nine sampling occasions at each site. Visual Encounter Survey (VES) was chosen as a sampling method. The butterflies were captured using a sweep net from 9am to 11am and 12pm to 2pm for each sampling site. A total of 145 individuals from 13 species from four families of butterflies were recorded. The most abundant species were recorded from the family Nymphalidae. Chilades pandava was the most abundant species obtained from the two recreational areas. From the t-test analysis, there was no significant difference between the diversity of Bukit H and Taman Jubli Perak. Shannon and Simpson's diversity indices showed both sites were interpreted as moderately low in diversity. This may be due to the different types of vegetation that exist at both sampling sites. This study will contribute to the first record of butterflies in Sungai Petani, Kedah, Peninsular Malaysia.

Local Habitat Characteristics Determine Butterfly Diversity and Community Structure in a Threatened Kihansi Gorge Forest, Southern Udzungwa Mountains, Tanzania

Background Many species inhabiting Kihansi gorge ecosystem in Southern Udzungwa mountains, Tanzania are threatened with extinction due to habitat loss caused by constructed hydropower plant that diverted over 90% of the water off the Kihansi River. Understanding ecological correlates and structure of an animal community in perturbed ecosystems is an important way to enhancing species conservation particularly in this system where several species are already threatened with extinction. This study assessed influences of local habitat characteristics on the butterfly abundance, species richness and diversity and examined how the butterfly community structures across three structurally heterogeneous habitats in the Kihansi gorge forest. Butterfly abundance data were collected using baited traps and measured environmental variables in the field where trapping occurred. To understand the diversity and butterfly richness, these parameters were computed under Primer software. Non-metric multidimensional scaling and analysis of community similarity were used to analyse the butterfly community structure. Further, the generalized linear models were used to assess how the measured variables explained observed species diversity, abundance, and richness. Results In total, 72 species of butterfly in five families were recorded. Butterfly, species diversity and richness did not vary across the habitat types or elevation gradient but showed strong correlation with some habitat characteristics. Also, there was evidence of butterfly communities structuring into distinct groups that showed greater separation associated with the habitat characteristics they utilise. Further, across the study area, butterfly species diversity was mostly likely to increase in high canopy and in trees with smaller diameter at breast height and at lower ground cover. Similarly, abundance significantly increased in the woodland and wooded grassland habitats, where there was high canopy and where tree density was high. Furthermore, butterfly species richness was strongly positively associated with high canopy cover and was mostly likely to increase in sites closer to water source. Conclusion Assessing habitat correlates of the butterfly communities provide important information on what components of the habitats are most useful to target when planning conservation especially in threatened ecosystems. This also helps to reveal existing gaps in important knowledge that would be useful to improving long-term monitoring of biodiversity in in fragile systems such as the Kihansi gorge forest.

Diversity pattern of butterfly communities (Lepidoptera) in different habitat types of Nahan, Himachal Pradesh, India

Diversity and similarity of butterfly communities were assessed in three different habitat types in the mountains of Nahan, Himachal Pradesh, from May 2012 to April 2013. A total of 75 species and five families were reported. Proportion of species was highest in deciduous dry forest (49%), followed by Shorea (Saal) forest (34%), and Pinus (Cheer) forest (17%). Family Pieridae was dominant followed by Nymphalidae in all three habitat types. Cluster analysis revealed that Cheer forest stood out clearly from Dry and Saal forest which represents the different species composition. We found significant differences in butterfly diversity in the three forest types based on Shannon index, Simpson dominance index, and Buzas & Gibson’s evenness. These differences may be attributable to variations in host and nectar plant distribution. Of the habitats surveyed, dry deciduous forest appeared to be the most suitable for butterfly conservation.

Knowledge gaps hamper understanding the relationship between fragmentation and biodiversity loss: the case of Atlantic Forest fruit-feeding butterflies

Background A key challenge for conservation biology in the Neotropics is to understand how deforestation affects biodiversity at various levels of landscape fragmentation. Addressing this challenge requires expanding the coverage of known biodiversity data, which remain to date restricted to a few well-surveyed regions. Here, we assess the sampling coverage and biases in biodiversity data on fruit-feeding butterflies at the Brazilian Atlantic Forest, discussing their effect on our understanding of the relationship between forest fragmentation and biodiversity at a large-scale. We hypothesize that sampling effort is biased towards large and connected fragments, which occur jointly in space at the Atlantic forest. Methods We used a comprehensive dataset of Atlantic Forest fruit-feeding butterfly communities to test for sampling biases towards specific geographical areas, climate conditions and landscape configurations. Results We found a pattern of geographical aggregation of sampling sites, independently of scale, and a strong sampling bias towards large and connected forest fragments, located near cities and roads. Sampling gaps are particularly acute in small and disconnected forest fragments and rare climate conditions. In contrast, currently available data can provide a fair picture of fruit-feeding butterfly communities in large and connected Atlantic Forest remnants. Discussion Biased data hamper the inference of the functional relationship between deforestation and biodiversity at a large-scale, since they are geographically clustered and have sampling gaps in small and disconnected fragments. These data are useful to inform decision-makers regarding conservation efforts to curb biodiversity loss in the Atlantic Forest. Thus, we suggest to expand sampling effort to small and disconnected forest fragments, which would allow more accurate evaluations of the effects of landscape modification.