Occurrence patterns of butterflies (Rhopalocera) in semi-natural pastures in southeastern Sweden

Low-intensity agricultural landscapes in Transylvania support high butterfly diversity: implications for conservation

European farmland biodiversity is declining due to land use changes towards agricultural intensification or abandonment. Some Eastern European farming systems have sustained traditional forms of use, resulting in high levels of biodiversity. However, global markets and international policies now imply rapid and major changes to these systems. To effectively protect farmland biodiversity, understanding landscape features which underpin species diversity is crucial. Focusing on butterflies, we addressed this question for a cultural-historic landscape in Southern Transylvania, Romania. Following a natural experiment, we randomly selected 120 survey sites in farmland, 60 each in grassland and arable land. We surveyed butterfly species richness and abundance by walking transects with four repeats in summer 2012. We analysed species composition using Detrended Correspondence Analysis. We modelled species richness, richness of functional groups, and abundance of selected species in response to topography, woody vegetation cover and heterogeneity at three spatial scales, using generalised linear mixed effects models. Species composition widely overlapped in grassland and arable land. Composition changed along gradients of heterogeneity at local and context scales, and of woody vegetation cover at context and landscape scales. The effect of local heterogeneity on species richness was positive in arable land, but negative in grassland. Plant species richness, and structural and topographic conditions at multiple scales explained species richness, richness of functional groups and species abundances. Our study revealed high conservation value of both grassland and arable land in low-intensity Eastern European farmland. Besides grassland, also heterogeneous arable land provides important habitat for butterflies. While butterfly diversity in arable land benefits from heterogeneity by small-scale structures, grasslands should be protected from fragmentation to provide sufficiently large areas for butterflies. These findings have important implications for EU agricultural and conservation policy. Most importantly, conservation management needs to consider entire landscapes, and implement appropriate measures at multiple spatial scales.

Local change of butterfly species in response to global warming and reforestation in Korea

Background

It is expected that the successful nationwide reforestation and global warming will greatly change the butterfly fauna in South Korea. We compared current data (2002 to 2007) regarding the abundance and presence of butterfly species at two sites in the central portion of the Korean Peninsula with similar data from the late 1950s and early 1970s for the same sites. The expected changes were documented by an abundance change of butterflies at the two study sites in a previous study. Using the same data, the most greatly changed species and the change of species presence were analyzed.

Results

Population changes of 99 butterfly species which occurred at both sites were significantly correlated between the two sites. The greatly increased species included three southern (S) species and one northern (N) species. However, the species showing great decline included five N species and no S species.

Conclusions

This change is consistent with the expectation of northward movement of butterfly species due to global warming. The current status of the greatly changed species is discussed along with other studies. The binary data (presence/absence) in the present study support the expected changes of butterfly species based on global warming and reforestation. The interactive effect of two environmental changes was also recognized, as well as the change of abundance in the previous study.

A realistic assessment of the indicator potential of butterflies and other charismatic taxonomic groups

Charismatic groups of animals and plants often are proposed as sentinels of environmental status and trends. Nevertheless, many claims that a certain taxonomic group can provide more-general information on environmental quality are not evaluated critically. To address several of the many definitions of indicator species, we used butterflies to explore in some detail the attributes that affect implementation of indicators generically. There probably are few individual species, or sets of species, that can serve as scientifically valid, cost-effective measures of the status or trend of an environmental phenomenon that is difficult to measure directly. Nevertheless, there are species with distributions, abundances, or demographic characteristics that are responsive to known environmental changes. In this context, single or multiple species can serve as indicators when targets are defined explicitly, ecological relationships between the target and the putative indicators are well understood, and data are sufficient to differentiate between deterministic and stochastic responses. Although these situations exist, they are less common than might be apparent from an extensive and often confounded literature on indicators. Instead, the public appeal of charismatic groups may be driving much of their acclaim as indicators. The same taxon may not be appropriate for marketing a general conservation mission and for drawing strong inference about specific environmental changes. To provide insights into the progress of conservation efforts, it is essential to identify scientific and practical criteria for selection and application of indicators and then to examine whether a given taxonomic group meets those criteria.