湖南蝶类研究

湖南蝶类共有158种,区系组成以东洋成分为主体,其次为东洋与古北共有成分.建议在4个方面加强利用研究,以促进湖南经济发展.表1,参6.     

A Realistic Assessment of the Indicator Potential of Butterflies and Other Charismatic Taxonomic Groups

Abstract:  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 .     

Ecological Correlates of Extinction Proneness in Tropical Butterflies

Abstract:  Widespread and rapid losses of natural habitats and biodiversity have made the identification of extinction-prone species a major challenge in conservation biology. We assessed the relative importance of biologically relevant species traits (e.g., body size, ecological specialization) obtained from published records to determine the extinction probability of butterflies in a highly disturbed tropical landscape (i.e., Singapore). We also developed a taxon-specific model to estimate the extinction proneness of butterflies in Southeast Asia. Logistic regression analyses showed that adult habitat specialization, larval host plant specificity, geographical distribution, sexual dichromatism, and congenor density were significant and independent determinants of butterfly extinctions in Singapore. Among these traits, specificity of larval host plant and adult habitat specialization were the best correlates of extinction risks. We used this phenomenological extinction-regression model to estimate the relative extinction proneness of 416 butterfly species in Southeast Asia. Our results illustrate the utility of available taxon-specific data for a localized area in estimating the extinction proneness of closely related species on a regional scale. When intensive field studies are not forthcoming, especially in regions suffering from rapid biodiversity losses (e.g., Southeast Asia), similar approaches could be used to estimate extinction threats for other taxonomic groups.     

Techniques and Guidelines for Monitoring Neotropical Butterflies

Long-term monitoring of selected species can identify changes in biological diversity, permitting the timely adjustment of management activities to reverse or avoid undesired trends. This paper addresses several related issues bearing on the development of inexpensive and easily implemented monitoring programs for tropical butterflies. First, we discuss the use of butterflies as ecological indicators. Next, we present field evaluations of butterfly sampling techniques, indicating that: (1) light-gap size greatly affects sampling results in forests and should be of critical concern in site selection and sampling design; (2) baited traps and visual censuses provide complementary data on butterfly abundances; (3) monitoring a subset of locally common butterfly species can provide data for comparing community composition and relative abundance of species in areas where species inventories are incomplete. Drawing on these results, we develop guidelines for designing monitoring programs. These address the formulation of explicit questions to be addressed through monitoring and the selection of appropriate study sites, study species, sampling techniques, and sampling frequency. A protocol for the ongoing butterfly monitoring program that emerged from these studies is appended. The techniques and guidelines presented here are intended to serve as an adaptable model for biologists designing monitoring projects to help guide applied conservation efforts in the tropics.     

Determining Optimal Population Monitoring for Rare Butterflies

Abstract: Determining population viability of rare insects depends on precise, unbiased estimates of population size and other demographic parameters. We used data on the endangered St. Francis' satyr butterfly (Neonympha mitchellii francisci) to evaluate 2 approaches (mark–recapture and transect counts) for population analysis of rare butterflies. Mark–recapture analysis provided by far the greatest amount of demographic information, including estimates (and standard errors) of population size, detection, survival, and recruitment probabilities. Mark–recapture analysis can also be used to estimate dispersal and temporal variation in rates, although we did not do this here. Models of seasonal flight phenologies derived from transect counts (Insect Count Analyzer) provided an index of population size and estimates of survival and statistical uncertainty. Pollard–Yates population indices derived from transect counts did not provide estimates of demographic parameters. This index may be highly biased if detection and survival probabilities vary spatially and temporally. In terms of statistical performance, mark–recapture and Pollard–Yates indices were least variable. Mark–recapture estimates were less likely to fail than Insect Count Analyzer, but mark–recapture estimates became less precise as sampling intensity decreased. In general, count‐based approaches are less costly and less likely to cause harm to rare insects than mark–recapture. The optimal monitoring approach must reconcile these trade‐offs. Thus, mark–recapture should be favored when demographic estimates are needed, when financial resources enable frequent sampling, and when marking does not harm the insect populations. The optimal sampling strategy may use 2 sampling methods together in 1 overall sampling plan: limited mark–recapture sampling to estimate survival and detection probabilities and frequent but less expensive transect counts.     

Effect of Experimental Selective Logging on Tropical Butterflies

Abstract: I investigated the effects of an experimental selective logging regime on the assemblage of fruit-feeding butterflies in replicated experimental plots in the Chiquibul Forest, Belize. Over a 12-month period, I caught 1187 individuals of 49 species using fruit-baited traps. Selective logging at densities of six stems per ha 3 years before the study had little effect on butterfly species richness, the abundance of individual species, or the shape of species-abundance distributions. There was no tendency for taxa with restricted geographical ranges to be particularly sensitive to selective logging. Mark-release-recapture results suggest that most butterflies move relatively short distances, but that some dispersal occurs between plots separated by distances of ≥1 km. The apparent similarity of the fruit-feeding butterfly assemblage in selectively logged and unlogged forest contrasts with previous studies of butterfly assemblages but mirrors results for birds in the same plots. A possible explanation is the high frequency of natural disturbance—hurricanes and associated fires—in the Chiquibul Forest. The species present appear to be adapted to naturally disturbed habitats and may therefore be relatively unaffected by selective logging. Local studies of the effects of selective logging must take into account the history of natural and human disturbance in the study area. The results support the case for "ecological forestry," in which sustainable management regimes work within the limits imposed by natural disturbance.     

Effects of Selective Logging on the Butterflies of a Bornean Rainforest

Abstract: Selective logging has been the main cause of disturbance to tropical forests in Southeast Asia, so the extent to which biodiversity is maintained in selectively logged forest is of prime conservation importance. We compared the butterfly assemblages of Bornean primary rainforest to those of rainforest selectively logged 6 years previously. We sampled by means of replicated transects stratified into riverine and ridge forests and we included roads in the logged forest. There was a three-fold variation in species richness and abundance over the 8-month sampling period. More species and individuals were observed in the logged forest, although between-replicate variability was high. Rarefied species richness was positively correlated with canopy openness within the range of disturbance levels encountered at our forest sites. Within families, there was no significant difference in the number of species between primary and logged forest. There was a significant difference in the relative abundance of species, but this was due largely to the abundance of one or two species. Community ordination separated the sites along a gradient of disturbance and revealed strong differences between riverine and ridge-forest butterfly assemblages in primary forest that were obscured in logged forest. There was no evidence that logging has resulted in a change in the composition of the butterfly assemblages from species with a local distribution to more widespread species. We conclude that at a logged forest site in close proximity to primary forest, low intensities of logging do not necessarily reduce the species richness or abundance of butterflies, although assemblage composition is changed.     

Declines in Common, Widespread Butterflies in a Landscape under Intense Human Use

Abstract:  Analyses of species' population losses typically show a dichotomy between strongly affected, rare, and localized species and apparently unaffected, common, and widespread species. We analyzed 16 years (1992–2007) of butterfly transect count data from The Netherlands in a reevaluation of the trends of common, widespread species. Fifty-five percent (11 of 20 species) of these species suffered severe declines in distribution and abundance. Overall, cumulative butterfly abundance declined by around 30%. Some of the species in decline used to be omnipresent in gardens and parks, and 2 of the species were previously considered agricultural pests. Based on their declines over the last 16 years, 2 of the 20 species ( Lasiommata megera and Gonepteryx rhamni ) reached endangered status in The Netherlands under the IUCN (International Union for Conservation of Nature) population-decline criterion, and 2 species ( Inachis io and Thymelicus lineola ) met vulnerable criterion. Butterflies in farmland, urban, and particularly woodland areas showed the largest decline in species abundance. The abundance of species associated with vegetation types found mainly in nature reserves (dunes, heathland, and, to a lesser extent, seminatural grassland) increased or remained stable. The decline of widespread species requires additional conservation strategies in the wider landscape.     

Transferability of Species Distribution Models: a Functional Habitat Approach for Two Regionally Threatened Butterflies

Abstract:  Numerous models for predicting species distribution have been developed for conservation purposes. Most of them make use of environmental data (e.g., climate, topography, land use) at a coarse grid resolution (often kilometres). Such approaches are useful for conservation policy issues including reserve-network selection. The efficiency of predictive models for species distribution is usually tested on the area for which they were developed. Although highly interesting from the point of view of conservation efficiency, transferability of such models to independent areas is still under debate. We tested the transferability of habitat-based predictive distribution models for two regionally threatened butterflies, the green hairstreak ( Callophrys rubi ) and the grayling ( Hipparchia semele ), within and among three nature reserves in northeastern Belgium. We built predictive models based on spatially detailed maps of area-wide distribution and density of ecological resources. We used resources directly related to ecological functions (host plants, nectar sources, shelter, microclimate) rather than environmental surrogate variables. We obtained models that performed well with few resource variables. All models were transferable—although to different degrees—among the independent areas within the same broad geographical region. We argue that habitat models based on essential functional resources could transfer better in space than models that use indirect environmental variables. Because functional variables can easily be interpreted and even be directly affected by terrain managers, these models can be useful tools to guide species-adapted reserve management.     

Modeling and Predicting Species Occurrence Using Broad-Scale Environmental Variables: an Example with Butterflies of the Great Basin

Abstract: If occurrence of individual species can be modeled as a function of easily quantified environmental variables (e.g., derived from a geographic information system [GIS]) and the predictions of these models are demonstrably successful, then the scientific foundation for management planning will be strengthened. We used Bayesian logistic regression to develop predictive models for resident butterflies in the central Great Basin of western North America. Species inventory data and values for 14 environmental variables from 49 locations (segments of canyons) in the Toquima Range ( Nevada, U.S.A.) were used to build the models. Squares of the environmental variables were also used to accommodate possibly nonmonotonic responses. We obtained statistically significant models for 36 of 56 (64%) resident species of butterflies. The models explained 8–72% of the deviance in occurrence of those species. Each of the independent variables was significant in at least one model, and squared versions of five variables contributed to models. Elevation was included in more than half of the models. Models included one to four variables; only one variable was significant in about half the models. We conducted preliminary tests of two of our models by using an existing set of data on the occurrence of butterflies in the neighboring Toiyabe Range. We compared conventional logistic classification with posterior probability distributions derived from Bayesian modeling. For the latter, we restricted our predictions to locations with a high ( 70%) probability of predicted presence or absence. We will perform further tests after conducting inventories at new locations in the Toquima Range and nearby Shoshone Mountains, for which we have computed environmental variables by using remotely acquired topographic data, digital-terrain and microclimatic models, and GIS computation.     

Open Corridors Appear to Facilitate Dispersal by Ringlet Butterflies (Aphantopus hyperantus) between Woodland Clearings

We studied the ringlet butterfly (Aphantopus hyperantus) in an area of woodland in eastern England. A. hyperantus occurs in open fields, rides (grassy tracks), and glades within the woodland. Mark-recapture methods showed that exchange rates of adult A. hyperantus between fields and glades can be predicted better by distance-via-rides than by direct distance. Behavioral observations showed that A. hyperantus readily moved from glades into rides but rarely moved from glades into dense woodland. The rides are likely to be corridors that act as conduits between fields and glades. In the A. hyperantus system, connectivity could reduce local extinctions and increase rates of recolonization in the event of local extinction.     

Cars, Cows, and Checkerspot Butterflies: Nitrogen Deposition and Management of Nutrient-Poor Grasslands for a Threatened Species

Abstract: Nutrient-poor, serpentinitic soils in the San Francisco Bay area sustain a native grassland that supports many rare species, including the Bay checkerspot butterfly ( Euphydryas editha bayensis ). Nitrogen (N) deposition from air pollution threatens biodiversity in these grasslands because N is the primary limiting nutrient for plant growth on serpentinitic soils. I investigated the role of N deposition through surveys of butterfly and plant populations across different grazing regimes, by literature review, and with estimates of N deposition in the region. Several populations of the butterfly in south San Jose crashed following the cessation of cattle grazing. Nearby populations under continued grazing did not suffer similar declines. The immediate cause of the population crashes was rapid invasion by introduced annual grasses that crowded out the larval host plants of the butterfly. Ungrazed serpentinitic grasslands on the San Francisco Peninsula have largely resisted grass invasions for nearly four decades. Several lines of evidence indicate that dry N deposition from smog is responsible for the observed grass invasion. Fertilization experiments have shown that soil N limits grass invasion in serpentinitic soils. Estimated N deposition rates in south San Jose grasslands are 10–15 kg  N/ha/year; Peninsula sites have lower deposition, 4–6 kg N/ha/year. Grazing cattle select grasses over forbs, and grazing leads to a net export of N as cattle are removed for slaughter. Although poorly managed cattle grazing can significantly disrupt native ecosystems, in this case moderate, well-managed grazing is essential for maintaining native biodiversity in the face of invasive species and exogenous inputs of N from nearby urban areas.     

A Hierarchical View of Genetic Structure in the Rare Annual Plant Clarkia springvillensis

Genetic structure at several spatial scales was examined in the rare California annual, Clarkia springvillensis . Using seven isozyme-encoding loci as genetic markers, we assessed the amount and distribution of genetic variation among three populations and eight subpopulations. Total genetic variation was lower than in species with similar life history traits but equivalent to that of other endemic plants. Spatial autocorrelation showed some evidence for very limited differentiation within subpopulations at a scale of 1–2 m. The subpopulations, separated by tens of meters, were found to be more differentiated from each other ( F _sp = 0.084) on average than were populations ( F,pt = 0.017). This local genetic differentiation was not correlated with physical distance between subpopulations. The low F_pt estimates suggest that substantial gene flow is occurring among populations. However, the lack of correlation between genetic and geographic distances and the significant differentiation of subpopulations suggest that genetic drift is occurring within populations. Therefore, we believe the apparent homogeneity of populations is due to each population's gene frequencies' being an average of several divergent subpopulations. If drift is causing differentiation within populations, it may eventually cause differentiation between populations. The importance of using a hierarchical approach to evaluating genetic structure is clear. Patterns occurring at one spatial scale may not be evident at others. One should not necessarily conclude that gene flow is substantial and that the risk of genetic erosion via drift is negligible just because differentiation between populations is small; the system may not be at equilibrium. This lesson is particularly important when recent changes in climate or land use are apparent.