Butterfly-plant interactions and body size patterns along an elevational gradient in the Manang region of central Nepal

Butterflies are widely studied due to their key ecosystem functions.For this reason,they are used in ecosystem assessment,formulating conservation plans and in raising the environmental awareness.Quantification of different factors affecting diversity of butterflies is important for their effective conservation.In this study,we investigated abiotic and biotic factors affecting species richness and community composition of butterflies along an elevational gradient in Manang region,central Nepal.We also tested if butterfly species follow the Bergmann’s rule.A total of 57 butterfly species belonging to 39 genera and 8 families were recorded in the study area.Out of a total of 127 plant species identified in the study region,only 67 plant species were visited by butterflies as nectar sources.Species richness of butterflies increased with increasing elevation.Species richness was significantly higher in places with shrubs compared to other places and also in autumn than in summer.Species richness of butterflies also depended on composition of plant species occurring at the localities.Butterfly species composition varied among sampling localities.It was also determined by habitat type,elevation,sampling time,plant species and interactions of elevation×time.The relationship between butterfly size and elevation was in the opposite direction than expected according to the Bergmann’s rule.In conclusion,protection of butterfly diversity can only be achieved by protecting different habitats across the diverse physiography of the region and different plant species,in particular herbs and shrubs.Our results do not support the Bergmann’s rule for butterflies along an elevational gradient in our region.

Species traits and shoot-root biomass allocation in 20 dry-grassland species

Aims A plant has a limited amount of resources at any time and it allo-cates them to different structures.in spite of the large number of previous studies on allocation patterns within single species,knowledge of general patterns in species allocation is still very limited.This is because each study was done in different condi-tions using different methodology,making generalization dif-ficult.We investigate intraspecific above-versus below-ground biomass allocation among individuals across a spectrum of dry-grassland plant species at two different developmental stages and ask whether allocation is age-and species specific,and whether differences among species can be explained by their life-history traits and phylogeny.Methods We collected data on above-and below-ground biomass of seedlings and adult plants of 20 species from a common garden experiment.We analysed data on shoot-root biomass allocation allometrically and studied the relationship between the allometric exponents(slopes on log-log scale),species life-history traits and phylogenetic distances.Important Findings We found isometric as well as allometric patterns of biomass alloca-tion in the studied species.Seedlings and adult individuals of more than half of the species differed in their above-versus below-ground biomass allometric exponents.Seedlings and adult individuals of the remaining species differed in their allometric coefficients(inter-cepts).Annual species generally allocated proportionally more to above-than below-ground biomass as seedlings than as adults,whereas perennial species showed the opposite pattern.Plant life-history traits,such as plant life span,age of first flowering,month in which the species begin flowering and specific leaf area were much more important in explaining differences in shoot-root allometry among species than were phylogenetic relationships.This suggests that allocation patterns vary greatly among closely related species but can be predicted based on species life-history traits.

Temperature and precipitation,but not geographic distance,explain genetic relatedness among populations in the perennial grass Festuca rubra

Aims Knowledge of genetic structure of natural populations and its determinants may provide key insights into the ability of species to adapt to novel environments.In many genetic studies,the effects of climate could not be disentangled from the effects of geographic proximity.We aimed to understand the effects of temperature and moisture on genetic diversity of populations and separate these effects from the effects of geographic distance.We also wanted to explore the patterns of distribution of genetic diversity in the system and assess the degree of clonality within the populations.We also checked for possible genome size variation in the system.Methods We studied genetic variation within and among 12 populations of the dominant grass Festuca rubra distributed across a unique regional-scale climatic grid in western Norway,Europe and explored the importance of temperature,precipitation and geo-graphic distance for the observed patterns.We also explored the distribution of genetic diversity within and among popula-tions,identified population differentiation and estimated degree of clonality.The analyses used microsatellites as the genetic marker.The analyses were supplemented by flow cytometry of all the material.Important Findings All the material corresponds to hexaploid cytotype,indicating that ploidy variation does not play any role in the system.The results indicate that temperature and precipitation were better predictors of genetic relatedness of the populations than geographic distance,suggesting that temperature and precipitation may be important determinants of population differentiation.In addition,precipitation,alone and in interaction with temperature,strongly affected population genotypic diversity suggesting increased clonality towards the coldest and especially the coldest wettest climates.At the same time,individuals from the coldest and wettest climates also had the high-est individual genetic diversity,suggesting that only the most hetero-zygous individuals survive under these harsh climates.Most of the genetic variation was distributed within populations,suggesting that most populations have sufficient genetic diversity to adapt to novel climatic conditions.The alpine populations,i.e.populations which are likely the most endangered by climate change,however,lack this potential due to the high levels of clonality as detected in our study.

Genotypic diversity and genotype identity of resident species drive community composition

物种丰富的植物群落更能抵抗入侵。近十年来的研究表明,遗传变异具有很多生态效应。本研究旨在检验本地物种遗传多样性的响应模式在不同生长形式的定殖物种之间是否存在差异,以及这种响应是否受到土壤养分的影响。我们设立常见草种紫羊茅(Festuca rubra)实验样地,在两种土壤养分水平下,设置3个遗传多样性水平(1、6或18个克隆基因型,表征基因型多样性)。在样地设立后第4年,将4种定殖者混合播种到样地中:匍匐性豆科植物白车轴草(Trifolium repens)、阔叶黄花茅(Anthoxanthum odoratum)、大莲座丛杂草长叶车前(Plantago lanceolata)和小莲座丛杂草兴安风铃草(Campanula rotundifolia)。我们观测三年来物种的建立和生长情况,检验定殖成功是否取决于基因型多样性、特定的羊茅属基因型、土壤养分或定殖者的生长形式。本地无性系牧草的基因型多样性和基因型同一性对其定殖成功和生物量有显著影响。然而,定殖物种的反应各异。本地物种对基因型多样性最大的响应是生长形式和结构与本地物种相似的草丛型禾草。大莲座丛植物在生长初期有响应,而匍匐性豆科植物则完全没有响应。种内遗传型多样性和本地物种的基因型同一性在植物群落聚合中起着重要作用。