Search results for "NSA"
showing 10 items of 6608 documents
Precision, Applicability, and Economic Implications: A Comparison of Alternative Biodiversity Offset Indexes
2021
AbstractThe rates of ecosystem degradation and biodiversity loss are alarming and current conservation efforts are not sufficient to stop them. The need for new tools is urgent. One approach is biodiversity offsetting: a developer causing habitat degradation provides an improvement in biodiversity so that the lost ecological value is compensated for. Accurate and ecologically meaningful measurement of losses and estimation of gains are essential in reaching the no net loss goal or any other desired outcome of biodiversity offsetting. The chosen calculation method strongly influences biodiversity outcomes. We compare a multiplicative method, which is based on a habitat condition index develo…
Larval intraspecific competition for food in the European grapevine moth Lobesia botrana.
2014
AbstractEffective pest management with lower amounts of pesticides relies on accurate prediction of insect pest growth rates. Knowledge of the factors governing this trait and the resulting fitness of individuals is thus necessary to refine predictions and make suitable decisions in crop protection. The European grapevine moth, Lobesia botrana, the major pest of grapes in Europe, is responsible for huge economic losses. Larvae very rarely leave the grape bunch on which they were oviposited and thus cannot avoid intraspecific competition. In this study, we determined the impact of intraspecific competition during the larval stage on development and adult fitness in this species. This was tes…
Harvest‐induced evolution and effective population size
2016
Much has been written about fishery-induced evolution (FIE) in exploited species, but relatively little attention has been paid to the consequences for one of the most important parameters in evolutionary biology-effective population size (N-e). We use a combination of simulations of Atlantic cod populations experiencing harvest, artificial manipulation of cod life tables, and analytical methods to explore how adding harvest to natural mortality affects N-e, census size (N), and the ratio N-e/N. We show that harvest-mediated reductions in N-e are due entirely to reductions in recruitment, because increasing adult mortality actually increases the N-e/N ratio. This means that proportional red…
Retroconversion of docosapentaenoic acid (n-6): an alternative pathway for biosynthesis of arachidonic acid in Daphnia magna.
2013
The aim of this study was to assess metabolic pathways for arachidonic acid (20:4n-6) biosynthesis in Daphnia magna. Neonates of D. magna were maintained on [13C] enriched Scenedesmus obliquus and supplemented with liposomes that contained separate treatments of unlabeled docosapentaenoic acid (22:5n-6), 20:4n-6, linoleic acid (18:2n-6) or oleic acid (18:1n-9). Daphnia in the control treatment, without any supplementary fatty acids (FA) containing only trace amounts of 20:4n-6 (~0.3 % of all FA). As expected, the highest proportion of 20:4n-6 (~6.3 %) was detected in Daphnia that received liposomes supplemented with this FA. Higher availability of 18:2n-6 in the diet increased the proportio…
Effect of ozone treatment on the microstructure, chemical composition and sensory quality of apple fruits
2018
The author(s) disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: This research commissioned by Agricultural services co-operative society ‘AUGL¸ NAMS’ has been conducted within framework ‘The research of fruit storage technologies’ funded by State program ‘Competence Centre for Food in Latvia’.
High variation in last male sperm precedence and genital morphology in the emerald damselfly, Lestes sponsa
2020
Abstract In organisms in which individuals mate multiply, knowledge of the proportion of offspring sired by the last male to mate (P2) under field conditions is important for a thorough understanding of how sexual selection works in nature. In many insect groups, pronounced intraspecific variation in P2 is commonplace. Interestingly, however, in stark contrast to these observations, compilation of P2 data in dragonflies and damselflies (Odonata) indicates that a high P2, seldom below 0.95, is a feature of this taxon. Here we used double digest restriction-site associated DNA sequencing to generate a panel of single nucleotide polymorphisms (SNPs) with which we could determine paternity and …
Detection of Allee effects in marine fishes: analytical biases generated by data availability and model selection
2017
The demographic Allee effect, or depensation, implies positive association between per capita population growth rate and population size at low abundances, thereby lowering growth ability of sparse populations. This can have far-reaching consequences on population recovery ability and colonization success. In the context of marine fishes, there is a widespread perception that Allee effects are rare or non-existent. However, studies that have failed to detect Allee effects in marine fishes have suffered from several fundamental methodological and data limitations. In the present study, we challenge the prevailing perception about the rarity of Allee effects by analysing nine populations of …
Increased susceptibility to oxidative damage as a cost of accelerated somatic growth in zebra finches.
2007
1. Most animals do not grow at their maximal rate. This might appear puzzling because the early attainment of a large body size incurs several selective benefits, such as reduced risk of predation and earlier reproductive output. Several hypotheses have been suggested to explain this paradox. Among them, the cost due to high levels of oxidative stress, as the consequence of sustained metabolic activity during growth, has been put forward.
Different emergence phenology of European grapevine moth (Lobesia botrana, Lepidoptera: Tortricidae) on six varieties of grapes.
2014
AbstractThe phenology of insect emergence affects reproductive success and is especially critical in short-lived species. An increasing number of studies have documented the effects of thermal and other climatic variations and of unpredictable habitats on the timing of adult insect emergence within and between populations and years. Numerous interacting factors may affect the phenology of adult emergence. Host-plant quality and availability is a key factor that has been largely neglected in studies of the phenology of phytophagous insects. The purpose of this study was to determine the effect of host plant characteristics on the rate of larval growth and the pattern of emergence in a wild p…
Optimal contract length for biodiversity conservation under conservation budget constraint
2014
We examine the optimal length of a contract period in a conservation program with payments for ecosystem services aiming at protecting biodiversity on privately owned forests. The government chooses the number of stands and the length of contracts so as to maximize biodiversity benefits under a binding conservation budget. We examine the implication of two alternative budgets: a separate budget for each period (periodic budget) or one budget that to be used in all periods (intertemporal budget). The impact of the budget type shows up in the fact that with intertemporal budget choice set is larger and more high quality stands are available for contracting. Based on theoretical characterizati…