Vaclavik T.,Helmholtz Center for Environmental Research |
Vaclavik T.,Palacky University |
Langerwisch F.,Potsdam Institute for Climate Impact Research |
Langerwisch F.,Berlin Brandenburg Institute of Advanced Biodiversity Research BBIB |
And 12 more authors.
Environmental Research Letters | Year: 2016
Much of our knowledge about land use and ecosystem services in interrelated social-ecological systems is derived from place-based research. While local and regional case studies provide valuable insights, it is often unclear how relevant this research is beyond the study areas. Drawing generalized conclusions about practical solutions to land management from local observations and formulating hypotheses applicable to other places in the world requires that we identify patterns of land systems that are similar to those represented by the case study. Here, we utilize the previously developed concept of land system archetypes to investigate potential transferability of research from twelve regional projects implemented in a large joint research framework that focus on issues of sustainable land management across four continents. For each project, we characterize its project archetype, i.e. the unique land system based on a synthesis of more than 30 datasets of land-use intensity, environmental conditions and socioeconomic indicators. We estimate the transferability potential of project research by calculating the statistical similarity of locations across the world to the project archetype, assuming higher transferability potentials in locations with similar land system characteristics. Results show that areas with high transferability potentials are typically clustered around project sites but for some case studies can be found in regions that are geographically distant, especially when values of considered variables are close to the global mean or where the project archetype is driven by large-scale environmental or socioeconomic conditions. Using specific examples from the local case studies, we highlight the merit of our approach and discuss the differences between local realities and information captured in global datasets. The proposed method provides a blueprint for large research programs to assess potential transferability of place-based studies to other geographical areas and to indicate possible gaps in research efforts. © 2016 IOP Publishing Ltd.
Jakoby O.,Helmholtz Center for Environmental Research |
Jakoby O.,Swiss Federal Institute of forest |
Quaas M.F.,University of Kiel |
Muller B.,Helmholtz Center for Environmental Research |
And 4 more authors.
Journal of Applied Ecology | Year: 2014
Summary: Management decisions by farmers are influenced by complex interrelations of ecological, economic and social factors. Of equal importance are the individual farmers' objectives. However, their relevance has been rarely considered in analyses of management decisions in farming systems. This study systematically analyses the role of farmers' objectives in their decision-making under various climatic conditions, with dryland grazing systems as a case study. We develop a generic ecological-economic simulation model to compare the performance of a range of fixed grazing strategies under two objectives: (i) maximizing expected utility under risk aversion and (ii) achieving stochastic viability ('safety first'). We investigate combined effects of several management components in rotational grazing systems and assess the robustness of the results under different climate scenarios. The two objectives considered have structurally different outcomes. The evaluation under the objective to maximize (risk averse) expected utility indicates a trade-off between mean income and income variability under which farmers would choose one individually optimal management strategy depending on their risk preferences. In contrast, a whole set of strategies is viable under the safety-first objective. Thus, it offers a solution space for decision support rather than selecting a single optimal strategy. Under both objectives, economically preferable strategies share common characteristics: short standing time, large paddock number and reasonably high stocking rate improve the efficiency of a farm enterprise in terms of higher mean income, lower variance, coverage of certain minimum income requirements while preserving pasture quality. Synthesis and applications. The outcomes of this study contribute to both management support at the farm scale and policy advice at the regional scale and beyond. An insight of practical relevance for individual farmers is that a strategy type with high-intensity, short-duration grazing management appears to be most robust under changing climate and economic conditions. Nevertheless, considering individual farmers' objectives is essential for determining the individually optimal strategy. Furthermore, for policymakers, we provide an approach to evaluate policy programmes governing farming activities in terms of effectiveness and implications (particularly side effects). The explicit consideration of the diversity of individual objectives is crucial for avoiding counterproductive incentives and improving sustainability of land-use policies. © 2014 British Ecological Society.
Morgado-Santos M.,University of Lisbon |
Miguel Pereira H.,University of Lisbon |
Miguel Pereira H.,iv German Center for Integrative Biodiversity Research |
Vicente L.,University of Lisbon |
Collares-Pereira M.J.,University of Lisbon
PLoS ONE | Year: 2015
Previous studies have shown that assortative mating acts as a driver of speciation by countering hybridization between two populations of the same species (pre-zygotic isolation) or through mate choice among the hybrids (hybrid speciation). In both speciation types, assortative mating promotes speciation over a transient hybridization stage. We studied mate choice in a hybrid vertebrate complex, the allopolyploid fish Squalius alburnoides. This complex is composed by several genomotypes connected by an intricate reproductive dynamics. We developed a model that predicts the hybrid complex can persist when females exhibit particular mate choice patterns. Our model is able to reproduce the diversity of population dynamic outcomes found in nature, namely the dominance of the triploids and the dominance of the tetraploids, depending on female mate choice patterns and frequency of the parental species. Experimental mate choice trials showed that females exhibit the preferences predicted by the model. Thus, despite the known role of assortative mating in driving speciation, our findings suggest that certain mate choice patterns can instead hinder speciation and support the persistence of hybrids over time without speciation or extinction. Copyright: © 2015 Morgado-Santos et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Oelze V.M.,Max Planck Institute for Evolutionary Anthropology |
Oelze V.M.,iv German Center for Integrative Biodiversity Research |
Douglas P.H.,Max Planck Institute for Evolutionary Anthropology |
Stephens C.R.,Max Planck Institute for Evolutionary Anthropology |
And 7 more authors.
PLoS ONE | Year: 2016
Dietary ecology of extant great apes is known to respond to environmental conditions such as climate and food availability, but also to vary depending on social status and life history characteristics. Bonobos (Pan paniscus) live under comparatively steady ecological conditions in the evergreen rainforests of the Congo Basin. Bonobos are an ideal species for investigating influences of sociodemographic and physiological factors, such as female reproductive status, on diet. We investigate the long term dietary pattern in wild but fully habituated bonobos by stable isotope analysis in hair and integrating a variety of long-term sociodemographic information obtained through observations. We analyzed carbon and nitrogen stable isotopes in 432 hair sections obtained from 101 non-invasively collected hair samples. These samples represented the dietary behavior of 23 adult bonobos from 2008 through 2010. By including isotope and crude protein data from plants we could establish an isotope baseline and interpret the results of several general linear mixed models using the predictors climate, sex, social rank, reproductive state of females, adult age and age of infants. We found that low canopy foliage is a useful isotopic tracer for tropical rainforest settings, and consumption of terrestrial herbs best explains the temporal isotope patterns we found in carbon isotope values of bonobo hair. Only the diet of male bonobos was affected by social rank, with lower nitrogen isotope values in low-ranking young males. Female isotope values mainly differed between different stages of reproduction (cycling, pregnancy, lactation). These isotopic differences appear to be related to changes in dietary preference during pregnancy (high protein diet) and lactation (high energy diet), which allow to compensate for different nutritional needs during maternal investment. © 2016 Oelze et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Meyer M.A.,Helmholtz Center for Environmental Research |
Meyer M.A.,Ludwig Maximilians University of Munich |
Seppelt R.,Helmholtz Center for Environmental Research |
Seppelt R.,iv German Center for Integrative Biodiversity Research |
And 3 more authors.
Environmental Research Letters | Year: 2016
Global demand for agricultural and forestry products fundamentally affects regional land-use change associated with environmental impacts (EIs) such as erosion. In contrast to aggregated global metrics such as greenhouse gas (GHG) balances, local/regional EIs of different agricultural and forestry production regions need methods which enable worldwide EI comparisons. The key aspect is to control environmental heterogeneity to reveal man-made differences of EIs between production regions. Environmental heterogeneity is the variation in biotic and abiotic environmental conditions. In the present study, we used three approaches to control environmental heterogeneity: (i) environmental stratification, (ii) potential natural vegetation (PNV), and (iii) regional environmental thresholds to compare EIs of solid biomass production. We compared production regions of managed forests and plantation forests in subtropical (Satilla watershed, Southeastern US), tropical (Rufiji basin, Tanzania), and temperate (Mulde watershed, Central Germany) climates. All approaches supported the comparison of the EIs of different land-use classes between and within production regions. They also standardized the different EIs for a comparison between the EI categories. The EIs for different land-use classes within a production region decreased with increasing degree of naturalness (forest, plantation forestry, and cropland). PNV was the most reliable approach, but lacked feasibility and relevance. The PNV approach explicitly included most of the factors that drive environmental heterogeneity in contrast to the stratification and threshold approaches. The stratification approach allows consistent global application due to available data. Regional environmental thresholds only included arbitrarily selected aspects of environmental heterogeneity; they are only available for few EIs. Especially, the PNV and stratification approaches are options to compare regional EIs of biomass or crop production such as erosion, biodiversity, or water quality impacts worldwide and thereby complement existing metrics assessing global EIs such as GHG emissions. © 2016 IOP Publishing Ltd.