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Protected areas are arguably the most important instrument of biodiversity conservation. To keep them fit under climate change, their management needs to be adapted to address related direct and indirect changes. In our study we focus on the adaptation of conservation management planning, evaluating management plans of 60 protected areas throughout Germany with regard to their climate change-robustness. First, climate change-robust conservation management was defined using 11 principles and 44 criteria, which followed an approach similar to sustainability standards. We then evaluated the performance of individual management plans concerning the climate change-robustness framework. We found that climate change-robustness of protected areas hardly exceeded 50 percent of the potential performance, with most plans ranking in the lower quarter. Most Natura 2000 protected areas, established under conservation legislation of the European Union, belong to the sites with especially poor performance, with lower values in smaller areas. In general, the individual principles showed very different rates of accordance with our principles, but similarly low intensity. Principles with generally higher performance values included holistic knowledge management, public accountability and acceptance as well as systemic and strategic coherence. Deficiencies were connected to dealing with the future and uncertainty. Lastly, we recommended the presented principles and criteria as essential guideposts that can be used as a checklist for working towards more climate change-robust planning.
Modelling and empirical studies have shown that input from the regional seed pool is essential to maintain local species diversity. However, most of these studies have concentrated on simplified, if not neutral, model systems, and focus on a limited subset of species or on aggregated measures of diversity only (e.g., species richness or Shannon diversity). Thus they ignore more complex species interactions and important differences between species. To gain a better understanding of how seed immigration affects community structure at the local scale in real communities we conducted computer simulation experiments based on plant functional types (PFTs) for a species-rich, fire-prone Mediterranean-type shrubland in Western Australia. We developed a spatially explicit simulation model to explore the community dynamics of 38 PFTs, defined by seven traits - regeneration mode, seed production, seed size, maximum crown diameter, drought tolerance, dispersal mode and seed bank type - representing 78 woody species. Model parameterisation is based on published and unpublished data on the population dynamics of shrub species collected over 18 years. Simulation experiments are based on two contrasting seed immigration scenarios: (1) the 'equal seed input number' scenario, where the number of immigrant seeds is the same for all PFTs, and (2) the 'equal seed input mass' scenario, where the cumulative mass of migrating seeds is the same for all PFTs. Both scenarios were systematically tested and compared for different overall seed input values. Without immigration the local community drifts towards a state with only 13 coexisting PFTs. With increasing immigration rates in terms of overall mass of seeds the simulated number of coexisting PFTs and Shannon diversity quickly approaches values observed in the field. The equal seed mass scenario resulted in a more diverse community than did the seed number scenario. The model successfully approximates the frequency distributions (relative densities) of all individual plant traits except seed size for scenarios associated with equal seed input mass and high immigration rate. However, no scenario satisfactorily approximated the frequency distribution for all traits in combination. Our results show that regional seed input can explain the more aggregated measures of local community structure, and some, but not all, aspects of community composition. This points to the possible importance of other (untested) processes and traits (e.g., dispersal vectors) operating at the local scale. Our modelling framework can readily allow new factors to be systematically investigated, which is a major advantage compared to previous simulation studies, as it allows us to find structurally realistic models, which can address questions pertinent to ecological theory and to conservation management.
In most stochastic models addressing the persistence of small populations, environmental noise is included by imposing a synchronized effect of the environment on all individuals. However, buffer mechanisms are likely to exist that may counteract this synchronization to some degree. We have studied whether the flexibility in the mating system, which has been observed in some bird species, is a potential mechanism counteracting the synchronization of environmental fluctuations. Our study organism is the lesser spotted woodpecker Picoides minor (Linnaeus), a generally monogamous species. However, facultative polyandry, where one female mates with two males with separate nests, was observed in years with male-biased sex ratio. We constructed an individual-based model from data and observations of a population in Taunus, Germany. We tested the impact of three behavioural scenarios on population persistence: (1) strict monogamy; (2) polyandry without costs; and (3) polyandry assuming costs in terms of lower survival and reproductive success for secondary males. We assumed that polyandry occurs only in years with male-biased sex ratio and only for females with favourable breeding conditions. Even low rates of polyandry had a strong positive effect on population persistence. The increase of persistence with carrying capacity was slower in the monogamous scenario, indicating strong environmental noise. In the polyandrous scenarios, the increase of persistence was stronger, indicating a buffer mechanism. In the polyandrous scenarios, populations had a higher mean population size, a lower variation in number of individuals, and recovered faster after a population breakdown. Presuming a realistic polyandry rate and costs for polyandry, there was still a strong effect of polyandry on persistence. The results show that polyandry and in general flexibility in mating systems is a buffer mechanism that can significantly reduce the impact of environmental and demographic noise in small populations. Consequently, we suggest that even behaviour that seems to be exceptional should be considered explicitly when predicting the persistence of populations
We studied the effects of overgrazing on the foraging behaviour of the lizard Pedioplanis l. lineoocellata (Spotted Sand Lizard), a sit-and-wait forager, in habitats of differing vegetation states to determine the effects of habitat degradation on this species. At high grazing intensity where vegetation cover and diversity is low, the lizard P. lineoocellata moves more frequently, spends more time moving and covers larger distances than in habitats where vegetation cover and diversity is high. These behavioural changes in movement patterns can be explained by less abundant prey in habitats with low vegetation cover and diversity. Although morphology, phylogeny and physiology of P. lineoocellata should constrain the change in foraging behaviour, the species has modified its foraging strategy from sit- and-wait to actively foraging. We assume that this behavioural flexibility of P. lineoocellata is a buffer mechanism enabling the species to use and survive in degraded (unfavourable) habitats.
Disturbances' role in shaping communities is well documented but highly disputed. We suggest replacing the overused two-trait trade-off approach with a functional group scheme, constructed from combinations of four key traits that represent four classes of species' responses to disturbances. Using model results and field observations from sites affected by two highly different disturbances, we demonstrated that popular dichotomous trade-offs are not sufficient to explain community dynamics, even if some emerge under certain conditions. Without disturbances, competition was only sufficient to predict species survival but not relative success, which required some escape mechanism (e.g., long-term dormancy). With highly predictable and large-scale disturbances, successful species showed a combination of high individual tolerance to disturbance and, more surprisingly, high competitive ability. When disturbances were less predictable, high individual tolerance and long-term seed dormancy were favored, due to higher environmental uncertainty. Our study demonstrates that theories relying on a small number of predefined trade-offs among traits (e.g., competition-colonization trade-off) may lead to unrealistic results. We suggest that the understanding of disturbance-community relationships can be significantly improved by employing sets of relevant trait assemblies instead of the currently common approach in which trade-offs are assumed in advance.
Understanding animal movement is essential to elucidate how animals interact, survive, and thrive in a changing world. Recent technological advances in data collection and management have transformed our understanding of animal "movement ecology" (the integrated study of organismal movement), creating a big-data discipline that benefits from rapid, cost-effective generation of large amounts of data on movements of animals in the wild. These high-throughput wildlife tracking systems now allow more thorough investigation of variation among individuals and species across space and time, the nature of biological interactions, and behavioral responses to the environment. Movement ecology is rapidly expanding scientific frontiers through large interdisciplinary and collaborative frameworks, providing improved opportunities for conservation and insights into the movements of wild animals, and their causes and consequences.
Patterns of past vegetation changes over time and space can help facilitate better understanding of the interactions among climate, ecosystem, and human impact. Biome changes in China over the last 22,000 yr (calibrated radiocarbon date, a BP) were numerically reconstructed by using a standard approach of pollen-plant functional type-biome assignment (biomization). The biomization procedure involves pollen data from 2434 surface sites and 228 fossil sites with a high quality of pollen count and C-14 dating, 51 natural and three anthropogenic plant functional types (PFTs), as well as 19 natural and one anthropogenic biome. Surface pollen-based reconstruction of modern natural biome patterns is in good agreement (74.4%) with actual vegetation distribution in China. However, modem large-scale anthropogenic biome reconstruction has not been successful based on the current setup of three anthropogenic PFTs (plantation, secondary, and disturbed PFT) because of the limitation of non-species level pollen identification and the difficulty in the clear assignment of disturbed PFTs. The non-anthropogenic biome distributions of 44 time slices at 500-year intervals show large-scale discrepant and changed vegetation patterns from the last glacial maximum (LGM) to the Holocene throughout China. From 22 ka BP to 19 ka BP, temperate grassland, xerophytic shrubland, and desert dominated northern China, whereas cold or cool forests flourished in central China. Warm-temperate evergreen forests were restricted to far southern China, and tropical forests were absent During 18.5 ka BP to 12 ka BP, cold, cool, and dry biomes extended to some parts of northern, westem, and eastern China. Warm-temperate evergreen and mixed forests gradually expanded to occupy the whole of southern China. A slight northward shift of forest biomes occurred from 15 ka BP to 12 lea BP. During 11.5 ka BP to 9 ka BP, temperate grassland and shrubland gradually stretched to northern and western China. Cold and cool forests widely expanded into northern and central China, as well as in the northern margin of South China along with temperate deciduous forest. Since the early mid-Holocene (approximately 8.5 ka BP to 5.5 ka BP), all forest biomes shifted northward at the expense of herbaceous and shrubby biomes. Simultaneously, cold and cool forest biomes occupied the marginal areas of the Tibetan Plateau and the high mountains in western China. During the middle to late Holocene, from 5 ka to the present, temperate grassland and xerophytic shrubland expanded to the south and east, whereas temperate deciduous forests slightly shifted southward. After 3 lea BP, forest biomes were absent in western China and on the Tibetan plateau surface. Dramatic biome shifts from the LGM to the Holocene were observed in the forest-grassland ecotone and transitional zones between temperate and subtropical climates, between subtropical and tropical regions, and in the mountainous margins of the eastern Tibetan Plateau. Evidence showed more human disturbances during the late Holocene. More pollen records and historical documents are therefore further needed to understand fully the human disturbance-induced large-scale forest changes. In addition, more classifications of anthropogenic biome or land cover, more distinct assignment of pollen taxa to anthropogenic PFTs, and more effective numerical and/or mechanistic techniques in building large-scale human disturbances are required. (C) 2014 Elsevier B.V. All rights reserved.