Vulnerability of mires under climate change: implications for nature conservation and climate change adaptation

Wetlands in general and mires in particular belong to the most important terrestrial carbon stocks globally. Mires (i.e. bogs, transition bogs and fens) are assumed to be especially vulnerable to climate change because they depend on specific, namely cool and humid, climatic conditions. In this paper, we use distribution data of the nine mire types to be found in Austria and habitat distribution models for four IPCC scenarios to evaluate climate change induced risks for mire ecosystems within the 21st century. We found that climatic factors substantially contribute to explain the current distribution of all nine Austrian mire ecosystem types. Summer temperature proved to be the most important predictor for the majority of mire ecosystems. Precipitation—mostly spring and summer precipitation sums—was influential for some mire ecosystem types which depend partly or entirely on ground water supply (e.g. fens). We found severe climate change induced risks for all mire ecosystems, with rain-fed bog ecosystems being most threatened. Differences between scenarios are moderate for the mid-21st century, but become more pronounced towards the end of the 21st century, with near total loss of climate space projected for some ecosystem types (bogs, quagmires) under severe climate change. Our results imply that even under minimum expected, i.e. inevitable climate change, climatic risks for mires in Austria will be considerable. Nevertheless, the pronounced differences in projected habitat loss between moderate and severe climate change scenarios indicate that limiting future warming will likely contribute to enhance long-term survival of mire ecosystems, and to reduce future greenhouse gas emissions from decomposing peat. Effectively stopping and reversing the deterioration of mire ecosystems caused by conventional threats can be regarded as a contribution to climate change mitigation. Because hydrologically intact mires are more resilient to climatic changes, this would also maintain the nature conservation value of mires, and help to reduce the severe climatic risks to which most Austrian mire ecosystems may be exposed in the 2nd half of the 21st century according to IPCC scenarios.     

Strategies for genetic conservation of trees in the Peruvian Amazon

Forestry practices and high rates of land clearance for agriculture are causing genetic erosion of valuable tree species in the Peruvian Amazon, thereby endangering the economic sustainability of rural communities and limiting Peru's opportunities for the development of new timber and non-timber forest products. The potential utility and limitations of six low-input interventions to help forestall further genetic erosion in the region are discussed, with a focus on local community involvement. Improved agroforestry systems may help reduce deforestation by increasing farm productivity, although methods to increase the currently low adoption rate of these technologies need to be developed. Use of strategic tree domestication techniques can also improve farm productivity and prevent inadvertent genetic drift and inbreeding associated with traditional domestication practices, although to have a major impact, current programs need to be extended across the region. Woodlot forestry could supplant selective extraction of timber and offers an attractive opportunity for poverty alleviation if appropriate credit and land tenure policies can be developed. However, it may also result in increased deforestation if activities on public land cannot be controlled. The implementation of improved seed collection systems and simple seed transfer guidelines would help to reduce the collection of seed of poor quality and low genetic diversity, and avoid maladapted plantings, although such programs are difficult to monitor and seed costs may increase. Strategic identification and design of in situ conservation areas would help to ensure the viability of conserved populations, but requires the forfeiture of significant revenue from timber concessions.     

Allowing for human socioeconomic impacts in the conservation of plants under climate change

Abstract

The impact of climate change on conservation planning is affected by the availability of data (especially in data-sparse countries) and socioeconomic impacts. We build models using MaxEnt for Egyptian medicinal plants as a model system, projecting them to different future times under two IPCC 4th assessment emission scenarios (A2a and B2a) assuming unlimited and no dispersal. We compare the effect of two indices of socioeconomic activity [Human Influence Index (HII) and human population density/km²] as cost layers in spatial prioritization for conservation using zonation. We assess the efficacy of Egypt's network of Protected Areas (PAs) by comparing the predicted conservation value inside and outside each PA under the various scenarios. The results show that there are many locations in Egypt (the main cities, agricultural land, coastal areas) that are highly ranked for conservation before human socioeconomic impacts are included. The HII had a stronger impact than using human population density. The PA value excess (inside–outside) varied significantly with the type of cost and dispersal, but not with climate-change scenario or Zonation settings. We conclude that human socioeconomic impacts add new scope and insights for future conservation; and conservation planning without consideration of such impacts cannot be complete.     

Biotic interactions influence the projected distribution of a specialist mammal under climate change

Aim

To measure the effects of including biotic interactions on climate‐based species distribution models (SDMs) used to predict distribution shifts under climate change. We evaluated the performance of distribution models for an endangered marsupial, the northern bettong (Bettongia tropica), comparing models that used only climate variables with models that also took into account biotic interactions.

Location

North‐east Queensland, Australia.

Methods

We developed separate climate‐based distribution models for the northern bettong, its two main resources and a competitor species. We then constructed models for the northern bettong by including climate suitability estimates for the resources and competitor as additional predictor variables to make climate + resource and climate + resource + competition models. We projected these models onto seven future climate scenarios and compared predictions of northern bettong distribution made by these differently structured models, using a ‘global’ metric, the I similarity statistic, to measure overlap in distribution and a ‘local’ metric to identify where predictions differed significantly.

Results

Inclusion of food resource biotic interactions improved model performance. Over moderate climate changes, up to 3.0 °C of warming, the climate‐only model for the northern bettong gave similar predictions of distribution to the more complex models including interactions, with differences only at the margins of predicted distributions. For climate changes beyond 3.0 °C, model predictions diverged significantly. The interactive model predicted less contraction of distribution than the simpler climate‐only model.

Main conclusions

Distribution models that account for interactions with other species, in particular direct resources, improve model predictions in the present‐day climate. For larger climate changes, shifts in distribution of interacting species cause predictions of interactive models to diverge from climate‐only models. Incorporating interactions with other species in SDMs may be needed for long‐term prediction of changes in distribution of species under climate change, particularly for specialized species strongly dependent on a small number of biotic interactions.     

A straightforward conceptual approach for evaluating spatial conservation priorities under climate change

Despite wide evidence of a quickly changing world, systematic conservation planning analyses are usually static assuming that the biodiversity being preserved in sites do not change through time. Here we generated a comprehensive ensemble forecasting experiment for 444 amphibian species inhabiting the Atlantic Forest Biodiversity Hotspot. Models were based on four methods for modeling ecological niches, and three future climate simulations. Combinations of these models were used to estimate species occurrences. We used species occurrences to optimize the current and future representation of amphibians with different conservation targets based on their geographic range size. We compared spatial priority outcomes (variance of site selection frequency scores) under dynamic conditions, using a bi-dimensional plot in which the relative importance of each site in achieving conservation targets was assessed both for current time and to 2050. Projections for 2050 show that species richness pattern will remain approximately constant, whereas high turnover rates are forecasted. Selection frequency of several locations varied widely, with recurrent sites located at the north and southeast of the biome. As for 2050, spatial priorities concentrate in the northern part of the biome. Thirty-three sites have high priority for conservation as they play an important role now and will still stand as priority locations in 2050. We present a conceptual model for dynamic spatial conservation prioritization that helps to identify priority sites under climate change. We also call attention to sites in which risk of investment is high, and to those that may become interesting options in the future.     

Adapting systematic conservation planning for climate change

With the high rate of ecosystem change, effective systematic conservation planning must account for ongoing and imminent threats to biodiversity to ensure its persistence. Accordingly, guidance on appropriate conservation actions in the face of climate change has been accumulating. We review this guidance and bring together the key recommendations needed to successfully account for climate change impacts, relevant to the scale at which natural resource management is carried out. We discuss how the traditional conservation tools of protection and restoration need to be adjusted to be effective in the face of climate change. We highlight the conservation innovations such as moveable and temporary reserves, and Targeted Gene Flow. We build on recent work to provide critical advice for considering climate change in conservation planning. In particular, we discuss how stating explicit objectives related to climate change adaptation, quantifying uncertainty, and exploring trade-offs will better place conservation plans to meet objectives for multiple goals such as protection of species, ecosystems, geophysical diversity and ecological processes.     

Safeguarding sloths and anteaters in the future: Priority areas for conservation under climate change

Sloths and anteaters form the monophyletic order Pilosa, which is currently represented by only 16 extant species distributed exclusively in the Neotropics. This present-day low species richness is an inheritance of the Pleistocene megafaunal extinctions, where over 65 Pilosa species known from the fossil record went extinct. The large number of species lost in the recent past suggests that this group is greatly vulnerable to extinction. Here, we propose long-term priority conservation areas for the order Pilosa, considering different future climate change scenarios, biotic stability, and the multiple dimensions of the group's biodiversity, such as species richness, species endemism, and phylogenetic diversity. Projections of species distribution for future scenarios show increased fragmentation and clear habitat loss as the Amazon Forest is replaced by savanna-like habitats. Conservation solutions were highly congruent for the different dimensions of biodiversity, with priority areas emerging mainly in the Atlantic Forest, Amazonian wetlands, highlands of Ecuador, and the Central American isthmus. Expanding the currently protected areas network by 6% with the proposed priority areas, independently of which future climatic scenario is considered, can increase sloths and anteaters' coverage in the future by 12%. As a group of high phylogenetic and ecological importance, future conservation planning should deliberately aim to protect areas favorable to Pilosa, especially given the current scenario of environmental dismantling and neglect of critical Neotropical biomes.     

Evaluating the effectiveness of conservation site networks under climate change: accounting for uncertainty

We forecasted potential impacts of climate change on the ability of a network of key sites for bird conservation (Important Bird Areas; IBAs) to provide suitable climate for 370 bird species of current conservation concern in two Asian biodiversity hotspots: the Eastern Himalaya and Lower Mekong. Comparable studies have largely not accounted for uncertainty, which may lead to inappropriate conclusions. We quantified the contribution of four sources of variation (choice of general circulation models, emission scenarios and species distribution modelling methods and variation in species distribution data) to uncertainty in forecasts and tested if our projections were robust to these uncertainties. Declines in the availability of suitable climate within the IBA network by 2100 were forecast as ‘extremely likely’ for 45% of species, whereas increases were projected for only 2%. Thus, we predict almost 24 times as many ‘losers’ as ‘winners’. However, for no species was suitable climate ‘extremely likely’ to be completely lost from the network. Considerable turnover (median = 43%, 95% CI = 35–69%) in species compositions of most IBAs were projected by 2100. Climatic conditions in 47% of IBAs were projected as ‘extremely likely’ to become suitable for fewer priority species. However, no IBA was forecast to become suitable for more species. Variation among General Circulation Models and Species Distribution Models contributed most to uncertainty among forecasts. This uncertainty precluded firm conclusions for 53% of species and IBAs because 95% confidence intervals included projections of no change. Considering this uncertainty, however, allows robust recommendations concerning the remaining species and IBAs. Overall, while the IBA network will continue to sustain bird conservation, climate change will modify which species each site will be suitable for. Thus, adaptive management of the network, including modified site conservation strategies and facilitating species' movement among sites, is critical to ensure effective future conservation.     

The role of remnants of Amazon savanna for the conservation of Neotropical mammal communities in eucalyptus plantations

In this study, we investigated the effects of the partial conversion of native Amazon savanna into a eucalyptus plantation on the richness, composition, and abundance of medium and large mammals. Considering these plantations as an integral component of a patchwork savanna landscape, we verified how the negative effects of these plantations can be buffered by the conservation of remnants of native habitat within their area. We analyzed the contribution of each type of Amazonian savanna to the maintenance of the mammalian fauna and the potential of eucalyptus plantations to substitute these native habitats. A total of 23 mammal species were recorded in line-transect surveys conducted within the conserved savanna. By contrast, only eight species were recorded in the eucalyptus plantation and none of them were exclusive to this vegetation. However, the landscape patchwork formed by plantations and savanna was more diverse and contained 19 species of mammals, highlighting the potential importance of remnant savanna vegetation. The maintenance of remnants of savanna habitat may thus be essential for ensuring the conservation of mammals in the anthropogenic landscape of this region. It will also be important to include as many different subtypes of native savanna vegetation as possible and to consider the connectivity between habitats.     

Scale effects in species distribution models: implications for conservation planning under climate change

Predictions of future species' ranges under climate change are needed for conservation planning, for which species distribution models (SDMs) are widely used. However, global climate model-based (GCM) output grids can bias the area identified as suitable when these are used as SDM predictor variables, because GCM outputs, typically at least 50x50 km, are biologically coarse. We tested the assumption that species ranges can be equally well portrayed in SDMs operating on base data of different grid sizes by comparing SDM performance statistics and area selected by four SDMs run at seven grid sizes, for nine species of contrasting range size. Area selected was disproportionately larger for SDMs run on larger grid sizes, indicating a cut-off point above which model results were less reliable. Up to 2.89 times more species range area was selected by SDMs operating on grids above 50x50 km, compared to SDMs operating at 1 km2. Spatial congruence between areas selected as range also diverged as grid size increased, particularly for species with ranges between 20000 and 90000 km2. These results indicate the need for caution when using such data to plan future protected areas, because an overly large predicted range could lead to inappropriate reserve location selection.     

Hopes and challenges for giant panda conservation under climate change in the Qinling Mountains of China

One way that climate change will impact animal distributions is by altering habitat suitability and habitat fragmentation. Understanding the impacts of climate change on currently threatened species is of immediate importance because complex conservation planning will be required. Here, we mapped changes to the distribution, suitability, and fragmentation of giant panda habitat under climate change and quantified the direction and elevation of habitat shift and fragmentation patterns. These data were used to develop a series of new conservation strategies for the giant panda. Qinling Mountains, Shaanxi, China. Data from the most recent giant panda census, habitat factors, anthropogenic disturbance, climate variables, and climate predictions for the year 2050 (averaged across four general circulation models) were used to project giant panda habitat in Maxent. Differences in habitat patches were compared between now and 2050. While climate change will cause a 9.1% increase in suitable habitat and 9% reduction in subsuitable habitat by 2050, no significant net variation in the proportion of suitable and subsuitable habitat was found. However, a distinct climate change‐induced habitat shift of 11 km eastward by 2050 is predicted firstly. Climate change will reduce the fragmentation of suitable habitat at high elevations and exacerbate the fragmentation of subsuitable habitat below 1,900 m above sea level. Reduced fragmentation at higher elevations and worsening fragmentation at lower elevations have the potential to cause overcrowding of giant pandas at higher altitudes, further exacerbating habitat shortage in the central Qinling Mountains. The habitat shift to the east due to climate change may provide new areas for giant pandas but poses severe challenges for future conservation.     

Land cover change and management implications for the conservation of a seabird in an urban coastal zone under climate change

Little Penguin (Eudyptula minor) is one of the most ecologically important seabirds in New Zealand and depends strongly on terrestrial ecosystems for nesting, moulting and breeding. Wellington, New Zealand, is one of the world's most important biodiversity hot spots for this species, mostly in confluence with human urban settlements. This species is currently suffering from the local impacts of climate change associated with urbanisation. Two suburbs of Wellington, New Zealand, that are used seasonally by Little Penguin as terrestrial habitat were selected as the study area to address two issues: (i) how local impacts of climate change may affect the population and habitat structure of species in urban coastal zones where land cover change occurs; and (ii) how landscape management practices may help to mitigate the impacts imposed by climate change on the species in such a context. Remote Sensing and Geographical Information Systems techniques were applied to quantify and measure the extent of the prehuman forests and current land cover classes in the study area to reveal the degree to which land cover has changed from predevelopment to the present time. The research shows that land cover change in the study area has been widespread and partly irreversible, particularly in areas covered by the class Built‐up Area. Results reveal that there are still spatial opportunities to safeguard this vulnerable species against the ill effects of climate change through landscape management practices.     

Plant communities and environmental factors in the Guayana Highlands: monitoring for conservation under future climate change

The Guayana Highlands (GH) constitute a highly diverse, but relatively poorly studied Neotropical biome, comprised of ～50 flat-topped mountain summits (called tepuis). Previous studies based on warming forecasts for the region suggested that an upward displacement of environmental conditions of 500–700 m could occur by 2100, potentially resulting in the extinction of c. 50% of its endemic flora due to total habitat loss. To assess the ecological responses of the species to climate change, and select the appropriate conservation measures, long-term monitoring of the GH plant communities will be necessary. In this study, the baseline state for future comparisons was established for the best explored tepui in terms of its flora, Roraima-tepui (2810 m), through a floristic characterization of its different vegetation types. We also identified the environmental gradients underlying the major plant communities, and assessed the effects of human activities on the chemistry of soils and water at three field camps. Our results yielded five main community types: three meadows, one shrubland, and one forest, with their corresponding diagnostic species. The herbaceous communities were mainly influenced by the presence of flat sandy soils, with varying flooding capacity. Shrublands and forests were characterized by irregular organic soils with very low pH. Finally, pH values below 3 were measured on an organic soil of a field camp, although further studies will be necessary to attribute this deviation to human activities.