Using species traits to guide conservation actions under climate change

Few assessments of species vulnerability to climate change used to inform conservation management consider the intrinsic traits that shape species’ capacity to respond to climate change. This omission is problematic as it may result in management actions that are not optimised for the long-term persistence of species as climates shift. We present a tool for explicitly linking data on plant species’ life history traits and range characteristics to appropriate management actions that maximise their capacity to respond to climate change. We deliberately target data on easily measured and widely available traits (e.g. dispersal syndrome, height, longevity) and range characteristics (e.g. range size, climatic/soil niche breadth), to allow for rapid comparison across many species. We test this framework on 1237 plants, categorising species on the basis of their potential climate change risk as related to four factors affecting their response capacity: reproduction, movement capability, abiotic niche specialisation and spatial coverage. Based on these four factors, species were allocated risk scores, and these were used to test the hypothesis that the current protection status under national legislation and related management actions capture species response capacity to climate change. Our results indicate that 20% of the plant species analysed (242 species) are likely to have a low capacity to respond to climate change based on the traits assessed, and are therefore at high risk. Of the 242 high risk species, only 10% (24 species) are currently listed for protection under conservation legislation. Importantly, many management plans for these listed species fail to address the capacity of species to respond to climate change with appropriate actions: 70% of approved management plans do not include crucial actions which may improve species’ ability to adapt to climate change. We illustrate how the use of easily attainable traits associated with ecological and evolutionary responses to changing environmental conditions can inform conservation actions for plant species globally.     

Ecological responses of plant species and communities to climate warming: upward shift or range filling processes?

The fate of alpine species in response to climate warming is still unclear. We analyze effects of climate warming on the composition of alpine plants communities and unravel the range filling of communities within a belt from long-term true upward shift processes. In the European Alps we re-sampled in 2003 the vegetation at sites studied in 1953 and analyzed the changes at intra- and inter-community level. Since 1953 all communities experienced a high species turnover, leading to an overall increase in species richness as new species exceeded species losses. The dominant species mainly declined allowing the potential expansion of competitors and/or of new species. The main recruitment sources are neighbor communities within the same elevation belt performing biotic exchanges with other plant communities in the same altitudinal belts. The changes of species distribution curves with elevation emphasized that more than half of the most widespread persisting species exhibited downward shifts instead of upward shifts. Upward shifts from lower elevation belts and of nonnative species were very limited. One third of the persisting species declined and could be used as a proxy to measure the extinction debt. Therefore the fate of plant communities will depend on the ability of the original species to persist and fill the available ecological gaps. Species persistence may be crucial in developing adaptation and environmental protection strategies.     

Relationship between projected changes in future climatic suitability and demographic and functional traits of forest tree species in Spain

The response of plant species to future climate conditions is probably dependent on their ecological characteristics, including climatic niche, demographic rates and functional traits. Using forest inventory data from 27 dominant woody species in Spanish forests, we explore the relationships between species characteristics and projected changes in their average climatic suitability (occurrence of suitable climatic conditions for a species in a given territory) obtained by empirical niche-based models, under a business-as-usual climate change scenario (A1, HadCM3, 2001–2100). We hypothesize that most species will suffer a decline in climatic suitability, with a less severe for species (i) currently living in more arid climates or exhibiting a broader current climatic niche; (ii) with higher current growth rates; (iii) with functional traits related to resistance to water deficits. The analysis confirm our hypothesis since apart from a few Mediterranean species, most species decrease their climatic suitability in the region under future climate, characterized by increased aridity. Also, species living in warmer locations or under a wider range of climatic conditions tend to experience less decrease in climatic suitability. As hypothesized, a positive relationship was detected between current relative growth rates and increase in future climatic suitability. Nevertheless, current tree mortality did not correlate with changes in future climatic suitability. In contrast with our hypothesis, functional traits did not show a clear relationship with changes in climate suitability; instead species often presented idiosyncratic responses that, in some cases, could reflect past management. These results suggest that the extrapolation of species performance to future climatic scenarios based on current patterns of dominance is constrained by factors other than species autoecology, particularly human activity.     

Potential impact of climate change and reindeer density on tundra indicator species in the Barents Sea region

Climate change is expected to alter the distribution of habitats and thus the distribution of species connected with these habitats in the terrestrial Barents Sea region. It was hypothesised that wild species connected with the tundra and open-land biome may be particularly at risk as forest area expands. Fourteen species of birds were identified as useful indicators for the biodiversity dependent upon this biome. By bringing together species distribution information with the LPJ-GUESS vegetation model, and with estimates of future wild and domestic reindeer density, potential impacts on these species between the present time and 2080 were assessed. Over this period there was a net loss of open land within the current breeding range of most bird species. Grazing reindeer were modelled as increasing the amount of open land retained for nine of the tundra bird species.     

Simulating potential effects of climatic warming on altitudinal patterns of key species in Mediterranean-alpine ecosystems

In this paper we study an isolated high-mountain (Sierra Nevada, SE Iberian Peninsula) to identify the potential trends in the habitat-suitability of five key species (i.e. species that domain a given vegetation type and drive the conditions for appearance of many other species) corresponding to four vegetation types occupying different altitudinal belts, that might result from a sudden climatic shift. We used topographical variables and downscaled climate warming simulations to build a high-resolution spatial database (10 m) according to four different climate warming scenarios for the twenty-first century. The spatial changes in the suitable habitat were simulated using a species distribution model, in order to analyze altitudinal shifts and potential habitat loss of the key species. Thus, the advance and receding fronts of known occurrence locations were computed by introducing a new concept named differential suitability, and potential patterns of substitution among the key species were established. The average mean temperature trend show an increase of 4.8°C, which will induce the vertical shift of the suitable habitat for all the five key species considered at an average rate of 11.57 m/year. According to the simulations, the suitable habitat for the key species inhabiting the summit area, where most of the endemic and/or rare species are located, may disappear before the middle of the century. The other key species considered show moderate to drastic suitable habitat loss depending on the considered scenario. Climate warming should provoke a strong substitution dynamics between species, increasing spatial competition between both of them. In this study, we introduce the application of differential suitability concept into the analysis of potential impact of climate change, forest management and environmental monitoring, and discuss the limitations and uncertainties of these simulations.     

The vulnerability of native rangeland plant species to global climate change in the West Asia and North African regions

This study aimed to evaluate the impact of climate change on the geographical distribution of selected native species from two areas from West Asia and North Africa. Three species representing two genera were selected for assessment of their vulnerability to climate change. The first species was Salsola vermiculata L. which is common to both study areas. The second genus was represented by two species, Haloxylon salicornicum (Moq.) Bunge from the Syrian rangelands and H. schmittianum Pomel from southern Tunisia. To assess the vulnerability of these species to climate change we used ecological-based models. The data inputs were composed of the species occurrence data and the environmental data which included eight climatic layers, three soil property layers in addition to an altitude layer. Since environmental parameters only enable assessing the sensitivity of target species to climate change, a grazing pressure layer was used to assess the species vulnerability. Only climatic parameters were considered as changing across three periods; current situation, 2020 and 2050. The main results indicated that threatened range species, such as S. vermiculata which were subjected to continuous grazing pressure, showed high vulnerability to climate change as expressed by the predicted decrease in the areas of their distribution. However, species with low palatability and broad ecological niches (i.e. H. salicornicum and H. schmittianum) had an advantage due to the reduced competition for water and nutrients. An adaptation strategy to increase the resilience of the most vulnerable species should involve management of grazing pressure and the establishment of other mitigation measures.     

Consequences of inter-specific competition among multiple adaptive species in Daisyworld

Summary We investigate the consequences of Darwinian selection in a daisymodel with uniform temperature, inter-specific competition and multiple daisies. The assumption of a higher competition between species than within them allows for the coexistence of more than two species in equilibrium. Thus, it is the first time that a high biodiversity with equal environment-altering traits at the same trophic level in a daisymodel is reported under stationary conditions. Adaptation in the biota occurs through mutations, leading to changes in the optimum temperature in order to achieve the maximum growth rate at the individual level. We study the planetary sensitivity (i.e. the variation of the global mean temperature due to a 1% change in solar radiation) as a function of the strength of the inter-specific competition and of the number of different species that grow in the model. We find the following: 1) by fixing the parameter that defines the strength of the inter-specific competition, the planetary sensitivity increases as biodiversity increases; 2) by keeping constant the number of different species in the planet, the planetary sensitivity also increases as competition between species increases. In any case, however, the planetary sensitivity associated with adaptive daisies is much greater than that obtained from non-adaptive species. However, the range of mean solar radiation where biota grows in the planet is substantially larger for adaptive species than for non-adaptive ones. This result suggests that adaptation of multiple species with the same environmental-altering traits may not imply a strong regulation of the mean planetary temperature, which differs with recent studies that analyse adaptation of single species. Similar results are obtained by using a constrained adaptation and non-uniform temperatures.     

Predicting the impacts of climate change on genetic diversity in an endangered lizard species

Many endangered species persist as a series of isolated populations, with some populations more genetically diverse than others. If climate change disproportionately threatens the most diverse populations, the species’ ability to adapt (and hence its long-term viability) may be affected more severely than would be apparent by its numerical reduction. In the present study, we combine genetic data with modelling of species distributions under climate change to document this situation in an endangered lizard (Eulamprus leuraensis) from montane southeastern Australia. The species is known from only about 40 isolated swamps. Genetic diversity of lizard populations is greater in some sites than others, presumably reflecting consistently high habitat suitability over evolutionary time. Species distribution modelling suggests that the most genetically diverse populations are the ones most at risk from climate change, so that global warming will erode the species’ genetic variability faster than it curtails the species’ geographic distribution.     

植物种群资源竞争与共存的理论模型研究

自然生态系统不同植物种群之间存在着广泛的竞争,且多种植物种群可以共存,即具有生物多样性。经典的资源竞争模型(莫诺模型)支持生态学上的"竞争排斥原理",不适用于阐释自然生态系统不同植物种群间的竞争与共存。根据植物生态系统的特点,引入植物种群的生长率随着物种个体大小/个体数增加而逐渐趋于饱和的性质,建立自抑制资源竞争模型。该模型与莫诺模型的本质区别在于,物种的临界可利用资源随种群密度增加而上升,从而可以达到不同物种间的平衡。数学分析及数值模拟结果表明,该模型可允许多物种稳定共存(即共存的物种种类数可以多于供给其生长的资源种类数),同时优势物种随资源供给率增加而依次变化。     

Potential response of pacific northwestern forests to climatic change,effects of stand age and initial composition

We used an individual-based forest simulator (a gap model) to assess the potential effects of anthropogenic climatic change on conifer forests of the Pacific Northwestern United States. Steady-state simulations suggested that forest zones could be shifted on the order of 500–1000 m in elevation, which could lead to the local extirpation of some high-altitude species. For low-elevation sites, species which currently are more abundant hundreds of kilometers to the south would be favored under greenhouse scenarios. Simulations of transient responses suggested that forest stands could show complex responses depending on initial species composition, stand age and canopy development, and the magnitude and duration of climatic warming. Assumptions about species response to temperature, which are crucial to the model's behaviors, were evaluated using data on species temperature limits inferred from regional distributions. The high level of within-species variability in these data, and other confounding factors influencing species distributions, argue against over-interpreting simulations. We suggest how we might resolve critical uncertainties with further research.     

Model simulations of rainout and washout from a warm stratiform cloud

A one-dimensional, time-dependent cloud model with parameterized microphysics is used to investigate the processes which control the rainout and washout of soluble gases from warm, precipitating stratiform clouds. Calculations are presented simulating the distributions of soluble species within and below the cloud layer and in the precipitating raindrops as a function of time and species' solubility. Our calculations indicate that for species with low solubility, wet removal processes are relatively slow and thus do not significantly affect the species' gas-phase abundance. As a result, the removal of low-solubility species by rainout and washout is controlled by thermodynamic processes with the concentration of the species in cloud and rainwater largely determined by the species' solubility. For highly soluble species on the other hand, dissolution into cloud droplets and removal in rain is quite rapid and the abundance of highly soluble species within and below the cloud falls rapidly as soon as the precipitation begins. Because of this rapid decrease in concentration, we find that for highly soluble species: concentrations in cloud droplets near the cloud base can exceed that of raindrops by factors of 2 to 10; washout can dominate over rainout as a removal mechanism; and that, after an extended period of rainfall, the rate of removal becomes independent of the microphysical properties and rainfall rate of the cloud and is controlled by the rate of transport of material into the precipitating column by horizontal advection.     

Relating Tree Physiology to Past and Future Changes in Tropical Rainforest Tree Communities

Predicting future changes in tropical rainforest tree communities requires a good understanding of past changes as well as a knowledge of the physiology, ecology and population biology of extant species. Climate change during the next hundred years will be more similar to climate fluctuations that have occurred in the last few thousand years and of a much smaller magnitude than the extent of climate change experienced during last glaciation or at the Pleistocene–Holocene transition. Unfortunately, the extent to which tropical rainforest tree communities have changed during the last few thousand years has been little investigated. As a consequence we lack the detailed evidence for population and range shifts of individual tropical species resulting from climate change analogous to the evidence available for temperate zone forests. Some evidence suggests that the rate of tropical forest change in the last several thousand years may have been high. If so, then CO₂ increases and the likely alterations in temperature, forest turnover rate, rainfall, or severe droughts may drive substantial future forest change. How can we predict or model the effects of climate change on a highly diverse tree community? Explanations for the regulation of tropical tree populations often invoke tree physiology or processes that are subject to physiological regulation such as herbivory, pathology or seed production. In order to incorporate such considerations into climate change models, the physiology of a very diverse tree community must be understood. My work has focused on simplifying this diversity by categorizing the shade-tolerant species into functional physiological groups. Most species and most individual trees are shade-tolerant species, gap-requiring species being relatively uncommon. Additionally, in a regenerating gap most of the individuals are shade-tolerant species that established before gap formation. Despite the fact that the shade-tolerant species are of major ecological importance, their comparative physiology has received little attention. I have found that shade-tolerant species differ substantially in their responses to light flecks, treefall light gaps and drought. Furthermore, among phylogenetically unrelated species, these differences in physiology can be predicted from leaf lifetime. These results provide a general framework for understanding the mechanics of tropical rainforests from a physiological perspective that can be used to model their responses to climate change.     

Evidence for cryptic northern refugia among high- and temperate-latitude species in Beringia

Stewart and Dalén (2008) argue that only temperate species were locked in cryptic northern refugia during Pleistocene glacial cycles, while species presently found at high latitudes had much wider distributions during glaciations. We present evidence supporting the existence of cryptic northern refugia that likely harbored both high- and temperate-latitude species in the Bering Sea region. Genetic signals of refugial isolation are found in island populations of rock ptarmigan (Lagopus muta), rock sandpiper (Calidris ptilocnemis), common raven (Corvus corax), and winter wren (Troglodytes troglodytes). These species have high-latitude, a mixture of high- and temperate-latitude, and temperate-latitude distributions. In addition, there are no data showing historically larger distributions of the high-latitude rock sandpiper or rock ptarmigan in North America during the Pleistocene. Although exact dating of isolation events is not possible using molecular genetic data, the species we examined have similar genetic signals and thus were isolated at similar times. It is evident that Pleistocene glaciations produced refugial genetic signatures among multiple bird species in the North Pacific Ocean.     

Effects of climate warming on the distributions of invasive Eurasian annual grasses: a South African perspective

Threats posed by Eurasian annual grasses to ecosystem function have received little attention. Therefore, protocols for prioritising these alien annual species and likely future dimensions of their spread are urgently required. Here we modelled these grasses potential distribution and shifts in distribution ranges in South Africa under current and future climate scenarios. We applied a modelling framework (BIOMOD), which integrated a variety of parametric statistical and non-parametric rule based models to point distribution records of 29 invasive grass species. Correspondence between modelled and recorded distributions was calculated using the model accuracy criteria called the AUC (Area under the Curve). Based on this criteria 12 C₃ species were excellently modelled (AUC = 0.9–1), 11 C₃ species had good model accuracy (AUC = 0.7–0.8) and four C₃ and four C₄ species fell into the fair (AUC = 0.6–0.7) model accuracy class. Mean temperature of the coldest month was the strongest environmental parameter, for most of the alien grass distributions. Modelled distributions of the alien annual grasses projected into the future indicated range contractions in all C₃ species, except Briza minor, which were accompanied by shifts in species distribution ranges into higher altitudes. All C₄ species displayed habitat loss of relatively similar magnitude with climate warming and shifts in their distribution ranges also into higher elevations. These findings conclude that climate change will hinder the spread of European annual grasses in southern Africa. However, shifts in their distributions into pristine areas at higher elevations could pose a threat to the natural vegetation by altering fire regimes.     

Ecological Implications of Changes in Drought Patterns: Shifts in Forest Composition in Panama

CO₂ concentration is increasing, temperature is likely to rise, and precipitation patterns might change. Of these potential climatic shifts, it is precipitation that will have the most impact on tropical forests, and seasonal patterns of rainfall and drought will probably be more important than the total quantity of precipitation. Many tree species are limited in distribution by their inability to survive drought. In a 50 ha forest plot at Barro Colorado Island in Panama (BCI), nearly all tree and shrub species associated with moist microhabitats are declining in abundance due to a decline in rainfall and lengthening dry seasons. This information forms the basis for a simple, general prediction: drying trends can rapidly remove drought-sensitive species from a forest. If the drying trend continues at BCI, the invasion of drought-tolerant species would be anticipated, but computer models predict that it could take 500 or more years for tree species to invade and become established. Predicting climate-induced changes in tropical forest also requires geographic information on tree distribution relative to precipitation patterns. In central Panama, species with the most restricted ranges are those from areas with a short dry season (10–14 weeks): 26–39% of the tree species in these wet regions do not occur where it is drier. In comparison, just 11–19% of species from the drier side of Panama (18 week dry season) are restricted to the dry region. From this information, I predict that a four-week extension of the dry season could eliminate 25% of the species locally; a nine-week extension in very wet regions could cause 40% extinction. Since drier forests are more deciduous than wetter forests, satellite images that monitor deciduousness might provide a way to assess long-term forest changes caused by changes in drought patterns. I predict that increasing rainfall and shorter dry seasons would not cause major extinction in tropical forest, but that drying trends are a much greater concern. Longer dry seasons may cause considerable local extinction of tree species and rapid forest change, and they will also tend to exacerbate direct human damage, which tends to favor drought-adapted and invasive tree species in favor of moisture-demanding ones.     

Conservation and management of ecological systems in a changing California

Climate change in California is altering habitat conditions for many species and exacerbating stress from other factors such as alien invasive species, pollution, and habitat fragmentation. However, the current legal and planning framework for species protection does not explicitly take climate change into account. The regulatory framework is primarily reactive, kicking in only after species’ health is gravely threatened. Neither federal nor state regulations require forward-looking, climate-sensitive species or ecosystem protection plans. Habitat planning is poorly funded and often piecemeal. In this context, the wrong lands may be protected, with development allowed to occur in areas that would be most beneficial for species conservation in the future. A more forward-looking approach to habitat conservation is needed, one based on a statewide strategy to identify and protect critical habitat areas, including corridors to enable species migration. The approach would also require development of assessment indicators and assistance strategies not dependent on current habitat structure, and a governance structure to implement regular, periodic updates of management plans in relation to agreed-upon performance indicators. Such a strategy should integrate habitat conservation planning with other state and regional plans and objectives, such as for transportation infrastructure, urban development, and mitigation of climate change.     

积云发展对酸化剂清除的数值模拟

本文利用云内成雨清除模式和云下雨水冲刷清除模式讨论了云内和云下致酸物质的清除、酸化过程。计算结果表明，雨不酸化主要是在云内形成、而云底之下雨水对清除酸化过程是不重要的。而对流引起的上升气流和下沉气流对污染层内致酸物质的浓度变化有较大影响。     

Land use biodiversity impacts embodied in international food trade

Agricultural land use to meet the demands of a growing population, changing diets, lifestyles and biofuel production is a significant driver of biodiversity loss. Globally applicable methods are needed to assess biodiversity impacts hidden in internationally traded food items. We used the countryside species area relationship (SAR) model to estimate the mammals, birds, amphibians and reptiles species lost (i.e. species ‘committed to extinction’) due to agricultural land use within each of the 804 terrestrial ecoregion. These species lost estimates were combined with high spatial resolution global maps of crop yields to calculate species lost per ton for 170 crops in 184 countries. Finally, the impacts per ton were linked with the bilateral trade data of crop products between producing and consuming countries from FAO, to calculate the land use biodiversity impacts embodied in international crop trade and consumption. We found that 83% of total species loss is incurred due to agriculture land use devoted for domestic consumption whereas 17% is due to export production. Exports from Indonesia to USA and China embody highest impacts (20 species lost at the regional level each). In general, industrialized countries with high per capita GDP tend to be major net importers of biodiversity impacts from developing tropical countries. Results show that embodied land area is not a good proxy for embodied biodiversity impacts in trade flows, as crops occupying little global area such as sugarcane, palm oil, rubber and coffee have disproportionately high biodiversity impacts.     

Ungulate herbivory modifies the effects of climate change on mountain forests

Recent temperature observations suggest a general warming trend that may be causing the range of tree species to shift to higher latitudes and altitudes. Since biotic interactions such as herbivory can change tree species composition, it is important to understand their contribution to vegetation changes triggered by climate change. To investigate the response of forests to climate change and herbivory by wild ungulates, we used the forest gap model ForClim v2.9.6 and simulated forest development in three climatically different valleys in the Swiss Alps. We used altitudinal transects on contrasting slopes covering a wide range of forest types from the cold (upper) to the dry (lower) treeline. This allowed us to investigate (1) altitudinal range shifts in response to climate change, (2) the consequences for tree species composition, and (3) the combined effect of climate change and ungulate herbivory. We found that ungulate herbivory changed species composition and that both basal area and stem numbers decreased with increasing herbivory intensity. Tree species responded differently to the change in climate, and their ranges did not change concurrently, thus causing a succession to new stand types. While climate change partially compensated for the reductions in basal area caused by ungulate herbivory, the combined effect of these two agents on the mix of the dominant species and forest type was non-compensatory, as browsing selectively excluded species from establishing or reaching dominance and altered competition patterns, particularly for light. We conclude that there is an urgent need for adaptive forest management strategies that address the joint effects of climate change and ungulate herbivory.     

The protection of Antarctic terrestrial ecosystems from inter- and intra-continental transfer of non-indigenous species by human activities: A review of current systems and practices

Invasions by non-indigenous species are amongst the greatest threats to global biodiversity, causing substantial disruption to, and sometimes local extinction of, individual species and community assemblages which, in turn, can affect ecosystem structure and function. The terrestrial environment of Antarctica consists of many isolated ‘islands’ of ice-free ground. Prolonged isolation makes Antarctic biodiversity vulnerable to human-mediated impacts, in particular (1) the introduction of non-indigenous species from outside Antarctica, and (2) the redistribution of indigenous Antarctic species between biologically distinct areas within the continent. The Protocol on Environmental Protection to the Antarctic Treaty, the primary instrument through which environmental management is addressed within the Antarctic Treaty System, says little about unintentional introduction of non-indigenous species to Antarctica, and nothing specifically about human-mediated transfer of native species from one area to another. We review the effectiveness of the Antarctic protected area system, the primary means through which area-specific environmental protection is achieved under the Antarctic Treaty System. This reveals that the measures described in most Antarctic Specially Protected Area (ASPA) and Antarctic Specially Managed Area (ASMA) Management Plans, by themselves, may not be sufficient to (1) minimise the possibility of introduction of plants, animals and microbes not native to the protected area or (2) adequately protect the many unusual assemblages of species, type localities or only known habitats of certain species found in Antarctica. We discuss issues that should be considered in the development of a more effective system, including the implementation of appropriate biosecurity measures across different spatial scales and applied to different biological groups.