The Mediterranean Basin is a biodiversity hotspot. Wetlands make a key contribution to this status, but many of them remain outside the Ramsar network fifty years after the establishment of the ...Ramsar Convention. Here we evaluate the extent to which the Mediterranean Ramsar network covers wetlands of international importance for wintering waterbirds using the Ramsar Convention criteria 2 (species of conservation concern), 5 (> 20,000 waterbirds) and 6 (1% of a population). These criteria were applied to 4186 sites in 24 Mediterranean countries using counts of 145 wintering waterbird species from 1991 to 2017. We identified 161 sites of international importance for waterbirds that have not yet been declared as Ramsar sites, which could be added to the 180 current Mediterranean Ramsar sites established based on waterbird criteria (criteria 5 and/or 6). Among these sites, a subset of 32 very important sites reached double the required level for at least one criterion and 95 were not protected by any site conservation status. Coastal wetlands represented half of the Ramsar gap for waterbirds. We identified that an additional 1218 monitored sites could be provisionally considered as internationally important and thus require more survey efforts to assess their status. This study highlights a lack of participation of the Mediterranean countries to build the Ramsar network for wetland protection. Our results should help policymakers and managers to prioritize future Ramsar site designation, notably in the Middle East and Western European region where important gaps were identified.
Climate warming is driving changes in species distributions and community composition. Many species have a so‐called climatic debt, that is, shifts in range lag behind shifts in temperature ...isoclines. Inside protected areas (PAs), community changes in response to climate warming can be facilitated by greater colonization rates by warm‐dwelling species, but also mitigated by lowering extirpation rates of cold‐dwelling species. An evaluation of the relative importance of colonization‐extirpation processes is important to inform conservation strategies that aim for both climate debt reduction and species conservation. We assessed the colonization‐extirpation dynamics involved in community changes in response to climate inside and outside PAs. To do so, we used 25 years of occurrence data of nonbreeding waterbirds in the western Palearctic (97 species, 7071 sites, 39 countries, 1993–2017). We used a community temperature index (CTI) framework based on species thermal affinities to investigate species turnover induced by temperature increase. We determined whether thermal community adjustment was associated with colonization by warm‐dwelling species or extirpation of cold‐dwelling species by modeling change in standard deviation of the CTI (CTISD). Using linear mixed‐effects models, we investigated whether communities in PAs had lower climatic debt and different patterns of community change than communities outside PAs. For CTI and CTISD combined, communities inside PAs had more species, higher colonization, lower extirpation, and lower climatic debt (16%) than communities outside PAs. Thus, our results suggest that PAs facilitate 2 independent processes that shape community dynamics and maintain biodiversity. The community adjustment was, however, not sufficiently fast to keep pace with the large temperature increases in the central and northeastern western Palearctic. Our results underline the potential of combining CTI and CTISD metrics to improve understanding of the colonization‐extirpation patterns driven by climate warming.
Beneficios de las Áreas Protegidas para las Aves Acuáticas No Reproductoras que Están Ajustando su Distribución Debido al Calentamiento Climático
Resumen
El calentamiento climático está generando cambios en la distribución y en la composición comunitaria de las especies. Muchas de ellas tienen una deuda climática, es decir, los cambios en la distribución se atrasan con respecto a los cambios en las isoclinas térmicas. Dentro de las áreas protegidas (APs), los cambios comunitarios como respuesta al calentamiento climático pueden facilitarse mediante tasas mayores de colonización por especies de climas cálidos, pero también pueden mitigarse al reducir las tasas de extirpación de las especies de climas fríos. Se requiere una evaluación de la importancia relativa de los procesos de colonización‐extirpación para orientar las estrategias de conservación que buscan la reducción de la deuda climática y la conservación de las especies. Analizamos las dinámicas de colonización‐extirpación que participan en los cambios comunitarios como respuesta al clima dentro y fuera de las APs. Para realizar lo anterior, usamos datos tomados durante 25 años de la presencia de aves acuáticas no reproductoras en el Paleártico occidental (97 especies, 7,071 sitios, 39 países, 1993–2017). Usamos un marco de trabajo del índice de temperatura comunitaria (ITC) basado en las afinidades térmicas de las especies para así investigar la rotación de especies inducida por el incremento en la temperatura. Determinamos si el ajuste térmico en la comunidad estuvo asociado con la colonización por especies de climas cálidos o con la extirpación de especies de climas fríos al modelar el cambio mediante una desviación estándar del ITC (ITCDS). Con los modelos lineales de efectos mixtos investigamos si las comunidades dentro de las APs tenían una deuda climática más baja y patrones diferentes de cambio comunitario que las comunidades localizadas fuera de las APs. Con la combinación del ITC y deL ITCDS, las comunidades dentro de las APs tuvieron más especies, una mayor colonización, una menor extirpación y una deuda climática más baja (16%) que las comunidades fuera de las APs. Por lo tanto, nuestros resultados sugieren que las APs facilitan dos procesos independientes que moldean las dinámicas comunitarias y mantienen la biodiversidad. Sin embargo, el ajuste comunitario no fue lo suficientemente rápido para mantener el paso de los grandes incrementos en la temperatura de las regiones central y noreste del Paleártico occidental. Nuestros resultados resaltan el potencial que tiene la combinación de las medidas del ITC y del ICTDS para mejorar el entendimiento de los patrones de colonización‐extirpación causados por el calentamiento climático.
【摘要】
气候变暖正在引起物种分布和群落组成的变化。许多物种都背负着所谓的 “气候债务”, 即分布范围的变化滞后于温度的变化。气候变暖背景下, 保护地中适应温暖环境的物种较高的定殖率可以促进群落变化, 适应寒冷环境的物种灭绝率下降也可以减缓影响。评估定殖–灭绝过程的相对重要性, 对于制定旨在减少气候债和促进物种保护的保护战略而言十分重要。本研究利用西古北界非繁殖水鸟 25 年的出现记录 (97 个物种, 7071 个位点, 39 个国家, 1993–2017 年) , 评估了保护地内外鸟类群落响应气候变化过程中的定殖–灭绝动态。我们使用基于物种对温度亲和性的群落温度指数框架探究了温度升高引起的物种更替。通过模拟群落温度指数标准偏差的变化, 我们确定了群落对温度的调整是否与适应温暖环境的物种的定殖或适应寒冷环境的物种的灭绝有关。接下来, 我们利用线性混合效应模型分析了保护地内与保护地外的群落相比是否具有较低的气候债务和不同的群落变化格局。结合群落温度指数与其标准偏差, 我们发现保护地内的群落比保护地外的具有更多的物种、更高的定殖率、更低的灭绝率和更低的气候债务 (16%) 。因此, 我们的结果表明, 保护地促进了群落动态形成和生物多样性维持这两个独立过程。然而, 群落调整的速度不足以跟上古北界中部和东北部地区气温的大幅上升。我们的结果强调了群落温度指数和群落温度指数标准偏差这两个指标相结合, 有潜力提高对气候变暖导致的定殖–灭绝格局的理解。【翻译: 胡怡思; 审校: 聂永刚】
Article impact statement: Protected areas are needed to facilitate waterbird distribution change in response to climate warming in the western Palearctic.
Migratory waterbirds require an effectively conserved cohesive network of wetland areas throughout their range and life-cycle. Under rapid climate change, protected area (PA) networks need to be able ...to accommodate climate-driven range shifts in wildlife if they are to continue to be effective in the future. Thus, we investigated geographical variation in the relationship between local temperature anomaly and the abundance of 61 waterbird species during the wintering season across Europe and North Africa during 1990–2015. We also compared the spatio-temporal effects on abundance of sites designated as PAs, Important Bird and Biodiversity Areas (IBAs), both, or neither designation (Unlisted). Waterbird abundance was positively correlated with temperature anomaly, with this pattern being strongest towards north and east Europe. Waterbird abundance was higher inside IBAs, whether they were legally protected or not. Trends in waterbird abundance were also consistently more positive inside both protected and unprotected IBAs across the whole study region, and were positive in Unlisted wetlands in southwestern Europe and North Africa. These results suggest that IBAs are important sites for wintering waterbirds, but also that populations are shifting to unprotected wetlands (some of which are IBAs). Such IBAs may therefore represent robust candidate sites to expand the network of legally protected wetlands under climate change in north-eastern Europe. These results underscore the need for monitoring to understand how the effectiveness of site networks is changing under climate change.
Sea-level rise (SLR) is expected to cause major changes to coastal wetlands, which are among the world's most vulnerable ecosystems and are critical for nonbreeding waterbirds. Because strategies for ...adaptation to SLR, such as nature-based solutions and designation of protected areas, can locally reduce the negative effects of coastal flooding under SLR on coastal wetlands, it is crucial to prioritize adaptation efforts, especially for wetlands of international importance for biodiversity. We assessed the exposure of coastal wetlands important for nonbreeding waterbirds to projected SLR along the Mediterranean coasts of 8 countries by modeling future coastal flooding under 7 scenarios of SLR by 2100 (from 44- to 161-cm rise) with a static inundation approach. Exposure to coastal flooding under future SLR was assessed for 938 Mediterranean coastal sites (≤30 km from the coastline) where 145 species of nonbreeding birds were monitored as part of the International Waterbird Census and for which the monitoring area was delineated by a polygon (64.3% of the coastal sites monitored in the Mediterranean region). Thirty-four percent of sites were threatened by future SLR, even under the most optimistic scenarios. Protected study sites and study sites of international importance for waterbirds were, respectively, 1.5 and 2 times more exposed to SLR than the other sites under the most optimistic scenario. Accordingly, we advocate for the development of a prioritization scheme to be applied to these wetlands for the implementation of strategies for adaptation to SLR to anticipate the effects of coastal flooding. Our study provides major guidance for conservation planning under global change in several countries of the Mediterranean region.
Thermal adjustment of waterbird communities to climate warming is crucial but hampered by natural habitat conversion, increasing their climatic debt. As it is, in contrast, facilitated in protected ...areas, assessing the adequacy of the current protected areas network with respect to future climate and land-use changes and identifying priority sites to protect is of major importance. In this study, we assess the thermal adjustment limitations that non-breeding waterbird communities might experience by the end of the 21st century in the Mediterranean region to highlight priorities for wetland protection. Priorities were set by combining the exposure of waterbird communities to natural habitat conversion and climate warming with their thermal specialization. The latter was calculated using winter abundance data of 151 species from 2932 sites of the International Waterbird Census in 21 Mediterranean countries. Exposure was assessed using future projections of temperature and land-use under four CMIP6 scenarios (SSP1–2.6, SSP2–4.5, SSP3–7.0, and SSP5–8.5). We found that strictly protected areas are located in wetlands whose waterbird communities, without protection, would likely experience high limitations in thermal adjustment in the coming decades. This highlights that the location of existing protected areas may effectively support the thermal adjustment of waterbird communities to future climate warming. However, 490 sites considered at risk lack protection, including 32 sites of international importance for waterbirds, stressing the need to strengthen the protected areas network in these sites in priority. Our study provides important guidance for conservation planning in the Mediterranean region to support waterbird responses to climate change.
Display omitted
PDF
