Estimating the Direct and Indirect Impacts of Climate Change On Small Wetland Ecosystems

政府间气候变化专门委员会在2018年发布了一份报告，估计我们几乎肯定会在未来25年内看到气温上升1.5摄氏度的后果。证据明确表明，我们的气候正在发生变化，这些变化是由人类活动造成的，其经济和社会后果将是巨大和消极的。减轻气候变化的影响将需要对未来30-100年气候变化的影响进行合理准确的预测。 温度和降水量的变化可能对小型湿地群落产生直接和间接影响。直接影响是由于将某些生物推到它们能够茁壮成长或持续存在的温度或水文周期范围之外而造成的，间接影响是由于改变水生系统内物种之间的生物相互作用而造成的。这种由相互作用的变化引起的潜在间接影响的一个例子是在绿色青蛙和林蛙蝌蚪之间。绿色青蛙和树蛙受益于更深的直接影响，更持久的池塘，由于降水增加，因为他们不太可能经历死亡的池塘干燥的结果。然而，增加的水分周期对林蛙的有益影响可能被绿色蛙蝌蚪对林蛙卵的消耗增加或绿色蛙幼虫对林蛙幼虫的蛙病毒传播增加所抵消或抵消。 位于圣约翰的新玩法大学的胡拉汉实验室将使用天然池塘中的林蛙作为模型系统，辅以实验室实验和对未操作系统的观察，以研究变暖的直接和间接影响。我们将使用太阳能电池板加热装置和聚乙烯管，将新玩法CFB Gagetown长期实验湿地区的六个天然池塘的温度提高约6摄氏度。 每个操作池将与一个类似的控制池配对。我们将测量林蛙的生长、发育、存活率、两栖动物疾病的流行率和毒性，以及处理和控制池塘中的绿色青蛙和林蛙幼虫的丰度。 我们将建立预测模型，描述温度对林蛙生长，发育和生存的直接影响，以及变暖对林蛙捕食者（如绿色青蛙和龙蝇幼虫）和林蛙疾病（如壶菌病和蛙病毒）的间接影响。 这些预测模型将被政策制定者和保护专业人员用来制定政策和战略，以减轻气候变化对自然系统的影响。

The Intergovernmental Panel on Climate Change released a report in 2018 estimating the consequences of the 1.5o C increase in temperature that we are almost certain to see in the next 25 years. The evidence is unequivocal that our climate is changing, that the changes are caused by human activities and the economic and social consequences will be large and negative. Mitigation of climate change impacts is going to require reasonably accurate predictions of the effects of climate change over the next 30-100 years. Changes in temperature and precipitation are likely to have both direct and indirect impacts on small wetland communities. Direct impacts are caused by pushing some organisms outside the range of temperatures or hydro-period where they can thrive or persist and indirect impacts are caused by changing biological interactions among species within aquatic systems. One example of such a potential indirect effect caused by changes in interactions, is between green frog and wood frog tadpoles. Green frogs and wood frogs benefit from the direct effect of deeper, longer lasting ponds due to increased precipitation because they are less likely to undergo mortality as a result of pond drying. However, the beneficial effect on wood frogs of increased hydro-period may be offset or overwhelmed by increased consumption of wood frog eggs by green frog tadpoles or increased transmission of Rana virus from green frog larvae to wood frog larvae. The Houlahan lab at the University of New Brunswick in Saint John will use wood frogs in natural ponds as a model system supplemented by laboratory experiments and observations of unmanipulated systems, to examine the direct and indirect effects of warming. We will increase the temperature of six natural ponds at the Long-term Experimental Wetlands Area on CFB Gagetown in New Brunswick by ~ 6 degrees C using solar panel heating units and polyethylene tubing. Each of the manipulated ponds will be paired with a similar control pond. We will measure wood frog growth, development, survival, amphibian disease prevalence and virulence, and green frog and dragonfly larval abundance in treatment and control ponds. We will build predictive models describing the direct impacts of temperature on wood frog growth, development and survival and indirect impacts through effects of warming on wood frog predators such as green frogs and dragon fly larvae, and wood frog diseases such as chytridiomycosis and Rana virus. These predictive models will be used by policymakers and conservation professionals to develop policies and strategies to mitigate climate change impacts in natural systems.