Impacts of pollution and climate change on ombrotrophic Sphagnum species in the UK: analysis of uncertainties in two empirical niche models
Impacts of pollution and climate change on ombrotrophic Sphagnum species in the UK: analysis of uncertainties in two empirical niche models
复制标题
污染和气候变化对英国反营养泥炭藓物种的影响：两个经验生态位模型的不确定性分析
DOI：
--
复制
发表时间：
2010
期刊：
影响因子：
--
通讯作者：
Joanna M. Clark
中科院分区：
文献类型：
--
作者：
S. Smart;P. Henrys;W. Scott;Jane R. Hall;C. Evans;A. Crowe;E. Rowe;U. Dragosits;T. Page;J. D. Whyatt;A. Sowerby;Joanna M. Clark
预测气候变化对生态系统和生物多样性的影响的一个重大挑战是对不同模型内部和之间出现的不确定性来源进行量化。统计物种生态位模型越来越受欢迎，但还没有确定一种反映不同情况下不同表现的最佳技术。我们的目标是量化与应用两种互补的建模技术相关的不确定性。用广义线性混合模型(GLMM)和广义加性混合模型(GAMM)模拟了英国泥炭地富营养型泥炭疽实现的生态位。然后，根据对气候变化和大气氮硫沉积的预测，这些模型被用来预测2020至2050年间泥炭藓覆盖率的变化。GLMM预测中90%以上的变化是由于生态位模型参数的不确定性，GAMM下降到14%。在剔除了其他因素后，英国泥炭地泥炭苔藓盖度预测值的平均变化是第二大变化来源(GLMM为8%，GAMM为86%)。需要权衡GAMG的更好性能与其过度匹配训练数据的趋势。虽然我们的生态位模型只是一个初步的近似值，但我们使用它们对气候变化、氮和硫沉积的相对重要性以及泥炭藻盖层预期最大变化的地理位置进行了初步评估。预计的覆盖率变化都很小(在平均4平方米的单位面积中一般为1%)，但也有很大的不确定性。预计受气候变化和大气污染影响最大的泥炭地是达特穆尔、布雷肯灯塔和西湖区。
A significant challenge in the prediction of climate change impacts on ecosystems and biodiversity is quantifying the sources of uncertainty that emerge within and between different models. Statistical species niche models have grown in popularity, yet no single best technique has been identified reflecting differing performance in different situations. Our aim was to quantify uncertainties associated with the application of 2 complimentary modelling techniques. Generalised linear mixed models (GLMM) and generalised additive mixed models (GAMM) were used to model the realised niche of ombrotrophic Sphagnum species in British peatlands. These models were then used to predict changes in Sphagnum cover between 2020 and 2050 based on projections of climate change and atmospheric deposition of nitrogen and sulphur. Over 90% of the variation in the GLMM predictions was due to niche model parameter uncertainty, dropping to 14% for the GAMM. After having covaried out other factors, average variation in predicted values of Sphagnum cover across UK peatlands was the next largest source of variation (8% for the GLMM and 86% for the GAMM). The better performance of the GAMM needs to be weighed against its tendency to overfit the training data. While our niche models are only a first approximation, we used them to undertake a preliminary evaluation of the relative importance of climate change and nitrogen and sulphur deposition and the geographic locations of the largest expected changes in Sphagnum cover. Predicted changes in cover were all small (generally <1% in an average 4 m2 unit area) but also highly uncertain. Peatlands expected to be most affected by climate change in combination with atmospheric pollution were Dartmoor, Brecon Beacons and the western Lake District.