Key Laboratory of Wetland Ecology and Environment, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, 4888 Shengbeida Road, Changchun 130102, China; Department of Ecology and Genetics, Evolutionary Biology Centre, Uppsala University, Norbyvägen 18D, SE-752 36 Uppsala, Sweden.
Key Laboratory of Wetland Ecology and Environment, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, 4888 Shengbeida Road, Changchun 130102, China.
Sci Total Environ. 2018 Mar;616-617:198-207. doi: 10.1016/j.scitotenv.2017.10.300. Epub 2017 Nov 6.
The information of species' response (optimum or critical limits along environmental gradients) is a key to understanding ecological questions and to design management plans. A large number of plots (762) from 70 transects of 13 wetland sites in Northeast China were sampled along flooding gradient from marsh to wet meadow. Species response (abundance and occurrence) to flooding were modelled with Generalized Additive Models for 21 dominant plant species. We found that 20 of 21 species showed a significant response to flooding for the occurrence and abundance models, and four types of response were found: monotonically increasing, monotonically decreasing, skewed unimodal and symmetric unimodal. The species with monotonically increasing response have the deepest flooding optimum and widest niche width, followed by those with unimodal curve, and the monotonically decreasing ones have the smallest values. The optima and niche width (whether based on occurrence or abundance models) both significantly correlated with the frequency, but not with mean abundance. Abundance models outperformed occurrence models based on goodness of fit. The abundance models predicted a rather sharp shift from dominance of helophytes (Carex pseudo-curaica and C. lasiocarpa) to wet meadow species (Calamagrostis angustifolia and Carex appendiculata) if water levels drop from about 10cm above soil surface to below the surface. The defined optima and niche width based on the abundance models can be applied to better instruct restoration management. Given the time required to collect abundance data, an efficient strategy could be to monitor occurrence in many plots and abundance in a subset of these.
物种响应信息（沿环境梯度的最佳或临界限制）是理解生态问题和设计管理计划的关键。在中国东北地区的 13 个湿地站点的 70 个样带中，沿着从沼泽到湿地草甸的洪水梯度采集了大量（762 个）样方。使用广义加性模型对 21 种主要植物物种的物种响应（丰度和出现）进行了建模。我们发现，在出现和丰度模型中，21 种中有 20 种对洪水有显著的响应，并且发现了四种响应类型：单调递增、单调递减、偏单峰和对称单峰。具有单调递增响应的物种具有最深的洪水最佳值和最宽的生态位宽度，其次是具有单峰曲线的物种，而单调递减的物种具有最小的值。最佳值和生态位宽度（无论是基于出现还是丰度模型）都与频率显著相关，但与平均丰度无关。丰度模型的拟合优度优于出现模型。丰度模型预测，如果水位从土壤表面上方约 10 厘米降至表面以下，水生植物（假薹草和 Lasio-carpa 薹草）将向湿地草甸物种（狭叶细叶薹草和丛毛薹草）转变。基于丰度模型定义的最佳值和生态位宽度可以更好地指导恢复管理。考虑到收集丰度数据所需的时间，一种有效的策略可以是在许多样方中监测出现情况，并在其中一部分样方中监测丰度。
