Human eutrophication drives biogeographic salt marsh productivity patterns in China
Human eutrophication drives biogeographic salt marsh productivity patterns in China
复制标题
人类富营养化驱动中国盐沼生物地理生产力模式
DOI：
10.1002/eap.2045
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发表时间：
2019
影响因子：
5
通讯作者：
Bo Li
中科院分区：
文献类型：
--
作者：
Xiao Xu;Hao Liu;Chenhao Zhou;Lianghao Pan;Changming Fang;Ming Nie;Bo Li
盐沼是重要的天然碳汇，具有很大的吸收外源养分输入的能力。然而，营养物质对生物地理生产力模式的影响在盐沼中的研究还很少。我们进行了实地调查，以研究复杂的环境如何影响中国海岸线上18,000公里纬度梯度上的两种常见盐沼植物--入侵互花米草和原生芦荟的生产力。我们采集了地上生物量的峰值作为生产力的指标，并测量了叶功能性状(例如叶面积、比叶面积[SLA]、叶氮[N]和磷[P])、土壤养分(溶解无机N[DIN]和有效P[AP])和盐度。我们收集了年平均气温(MAT)和外源养分(N和P)的数据。然后，我们利用线性混合效应模型和结构方程模型检验了这些非生物因素是如何影响盐沼生产力的。使用基于特征的方法，我们还研究了盐沼生产力如何响应纬度范围内不断变化的环境。与温度和其他变量(如DIN、AP、盐度)相比，外源营养物质(N和P)是解释两者生物地理生产力格局的主要因素。Alterniflora和P.澳大利亚人。与叶大小相关的性状(如叶面积)，而不是叶经济性状(如SLA、叶N和P)可以用来表明外源营养对这两个物种生产力的积极影响。我们的结果表明，人类富营养化超过温度成为生物地理盐沼生产力格局的主要驱动力，挑战了目前主要由温度控制生物地理生产力格局的模型。我们的发现对OFS的管理具有潜在的广泛意义。互花米草是全球入侵者，因为它受益于沿海富营养化。此外，需要将外源养分可获得性和叶片大小整合到用于预测盐沼全球植物生产力的地球系统模型中。
Salt marshes are important natural carbon sinks with a large capacity to absorb exogenous nutrient inputs. The effects of nutrients on biogeographic productivity patterns, however, have been poorly explored in salt marshes. We conducted field surveys to examine how complex environments affect productivity of two common salt marsh plants, invasiveSpartina alternifloraand nativePhragmites australis, along an 18,000‐km latitudinal gradient on the Chinese coastline. We harvested peak aboveground biomass as a proxy for productivity, and measured leaf functional traits (e.g., leaf area, specific leaf area [SLA], leaf nitrogen [N] and phosphorus [P]), soil nutrients (dissolved inorganic N [DIN] and available P [AP]), and salinity. We compiled data on mean annual temperature (MAT) and exogenous nutrients (both N and P). Then, we examined how these abiotic factors affect salt marsh productivity using both linear mixed effect models and structural equation modeling. Using a trait‐based approach, we also examined how salt marsh productivity responds to changing environments across latitude. Exogenous nutrients (both N and P), compared with temperature and other variables (e.g., DIN, AP, salinity), were the dominant factors in explaining the biogeographic productivity patterns of bothS. alternifloraandP. australis. Leaf size‐related traits (e.g., leaf area), rather than leaf economic traits (e.g., SLA, leaf N and P), can be used to indicate the positive effects of exogenous nutrients on the productivity of these two species. Our results demonstrated that human eutrophication surpassed temperature as the major driver of biogeographic salt marsh productivity pattern, challenging current models in which biogeographic productivity pattern is primarily controlled by temperature. Our findings have potential broad implications for the management ofS. alterniflora, which is a global invader, as it has benefited from coastal eutrophication. Furthermore, exogenous nutrient availability and leaf size need to be integrated into earth system models that are used to predict global plant productivity in salt marshes.