Nutrient resorption from senescing tissues is the most critical nutrient source for plants in degradation grasslands, playing critical roles to primary productivity and interspecies competitiveness. Hence within-species and among-species variation of nutrient resorption is one of the mechanisms explaining the increasing productivity and decreasing biodiversity after enclosure. Yet, the response of plant nutrient resorption to enclosure remains poorly documented. We conducted a 6-year manipulative field study to estimate the effects of enclosure on nutrient resorption efficiency in five dominant species in a degraded subalpine pasture. Both soil, mature and senesced leaves showed significant increases in N, P, and K contents in response to enclosure. Despite some species-specific differences, enclosure generally increased the nutrient resorption in graminoids, but decreased in forbs (with the exception of phosphorus for Potentilla anserine), indicating an important difference in the adaptation of plant functional types to enclosure which may in turn strongly impact the productivity and structure of pasture vegetation under long-term enclosure. This study shows the positive effects of enclosure management on soil and plant nutrients accumulation, and our results highlight the importance of among-species and within-species variations in plant nutrient resorption to explain the effects of enclosure on biodiversity loss and productivity increase in a degraded ecosystem.

中文翻译：

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围栏增加了亚高山牧场衰老叶片的养分吸收

衰老组织的营养吸收是退化草原植物最重要的营养来源，对初级生产力和种间竞争力起着至关重要的作用。因此，养分吸收的物种内和物种间变化是解释围栏后生产力增加和生物多样性减少的机制之一。然而，植物养分吸收对围栏的反应仍然鲜有记载。我们进行了一项为期 6 年的人工田间研究，以估计围栏对退化的亚高山牧场中五种优势物种养分吸收效率的影响。土壤、成熟和衰老的叶子都显示出响应于围栏的 N、P 和 K 含量显着增加。尽管存在一些物种特异性差异，围栏通常会增加禾本科植物的养分吸收，但会减少杂草（Potentilla anserine 的磷除外），表明植物功能类型对围栏的适应存在重要差异，这可能反过来强烈影响牧场植被的生产力和结构长期封闭环境下。这项研究显示了围栏管理对土壤和植物养分积累的积极影响，我们的结果强调了植物养分吸收的物种间和物种内变化的重要性，以解释围栏对退化的生物多样性丧失和生产力提高的影响。生态系统。表明植物功能类型适应围栏的重要差异，这可能反过来强烈影响长期围栏下牧场植被的生产力和结构。这项研究显示了围栏管理对土壤和植物养分积累的积极影响，我们的结果强调了植物养分吸收的物种间和物种内变化的重要性，以解释围栏对退化的生物多样性丧失和生产力提高的影响。生态系统。表明植物功能类型适应围栏的重要差异，这可能反过来强烈影响长期围栏下牧场植被的生产力和结构。这项研究显示了围栏管理对土壤和植物养分积累的积极影响，我们的结果强调了植物养分吸收的物种间和物种内变化的重要性，以解释围栏对退化的生物多样性丧失和生产力提高的影响。生态系统。