SPP 1685: Ecosystem Nutrition: Forest Strategies for Limited Phosphorus Resources

SPP 1685：生态系统营养：有限磷资源的森林战略

• 批准号: 220238996
• 金额: --
• 依托单位: Professur für Bodenökologie
• 依托单位国家: 德国
• 项目类别: Priority Programmes
• 财政年份: 2013
• 资助国家: 德国
• 起止时间: 2012-12-31 至 2021-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/220238996?language=en
• 关键词: SPP; 1685; Ecosystem; Nutrition; Forest

Phosphorus is a limited resource and there is increasing debate regarding the principles of tight P recycling. Forest ecosystems show commonly high P use efficiencies and the processes behind this phenomenon are still unresolved. The members of the priority programme SPP 1685 have applied and refined the concept of ecosystem nutrition, which is based on the integration of results obtained from different spatial and temporal scales and from different disciplines, to unravel these processes. The studies conducted in the first phase, were directed to the identification of processes, interactions and feedbacks associated with the P nutrition of temperate forest ecosystems. We tested the hypothesis that plant and microbial communities established at P rich sites follow a P acquiring strategy introducing P from primary minerals into the biogeochemical P cycle. With decreasing P supply by the parent material, the strategy changes into tight P cycling to sustain the P demand of the forests. The analyses of five beech forest ecosystems on silicate rock representing a P geosequence with different parent materials and thus different total P stocks (160 ¿ 900 g P m-2; down to 1m soil depth) were adjusted to test this hypothesis. These analyses were linked to additional experimental approaches used by individual projects. Spatial scales from micrometers up to the catchment scale and temporal scales from seconds to millions of years have been covered by individual projects. In addition, many methods have been developed or adjusted to the specific requirements related to the challenging analysis of P in forest ecosystems, where P concentrations are in part extremely low. These methodological developments provide promising tools also for ongoing analyses planned for the second phase of the priority programme. Valuable information regarding the P-status of soils and its spatial heterogeneity, the response of plants, plant roots and microbes, and regarding the P fluxes within the ecosystems has been gathered in the first phase of the priority programme. In fact, many of the studies provide evidence for intense P acquiring of beech forests at P- rich sites and tight recycling of P at P- poor sites. Changes in the diversity, activity and spatial distribution soil organisms and in the P-uptake efficiency of plant roots and the transfer of P within plants seem to be the processes behind these different strategies. By using these strategies the organisms change the soil properties, for example the turnover rate of the forest floor, the quality of soil organic matter and the spatial distribution and speciation of P in soils as well as P fluxes. The experience and developments gained from the first phase provide unique opportunities to address still open questions regarding controls and drivers of P strategies, relations between the P dynamics on different temporal and spatial scales or between P and OC dynamics, and human impact on P nutrition.

磷是一种有限的资源，关于紧密回收磷的原则的争论越来越多。森林生态系统普遍表现出较高的磷利用效率，这一现象背后的过程仍未解决。优先方案SPP 1685的成员应用并完善了生态系统营养的概念，其基础是综合从不同空间和时间尺度和不同学科获得的成果，以揭示这些过程。第一阶段的研究旨在确定与温带森林生态系统磷营养有关的过程、相互作用和反馈。我们验证了一种假设，即在富磷地点建立的植物群落和微生物群落遵循一种将初级矿物中的磷引入生物地球化学磷循环的磷获取策略。随着母质磷供应的减少，这种策略转变为紧密的磷循环，以维持森林对磷的需求。对硅酸盐岩层上的5个山毛榉森林生态系统进行了分析，它们代表了不同母质的P地质序列，从而调整了不同的总磷储量(160？900g Pm-2；低至1m土层)以检验这一假说。这些分析与个别项目使用的其他实验方法有关。各个项目涵盖了从微米到集水区的空间尺度和从几秒钟到数百万年的时间尺度。此外，已经开发或调整了许多方法，以适应与森林生态系统中磷的挑战性分析有关的具体要求，因为在森林生态系统中，磷的浓度部分极低。这些方法的发展也为优先方案第二阶段计划进行的持续分析提供了有希望的工具。在优先方案的第一阶段，收集了关于土壤的磷状况及其空间异质性、植物、植物根和微生物的反应以及关于生态系统内磷通量的宝贵信息。事实上，许多研究提供了在富磷地点山毛榉森林对磷的密集获取和在缺磷地点磷的紧密循环的证据。土壤有机体的多样性、活性和空间分布的变化，以及植物根系对磷的吸收效率和植物体内磷的转移似乎是这些不同策略背后的过程。通过使用这些策略，生物改变了土壤性质，如森林地面周转率、土壤有机质质量、土壤中P的空间分布和形态以及P的通量。从第一阶段获得的经验和发展为解决仍然悬而未决的问题提供了独特的机会，这些问题涉及磷战略的控制和驱动因素、不同时间和空间尺度上的磷动态之间的关系、磷和有机碳动态之间的关系以及人类对磷营养的影响。