Community patch dynamics governs direct and indirect nutrient recycling by aggregated animals across spatial scales
Community patch dynamics governs direct and indirect nutrient recycling by aggregated animals across spatial scales
复制标题
DOI：
10.1111/1365-2435.13982
复制
发表时间：
2022-01-12
影响因子：
5.2
通讯作者：
Forshay, Kenneth J.
中科院分区：
文献类型：
--
作者：
Atkinson, Carla L.;Forshay, Kenneth J.
1.动物可以对生态系统产生广泛的影响，因为它们改变了生态系统的地球化学和物理环境。特别是，当动物出现在高密度时，这些影响可能导致物理环境和地球化学热点或热点时刻的急剧变化。虽然迄今为止大多数研究都集中在动物在地球化学循环中的直接作用，但很少有人研究动物如何间接影响跨尺度的地球化学循环。淡水贻贝在世界范围内的许多河流生态系统中以空间异质性、密集性和物种丰富性的集合体出现。在这里，我们研究了贻贝群落如何（a）直接影响颗粒和溶解营养盐的通量和（B）间接影响N-2生产的通量，通过反硝化作用，跨越贻贝生物量的梯度和群落组成的差异，在斑块（0.25米（2））和河流到达尺度（60-80米）。我们结合测量氨（N）和可溶性活性磷（P）的排泄和C，N和P的生物沉积速率为10种生物量和分布估计7个混合物种聚集量化贻贝的直接贡献，生态地球化学循环和空间异质性的影响。此外，我们还对沉积物进行了精细的空间尺度采样，以确定贻贝生物量和丰富度如何影响斑块尺度和河段尺度下潜在的反硝化（间接通量）速率。我们预测，增加贻贝生物量将导致更大的直接和间接通量的营养盐，表现在异质性的营养盐再分配内和之间的流河段。我们还预测，群落组成的变化将导致不同的营养排泄和排泄化学计量。我们的研究结果表明，贻贝聚集直接影响可溶性和颗粒营养盐通量与社会组成，特别是系统发育部落组成，控制化学计量。贻贝聚集也间接影响营养盐通量更大的贻贝生物量和物种丰富度导致更高的反硝化率介导的沉积物和营养物质的可用性增强的相互作用。我们的研究结果强调了斑块社区作为地球化学控制点的重要性。可以在本文的支持信息中找到免费的简明语言摘要。
1. Animals can have pervasive effects on ecosystems as they modify their biogeochemical and physical environments. In particular, when animals occur in high densities these effects can result in dramatic changes in the physical environment and biogeochemical hotspots or hot moments. While most research to date has focused on the direct role of animals in biogeochemical cycles, few have examined how animals indirectly influence biogeochemical cycles across scales.2. Freshwater mussels occur as spatially heterogeneous, dense and species-rich aggregations in many river ecosystems world-wide. Here we examined how mussel communities (a) directly influence the flux of particulate and dissolved nutrients and (b) indirectly effect the flux of N-2 production, via denitrification, across a gradient of mussel biomass and differences in community composition at the patch- (0.25 m(2)) and stream reach-scales (60-80 m).3. We combined measurements of ammonia (N) and soluble reactive phosphorous (P) excretion and C, N and P biodeposition rates for 10 species with biomass and distribution estimates for seven mixed-species aggregations to quantify direct mussel contributions to biogeochemical cycling and the spatial heterogeneity of their impact. Additionally, we sampled sediments at a fine spatial scale to determine how mussel biomass and richness influence potential denitrification (indirect flux) rates at the patch- and reach-scales.4. We predicted that increasing mussel biomass would lead to greater direct and indirect fluxes of nutrients, manifesting in heterogeneous nutrient redistribution within and among stream reaches. We also predicted that variation in community composition would result in differential nutrient excretion and egestion stoichiometries.5. Our results indicate that mussel aggregations directly influence soluble and particulate nutrient fluxes with community composition, particularly phylogenetic tribe composition, controlling the stoichiometry. Mussel aggregations also indirectly influenced nutrient fluxes as greater mussel biomass and species richness resulted in higher denitrification rates as mediated by their interactions with the sediments and enhancement of nutrient availability. Our results underscore the importance of patchy communities in acting as biogeochemical control points. A free Plain Language Summary can be found within the Supporting Information of this article.