Trade‐offs in above‐ and below‐ground biomass allocation influencing seedling growth in a tropical forest
Trade‐offs in above‐ and below‐ground biomass allocation influencing seedling growth in a tropical forest
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DOI：
10.1111/1365-2745.13543
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发表时间：
2020-11
影响因子：
5.5
通讯作者：
M. Umaña;M. Cao;Luxiang Lin;N. Swenson;Caicai Zhang
中科院分区：
文献类型：
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作者：
M. Umaña;M. Cao;Luxiang Lin;N. Swenson;Caicai Zhang
植物将生物量分配给不同的器官，以响应资源变化，以最大限度地提高性能，但我们缺乏一个框架，充分整合植物对地上和地下资源同时变化的反应。虽然传统上，最优分配理论（OPT）已经解释了生物量分配模式对单一限制资源的响应，但众所周知，在自然群落中，多种资源限制了生长。我们研究的权衡参与植物生物量分配模式及其对植物生长的影响下，可变的地下和地上资源光，土壤N和P的幼苗社区。我们收集了97个物种的1，900多棵幼苗的叶、茎和根质量分数信息，并结合中国热带森林非生物资源的生长数据和局部尺度变化。我们确定了两个权衡轴，定义了幼苗的质量分配策略-分配到光合组织与非光合组织，分配到根与茎-这对土壤P和N以及光照的变化做出了反应。然而，分配模式并不总是遵循OPT的预测，即植物应该将生物量分配给获得最有限资源的器官。有限的土壤氮导致以牺牲非光合组织为代价的高分配给叶，而相反的趋势被发现在响应有限的土壤磷。此外，在地上和地下资源（光和土壤磷）的共同限制导致大量分配给茎以牺牲根。最后，我们发现，在高光照和土壤P的条件下，幼苗的生长增加，这些幼苗在光合作用方面的投资超过非光合作用组织或/和以茎为代价将质量分配给根。合成.地上和地下组织的生物量分配模式由两个独立的权衡来描述，这两个权衡允许植物具有不同的分配策略（例如，以茎为代价的高根分配或以非光合组织为代价的高叶分配），并在不同的限制资源下增强生长。确定驱动生物量分配的权衡对于解开植物对不同森林群落中资源同时变化的反应是重要的。
Plants allocate biomass to different organs in response to resource variation for maximizing performance, yet we lack a framework that adequately integrates plant responses to the simultaneous variation in above‐ and below‐ground resources. Although traditionally, the optimal partition theory (OPT) has explained patterns of biomass allocation in response to a single limiting resource, it is well‐known that in natural communities multiple resources limit growth. We study trade‐offs involved in plant biomass allocation patterns and their effects on plant growth under variable below‐ and above‐ground resources—light, soil N and P—for seedling communities. We collected information on leaf, stem and root mass fractions for more than 1,900 seedlings of 97 species paired with growth data and local‐scale variation in abiotic resources from a tropical forest in China. We identified two trade‐off axes that define the mass allocation strategies for seedlings—allocation to photosynthetic versus non‐photosynthetic tissues and allocation to roots over stems—that responded to the variation in soil P and N and light. Yet, the allocation patterns did not always follow predictions of OPT in which plants should allocate biomass to the organ that acquires the most limiting resource. Limited soil N resulted in high allocation to leaves at the expense of non‐photosynthetic tissues, while the opposite trend was found in response to limited soil P. Also, co‐limitation in above‐ and below‐ground resources (light and soil P) led to mass allocation to stems at the expense of roots. Finally, we found that growth increased under high‐light availability and soil P for seedlings that invested more in photosynthetic over non‐photosynthetic tissues or/and that allocated mass to roots at the expense of stem. Synthesis. Biomass allocation patterns to above‐ and below‐ground tissues are described by two independent trade‐offs that allow plants to have divergent allocation strategies (e.g. high root allocation at the expense of stem or high leaf allocation at the expense of allocation to non‐photosynthetic tissues) and enhance growth under different limiting resources. Identifying the trade‐offs driving biomass allocation is important to disentangle plant responses to the simultaneous variation in resources in diverse forest communities.