Seedling growth declines in warmed tropical forest soils
Seedling growth declines in warmed tropical forest soils
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DOI：
10.1111/btp.13238
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发表时间：
2023-08
期刊：
影响因子：
2.1
通讯作者：
A. Nottingham;Maria Montero‐Sanchez;M. Slot;Hubert A. Szczygieł;E. Velasquez;P. Meir
中科院分区：
文献类型：
--
作者：
A. Nottingham;Maria Montero‐Sanchez;M. Slot;Hubert A. Szczygieł;E. Velasquez;P. Meir
植物对气候变暖的反应可能会对进一步的气候变化产生很大的反馈。这种反馈对热带森林特别重要，因为那里是植物生产力和生物多样性的全球高峰。在这里，我们测试了热带森林树木幼苗生长，光合作用和草食动物对3年原位全土壤剖面变暖的反应。我们研究了六个物种，其中三个是已知的固氮剂，我们假设生长的变暖反应将由植物的营养物质可用性介导。在不同物种中，与环境温度下的土壤相比，温暖土壤中的生长显著降低，并且观察到光饱和光合作用的相同模式，表明生长下降与C固定减少相关。在物种内，两个物种的相对生长下降是显着的，Inga laurina和Tachiopterversicolor，这两个物种都是固氮菌。总之，我们的研究结果表明，生长下降可能是由于变暖对固氮的负面影响，而不是通过土壤有机质的养分矿化的变化，在干湿季过渡期间，土壤有机质对N的矿化没有变化，而对P的矿化增加。总的来说，我们的研究表明，地下变暖导致幼苗生长和光合作用的物种特异性下降，需要进一步调查，这种生长下降在固氮物种中更大。
The response of plants to a warming climate could have a large feedback on further climatic change. This feedback is especially important for tropical forests, where the global peak in plant productivity and biodiversity occurs. Here we test the response of tropical forest tree seedling growth, photosynthesis and herbivory to 3 years of in situ full‐soil profile warming. We studied six species, three of which are known nitrogen‐fixers and we hypothesized that the warming response of growth will be mediated by nutrient availability to plants. Across species, growth was significantly lower in warmed soil compared to soil at ambient temperature, and the same pattern was observed for light‐saturated photosynthesis, pointing toward a growth decline associated with decreased C fixation. Within species, the relative growth decline was significant for two species, Inga laurina and Tachigali versicolor, both of which are N‐fixers. Together our results suggest a growth decline may have resulted from a negative effect of warming on N‐fixation, rather than via changes in nutrient mineralization from soil organic matter, which was unchanged for N and increased for P during the dry‐to‐wet season transition. Overall, our study demonstrates that belowground warming causes species‐specific declines in the growth and photosynthesis of seedlings, with a suggestion—requiring further investigation—that this growth decline is larger in N‐fixing species.