Aridity drives phylogenetic diversity and species richness patterns of nitrogen‐fixing plants in North America
Aridity drives phylogenetic diversity and species richness patterns of nitrogen‐fixing plants in North America
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DOI：
10.1111/geb.13535
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发表时间：
2022-05
影响因子：
6.4
通讯作者：
J. Doby;Daijiang Li;R. Folk;C. Siniscalchi;R. Guralnick
中科院分区：
文献类型：
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作者：
J. Doby;Daijiang Li;R. Folk;C. Siniscalchi;R. Guralnick
固氮植物是全球植物群落的重要组成部分，但固氮植物多样性的驱动因素，特别是在温带地区，仍然没有得到充分的研究。在这里，我们研究了北美温带大部分地区的固氮和非固氮植物系统发育多样性（PD）和物种丰富度（SR）的大规模模式，重点是与土壤氮和干旱的关系。我们还测试了是否外来物种，有或没有固氮共生，与本地物种相比，具有更少的非生物限制。位置美国和波多黎各。时间段当前。主要分类群研究维管植物，重点是固氮组方法利用美国国家生态观测网（氖）植物样地数据，沿沿着选取所有样地的植物样地数据（N固定-非N固定和天然-外来），计算小区级SR，PD和平均成对系统发育距离（MPD）。然后，我们使用线性混合模型来调查多样性值和关键土壤测量之间的关系，沿着与干旱，温度和火灾frequency.ResultsAridity是唯一的预测比例系统发育多样性的固氮菌。在干旱地区，固氮菌的SR仍然略有下降，而原生固氮菌的MPD随着干旱而增加，这表明与原生非固氮菌相比，在最干旱的条件下，固氮菌具有独特的谱系。在低氮土壤中，天然固氮菌和非固氮菌的SR均增加。干旱并没有影响SR的外来非固氮，不像其他群体，而外来固氮菌表现出较低的MPD在越来越高的N土壤中，这表明过滤，相反的是发现本地N fixers.Main conclusionsOur研究结果表明，它不是氮，或任何土壤养分，具有最强的影响相对成功的固氮植物群落。相反，干旱是关键的驱动力，至少对本地物种，符合其他生物群落的经验结果，并增加了对固氮作为避免水分流失的关键机制的理解。
AimNitrogen (N)‐fixing plants are an important component of global plant communities, but the drivers of N‐fixing plant diversity, especially in temperate regions, remain underexplored. Here, we examined broad‐scale patterns of N‐fixing and non‐fixing plant phylogenetic diversity (PD) and species richness (SR) across a wide portion of temperate North America, focusing on relationships with soil N and aridity. We also tested whether exotic species, with and without N‐fixing symbiosis, have fewer abiotic limitations compared with native species.LocationUSA and Puerto Rico.Time periodCurrent.Major taxa studiedVascular plants, focusing on N‐fixing groups (orders Fabales, Fagales, Rosales and Cucurbitales).MethodsWe subset National Ecological Observatory Network (NEON) plant plot data from all sites along two axes (N fixing–non‐N fixing and native–exotic), calculating plot‐level SR, PD and mean pairwise phylogenetic distance (MPD). We then used linear mixed models to investigate relationships between diversity values and key soil measurements, along with aridity, temperature and fire frequency.ResultsAridity was the sole predictor of proportional phylogenetic diversity of N fixers. The SR of N fixers still decreased marginally in arid regions, whereas native N‐fixer MPD increased with aridity, indicative of unique lineages of N fixers in the driest conditions, in contrast to native non‐N fixers. The SR of both native N fixers and non‐N fixers increased in low‐N soils. Aridity did not affect SR of exotic non‐N fixers, unlike other groups, whereas exotic N fixers showed lower MPD in increasingly high‐N soils, suggesting filtering, contrary what was found for native N fixers.Main conclusionsOur results suggest that it is not nitrogen, or any soil nutrient, that has the strongest effect on the relative success of N fixers in plant communities. Rather, aridity is the key driver, at least for native species, in line with empirical results from other biomes and increased understanding of N fixation as a key mechanism to avoid water loss.