Tropical tree growth is correlated with soil phosphorus, potassium, and calcium, though not for legumes
Tropical tree growth is correlated with soil phosphorus, potassium, and calcium, though not for legumes
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DOI：
10.1890/11-1013.1
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发表时间：
2012-05-01
影响因子：
6.1
通讯作者：
Finley, Andrew O.
中科院分区：
文献类型：
--
作者：
Baribault, Thomas W.;Kobe, Richard K.;Finley, Andrew O.
人们普遍认为热带森林生产力受到土壤磷(P)的限制，但消耗P的生物地球化学过程也可能消耗碱阳离子，表明多重资源限制。几种资源的限制可能来自物种和功能多样性，以及群体之间资源需求的差异，包括将磷限制最小化的生态生理策略。我们假设树木生长与土壤碱阳离子和磷有效性呈正相关，与本地竞争呈负相关；间接利用固定氮获取其他资源时，豆科植物生长与土壤资源呈弱相关；低密度树种的生长与土壤资源有效性的关系比高密度树种的生长与土壤资源有效性的关系更强。测量了位于低地潮湿热带森林自然土壤资源梯度上的5个已测绘林分的直径生长和土壤资源有效性（哥斯达黎加La Selva Biological Station）。利用贝叶斯多元空间回归模型估计了每棵树的土壤资源有效性和相关的不确定性，其中单个树的生长是直径、当地邻居和土壤资源的函数。另外，利用线性回归对立地水平平均树木生长和资源可用性进行建模。单株直径生长和立地平均基面积增加与土壤碱基阳离子和磷含量相关，但与氮含量关系不大；只有3种植物的个体生长与邻域指数呈负相关。豆科植物的生长在个体和立地水平上与土壤资源无关。当以木材密度对树种进行分类时，生长与土壤磷或碱阳离子有效性相关，其中密度最低的树种与土壤磷的相关性最强。一些资源可能会限制热带森林的生产力，因为树木生长与土壤磷和碱阳离子的相关性相似，但官能团的响应不同。豆科植物与土壤资源的生长关系可以忽略不计，这表明固氮可以缓解矿质养分的限制。土壤磷与低密度树种生长、碱阳离子与高密度树种生长的相关性表明不同功能群间资源需求存在差异。因此，热带树木的生长可能受到碱基和/或磷的限制，资源限制的程度和类型取决于功能或分类类群。
Tropical forest productivity is widely assumed to be limited by soil phosphorus (P), but biogeochemical processes that deplete P also could deplete base cations, suggesting multiple resource limitation. Limitation by several resources could arise from species and functional diversity and from variation among groups in resource requirements, including ecophysiological strategies that minimize P limitation. We hypothesized that tree growth is positively related to soil base cation and P availability and negatively related to local competition; Fabaceae growth is weakly correlated with soil resources if fixed N is used indirectly to acquire other resources; growth of species with low wood density is more strongly related to soil resource availability than that of species with high wood density. Diameter growth and soil resource availability were measured in five mapped stands situated across natural soil resource gradients in lowland wet tropical forest (La Selva Biological Station, Costa Rica). Soil resource availability, and associated uncertainty, was estimated for each tree using a Bayesian multivariate spatial regression model, with individual tree growth being a function of diameter, local neighborhood, and soil resources. Separately, site-level mean tree growth and resource availability were modeled using linear regression. Individual diameter growth and site mean basal area increment correlated with soil base cations and P, but rarely with N; individual growth correlated negatively with neighborhood index for only three species. Growth of Fabaceae was unrelated to soil resources at both individual and site levels. When species were categorized by wood density, growth was related to soil P or base cation availability, with the strongest correlation between the lowest-density species and soil P. Several resources may limit tropical forest productivity, because tree growth was similarly correlated with soil P and base cations, but functional groups responded differently. Negligible growth relationships with soil resources in Fabaceae suggest that N fixation may alleviate mineral nutrient limitations. Correlations of soil P with growth of species of low wood density and base cations with species of higher density suggests variation in resource demands among functional groups. Thus, tropical tree growth may be limited by base cations and/or P, with degree and type of resource limitation dependent on functional or taxonomic group.