高蓄水森林对于适应全球变暖下的干旱气候至关重要,一个核心问题是哪种类型的森林可以在生态系统中保护更多的水。本文探讨了森林结构,植物多样性,和土壤物理影响森林持水能力。我们通过测量1440个土壤和凋落物样品的持水量,调查了720个采样地块,8400片叶子,和1680个分支,共测量18,054棵树(28种)。持水量用四个土壤指数(Maxwc,最大持水能力;Fcwc,田间持水量;Cpwc,土壤毛细管持水能力;Ncpwc,非毛细管保水能力),两个垃圾度量(Maxwcl,垃圾的最大持水能力;Ewcl,垃圾的有效持水量),和树冠截留(C,该地块中所有树种的所有树枝和树叶的估计水截留总和)。我们发现大型树木地块的保水能力在垃圾中高出4-25%,54-64%在树冠中,土壤中的6-37%,而不是小型地块。与最低丰富度相比,较高的物种丰富度增加了所有土壤的持水能力。较高的Simpson和Shannon-Wiener地块的Ewcl和C比最低地块高10-27%。堆积密度与Maxwc的负相关性最强,Cpwc,和Fcwc,而田间土壤含水量对它们有积极影响。土壤物理学,森林结构,植物多样性解释了90.5%,5.9%,和0.2%的持水变化,分别。树的大小增加了C,Ncpwc,直接Ewcl(p<0.05),丰富度直接增加Ewcl(p<0.05)。然而,均匀角度指数(树木分布均匀度)的直接影响与土壤物理学的间接影响相平衡。我们的发现强调,大型树木和丰富物种的混交林可以有效地提高生态系统的持水能力。
High water-holding forests are essential for adapting to drought climates under global warming, and a central issue is which type of forests could conserve more water in the ecosystem. This paper explores how forest structure, plant diversity, and soil physics impact forest water-holding capacities. We investigated 720 sampling plots by measuring water-holding capacities from 1440 soil and litter samples, 8400 leaves, and 1680 branches and surveying 18,054 trees in total (28 species). Water-holding capacities were measured as four soil indices (Maxwc, maximum water-holding capacity; Fcwc, field water-holding capacity; Cpwc, soil capillary water-holding capacity; Ncpwc, non-capillary water-holding capacity), two litter metrics (Maxwcl, maximum water-holding capacity of litters; Ewcl, effective water-holding capacity of litters), and canopy interception (C, the sum of estimated water interception of all branches and leaves of all tree species in the plot). We found that water-holding capacity in the big-sized tree plots was 4-25 % higher in the litters, 54-64 % in the canopy, and 6-37 % in the soils than in the small-sized plots. The higher species richness increased all soil water-holding capacities compared to the lowest richness plot. Higher Simpson and Shannon-Wiener plots had 10-27 % higher Ewcl and C than the lowest plots. Bulk density had the strongest negative relations with Maxwc, Cpwc, and Fcwc, whereas field soil water content positively affected them. Soil physics, forest structure, and plant diversity explained 90.5 %, 5.9 %, and 0.2 % of the water-holding variation, respectively. Tree sizes increased C, Ncpwc, Ewcl directly (p < 0.05), and richness increased Ewcl directly (p < 0.05). However, the direct effects from the uniform angle index (tree distribution evenness) were balanced by their indirect effect from soil physics. Our findings highlighted that the mixed forests with big-sized trees and rich species could effectively improve the water-holding capacities of the ecosystem.