Tree Diameter Distributions and Replacement Processes in Southeast Texas Forests
Tree Diameter Distributions and Replacement Processes in Southeast Texas Forests
复制标题
德克萨斯州东南部森林的树木直径分布和更新过程
DOI：
10.1093/forestscience/24.2.153
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发表时间：
1978
期刊：
影响因子：
1.4
通讯作者：
P. Marks
中科院分区：
文献类型：
--
作者：
P. Harcombe;P. Marks
15林分取样沿着在得克萨斯州东南部的水分梯度，研究大小级分布的物种。重要树种（> 10%相对断面积）在中温带和湿润森林中的树苗一般很少，但在干燥森林中则不然。一个给定的优势物种往往表现出更大的繁殖失败（即，较差的代表性的树苗）在潮湿的比在梅西奇森林。林下灌木物种的树苗大小的范围内（1-10厘米），使整个林分大小类分布没有表现出代表性不足的小茎。重要冠层树木的幼树代表性不足可能是死亡的结果，也可能是周期性的种子设置inFagus grandifolia。从干燥到潮湿的森林的树苗死亡率增加的解释是从两个上层和下层物种的竞争增加。这种代表性不足的情况足以引起人们对这些森林的长期稳定性的质疑。据推测，更换上层树木的树苗发生以下干扰时，树苗死亡率放宽。多树冠层间隙可能是最重要的，允许在得克萨斯州东南部的森林更换。森林科学24：153-166。
Fifteen forest stands were sampled along a moisture gradient in southeast Texas to examine size class distributions of species. Important tree species (> 10 percent relative basal area) were generally poorly represented as saplings in mesic and wet forests but not in dry forests. A given dominant species tended to show greater reproductive failure (i.e., poorer representation of saplings) in wet than in mesic forests. Understory shrub species were well represented over the range of sapling sizes (1-10 cm) so that whole stand size class distributions showed no underrepresentation of smaller stems. Underrepresentation of saplings of important canopy trees is probably the result of mortality, and possibly also periodic seed set inFagus grandifolia. Increased mortality of saplings from dry to wet forests is explained in terms of increased competition from both overstory and understory species. The underrepresentation is marked enough to raise questions concerning the long-term stability of these forests. It is postulated that replacement of overstory trees by saplings occurs following disturbance when sapling mortality is relaxed. Multiple-tree canopy gaps may be most important in allowing replacement in southeast Texas forests. Forest Sci. 24:153-166.