Factors Influencing Understory Seedling Establishment of Engelmann Spruce (Picea engelmannii) and Subalpine Fir (Abies lasiocarpa) in Southeast Wyoming
Factors Influencing Understory Seedling Establishment of Engelmann Spruce (Picea engelmannii) and Subalpine Fir (Abies lasiocarpa) in Southeast Wyoming
复制标题
影响怀俄明州东南部英格曼云杉 (Picea engelmannii) 和亚高山冷杉 (Abies lasiocarpa) 林下幼苗建立的因素
DOI：
10.1139/b82-337
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发表时间：
1982
期刊：
影响因子：
--
通讯作者：
W. K. Smith
中科院分区：
文献类型：
--
作者：
A. Knapp;W. K. Smith
在落基山脉中部和北部成熟的云杉冷杉林下，长果冷杉的苗木一般比欧洲云杉树苗丰富，但关于可能影响这两种针叶树种建立的环境或植物因素的信息很少。在怀俄明州东南部的梅迪辛堡山脉进行的田间测量表明，毛果树苗在低林下光照条件下具有较高的光合作用速率，而达到光合作用饱和所需的入射辐射水平较低。然而，这两种针叶树都发生在日总太阳辐射同样低的林下位置(<；2 MJ∙m−2∙day−1)，因此，缺乏光照似乎不是导致林下黄杨幼苗数量较少的原因。相比之下，在枯枝落叶层较薄的地区，毛果松苗的数量要比毛果松苗多得多。
Although seedlings of Abies lasiocarpa are generally more abundant than those of Picea engelmannii in the understory of mature spruce–fir forests throughout the central and northern Rocky Mountains, little information exists concerning environmental or plant factors that may influence the establishment of these two conifers. Field measurements in the Medicine Bow Mountains of southeast Wyoming showed that seedlings of A. lasiocarpa had greater photosynthetic rates at low understory light levels and required lower levels of incident radiation for saturation of photosynthesis compared with those of P. engelmannii. However, both conifers occurred in understory locations where total daily solar radiation was equally low (<2 MJ∙m−2∙day−1) and thus, a lack of light did not appear to be responsible for the low number of P. engelmannii seedlings in the understory. In contrast, seedlings of P. engelmannii were substantially more abundant at locations with thinner litter layers compared with those of A. lasiocarpa....