Kaufmann Merrill R., Ryan Michael G.
USDA Forest Service, Rocky Mountain Forest and Range Experiment Station, Fort Collins, CO 80526, USA.
Tree Physiol. 1986 Dec;2(1_2_3):47-59. doi: 10.1093/treephys/2.1-2-3.47.
Annual volume growth of subalpine trees in the central Rocky Mountains was studied in relation to site and stand conditions. Growth of individual trees was most strongly influenced by estimated potential absorbed radiation, which varied with physiographic conditions and tree leaf area. Growth efficiency was estimated by the ratio of annual volume growth to potential radiation absorption by the crown. Growth efficiency was higher in young lodgepole pine (Pinus contorta var. latifolia Engelm.) than in Engelmann spruce (Picea engelmannii Parry ex Engelm.) or subalpine fir (Abies lasiocarpa (Hook.) Nutt.). In all species, growth efficiency declined sharply with age, and suppressed and overtopped trees had growth efficiencies equal to the highest efficiencies observed for dominant/codominant or intermediate trees. Lodgepole pine growth was most responsive to site and stand variables, Engelmann spruce was intermediate, and subalpine fir was rather unresponsive.
对落基山脉中部亚高山树木的年材积生长量与立地条件和林分状况的关系进行了研究。单株树木的生长受估计的潜在吸收辐射影响最大，潜在吸收辐射随地形条件和树叶面积而变化。生长效率通过年材积生长量与树冠潜在辐射吸收量的比值来估算。幼龄黑松（Pinus contorta var. latifolia Engelm.）的生长效率高于恩氏云杉（Picea engelmannii Parry ex Engelm.）或亚高山冷杉（Abies lasiocarpa (Hook.) Nutt.）。在所有树种中，生长效率均随年龄急剧下降，被抑制和被压木的生长效率与优势/共优势或中庸树木所观察到的最高效率相当。黑松的生长对立地和林分变量反应最为敏感，恩氏云杉居中，而亚高山冷杉则反应相当迟钝。
