黔中喀斯特山地8种树种早期生长和叶片养分动态的研究

通过研究贵州普定县典型喀斯特山地8个3年生树种生长特性、叶片养分含量以及落叶前后叶片养分含量的变化,分析了它们对该立地的适应性,从而为喀斯特困难立地造林适生树种的选择提供可靠依据。结果表明: (1)3年生冰脆李的生长量明显优于其他树种,其高生长比香椿、核桃分别大1391%和1537%;植株胸径大于等于10cm株数的百分比以冰脆李最高达到919%,其次是榆树和青檀,分别是495%和488%;? (2)8个树种落叶的全N、全P和全K的总含量变动为136%~252%,其中全N、全P含量以滇楸最高,全K含量以冰脆李最大； (3)从各树种落叶前后各元素含量及其转移情况看,冰脆李、青檀表现出对大部分营养元素具有较高的循环利用养分或保持养分的能力,而香椿及刺槐相对较弱。综合生长状况、落叶对土壤的改良以及养分内循环率等方面的因素认为,冰脆李、青檀、榆树等树种对高钙、干旱的石灰岩生境有良好适应性,是喀斯特山地造林绿化较适宜的树种。

Studies on the early growth and dynamics of leaf nutrient of eight tree species in the Karst mountain areas of Guizhou province

The trial for selecting suitable tree species on Karst areas was established at a typical Karst mountainous region in Puding County, Guizhou Province. The growth characteristics, leaf nutrients content dynamic and transfer rate for eight testing tree species were investigated. The results indicated that the growth of 3-year-old Prunus salicina was significantly higher than that of the other species, such as 139.1% and 153.7% higher than Toona sinensis and Juglans regia in height growth, respectively. The maximum percentage of DBH more than 1.0 cm was 91.9% for P. salicina. Next were 49.5% and 48.8% for Ulmus pumila and Pteroceltis tatarinowii, respectively. The contents of total N, total P and total K ranged from 1.36% to 2.52% in the leaves of testing species. The highest content of total N and total P was found in the leaves of Catalpa bungei, while the highest content of total K was observed in P. salicina leaves. The results indicated that P. salicina, P. tatarinowii, U. pumila bad well adaptability on the Karst area both in the growth status and the improvement to the soil with the fallen leaf. Thus these three species could be selected as main planting tree species in the Karst mountainous region. The results from the studies provided some scientific proof to the selection of trees species in Karst mountainous area, but further studies are still required.