黔中喀斯特地区典型次生林内凋落叶化学计量特征

Stoichiometry Traits in Litter Leaves of Typical Secondary Forest at Karst Regions of Central Guizhou Province

为了研究退化喀斯特森林养分循环特征,以黔中喀斯特常绿落叶阔叶次生林内的10个优势种凋落叶为对象,开展化学计量学特征研究。研究结果表明:凋落叶中C、N、P元素与凋落叶的质量比分别为(497.88±12.97)mg/g、(12.19±0.54)mg/g和(0.89±0.05)mg/g。m(C)∶m(N)、m(C)∶m(P)和m(N)∶m(P)值分别为43.17±2.07、620.03±42.33和14.60±0.81。不同生活型树种凋落叶中C和P元素与凋落叶的质量比及m(C)∶m(P)均表现为常绿树种大于落叶树种(P<0.05)。凋落叶中N、P与凋落叶的质量比呈正相关。同其他研究结果相比,喀斯特地区树种凋落叶中C、N、P元素与凋落叶的质量比具有地域差异。黔中次生森林凋落叶中C、N、P与凋落叶的质量比普遍较高,凋落叶的分解速率较快,N、P元素成比例矿化释放,但是矿质养分和凋落叶的分解不受有机物与凋落叶质量比的影响。

To study the characteristics of nutrient cycling in degraded Karst forest,10 dominant species in evergreen and deciduous broad-leaved secondary forest from central Guizhou Karst were researched. The chemical stoichiometry traits were analyzed. The results showed that the mass ratios of C,N,P to litter leaves are( 497. 88 ± 12. 97) mg/g,( 12. 19 ± 0. 54) mg/g and( 0. 89 ± 0. 05) mg/g,respectively.The ratios of m( C) ∶ m( N),m( C) ∶ m( P) and m( N) ∶ m( P) are 43. 17 ± 2. 07,620. 03 ± 42. 33 and14. 60 ± 0. 81,respectively. The mass ratios of C and P to litter leaves as well as m( C) ∶ m( P) in litter leaves of different life type trees show that evergreen trees species are more than deciduous trees species( P < 0. 05).The mass ratio of N and P to litter leaves is positive. Compared with other research results,the mass ratios of C,N,P to litter leaves of various tree species in Karst area shows areal variation. The mass ratios of C,N,P to litter leaves in central Guizhou secondary forest are generally high. The decomposition rate of leaf litter is faster. The N and P elements mineralization are released in proportion to mineralization,and the decomposition of litter leaves is not affected by the mass ratio of organic matter.