为了解喀斯特石漠化过程中地表凋落物稳定氮同位素的变异特征及其影响因素，对喀斯特高原区贵州省清镇市王家寨峰丛洼地同一流域内不同类型石漠化、不同等级石漠化以及不同干扰方式石漠化地表凋落物的氮同位素组成及其空间分异特征进行了研究。结果表明：流域内黄壤区样地的地表凋落物δ15 N 值主要为-4.00‰~-1.83‰，平均值-3.13‰；黑色石灰土区样地的地表凋落物δ15 N 值主要为-4.49‰~-2.44‰，平均值-3.39‰；环境水热条件是影响地表凋落物δ15 N 值的主要因素；除了在黑色石灰土区的轻度石漠化与无石漠化间差异显著外，无论是黄壤区样地还是黑色石灰土区样地，其地表凋落物δ15 N 值在各等级石漠化样地间、不同干扰方式环境下、甚至在不同坡位上都无显著性差异体现，两土壤类型间的总体差异也不显著(P ≤0.05)，这主要与喀斯特区高度的生境异质性有关。
Characteristics of Nitrogen Isotope in Surficial Litters Under Karst Rocky Desertification
This study investigated isotopic composition and spatial distribution of nitrogen of surficial litters in karst rocky desertification areas with different type,grade and disturbed model within a small catchment of the Wangji-azhai peak-cluster depression basin,Qingzhen,Guizhou.Results showed that the mostδ1 5 N values of surficial lit-ters in yellow soil areas are between - 4.00‰ to - 1 .83‰ with an average of - 3.13‰,and that between-4.49‰~ -2.44‰ with an average of -3.39‰ in black calcareous areas.The hydrothermal condition of the environment is the key factor controls litters’δ1 5 N values.The δ1 5 N values of surficial litters show no significant difference for all sampling sites except those from slight or no rocky desertification sites in black calcareous areas. We suggest not significant (P ≤ 0.05)overall difference of surficial litters’δ1 5 N values in yellow soil and black calcareous areas as a result of the high habitat heterogeneity of the karst area.
karst rocky desertificationsurficial littercomposition of nitrogen isotopespatial distribution charac-
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