Shifting cultivation (locally known as “jhum”) is a major driver of deforestation and loss of ecosystem services in rainforests. For developing any effective conservation of biodiversity and carbon service program, an in-depth understanding to the recovery of vegetation and carbon after abandonment of jhum is essential. We estimated species richness, abundance and composition of trees, shrubs and herbs, carbon distribution in aboveground and belowground components along a chronosequence of jhum fallow in northeast India, and elucidated the factors affecting the recovery processes of jhum fallows. Species composition and other plant community attributes, carbon storage in different pools were studied in 5 jhum fallows (< 5, 5–10, 11–15, 16–20, 21–25 years old) and an old-growth forest. The data were subjected to linear mixed effect modeling using R-package “nlme” for identifying the important factors contributing to the recovery of vegetation and carbon. Species composition varied significantly (P < 0.05) between jhum fallows and old-growth forest. Tree density varied from 28 stems ha−1 in 5 years old jhum fallow to 163 stems ha−1 in old-growth forest. Both biomass carbon in all components and soil organic carbon were significantly (P = 0.01) lower in jhum fallows than in the old-growth forest except living non-woody biomass component. The recovery of aboveground biomass carbon was faster during early successive years than the mid-successive jhum fallows. Total ecosystem carbon and soil organic carbon stock in the oldest jhum fallow was 33% and 62% of those in the old-growth forest, respectively. The fallow age was found to be the most important explanatory factor in the recovery process of vegetation and carbon stock in re-growing fallows. The shifting cultivation fallows gradually recovered both vegetation and carbon and are potential repository sites for biodiversity conservation, which may take much longer time to reach up to old-growth forest in northeast India.

中文翻译：

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南亚Mizoram-Manipur-Kachin雨林生态区改种后的植被和生态系统碳回收

轮换种植（当地称为“ jhum”）是毁林和雨林生态系统服务丧失的主要驱动力。为了制定任何有效的生物多样性保护和碳服务计划，深入了解废弃竹炭后植被和碳的恢复至关重要。我们估算了印度东北部次贷休耕的时间序列的物种丰富度，树木，灌木和草本植物的丰度和组成，地上和地下成分中的碳分布，并阐明了影响次休草恢复过程的因素。在5个休耕休耕期（<5、5-10、11-15、16-20、21-25岁）和一个古老的森林中研究了物种组成和其他植物群落属性，不同库中的碳存储。使用R-package“ nlme”对数据进行线性混合效应建模，以识别有助于植被和碳回收的重要因素。枯草休耕地和老龄林之间的物种组成差异显着（P <0.05）。树木密度从5岁幼小休耕期的28个茎秆ha-1到老龄林的163个茎秆ha-1不等。除了生活中的非木质生物量组分外，所有其他组分的生物量碳和土壤有机碳均显着降低（P = 0.01），低于休闲林。连续几年中，地上生物量碳的回收要比中期成功的休耕休耕快。最老的休耕地的生态系统碳总量和土壤有机碳储量分别是老生长森林中的33％和62％。人们发现，休耕年龄是休耕中植被和碳储量恢复过程中最重要的解释性因素。不断变化的耕种休耕期逐渐恢复了植被和碳，并且成为了生物多样性保护的潜在储存地，可能需要更长的时间才能到达印度东北部的古老森林。