黑龙江省森林覆盖及类型变化对森林碳汇的影响OA

Clarifying the effects of forest cover and type changes on forest carbon sinks helps formulate scientific policies to enhance forest carbon sinks,and provides support for the country to achieve carbon peaking and carbon neutrality goals.Taking Heilongjiang Province as the study area,this study estimated carbon sinks by combining the 3-PGS(physi-ological principles predicting growth with satellites)model and the GSMSR(geostatistical model of soil respiration)model.Atlas analysis and structural equation model were used to quantify the impacts of forest cover and type changes on carbon sinks,and the standardized anomaly index(SAI)was applied to analyze the interannual anomaly characteristics of carbon sinks.The results showed that:from 2000 to 2020,the forest coverage rate in Heilongjiang Province rose from 48.95%to 51.76%.The overall carbon sink level showed a fluctuating upward trend,with a cumulative carbon sink of 57.92×107 t C,offsetting approximately 34.85%of carbon emissions over the same period.Carbon sink changes were divided into three stages:a fluctuating decrease from 2000 to 2004,with an average annual carbon sequestration of 2.31×107 t C;a steady increase from 2005 to 2013,2.03%higher than the average;an accelerated growth followed by a slowdown after peaking in 2017 from 2014 to 2020,and a moderate abnormal reduction occurred in 2020 due to extreme rainfalls.In terms of key factors influencing carbon sinks,ecological restoration such as returning farmland to forests and grassland afforestation positively promotes carbon sink enhancement.Meanwhile,internal forest structure adjustment is also a key driver,and broad-leaved and mixed forests show significant positive effects.Spatially,the forest ecosystem in Heilongjiang Province presents a pattern of"efficient carbon sequestration in the central and eastern parts and steady im-provement in the northern region".