Abstract:

Forests are the largest carbon pools in terrestrial ecosystems, and forest carbon sinks play a key role in helping China achieve carbon peaking and carbon neutrality goals. The study on the structural characteristics of forest resources carbon storage in Luoxu nature reserve is conducive to revealing the spatial distribution of forest carbon storage and carbon density in the Alpine Gorge Region of Northwest Sichuan, and is of great significance for improving the level of regional forest ecosystem protection and management and developing forest management carbon sinks. In the reserve, there are not only important zonal forest vegetation-dark coniferous forests such as Picea likiangensis var. rubescens and Sabina Squamata, but also shrub forests such as Salix cupularis and Rhododendron parvifolium. Based on the inventory data of forest resources planning and design in 2019, superimposing forest vector data and DEM data, this paper explores forest carbon storage, carbon density and its spatial distribution by applying biomass conversion and expansion methods and GIS spatial analysis. The results showed that the carbon storage and carbon density of coniferous forests are 138067.7 t and 11.8 t∙hm^-2, and the carbon storage and carbon density of shrub forest are 81228.9 t and 2.9 t∙hm^-2, which are the main contributors of forest carbon storage. In arbor forests, mature forest has the largest carbon storage, accounting for 42.2%; the carbon storage and carbon density of coniferous forest are 76800.3 t and 33.9 t∙hm^-2, and the carbon storage and carbon density of shrub forest are 61267.4 t and 6.1 t∙hm^-2. The carbon storage of coniferous forests is concentrated between 3701 m and 4300 m, accounting for 95.2% of the total carbon storage of coniferous forest; the carbon storage of shrub forests is concentrated between 4101 m and 4700 m, accounting for 79.7% of the total carbon storage of shrub forest. The carbon storage of coniferous forests is concentrated in abrupt, steep and dangerous slopes, accounting for 97.2% of the total carbon storage of coniferous forests; the carbon storage and carbon density of steep slope, abrupt slope and dangerous slope rank among the top three. The carbon storage of shrub forests is concentrated between 26° and 45°, accounting for 80.3% of the total carbon storage of shrub forests. The proportion of carbon storage of coniferous forests in sunny slope, semi-sunny slope and shady slope, semi-shady slope is close, which are 51.5% and 48.5%, respectively; the carbon density of shady slope and semi-shady slope was significantly higher than that of sunny slope and semi-sunny slope. The carbon storage of shrub forests is mainly a shady slope and semi-shady slope, accounting for 67.4% of total carbon storage of shrub forests. In the reserve, the forest carbon storage and carbon density are obviously different from each other in altitude grade, and the carbon storage of steep, steep and dangerous slopes is large, and the shady and sunny slopes are almost the same. Most of the forests are young and middle-aged forests, and the young and middle-aged forests usually have relatively low carbon density. Classified management and scientific policy implementation are the key to improve the carbon sequestration capacity of regional forest resources.

Key words: alpine gorge region, forest vegetation, carbon storage, carbon density, GIS, spatial distribution

摘要：

森林是陆地生态系统最大的碳库,森林碳汇在中国实现碳达峰碳中和目标中起着十分关键的作用。研究分析洛须自然保护区森林资源碳储量结构特征,有利于揭示川西北高山峡谷区森林碳储量、碳密度空间分布规律,对于提升区域森林生态系统保护管理水平和开展森林经营碳汇具有重要意义。洛须自然保护区内不仅分布着重要的地带性森林植被--川西云杉（Picea likiangensis var. rubescens）和高山柏（Juniperus squamata）等暗针叶林,还广泛分布着高山柳（Salix cupularis）、小叶杜鹃（Rhododendron parvifolium）等灌木林。以2019年森林资源规划设计调查成果为基础,叠加森林矢量数据与DEM数据,通过应用生物量转换和扩展方法,并结合GIS空间分析,探究森林碳储量、碳密度及其空间分布。研究表明：针叶林碳储量138067.7 t、碳密度11.8 t∙hm^-2,灌木林碳储量81228.9 t、碳密度2.9 t∙hm^-2,是主要的森林碳储量贡献者。乔木林中,成熟林碳储量最大,占42.2%;川西云杉林碳储量76800.3 t、碳密度33.9 t∙hm^-2,高山柏林碳储量61267.4 t、碳密度6.1 t∙hm^-2。针叶林碳储量集中在3701-4300 m之间,占针叶林总碳储量的95.2%;灌木林碳储量集中在4101-4700 m之间,占灌木林总碳储量的79.7%。针叶林碳储量集中在陡、急、险坡,占针叶林总碳储量的97.2%;急坡、陡坡、险坡碳储量和碳密度均位列针叶林前3位。灌木林碳储量集中在26°-45°之间,占灌木林总碳储量的80.3%。针叶林森林碳储量在阳坡、半阳坡与阴坡、半阴坡比例接近,分别为51.5%、48.5%;阴坡、半阴坡碳密度明显高于阳坡、半阳坡。灌木林碳储量以阴坡、半阴坡为主,占灌木林总碳储量的67.4%。洛须自然保护区森林碳储量和碳密度垂直分异明显,陡、急、险坡碳储量贡献大,阴坡、阳坡整体均衡。乔木中幼林比重大,森林碳密度水平较低,分类经营、科学施策是提升区域森林固碳能力的关键。

关键词: 高山峡谷区, 森林植被, 碳储量, 碳密度, GIS, 空间分布