滨海盐渍区不同土地利用方式土壤-植被系统碳储量研究

发布时间：2018-12-07 06:39

【摘要】：盐渍区土地利用变化与土壤-植被系统固碳潜力耦合关系的研究对以植被建设、增加碳汇为目的的盐渍区最优土地利用方式的实施具有重要的理论和实际意义。本研究以滨海撂荒盐碱裸地为对照,连续观测和定量描述栽植3年和10年的柽柳林、栽植2年和8年的人工枸杞林及冬季咸水结冰灌溉结合地膜覆盖下的棉田的土壤有机碳和植被生物量的动态变化过程,探讨滨海盐渍区不同土地利用方式下土壤-植被系统固碳能力,为进一步提升区域碳储量提供理论依据。研究表明:1)柽柳、枸杞的栽植及结冰灌溉结合覆膜等土地利用方式在撂荒盐碱地实施后,土壤-植被系统固碳能力明显增强,且土壤容重显著减小;栽植10年的柽柳林和栽植8年的枸杞林土壤-植被系统碳储量最高,分别为118.24 t·hm~(-2)和96.27 t·hm~(-2),比冬季咸水结冰灌溉结合地膜覆盖棉田增加58.51 t·hm~(-2)和36.54 t·hm~(-2),比撂荒盐碱裸地增加83.39 t·hm~(-2)和61.42 t·hm~(-2)。2)对不同土地利用方式固碳趋势研究发现,栽植3年的柽柳林和栽植2年的枸杞林土壤-植物系统固碳速率较高,分别为10.08t·hm~(-2)·a~(-1)和2.71 t·hm~(-2)·a~(-1)。冬季咸水结冰灌溉结合地膜覆盖棉田固碳速率较低,仅为0.53 t·hm~(-2)·a~(-1)。栽植10年的柽柳和栽植8年的枸杞样地,植株固碳速率明显减慢,土壤-植被系统表现为一个弱的碳源。春季地表覆膜处理棉花存活率低且植株成熟后秸秆被移除,碳储量每年净减少0.86 t·hm~(-2)。撂荒盐碱裸地在无外源碳补充的条件下表现为碳源,土壤-植被系统碳储量减少速率为1.42 t·hm~(-2)·a~(-1)。综上所述,滨海盐渍区人工栽植柽柳和枸杞是提高区域碳储量的有效途径。
[Abstract]:The study on the coupling relationship between land use change and carbon sequestration potential of soil-vegetation system in saline area is of great theoretical and practical significance for the implementation of optimal land use mode in saline area for the purpose of vegetation construction and carbon sequestration. In this study, the cultivated Tamarix chinensis forest for 3 and 10 years was continuously observed and quantitatively described, compared with saline-alkali bare land in littoral abandoned land. Dynamic change process of soil organic carbon and vegetation biomass in cotton field planted for 2 and 8 years under artificial Lycium barbarum forest and salt water frozen irrigation combined with plastic film mulching in winter. The carbon sequestration capacity of soil-vegetation system under different land use patterns in coastal saline area is discussed, which provides a theoretical basis for further enhancing regional carbon storage. The results are as follows: 1) after the land use of Tamarix chinensis, Lycium barbarum and ice irrigation combined with film mulching were carried out in abandoned saline-alkali land, the carbon sequestration capacity of soil-vegetation system was obviously enhanced, and the soil bulk density was significantly reduced; The carbon storage of soil-vegetation system in Tamarix chinensis forest for 10 years and Lycium barbarum forest for 8 years was the highest, which was 118.24 t hm~ (-2) and 96.27 t hm~ (-2), respectively. Compared with winter salt water freezing irrigation combined with plastic film mulching, it increased by 58.51 t hm~ (-2) and 36.54 t hm~ (-2). The carbon sequestration trend of different land use patterns was studied by increasing 83.39 t hm~ (-2) and 61.42 t hm~ (-2). The soil-plant system carbon sequestration rate of Tamarix chinensis forest for 3 years and Lycium barbarum forest for 2 years was 10.08 t hm~ (-2) a ~ (-1) and 2.71 t hm~ (-2) a ~ (-1), respectively. The rate of carbon sequestration in winter was 0.53t hm~ (-2) a ~ (-1). After 10 years of planting Tamarix chinensis and 8 years of cultivation of Lycium barbarum, the rate of carbon sequestration of plant was obviously decreased, and the soil-vegetation system was a weak carbon source. The survival rate of cotton treated by surface film mulching in spring was low and the straw was removed after plant maturation, and the carbon storage decreased by 0.86t hm~ (-2) per year. Under the condition of no external carbon supplementation, the bare land of abandoned saline-alkali is a carbon source, and the rate of reduction of carbon storage in soil-vegetation system is 1.42 t hm~ (-2) a ~ (-1). To sum up, artificial cultivation of Tamarix chinensis and Lycium barbarum in coastal saline area is an effective way to improve regional carbon storage.
【作者单位】：中国科学院遗传与发育生物学研究所农业资源研究中心/中国科学院农业水资源重点实验室;中国科学院大学;
【基金】：国家科技支撑计划项目(2013BAD05B02,2013BAD05B05) 中国科学院科技服务网络计划(KFJ-SW-STS-141-04-1)资助~~
【分类号】：S154.4

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