围封对辽宁西北草地有机碳储量的影响

发布时间：2018-11-07 07:59

【摘要】：草地生态系统碳储量在全球碳库中起着重要作用。近些年,草地退化使生态系统碳储量受到严重影响。辽宁西北地区草地资源丰富,但一半以上的草地已趋于沙化、退化,使得生态系统碳储量大量流失,本研究以围封作为沙化草地恢复措施,分别在辽宁西北7个县中的草甸草原建立不同围封年限的样地,开展围封对草地生态系统碳储量影响的研究,为深入了解草地生态系统碳储量的影响机制和更好保护草原提供理论依据。本研究研究结果如下:1.围封样地的群落高度,植被覆盖度,土壤pH值、容重,植被、土壤碳含量,植被、土壤氮含量和磷养分含量等指标比对照样地有相应的改善。其中各围封样地植被群落高度和覆盖度都有所增加,增加量分别在4.64cm-96.04cm,1%-22.6%。各样地的土壤pH大部分有所降低,在中性范围左右,容重小幅度的增加。各围封样地的有机碳、全氮、全磷含量比未围封样地增加,且大部分达到显著水平。2.所有围封样地凋落物生物量、地上总植物生物量、植物根系总生物量和凋落物碳储量、地上总植物碳储量、植物根系碳储量都显著增加,同时土壤总碳储量也显著增加。其中七个县围封样地的凋落物生物量、地上总植物生物量、植物根系总生物量分别比未围封对照样地提高了11.04%-545.34%、56.08%-880.53%、460.25%-490.77%,七个县围封样地的凋落物碳储量、地上总植物碳储量、植物根系碳储量和土壤总碳储量分别比对照提高了27.93%-564.00%、69.62%-927.13%、388.57%-615.73%、11.98%-365.96%。此外,七个县围封样地的植物总生物量与植物总碳储量之间均有显著正相关关系(P0.05)。3.随土壤深度的增加根系碳储量和土壤碳储量均会降低,0-10cm土层的碳储量最高,其次是10-20cm土层,20-30cm土层最小。围封对每层根系碳储量和每层土壤碳储量有增加作用。4.土壤总碳储量占有最大的比重,在78.854%-97.368%之间;其次是地上植物总碳储量和植物根系总碳储量,且所占比重相差不大,分别在1.097%-11.597%和0.948%-10.641%之间;而凋落物碳储量所占比重最小,往往低于3%。并且围封样地的植物碳储量比比对照样地增加。
[Abstract]:Grassland ecosystem carbon storage plays an important role in the global carbon pool. In recent years, grassland degradation has seriously affected ecosystem carbon storage. The grassland resources in northwest Liaoning Province are rich, but more than half of the grassland has become desertified and degraded, resulting in a large loss of carbon storage in the ecosystem. In this study, enclosure was used as the restoration measure of desertified grassland. In 7 counties of northwest Liaoning Province, the meadow steppe with different enclosed years was established to study the effects of enclosure on the carbon storage of grassland ecosystem. It provides theoretical basis for further understanding the influence mechanism of grassland ecosystem carbon storage and better protection of grassland. The results are as follows: 1. The community height, vegetation coverage, soil pH value, bulk density, vegetation, soil carbon content, vegetation, soil nitrogen content and phosphorus nutrient content of enclosed plot were improved. The vegetation community height and coverage of each enclosed plot were increased in 4.64cm-96.04cm ~ (-1) -22.6cm ~ (-1), respectively. The soil pH in various plots was mostly decreased, and the bulk density increased slightly in the neutral range. The contents of organic carbon, total nitrogen and total phosphorus in the enclosed plots were higher than those in the unenclosed plots, and most of them reached a significant level of 2. 2. Litter biomass, total plant biomass, plant root biomass and litter carbon storage, total plant carbon storage, plant root carbon storage and soil total carbon storage increased significantly in all enclosed plots. The litter biomass, the aboveground total plant biomass and the total plant root biomass of the enclosed sample plots in seven counties were 11.04-545.34 and 56.08-880.53 and 460.25- 490.77, respectively. The litter carbon storage, the total plant carbon storage, the plant root carbon storage and the soil total carbon storage in the enclosed sample plots in seven counties were increased 27.93-564.00 and 69.62-927.130.388.57-615.73cm, respectively, compared with the control. 11.98- 365.96. In addition, there was a significant positive correlation between plant biomass and plant total carbon storage in the enclosed sample plots in seven counties (P0.05). With the increase of soil depth, both root carbon storage and soil carbon storage will decrease. 0-10cm soil layer has the highest carbon storage, followed by 10-20cm soil layer, and 20-30cm soil layer is the smallest. Enclosure has an increasing effect on root carbon storage per layer and soil carbon storage per layer. 4. The soil total carbon storage accounted for the largest proportion, in the range of 78.854-97.368%; The second was the total carbon storage of aboveground plants and the total carbon storage of plant roots, which were between 1.097% -11.597% and 0.948 -10.641%, respectively, while the proportion of litter carbon storage was the smallest, which was often lower than that of 3%. And the ratio of plant carbon reserves in enclosed plots increased by the same amount.
【学位授予单位】：辽宁大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：S812

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