长白山高山冻原生态系统植被生物量分布和养分生物循环研究(英文)

A study was conducted to test the correlation between biomass and elevation and the differences in concentration and storks of nutrients among five vegetation types (Felsenmeer alpine tundra vegetation-FA, Lithic alpine tundra vegetation-LA, Typical alpine tundra vegetation-TA, Meadow alpine tundra vegetation MA, and Swamp alpine tundra vegetation-SA) on alpine tundra of Changbai Mountains,Jilin Province, China in growing seasons of 2003, 2004 and 2005. The biomass of 43 mono-species and soil nutrients in alpine tundra ecosystem were also investigated. Dominant species from Ericaceae (such as Rhododendron chrysanthum and Vaccinium jliginosum var.alpinum) were taken to analyze organ biomass distribution. Result showed that the biomass and elevation had a significant correlation (Biomass=-237.3 In(Elevation) 494.36; R2=0.8092; P＜0.05). No significant differences were found in phosphorus and sulphur concentrations of roots, stems and leaves among the five vegetation types. There were significant differences in nitrogen and phosphorus stocks of roots, stems and leaves and in sulphur stock of stems and leaves among TA, MA, and SA vegetation types (p＜0.05). The nutrient stock of five vegetations was averagely 72.46 kg·hm-2, of which N, P, S were 48.55, 10.33 and 13.61 kg·hm-2, respectively. Soil N and S concentrations in meadow alpine tundra soil type was significantly higher than those in other four soil types (Cold desert alpine tundra soil, Lithic alpine tundra soil, Peat alpine tundra soil, and Gray alpine tundra soil). Phosphorous concentration in SA type was higher (p＜0.05) than in other types. Soil nutrient stock (0-20cm) was averagely 39.59 t·hm-2, of which N, P, S were 23.74, 5.86, 9.99 t·hm-2, respectively.     

陇西县首轮农村宅基地改革试点情况综述

2015—2017年陇西县被列为全国33个农村土地征收、集体经营性建设用地入市、宅基地制度改革（简称“三块地”改革）试点地区之一，本文围绕宅基地制度改革核心内容，从试点由来、试点情况、存在问题、推进经验、改革建议5个方面对陇西县首轮宅基地试点开展情况进行了系统综述，以期使陇西改革的试点经验和成果成为新一轮宅基地管理制度改革的借鉴基础。