Long-term effects of vegetation restoration and forest management on carbon pools and nutrient storages in northeastern Loess Plateau, China.

It is crucial for understanding the variations of carbon and nutrient pools within the ecosystems during long-term vegetation restoration to accurately assess the effects of different ecological restoration patterns. However, the long-term spatio-temporal variations of carbon and nutrient pools under different vegetation types remain unclear. The sites for long-term natural and planted forests (i.e., Natural secondary forest, Pinus tabulaeformis planted forest, Platycladus orientalis planted forest, and Robinia pseudoacacia planted forest) on the northeastern Loess Plateau, China were selected, to measure and analyze the differences and interannual variations of vegetation attributes at four synusiae and soil properties at 0-100 cm over the period of 12 years (2006-2017). The principal component analysis (PCA) and Mantel test were also conducted to explore the relationships among vegetation attributes, soil properties, and carbon and nutrient pools. The results showed that: compared with the planted forests, the natural secondary forest had lower arborous biomass (84.21 ± 1.53 t hm-2) and higher understory biomass and plant heights. Compared to planted forests, the secondary forest had higher soil carbon and nitrogen contents (13.74 ± 3.50 g kg-1 and 1.16 ± 0.34 g kg-1). The soil carbon pool in the secondary forest was 22.0% higher than planted forests, while the vegetation carbon pool in the P. tabulaeformis was 75.5% higher than other forests. Principal component analysis (PCA) and Mantel test revealed that vegetation attributes and soil properties had significant correlations with carbon and nutrient pools, especially at the arborous synusia (p < 0.01). The findings indicated that in the ecologically fragile Loess Plateau region, the selection of appropriate vegetation restoration types should be guided by varying ecological restoration goals and benefits, aiming to expected ecological outcomes. This insight offers a strategic implication for forest management that is tailored to improve carbon and nutrient pools in areas with similar environmental conditions.

[Agriculture and forestry ecosystem services value in Guangzhou-Foshan Metropolitan Area under the background of urbanization, Southern China.] / 城市化背景下广佛都市圈农林生态系统服务价值.

From the land use vector data of Guangzhou-Foshan Metropolitan Area (GFMA) in 1990, 1995, 2000, 2005 and 2010, four types of agriculture and forestry ecosystem (cropland, forestland, garden and water body) were extracted. Then, we evaluated the GFMA's agriculture and forestry ecosystem services value (AESV) based on Costanza's method after adjusting the 'ecosystem services value per unit area of China's terrestrial ecosystem' raised by Xie Gaodi through regional, functional and economic factor adjustment. The results showed that the total AESV had a wavelike upward trend due to the continuous development of economy and the increase of people's living standards in GFMA. The AESV in GFMA was 413.74×108, 612.83×108, 582.88×108, 773.44×108 and 698.67×108 yuan in 1990, 1995, 2000, 2005 and 2010, respectively. During the studied period, water body's service value grew fastest, which was 166.74×108 yuan, and followed by forestland and garden amounting to 103.01×108 and 47.74×108 yuan, respectively, while the cropland's service value decreased by 32.56×108 yuan and the decreasing rate was 23.1%. Accor-ding to the spatial distribution, the AESV tended to decline from the northeast and the southwest to the central part in GFMA from 1990 to 2010. The proportion of individual service value to the total services value changed little, and the contribution of individual service value decreased in the order of water supply, waste treatment, biodiversity protection, climate regulation, soil formation and protection, gas regulation, recreation and culture, raw material and food production.