ALBERT

Description: In situ observation of the aerosol optical properties is important to the validations of satellite and modeling results; however, the operational measurements can be affected by some objective factors. An experiment study has been performed in order to analyze the error in retrievals of aerosol optical properties from sunphotometer measurements caused by a variety of in situ objective factors. The standard instrument relative error analysis method was used to determine the relative error of aerosol optical depth (AOD) and Ångström exponent (AE) under the effects of five factors: spider web inside the collimator (F1); collimator bending (F2); dust inside the optical head (F3); incrustation scale inside the optical head (F4); and dust and incrustation scale inside the optical head (F5). The results showed that the five factors caused error for AOD retrieved at 1020, 870, 670 and 440 nm, with the maximum error occurring at 870 nm due to the more sensitive measurement signals. The error ranges of AOD derived from the direct solar measurements in the four bands were −0.34%–8.77%, −6.22%–9.68%, −0.05%–2.52%, −0.96%–3.48% and 5.42%–13.38% for F1, F2, F3, F4 and F5, respectively. The maximum error occurred under the influence of F5 with an average error value of 10%, while the minimum occurred owing to F3 with an average error value of 1%. All of the AEs retrieved from the experimental instruments were smaller than that from the reference instrument. The AE error values were 15.19%, 25.57%, 4.56%, 4.41% and 8.83% for F1, F2, F3, F4 and F5, respectively. The average AE retrieval error value was 11.7%.

Description: Sustainability, Vol. 10, Pages 902: Assessment of the Ecosystem Service Function of Sandy Lands at Different Times Following Aerial Seeding of an Endemic Species Sustainability doi: 10.3390/su10040902 Authors: Lei Zhang Guangyu Hong Zhuofan Li Xiaowei Gao Yongzhi Wu Xiaojiang Wang Pingping Wang Jie Yang Desertification is a global and pressing environmental problem in the course of environmental changes, and considerable efforts have been made to restore these degraded ecosystems. Aerial seeding has been widely used to accelerate ecological restoration around the world. However, few efforts have been made to assess the ecosystem service function after aerial seeding has occurred. In this study, we analyzed variations in the ecosystem service function after varying periods of elapsed time after aerial seeding of Hedysarum laeve Maxim. (14a, 30a and 38a) in the Mu Us Sandy Land, China. We also assessed the carbon sequestration ability, biodiversity, soil properties, wind-break and sand-fixation ability on a typical windward slope. We found that the overall assessment value of ecosystem services had generally increased with the elapsed time after aerial seeding. Additionally, the assessment values increased as the slope position moved downwards. Moreover, we observed a gradual replacement of H. laeve by Artemisia ordosica Krasch and grass species with the increase in elapsed years after aerial seeding, indicating a positive succession towards locally native vegetation. Compared with the local natural vegetation, our results suggest that the practice of aerial seeding stimulated vegetation restoration without the need for follow-up field interventions, and the practice of aerial seeding might fit more ecosystems with similar vegetation degradation problems.

Description: Sustainability, Vol. 9, Pages 2030: Trade-Offs between Economic and Environmental Optimization of the Forest Biomass Generation Supply Chain in Inner Mongolia, China Sustainability doi: 10.3390/su9112030 Authors: Min Zhang Guangyu Wang Yi Gao Zhenqi Wang Feng Mi The utilization of forest residue to produce forest biomass energy can mitigate CO2 emissions and generate additional revenue for related eco-enterprises and farmers. In China, however, the benefit of this utilization is still in question because of high costs and CO2 emissions in the entire supply chain. In this paper, a multi-objective linear programming model (MLP) is employed to analyze the trade-offs between the economic and environmental benefits of all nodes within the forest biomass power generation supply chain. The MLP model is tested in the Mao Wu Su biomass Thermoelectric Company. The optimization results show that (1) the total cost and CO2 emissions are decreased by US$98.4 thousand and 60.6 thousand kg, respectively; 3750 thousand kg of waste-wood products is reduced and 3750 thousand kg of sandy shrub stubble residue is increased; (2) 64% of chipped sandy shrub residue is transported directly from the forestland to the power plant, 36% of non-chipped sandy shrub residue is transported from the forestland to the power plant via the chipping plant; (3) transportation and chipping play a significant role in the supply chain; and (4) the results of a sensitivity analysis show that the farmer’s average transportation distance should be 84.13 km and unit chipping cost should be $0.01022 thousand for the optimization supply cost and CO2 emissions. Finally, we suggest the following: (1) develop long-term cooperation with farmers; (2) buy chain-saws for regularly used farmers; (3) build several chipping plants in areas that are rich in sandy shrub.