In recent year, there has been large-scale afforestation in the gobi region of western Inner Mongolia, China. However, this area has low annual precipitation of 35–55 mm, and a high annual evaporation capacity of 3842 mm. Further, water resources in this region are scarce and cannot support the sustainable growth of shrubs. Thus, without effective irrigation, the shrubs cannot survive and ultimately, large-scale afforestation in the gobi region will destroy “black vegetation”. The surface of this area is covered by dense gravel (65.43–82.08%; average of 77.14%) as a result of long-term erosion caused by strong winds. The sediments underlying the gravel layer are rich in sand (60.34–87.51%) and silt (11.26–35.18%). Once the surface gravel layer is destroyed, the underlying sand and silt expose and increase dust supply, and result in increased intensity and frequency of dust storms. Thus, large-scale afforestation in the gobi region is an ecological disaster for these very dry lands.

The Guanzhong–Tianshui economic zone is a strategic link in China’s Belt and Road network, faces the contradiction between ecological protection and economic development, and urgently needs to construct an ecological security pattern based on ecosystem services to permit sustainable development. In this study, we evaluated the ecological services of net primary productivity (NPP), water yield (WY), soil conservation (SC), habitat quality (HQ), and food production (FP). We explored the trade-offs and synergies between services using correlation analysis and geographically weighted regression and constructed an ecological security pattern through circuit theory. NPP, WY, SC, and FP increased during the study period, whereas HQ decreased. The NPP × WY, WY × SC, and WY × HQ shifted from synergies to trade-offs; NPP × SC, NPP × HQ, and SC × HQ were always synergies; NPP × FP, SC × FP, and FP × HQ were always trade-offs; and WY × FP shifted from trade-offs to synergies. We selected service bundles with significant synergies among NPP, SC, and HQ as ecological sources, which were mainly in the Qinling and Weibei mountains, comprising 47 ecological patches. We identified 58 ecological corridors, 330.83 km² of pinch points, and 401.30 km² of barriers, which form a mesh structure covering the study area, proposing a development pattern of six zones and one belt. Our results provide a framework for ecological protection and restoration, which may serve as a scientific foundation for upcoming regional land management initiatives.

Soiling of photovoltaic (PV) modules, especially non-uniform soiling, can lead to PV power loss. For example, soiling bands at the bottom edge of framed modules are caused by the accumulation of water and dirt at a lower tilt angle. However, few studies have investigated this issue. In this study, industrial and commercial metal rooftop PV power stations in central and eastern China were investigated, with a focus in Xi’an and Kaifeng cities. The results show that (1) soiling bands were widespread, even in Guangzhou city, where annual rainfall is approximately 1,800 mm; (2) soiling bands were found during every month in Xi’an city, even from July to September when heavy rainfall occurs frequently; (3) three types of soiling bands were observed on modules (rectangular, transverse trapezoidal, and triangular), with double triangular, arch, and shallow U-shape types also being observed in landscape-oriented modules; (4) the mean relative difference of the maximum direct current due to soiling bands between one maximum power point tracking system and its control from June 19 to October 2, 2019 in Kaifeng city was approximately 4.7%.

Accurately estimating the contribution of afforestation/deforestation to gross primary productivity (GPP) of an ecosystem is necessary to develop future afforestation policies. However, there is currently a lack of quantitative assessments of the potential consequences of afforestation and deforestation on GPP at a global scale. In this study, we used a 30 m high-resolution forest raster map and a satellite-driven GPP product to assess GPP differences under various afforestation/deforestation scenarios, using spatial rather than temporal comparisons. Our results showed that (1) the simultaneous occurrence of high-intensity afforestation and deforestation was extremely low globally (4.64%). Under this hypothetical scenario, the potential GPP of afforestation could reach 734.13 g C m⁻² yr⁻¹, significantly higher than that in the other scenarios. While the percentage of concurrent medium- to low-intensity afforestation and deforestation was up to 41.37%, the potential value of afforestation to promote GPP increase was only 219.56 g C m⁻² yr⁻¹. (2) The potential of afforestation to boost GPP varied significantly across space and time. Proximity to equatorial forests, such as evergreen broad-leaved forests, generally facilitate GPP accumulation. However, as latitudinal zonality increased, the fixed GPP potential of high-latitude coniferous forests decreased significantly. Summer (particularly June) showed the highest potential for afforestation to enhance GPP, more than twice as much as in the other seasons, and this pattern was consistent globally. (3) Afforestation costs vary substantially depending on forest type and cover. Afforestation in rainforest areas with a better water-heat balance often requires a higher GPP to achieve the desired effect. Low-density forests dominated by temperate or cold zones yield significantly lower GPP benefits than afforestation in tropical rainforests. This study quantifies the potential impact of afforestation on GPP for the first time and provides guidelines for future afforestation planning across various regions.