The mechanisms underlying the response of soil respiration (Rs) to nitrogen (N) addition remain to be explored in semiarid ecosystems. This study was conducted to determine the effect of N addition on soil microbial composition, Rs and the temperature sensitivity of Rs (Q₁₀). The N addition experiment was carried out in a semiarid grassland in China, with N fertilizer application rates of 0, 2, 4, 8, 16, or 32 g N m^-2 yr^-1. Microbial phospholipid fatty acids (PLFAs), Rs and Q₁₀ were measured, and their relationships with soil properties were determined for three growing seasons. The results showed that N addition significantly increased the content of soil dissolved organic carbon (DOC) and inorganic nitrogen (IN), and decreased soil pH. With respect to soil microbes, N addition reduced soil PLFAs, reduced the fungi to bacteria ratio (F:B) and increased the gram-positive bacteria to gram-negative bacteria ratio (G+:G-). Rs under the N2, N4, N8, N16 and N32 treatments decreased by 2.58%, 14.86%, 22.62%, 23.97% and 19.87%, respectively, compared to the N0 (control) treatment. The results of structural equation models showed that N addition reduced Rs by lowering soil PLFAs and altering the microbial composition. However, N addition had no significant effect on either Q₁₀, soil total organic carbon (TOC) or total nitrogen (TN), indicating that N addition alleviated soil carbon loss and was unlikely to change the potential for a bigger loss under global warming.

Climate change and human activities influence species biodiversity by altering their habitats. This paper quantitatively analyzed the effects of climate change on a migratory bird. The Lesser White-fronted Goose (LWfG), a species which migrates via the middle and lower reaches of the Yangtze River region, is an herbivorous species of high ecological value. It is an endangered species threatened by climate change and human activities, so comprehensive information about its distribution is required. To assess the effectiveness of conservation of the LWfG under climate change, both climate variables and human activities are often used to predict the potential changes in the distribution and habitat suitability for LWfG. In this work, the current scenario and the Global Circulation Models (GCMs) climate scenarios were used to simulate the future distribution of the species. However, besides climate change and human activities, the spatial pattern of plants surrounding the wetland is also known to be closely related to the distribution of LWfG. Therefore, the distribution model results of six plant species related to LWfG’s diet selection were used as environment variables to reflect the changes of suitable LWfG habitat. These environmental variables significantly improved the model’s performance for LWfG, since the birds were clearly influenced by the plant distribution factors. Meanwhile, the suitable habitat area decreases by 2070 in GCM models under two representative concentration pathways scenarios (RCP2.6 and RCP8.5). More appropriate management and conservation policies should be taken to adapt to future climate change. These adjustments include modifications of the size, shape and use of the conservation area for this species.

Given the high alpine grassland coverage and intensive animal grazing activity, the ecosystem and livelihood of the herders are extremely vulnerable in the headwater region of the Yellow River. A series of programs have been implemented by the Chinese government to restore degraded grasslands in this region, and major function-oriented zones (MFOZs) applied in 2014, have divided the region into three zones, i.e., the development prioritized, restricted, and prohibited zones, based on environmental carrying capacity, as well as the utilization intensity of grassland. This study identified various restoration approaches adopted in different MFOZs, and assessed the effects of the approaches in order to determine the most effective approaches. We collected 195 questionnaires from herders to analyze the effects of the various restoration approaches, and additional remote sensing and statistical data were also used for the analysis. Four distinct differences in the ecological and socioeconomic characteristics were found in three MFOZs. (1) Five technologies were applied in the study areas. (2) The grassland recovery rate was higher in development prioritized zones than in restricted and prohibited zones during 2000 and 2016, and especially high and very high coverage grasslands increased in the areas where crop-forage cultivation and grass seeding dominated in the prioritized zones. (3) The net income of households in the development prioritized zone was the best of all three zones. (4) The degree of awareness and willingness of herders to restore grassland was more positive in development prioritized zones than in restricted zones, where more herders adopted approaches with a combination of enclosure + deratization + crop-forage cultivation + warm shed. Based on these findings, it is recommended that decision-makers need to increase their efforts to narrow the gap of willingness and behavior between herders and other stakeholders, such as researchers and grassland administrators, in order to ensure grassland sustainability in the MFOZs. It is also beneficial to understand the effects of restoration on the ecological carrying capacities in different zones depending on the different development goals.

The Yabello rangeland is a semi-arid area in Borana, Ethiopia that is facing great degradation challenges. Increasing infestation of vegetation cover, over grazing and high seasonal variation have significantly affected the herbage composition and biomass in the Yabello rangeland. This study focused on assessing the effect of vegetation cover, grazing and season on both herbage composition and biomass in the Yabello rangeland. An experiment was conducted using randomized plots of 1 m × 1 m. Sites were selected based on vegetation cover type and grazing variation, and seasonal impacts were also assessed. Data on herbage composition, height and mass with respect to those parameters were analyzed using SAS statistical software version 9.1 (SAS Institute, 2001) and Microsoft Excel. A total of 26 grass species were recorded and Chloris roxburghiana Chrysopogon aucheri and Chrysopogon aucheri grass species showed the highest average single species cover height and biomass production, for all the sites among all parameters. As a result, those grass species are highly recommended for the rehabilitation of degraded rangeland in the study area. This study also showed that vegetation cover type grazing and seasonal variation were the key factors in determining herbage species composition, height and biomass production. Finally, we recommended that sustainable management which controls bush vegetation cover and balances grazing levels is essential for sustainable herbage production and biodiversity conservation in the area.

Identifying the cause of a threatened species can aid in how best to formulate recovery actions. Recovery can be based on broad concepts and may not reflect a specific community or species requirements. Urban sprawl and intensification of land are known as threatening processes. How a threatening process interacts with a threatened species can aid in the recovery efforts. In South Australia, the species Allocasuarina robusta provides an opportunity to understand how past land usage may direct recovery efforts. Information on past land usage can involve identifying and using data from multiple repositories. The investigation focused on the relationship between changes in land use and herbarium data to understand a relationship between a common and threatened species. As a species evolves and adapts, the conservation practices used, including the methods used for identifying future actions, needs to be reflective of a changing environment. A changing environment can have consequences to biodiversity, creating several issues for a land manager. Traditional species recovery techniques can slow the threatening process down. Sometimes these threats may be visible like grazing from fauna (native and introduced). The threat to Allocasuarina robusta is a change in land use originating from anthropogenic activities. Supplementary planting with tube stock is a well-grounded practice, but the implications from this practice may need further investigation. Natural regeneration is crucial for long term population survival, but in Allocasuarina robusta, this is not occurring. The Allocasuarina robusta investigation aims to explore the relationships between herbarium data and land-use histories to guide future recovery efforts.