The Qinghai-Xizang Plateau (QXP) serves as a crucial ecological barrier in China and Asia, exerting profound influences on global climate and biodiversity conservation. Gannan Tibetan Autonomous Prefecture (hereinafter referred as Gannan Prefecture), located on the northeastern edge of the QXP, represents a fragile alpine ecosystem in which land use change significantly impacts ecosystem services (ESs). This study established a comprehensive framework, utilizing the Patch-generating Land-Use Simulation (PLUS) model coupled with the Integrated Valuation of Ecosystem Services and Tradeoffs (InVEST) model to predict land use patterns under the natural development scenario, cultivated land protection scenario, and ecological protection scenario for Gannan Prefecture by 2030 and evaluated four critical ESs: habitat quality (HQ), water yield (WY), soil retention (SR), and carbon storage (CS). The primary aim is to elucidate the impacts of dynamic land use change on ESs. The results revealed that, from 2000 to 2020, HQ exhibited minimal variation, whereas CS experienced a slight decline. Conversely, WY and SR showed significant improvements. Under the natural development scenario, construction land was projected to increase by 4247.74 hm², primarily at the expense of forest land. The cultivated land protection scenario anticipated an increase in farmland by 2634.36 hm², which was crucial for maintaining food security. The ecological protection scenario predicted a notable expansion of forest land, accompanied by a restrained development rate of construction land. The ecological protection scenario also showed an increase in the ecosystem service index (ESI), encompassing 26.07% of the region. Forest land and grassland emerged as the primary contributors to ESs, while construction land substantially impacted WY. Water bodies exhibited minimal contribution to ESs. This study enhanced the understanding of land use change impacts on ESs in fragile and high-altitude ecosystems, offering essential theoretical frameworks and practical direction for forthcoming ecological policy and regional planning endeavors.

The implementation of long-term shelterbelt programs in the middle reaches of the Yellow River (MRYR), China not only has improved the overall ecological environment, but also has led to the changes of land use pattern, causing carbon storage exchanges. However, the relationship between carbon storage and land use change in the MRYR is not concerned, which results in the uncertainty in the simulation of carbon storage in this area. Land use changes directly affect the carbon storage capacity of ecosystems, and as an indicator reflecting the overall state of land use, land use degree has an important relationship with carbon storage. In this study, land use data and the integrated valuation of ecosystem services and trade-offs (InVEST) model were used to assess the trends in land use degree and carbon storage in the MRYR during 1980-2020. The potential impact index and the standard deviation ellipse (SDE) algorithm were applied to quantify and analyze the characteristics of the impact of land use changes on carbon storage. Subsequently, land use transitions that led to carbon storage variations and their spatial variations were determined. The results showed that: (1) the most significant periods of carbon storage changes and land use transitions were observed during 1990-1995 and 1995-2020, with the most changed areas locating in the east of Fenhe River and in northwestern Henan Province; (2) the positive impact of land use degree on carbon storage may be related to the environmental protection measures implemented along the Yellow River, while the negative impact may be associated with the expansion of construction land in plain areas; and (3) the conversion of other land use types to grassland was the primary factor affecting carbon storage changes during 1980-2020. In future land use planning, attention should be given to the direction of grassland conversion, and focus on reasonably limiting the development of construction land. To enhance carbon storage, it will be crucial to increase the area of high-carbon-density land types, such as forest land and grassland under the condition that the area of permanent farmland does not decrease.

The Liaohe River Basin (LRB) in Northeast China, a critical agricultural and industrial zone, has faced escalating water resource pressures in recent decades due to rapid urbanization, intensified land use changes, and climate variability. Understanding the spatiotemporal dynamics of water yield and its driving factors is essential for sustainable water resource management in this ecologically sensitive region. This study employed the Integrated Valuation of Ecosystem Services and Tradeoffs (InVEST) model to quantify the spatiotemporal patterns of water yield in the LRB (dividing into six sub-basins from east to west: East Liaohe River Basin (ELRB), Taizi River Basin (TRB), Middle Liaohe River Basin (MLRB), West Liaohe River Basin (WLRB), Xinkai River Basin (XRB), and Wulijimuren River Basin (WRB)) from 1993 to 2022, with a focus on the impacts of climate change and land use cover change (LUCC). Results revealed that the LRB had an average annual precipitation of 483.15 mm, with an average annual water yield of 247.54 mm, both showing significant upward trend over the 30-a period. Spatially, water yield demonstrated significant heterogeneity, with higher values in southeastern sub-basins and lower values in northwestern sub-basins. The TRB exhibited the highest water yield due to abundant precipitation and favorable topography, while the WRB recorded the lowest water yield owing to arid conditions and sparse vegetation. Precipitation played a significant role in shaping the annual fluctuations and total volume of water yield, with its variability exerting substantially greater impacts than actual evapotranspiration (AET) and LUCC. However, LUCC, particularly cultivated land expansion and grassland reduction, significantly reshaped the spatial distribution of water yield by modifying surface runoff and infiltration patterns. This study provides critical insights into the spatiotemporal dynamics of water yield in the LRB, emphasizing the synergistic effects of climate change and land use change, which are pivotal for optimizing water resource management and advancing regional ecological conservation.

The Tarim River Basin (TRB) is a vast area with plenty of light and heat and is an important base for grain and cotton production in Northwest China. In the context of climate change, however, the increased frequency of extreme weather and climate events is having numerous negative impacts on the region's agricultural production. To better understand how unfavorable climatic conditions affect crop production, we explored the relationship of extreme weather and climate events with crop yields and phenology. In this research, ten indicators of extreme weather and climate events (consecutive dry days (CDD), min Tmax (TXn), max Tmin (TNx), tropical nights (TR), warm days (Tx90p), warm nights (Tn90p), summer days (SU), frost days (FD), very wet days (R95p), and windy days (WD)) were selected to analyze the impact of spatial and temporal variations on the yields of major crops (wheat, maize, and cotton) in the TRB from 1990 to 2020. The three key findings of this research were as follows: extreme temperatures in southwestern TRB showed an increasing trend, with higher extreme temperatures at night, while the occurrence of extreme weather and climate events in northeastern TRB was relatively low. The number of FD was on the rise, while WD also increased in recent years. Crop yields were higher in the northeast compared with the southwest, and wheat, maize, and cotton yields generally showed an increasing trend despite an earlier decline. The correlation of extreme weather and climate events on crop yields can be categorized as extreme nighttime temperature indices (TNx, Tn90p, TR, and FD), extreme daytime temperature indices (TXn, Tx90p, and SU), extreme precipitation indices (CDD and R95p), and extreme wind (WD). By using Random Forest (RF) approach to determine the effects of different extreme weather and climate events on the yields of different crops, we found that the importance of extreme precipitation indices (CDD and R95p) to crop yield decreased significantly over time. As well, we found that the importance of the extreme nighttime temperature (TR and TNx) for the yields of the three crops increased during 2005-2020 compared with 1990-2005. The impact of extreme temperature events on wheat, maize, and cotton yields in the TRB is becoming increasingly significant, and this finding can inform policy decisions and agronomic innovations to better cope with current and future climate warming.

Understanding the ecological evolution is of great significance in addressing the impacts of climate change and human activities. However, the ecological evolution and its drivers remain inadequately explored in arid and semi-arid areas. This study took the Helan Mountain, a typical arid and semi-arid area in China, as the study area. By adopting an Enhanced Remote Sensing Ecological Index (ERSEI) that integrates the habitat quality (HQ) index with the Remote Sensing Ecological Index (RSEI), we quantified the ecological environment quality of the Helan Mountain during 2010-2022 and analyzed the driving factors behind the changes. Principal Component Analysis (PCA) was used to validate the composite ERSEI, enabling the extraction of key features and the reduction of redundant information. The results showed that the contributions of first principal component (PC1) for ERSEI and RSEI were 80.23% and 78.72%, respectively, indicating that the ERSEI can provide higher precision and more details than the RSEI in assessing ecological environment quality. Temporally, the ERSEI in the Helan Mountain exhibited an initial decline followed by an increase from 2010 to 2022, with the average value of ERSEI ranging between 0.298 and 0.346. Spatially, the ERSEI showed a trend of being higher in the southwest and lower in the northeast, with high-quality ecological environments mainly concentrated in the western foothills at higher altitudes. The centroid of ERSEI shifted northeastward toward Helan County from 2010 to 2022. Temperature and digital elevation model (DEM) emerged as the primary drivers of ERSEI changes. This study highlights the necessity of using comprehensive monitoring tools to guide policy-making and conservation strategies, ensuring the resilience of fragile ecosystems in the face of ongoing climatic and anthropogenic pressures. The findings offer valuable insights for the sustainable management and conservation in arid and semi-arid ecosystems.

Water is essential for agricultural production; however, climate change has exacerbated drought and water stress in arid and semi-arid areas such as Iran. Despite these challenges, irrigation water efficiency remains low, and current water management schemes are inadequate. Consequently, Iranian crops suffer from low water productivity, highlighting the urgent need for enhanced productivity and improved water management strategies. In this study, we investigated irrigation management conditions in the Hamidiyeh farm, Khuzestan Province, Iran and used the calibrated AquaCrop and WinSRFR (a surface irrigation simulation model) models to reflect these conditions. Subsequently, we examined different management scenarios using each model and evaluated the results from the second year. The findings demonstrated that combining simulation of the AquaCrop and WinSRFR models was highly effective and could be employed for irrigation management in the field. The AquaCrop model accurately simulated wheat yield in the first year, being 2.6 t/hm², which closely aligned with the measured yield of 3.0 t/hm². Additionally, using the WinSRFR model to adjust the length of existing borders from 200 to 180 m resulted in a 45.0% increase in efficiency during the second year. To enhance water use efficiency in the field, we recommended adopting borders with a length of 180 m, a width of 10 m, and a flow rate of 15 to 18 L/s. The AquaCrop and WinSRFR models accurately predicted border irrigation conditions, achieving the highest water use efficiency at a flow rate of 18 L/s. Combining these models increased farmers' average water consumption efficiency from 0.30 to 0.99 kg/m³ in the second year. Therefore, the results obtained from the AquaCrop and WinSRFR models are within a reasonable range and consistent with international recommendations. This adjustment is projected to improve the water use efficiency in the field by approximately 45.0% when utilizing the border irrigation method. Therefore, integrating these two models can provide comprehensive management solutions for regional farmers.

Salt stress might be an important factor that decreases the emergence of seedlings and reduces plants' growth, causing their endangered status. However, the effects of salt stress on the germination of the Mediterranean species are less concern. Limonium strictissimum (Salzm.) Arrigoni, part of the group related to Limonium articulatum (Loisel.) Kuntze, is a Cyrno-Sardinian endemism, which is included in the International Union for Conservation of Nature (IUCN) Red Lists as Endangered (EN). Fresh seeds of L. strictissimum harvested from the only known population in Sardinia and a population in southeastern Corsica were used with the aims to study the effects of temperature and salinity on the seed germination and to evaluate the ability to recover their germination after exposure to salt stress. In both populations, empty fruits with a lower percentage were observed in Sardinia than in Corsica. The seeds showed a high germination capacity, which was not influenced by temperature and did not even differ between the two populations. Compared with non-saline condition, the presence of salt in the substrate, independently of the concentration tested, inhibited seed germination in both populations, with germination percentages never exceeding 40%. The Sardinian population showed a recovery capacity after exposure to high salt stress, always above 50% regardless of the salt concentration and incubation temperature considered. The seeds previously exposed to 125 mM NaCl at 30°C had the lowest recovery percentage (56%), while the highest recovery percentage (84%) was recorded at 25°C with a concentration of 250 mM NaCl. Differently, the Corsican population recorded a higher recovery percentage (54%) in seeds previously exposed to 500 mM NaCl at 20°C, while for the concentration of 125 mM NaCl, the best recovery percentage (11%) was recorded at 30°C. The ability of L. strictissimum to recover germination after salt exposure can be interpreted as an adaptation to the coastal habitats in which it grows. This study provides new insights into the ecophysiology of L. strictissimum seed germination, which could help preserve and implement effective conservation measures for this endangered species with restricted populations.

Root system architecture has often been overlooked in plant research despite its critical role in plant adaptation to environmental conditions. This study focused on the root system architecture of the desert shrub Reaumuria soongorica in the Alxa steppe desert, Northwest China. Plant samples were collected during May-September 2019. Using excavation methods, in situ measurements, and root scanning techniques, we analyzed the root distribution, topology, and branching patterns of R. soongorica across an age sequence of 7-51 a. Additionally, we investigated the allometric relationships of root collar diameter with total coarse root length, biomass, and topological parameters. The results showed that the roots of R. soongorica were predominantly concentrated in shallow soil layers (10-50 cm), with lateral root branching and biomass allocation increasing with shrub age. The root topology exhibited a herringbone-like structure, with average topological and modified topological indices of 0.89 and 0.96, respectively, both of which adjusted with shrub age. The root system displayed a self-similar branching pattern, maintaining a constant cross-sectional area ratio of 1.13 before and after branching, deviating from the area-preserving rule. These adaptive traits allow R. soongorica to efficiently expand its nutrient acquisition zone, minimize internal competition, and optimize resource uptake from the upper soil layers. Furthermore, significant linear relationships were observed between log₁₀-transformed root collar diameter and log₁₀-transformed total coarse root length, biomass, and topological parameters. These findings advance non-destructive approaches for studying root characteristics and contribute to the development of root-related models. Besides, this study provides new insights into the adaptive strategies of R. soongorica under extreme drought conditions, offering valuable guidance for species selection and cultivation in desert restoration efforts.