Distribution and protection of Thesium chinense Turcz. under climate and land use change.

Wild medicinal plants are prominent in the field of Traditional Chinese Medicine (TCM), but their availability is being impacted by human activities and ecological degradation in China. To ensure sustainable use of these resources, it is crucial to scientifically plan areas for wild plant cultivation. Thesium chinense, a known plant antibiotic, has been overharvested in recent years, resulting in a sharp reduction in its wild resources. In this study, we employed three atmospheric circulation models and four socio-economic approaches (SSP1-2.6, SSP2-4.5, SSP3-7.0, and SSP5-8.5) to investigate the primary environmental factors influencing the distribution of T. chinense. We also examined changes in its suitable area using the Biomod2 package. Additionally, we utilized the PLUS model to project and analyze future land use changes in climate-stable regions for T. chinense. Our planning for wild tending areas of T. chinense was facilitated by the ZONATION software. Over the next century, the climate-stable regions for T. chinense in China is approximately 383.05 × 104 km2, while the natural habitat in this region will progressively decline. Under the current climate conditions, about 65.06% of the habitats in the high suitable areas of T. chinense are not affected by future land use changes in China. Through hotspot analysis, we identified 17 hotspot cities as ideal areas for the wild tending of T. chinense, including 6 core hotspot cities, 6 sub-hotspot cities, and 5 fringe hotspot cities. These findings contribute to a comprehensive research framework for the cultivation planning of T. chinense and other medicinal plants.

The socioecological benefits and consequences of oil palm cultivation in its native range: The Sustainable Oil Palm in West Africa (SOPWA) Project.

Agriculture is expanding rapidly across the tropics. While cultivation can boost socioeconomic conditions and food security, it also threatens native ecosystems. Oil palm (Elaeis guineensis), which is grown pantropically, is the most productive vegetable oil crop worldwide. The impacts of oil palm cultivation have been studied extensively in Southeast Asia and - to a lesser extent - in Latin America but, in comparison, very little is known about its impacts in Africa: oil palm's native range, and where cultivation is expanding rapidly. In this paper, we introduce a large-scale research programme - the Sustainable Oil Palm in West Africa (SOPWA) Project - that is evaluating the relative ecological impacts of oil palm cultivation under traditional (i.e., by local people) and industrial (i.e., by a large-scale corporation) management in Liberia. Our paper is twofold in focus. First, we use systematic mapping to appraise the literature on oil palm research in an African context, assessing the geographic and disciplinary focus of existing research. We found 757 publications occurring in 36 African countries. Studies tended to focus on the impacts of palm oil consumption on human health and wellbeing. We found no research that has evaluated the whole-ecosystem (i.e., multiple taxa and ecosystem functions) impacts of oil palm cultivation in Africa, a knowledge gap which the SOPWA Project directly addresses. Second, we describe the SOPWA Project's study design and-using canopy cover, ground vegetation cover, and soil temperature data as a case study-demonstrate its utility for assessing differences between areas of rainforest and oil palm agriculture. We outline the socioecological data collected by the SOPWA Project to date and describe the potential for future research, to encourage new collaborations and additional similar projects of its kind in West Africa. Increased research in Africa is needed urgently to understand the combined ecological and sociocultural impacts of oil palm and other agriculture in this unique region. This will help to ensure long-term sustainability of the oil palm industry-and, indeed, all tropical agricultural activity-in Africa.

Mitigation Measures Could Aggravate Unbalanced Nitrogen and Phosphorus Emissions from Land-Use Activities.

Socioeconomic factors and mitigation potentials are essential drivers of the dynamics of nutrient emissions, yet these drivers are rarely examined at broad spatiotemporal scales. Here, we combine material flow analysis and geospatial analysis to examine the past and future changes of nitrogen and phosphorus emissions in China. Results show that anthropogenic nitrogen and phosphorus emissions increased by 17% and 32% during 2000-2019, respectively. Meanwhile, many regions witnessed decreasing nitrogen emissions but rising phosphorus discharged to waterbody, leading to a 20% decrease in the nitrogen/phosphorus ratio. In addition to many prominent factors like fertilizer use, the increasing impervious land area around cities is a notable factor driving the emissions, indicating the urgency to limit building expansion, especially in North China Plain and other less-developed regions. Improving land-use efficiency and consuming behaviors could reduce nitrogen and phosphorus emissions by 65-77% in 2030, but the nitrogen/phosphorus ratio will increase unintendedly due to larger reduction potentials for phosphorus, which may deteriorate the aquatic ecosystem. We highlight that nitrogen and phosphorus emissions should be reduced with coordinated but differentiated measures by prioritizing nitrogen reduction through cropland and food-system management.

Response of streamflow and nutrient loads in a small temperate catchment subject to land use change.

The aim of this study was to quantify the effect of land use change (LUC) implemented to meet nutrient load targets for a freshwater lake in New Zealand. We used the Soil and Water Assessment Tool (SWAT) model in combination with a non-parametric statistical test to determine whether afforestation of 15% of a subcatchment area was adequate to meet assigned nutrient load targets. A regional management authority set nutrient load targets of reduction in total nitrogen (TN) by 0.9 t yr-1 and reduction in total phosphorus (TP) by 0.05 t yr-1 to avoid eutrophication in the receiving waters of a freshwater lake. The load reduction was designed to be achieved through 200 ha of LUC from pasture to trees. Analysis of nutrient loads before, during, and following LUC shows that a 15% increase in forest cover decreased the annual flow (7.2%), TP load (33.3%), and TN load (13.1%). As flow and water quality observations were discrete and at irregular intervals, we used a parametric test and the SWAT model as different lines of evidence to demonstrate the effect of afforestation on flow and water quality. Policymakers concerned with decisions about LUC to improve the quality of receiving waters can benefit from applying our findings and using a statistical and numerical modelling framework to evaluate the adequacy of land use change to support improvements in water quality.

A slurry approach to identify nutrient critical source areas from subtropical catchment erosion.

Targeting catchment nutrient critical source areas (CSAs) (areas contributing most of the nutrients in a catchment) is an efficient way to prioritize remediation sites for reducing nutrient runoff to waterways. We tested if the soil slurry approach - with particle sizes and sediment concentrations representative of those in streams during high rainfall events - can be used to identify potential CSAs within individual land use types, examine fire impacts, and identify the contribution of leaf litter in topsoil to nutrient export in subtropical catchments. We first confirmed the slurry approach met the prerequisite to identify CSAs with relatively higher nutrient contribution (not absolute load estimation) by comparing the slurry sampling with stream nutrient monitoring data. We validated that: 1) differences in slurry total nitrogen to phosphorus mass ratios from different land uses were consistent with stream monitoring data; and 2) our estimated nutrient export contribution from agricultural land, via the slurry approach, was comparable to that derived from monitoring data. Additionally, we found nutrient concentrations in slurries differed across soil types and management practice within individual land uses, correlating with nutrient concentrations in fine particles. These results indicate the slurry approach can be used to identify potential small-scale CSAs. Slurry results from burnt soils were also comparable to other studies showing increased levels of dissolved nutrient loss and higher nitrogen than phosphorus loss, than non-burnt soils. The slurry method also showed the contribution of leaf litter to slurry nutrient concentrations from topsoil was greater for dissolved nutrients than particulate nutrients, indicating different forms of nutrients need to be considered for impacts of vegetation. Our study reveals that the slurry method can be used to identify potential small-scale CSAs within the same land use from erosion and can account for impacts of vegetation and bushfires, providing timely information to guide catchment restoration actions.

Substantial increase in P release following conversion of coastal wetlands to aquaculture ponds from altered kinetic exchange and resupply capacity.

The reclamation of wetlands and its subsequent conversion to aquaculture may alter regional nutrient (im)mobilization and cycling, although direct assessments of phosphorus (P) cycling and its budget balance following wetland conversion are currently scarce. Here, parallel field experiments were conducted to investigate and compare the availability and mobilization mechanisms of P from natural coastal wetlands and the adjacent converted aquaculture ponds based on high-resolution diffusive gradient in thin films (DGT) and dialysis (HR-Peeper) techniques and the DGT-induced fluxes in sediments (DIFS) model. The study found that the conversion of wetland to pond strongly reduced the sediment P pool by changing its forms and distribution. High-resolution data showed that concentrations of labile P and soluble reactive P across the sediment-water profiles were markedly enhanced by the converted aquaculture pond, although they exhibited large spatiotemporal heterogeneity. Moreover, the synchronous distribution of labile P, iron (Fe) and sulfur (S) across profiles in coastal wetlands indicated that the dissolution of Fe (III) oxyhydroxide-phosphate complexes coupled with sulfate reduction were the main mechanisms regulating sediment P mobilization in coastal areas. However, the converted aquaculture pond weakened or even reversed this dependence by decoupling the Fe-S-P reactions by changing the sediment structure and nutrient balance. Substantial increases in labile P, Fe and S fluxes in the pond suggested the conversion of wetland to aquaculture facilitated the internal release of P, Fe and S from sediment into water. The high resupply parameter (R) and desorption rate (k-1) combined with low response time (Tc) in the pond, as fitted by DIFS model, indicated the strong resupply capacity and fast kinetic exchange of sediment P across the sediment-water interface, which is consistent with the high P diffusion fluxes recorded in the pond. It was concluded that converted aquaculture ponds act as an important source of P release in coastal areas, potentially exacerbating water quality degradation and eutrophication. Specific initiatives and actions are therefore urgently needed to alleviate the internal P-loading during aquaculture.

Fluvial Deposition and Land Use Change Control Selenium Occurrence in Mollisols of Cold Region Agroecosystems.

Mollisols support the most productive agroecosystems in the world. Despite their critical links to food quality and human health, the varying distributions of selenium (Se) species and factors governing Se mobility in the mollisol vadose zone remain elusive. This research reveals that, in northern mollisol agroecosystems, Se hotspots (≥0.32 mg/kg) prevail along the regional river systems draining the Lesser Khingan Mountains, where piedmont Se-rich oil shales are the most probable source of regional Se. While selenate and selenite dominate Se species in the water-soluble and absorbed pools, mollisol organic matter is the major host for Se. Poorly crystalline and crystalline Fe oxides are subordinate in Se retention, hosting inorganic and organic Se at levels comparable to those in the adsorbed pool. The depth-dependent distributions of mollisol Se species for the non-cropland and cropland sites imply a predominance of reduced forms of Se under the mildly acidic and reducing conditions that, in turn, are variably impacted by agricultural land use. These findings therefore highlight that fluvial deposition and land use change together are the main drivers of the spatial variability and speciation of mollisol Se.

Spatial optimization of ecological ditches for non-point source pollutants under urban growth scenarios.

Non-point source (NPS) pollution is regarded as the major threat to water quality worldwide, and ecological ditches (EDs) are considered an important and widely used method to collect and move NPS pollutants from fields to downstream water bodies. However, few studies have been conducted to optimize the spatial locations of EDs, particularly when the watershed experiences urbanization and rapid land-use changes. As land-use patterns change the spatial distribution of NPS loads, this study used a cellular automata-Markov method to simulate future land-use changes in a typical agricultural watershed. Three scenarios are included as follows: historical trend, rapid urbanization, and ecological protection scenarios. The spatial distributions of particulate phosphorus loads were simulated using the revised universal soil loss equation and sediment transport distribution model. The results suggested that the total particulate phosphorus (TP) load in the Zhuxi watershed decreased by 10,555.2 kg from 2000 to 2020, primarily because the quality and quantity of forests in Zhuxi County improved over the last 20 years. The TP load in Zhuxi watershed would be 2588.49, 2639.15, and 2553.32 kg in 2040 in historical trend, rapid urbanization, and ecological protection scenarios, respectively, compared with 2308.1 kg in 2020. This indicated that urban expansion increases the TP load, and the faster the expansion rate, the more the TP load. Consequently, the optimal locations of EDs were determined based on the intercepted loads and the period during which they existed during land-use changes. The results suggested that rapid urbanization would consequently reduce the space available for building EDs and also increase the cost of building EDs to control the NPS pollution in the watershed.

Watershed health assessment using the coupled integrated multistatistic analyses and PSIR framework.

Quantitatively assessing watershed health under anthropogenic activities and management responses is important for the scientific planning and management of watersheds. The current research on watershed health assessments insufficiently reflects watershed scale information from different dimensions, which leads to the incomplete understanding of watersheds and thus the lack of systematic management. This study investigated the health status in the Chaohu Lake watershed (CLW) based on monthly sampling data at 46 river sites in 2018. Watershed health assessment comprehensively considered four dimensions including socioeconomic and natural pressures, nonpoint pollution export, river water quality and management responses with the pressure-state-impact-response (PSIR) framework. Canonical correlation analysis (CCA) and variance partitioning analysis (VPA) were integrated to further quantify the inter-relationships among the variables of each PSIR index. An obstacle degree model was applied to examine the factors of mainly affecting the status of watershed health. The results showed that phosphorus, nitrogen and sediment exports of CLW increased more and river water quality in CLW worsened due to socioeconomic and natural pressures. Water quality improvement effectively responds to increasing woodland and grassland. Compared with natural factors, phosphorus, nitrogen and sediment exports had closer relationships with the pressures from socioeconomic activities. Moreover, socioeconomic pressures explained more changes in phosphorus and nitrogen exports, while natural factors explained relatively more changes in sediment exports. Phosphorus, nitrogen and sediment exports and woodland and grassland coverage explained <35 % of the variation in river water quality. Additionally, the obstacle degrees of pressures and phosphorus, nitrogen and sediment exports were lower, and the obstacle degrees of river water quality and woodland and grassland coverage were higher in urban sub-watersheds, which was the opposite in agricultural sub-watersheds. This research provides a new evaluation framework of watershed health and its obstacle factors, which is crucial to improve watershed health.

Anthropogenic legacies shaping the present composition of demarcation trees in a temperate upland field landscape in Japan.

BACKGROUND: Isolated trees are often planted in agricultural landscapes around the world, but their planting background often remains unclear. In this study, we examined the history of demarcation trees in Ibaraki Prefecture in eastern Japan by using land dispute records mainly from the early modern period (from 1600 to 1868), the Rapid Survey Map (RSM) drawn in the late nineteenth century, demarcation tree records from 2011, and interviews of the local residents. METHODS: We reviewed 39 documents on land disputes to examine the temporal and spatial usage of demarcation tree species in the early modern period. The association between the present distribution of 1486 individuals of six demarcation tree species and past land use in the RSM were analyzed with Fisher's exact test and residual analysis. In addition, we conducted interviews with 48 farmers, most of whom were over 60 years old. RESULTS: The demarcation plants in vast communal lands and village boundaries in the early modern period were mostly visually prominent tall trees, usually pines. In contrast, smaller trees were planted for demarcation in small-scale areas of forests and farmlands. Although Pourthiaea villosa (Thunb.) DC. Has been planted since the mid-eighteenth century, its planting seems to have accelerated as communal forests were divided mainly in the Meiji period (from 1868 to 1912). The present dominant state of Deutzia crenata Siebold et Zucc. in older farmlands and its ritual use, history of upland field development in the Kanto region, and ancient demarcation use in central Japan indicate its original use may date back to the medieval (from 1185 to 1600) or ancient ritsuryo period (from the seventh century to 1185). Tea (Camellia sinensis (L.) Kuntze) and mulberry (Morus spp.) individuals were considered as early modern or modern crop remnants. Results from the map-based analysis and interviews clarified the recent increase in the use of Euonymus japonicus Thunb. and Celtis sinensis Pers. for demarcation. CONCLUSIONS: Chronologically dynamic anthropogenic legacies have shaped the present agricultural landscape with different demarcation tree species. A better understanding of the dynamic transformation of vegetation under human influence adds to the historical heritage value of the landscape and should motivate its conservation.

The management success of the invasive late goldenrod (Solidago gigantea Aiton.) in a nature conservation area is strongly related to site, control measures and environmental factors.

The late goldenrod (Soldiago gigantea Aiton; Asteraceae) is one of the most abundant invasive species in various types of habitats. Its long-creeping plagiotropic rhizomes enable the plant to build up dense, monospecific stands within a short time. Particularly in nature conservation areas, the invasion of goldenrod can cause severe disruptions in the naturally occuring mutualims between plants, insects and higher trophic levels, subsequently impeding the achievement of nature conservation goals. As management options of goldenrod in nature conservation areas are limited, this three-year study aimed to test the effectiveness of three management treatments (two-time mowing, triticale cultivation, and reverse rotary cutting) on four different sites in the Austrian Donau-Auen National Park. The number and height of goldenrod shoots were recorded three times a year on twelve permanent trial plots on each site to test for the effectiveness of the treatments. In addition, vegetation surveys were performed to observe the recovery potential of native plant species. Even though the three-years mowing and the triticale cultivation reduced goldenrod by 95.6% and 97.2% resp., we could find no relation between the effectiveness of the treatment and the intensity of disturbance created by the control option. On the contrary, with a reduction of only 5.4% in goldenrod density the most intensive treatment, the rotary cutting, showed the lowest efficiency. The highest positive effect on the re-establishment of native plant species was recorded with two mowing events per year. Even though the study revealed that certain management options have the potential to effectively reduce goldenrod and to simultaneously increase the establishment success of native species, results can only be seen as so-called snapshots. For example, as shown on site EJW one unforeseeable wild boar digging event transformed a 84.5% reduction into a 4.7% increase in goldenrod density. Therefore, a proper and regular monitoring is essential to be able to react to the effects of unpredictable events that can have severe impact on vegetation dynamics.

Phosphorus in soils and fluvial sediments from a Cerrado biome watershed under agricultural expansion.

Over the past decades, lands alongside Gurguéia River have witnessed rapid expansion of soybean agriculture which has increased soil degradation and affected nutrient concentration in sediment, especially phosphorus (P). The present study aimed to quantify the P concentration in soils under different land uses (i.e., croplands, grasslands, and cerrado) and fluvial sediments (suspended sediment, channel bank, and riverbed sediments), assessing pollution over the main watercourse in cerrado biome Gurguéia watershed, located in Piauí State, Brazil. In total, 136 composite soil samples at a depth of 0-5 cm, under different land uses, as well as 51 composite fluvial sediment samples were collected over the watershed. The land use change from native cerrado had resulted in an increase of total phosphorus (TP) whose concentration was higher in cropland areas, followed by suspended sediment, channel bank, and riverbed sediments. This high concentration in cropland areas resulted from phosphate fertilizer inputs. The transfer of phosphorus to water bodies was evidenced, since an increase of TP was observed in suspended sediment, channel bank and riverbed  sediments. Mineralogical signatures in sediments were identified by X-ray diffraction analysis which showed the occurrence of kaolinite, illite, smectite, iron oxides, and other minerals in lesser proportions. The presence of 1:1 minerals was higher in riverbed sediments and downstream sampling points, while 2:1 minerals were present in higher proportions in suspended sediment and channel bank sediment, as well as at the upstream and middle sampling points. This finding shows that land use change from cerrado to cropland due to soybean agriculture expansion might increase P discharges from terrestrial to aquatic environments, with sediments being the major carrier of this element.

Agricultural intensification leads to higher nitrate levels in Lake Ontario tributaries.

Eutrophication remains the most widespread water quality impairment globally and is commonly associated with excess nitrogen (N) and phosphorus (P) inputs to surface waters from agricultural runoff. In southern Ontario, Canada, increases in nitrate (NO3-N) concentrations as well as declines in total phosphorus (TP) concentration have been observed over the past four decades at predominantly agricultural watersheds, where major expansions in row crop production at the expense of pasture and forage have occurred. This study used a space-for-time approach to test whether 'agricultural intensification', herein defined as increases in row crop area (primarily corn-soybean-winter wheat rotation) at the expense of mixed livestock and forage/pasture, could explain increases in NO3-N and declines in TP over time. We found a clear, positive relationship between the extent of row crop area within watersheds and NO3-N losses, such that tributary NO3-N concentrations and export were predicted to increase by ~0.4 mg/L and ~130 kg/km2 respectively, for every 10% expansion in row crop area. There was also a significant positive relationship between row crop area and total dissolved phosphorus (TDP) concentration, but not export, and TP was not correlated with any form of landcover. Instead, TP was strongly associated with storm events, and was more sensitive to hydrologic condition than to landcover. These results suggest that pervasive shifts toward tile-drained corn and soybean production could explain increases in tributary NO3-N levels in this region. The relationship between changes in agriculture and P is less clear, but the significant association between dissolved P and row crop area suggests that increased adoption of reduced tillage practices and tile drainage may enhance subsurface losses of P.

Soil microbial stoichiometry and community structure responses to long-term natural forest conversion to plantations in a subtropical region.

Soil microbial stoichiometry reflects carbon (C) and nutrient (e.g., nitrogen (N) and phosphorus (P)) elemental balances under land-use change (LUC). However, how soil microbial community (SMC) structure and stoichiometry respond to long-term LUC in forests is still unclear. Here, we investigated three 36-year-old typical plantations, Cryptomeria fortunei, Metasequoia glyptostroboides, and Cunninghamia lanceolata, and the natural forest to assess their soil microbial stoichiometry and SMC structure. Three plots (30×30 m2) were randomly set in each forest site. In each plot of every forest site, soil samples of three depths (0-10, 10-30, and 30-60 cm) were collected. Dissolved organic C, N, and P (abbreviated as DOC, DON, and DOP, respectively) and environmental factors were measured. We also detected microbial biomass C, N, and P as well as SMC structure. The results showed that the soil microbial C:N:P stoichiometry had a strong or strict homeostasis regardless of soil depth and exhibited decoupling from the SMC structure at each depth. The SMC structure across forest types was mainly driven by mean annual soil temperature (MAST) and DOC at 0-10 cm depth, by soil water content and MAST at 10-30 cm depth, and by DOC to DOP ratio at 30-60 cm depth. Thus, SMC structure could be jointly regulated by available resources and environment. These results suggest that the C dynamics in forests tend to gain resilience or re-equilibrium over more than three decades after forest conversion. These findings highlight the importance of reforested plantations forest management for sustaining soil C over a long term.

The effects of climate variability and land-use change on streamflow and nutrient loadings in the Sesan, Sekong, and Srepok (3S) River Basin of the Lower Mekong Basin.

This paper aimed at examining the climate variability and land-use change effects on streamflow and pollutant loadings, namely total suspended sediment (TSS), total nitrogen (T-N), and total phosphorus (T-P), in the Sesan, Sekong, and Srepok (3S) River Basin in the period 1981-2010. The well-calibrated and validated Soil and Water Assessment Tool (SWAT) was used for this purpose. Compared to the reference period, climate variability was found to be responsible to a 1.00% increase in streamflow, 2.91% increase in TSS loading, 11.35% increase in T-N loading, and 19.12% reduction in T-P loading for the whole basin. With regard to the effect of land-use change (LUC), streamflow, TSS, T-N, and T-P loadings increased by 0.01%, 3.70%, 10.12%, and 10.94%, respectively. Therefore, the combination of climate variability and LUC showed amplified increases in streamflow (1.03%), TSS loading (7.09%), and T-N loading (25.05%), and a net effect of decreased T-P loading (10.35%). Regarding the Sekong and Srepok River Basins, the streamflow, TSS, T-N and T-P showed stronger responses to climate variability compared to LUC. In case of the Sesan River Basin, LUC had an effect on water quantity and quality more strongly than the climate variability. In general, the findings of this work play an essential role in providing scientific information to effectively support decision makers in developing sustainable water resources management strategies in the study area.

Effects of agricultural landscape structure, insecticide residues, and pollen diversity on the life-history traits of the red mason bee Osmia bicornis.

Agricultural landscapes have changed substantially in recent decades, shifting from the dominance of small fields (S) with diverse cropping systems toward large-scale monoculture (L), where landscape heterogeneity disappears. In this study, artificial nests of the red mason bee, Osmia bicornis, were placed in S and L landscape types on the perimeter of oilseed rape fields representing different oilseed rape coverages (ORC, % land cover). The local landscape structure around each nest was characterised within a 100, 200, 500, and 1000 m radius using ORC and 14 landscape characteristics, which were then reduced by non-metric multidimensional scaling (nMDS) to two axes: nMDS1 characterised the dataset primarily according to land fragmentation and the main crop, whereas nMDS2 captured the prevalence of more natural areas in the landscape. Pollen diversity and insecticide risk levels in the pollen provisions collected by the bees were analysed, and their dependence on the landscape structure was tested. Thereafter, the effects of pollen diversity, insecticide risk, and landscape structure on the life-history traits of bees and their sensitivity to topically applied Dursban 480 EC were determined. Pollen taxa richness in a single nest ranged from 3 to 12, and 34 pesticides were detected in the pollen at concentrations of up to 320 ng/g for desmedipham. The O. bicornis foraging range was relatively large, indicating that the landscape structure within a radius of ~1000 m around the nest is important for this species. Pollen diversity in the studied areas was of minor importance for bee performance, but the ORC or landscape structure significantly affected the life-history traits of the bees. Contamination of pollen with insecticides affected the bees by decreasing the mass of newly emerged adults but their sensitivity to Dursban 480 EC was not related to environmental variables.

Heavy grazing of buffel grass pasture in the Brigalow Belt bioregion of Queensland, Australia, more than tripled runoff and exports of total suspended solids compared to conservative grazing.

Loss of sediment and particulate nutrients in runoff from the extensive grazing lands of the Fitzroy Basin, central Queensland, continue to contribute to the declining health of the Great Barrier Reef. This study measured differences in hydrology and water quality from conservative and heavy grazing pressures on rundown improved grass pastures in the Fitzroy Basin. Conservative grazing pressure was defined as the safe long-term carrying capacity for rundown buffel grass pasture, whereas heavy grazing pressure was defined as the recommended stocking rate for newly established buffel grass pasture. Heavy grazing of rundown pasture resulted in 2.5 times more bare ground and only 8% of the pasture biomass compared to conservative grazing. Heavy grazing also resulted in 3.6 times more total runoff and 3.3 times the peak runoff rate compared to conservative grazing. Loads of total suspended solids, nitrogen and phosphorus in runoff were also greater from heavy than conservative grazing.

Estimating induced land use change emissions for sustainable aviation biofuel pathways.

Sustainable aviation fuels (SAFs) are expected to play an essential role in achieving the aviation industries' goal of carbon-neutral growth. However, producing biomass-based SAFs may induce changes in global land use and the associated carbon stock. The induced land use change (ILUC) emissions, as a part of the full life-cycle emissions for SAF pathways, will affect whether and to what extent SAFs reduce emissions compared with petroleum-based jet fuels. Here, we estimate the ILUC emission intensity for seventeen SAF pathways considered by the International Civil Aviation Organization (ICAO), covering five ASTM-certified technologies, nine biomass-based feedstocks, and four geographical regions. We introduce the SAF pathways into a well-established computable general equilibrium (CGE) model, GTAP-BIO, and its coupled emission accounting model, AEZ-EF, to study economy-wide implications of SAF production and estimate ILUC emissions intensity for each pathway. The estimated SAF ILUC emission intensities, using a 25-year amortization period, range from -58.5 g CO2e MJ-1 for the USA miscanthus alcohol (isobutanol)-to-jet (ATJ) pathway to 34.6 g CO2e MJ-1 for the Malaysia & Indonesia palm oil Hydrotreated Esters of Fatty Acids (HEFA) pathway. Notably, the vegetable oil pathways tend to have higher ILUC emission intensities due to their linkage to palm expansion and peatland oxidation in Southeast Asia. The cellulosic pathways studied provide negative ILUC emissions, mainly driven by the high carbon sequestrations in crop biomass and soil. Using the core life-cycle emissions established by ICAO, we show that fifteen of the assessed pathways have a lower full life-cycle emission intensity than petroleum-based jet fuels (89 g CO2e MJ-1), offering promising options to reduce aviation emissions.

Integrating vegetation suitability in sustainable revegetation for the Loess Plateau, China.

Revegetation is accelerating globally due to its benefits for ecosystem restoration, desertification prevention, and climate change mitigation. The Loess Plateau has suffered serious erosion in the past decades, and revegetation projects, such as those under the 'Grain for Green' program, have been conducted for soil erosion prevention. The irrational distribution of artificial plantations had negative consequences, including vegetation degradation, soil drying, and decreases in streamflow. Determining the suitable plant species is critical in guiding the design of revegetation programs and may help delimit the suitable boundaries for artificial plantations. In this study, we used an eco-hydrological model to quantify the suitability of two typical revegetation species (Robinia pseudoacacia and Stipa bungeana) using a developed vegetation suitability equation, which estimates the water use/water stress trade-off. The results showed that R. pseudoacacia was more sensitive to water stress than S. bungeana. The water use of both species varied along the precipitation gradient, and S. bungeana generally had a higher water use than R. pseudoacacia. Suitable areas for R. pseudoacacia were mainly located in the northeastern part of the plateau. By overlaying the suitable boundaries for R. pseudoacacia on the current land cover, we found that the area of forests distributed in unsuitable regions reached 7.31% of the entire Loess Plateau. Converting forests beyond the suitable boundary to grasslands would increase the water yield (0.51%-12.23%) and slightly decrease the soil retention capacity (0.01%-0.08%), resulting in a 'win-win' situation for sustainable plant-soil ecosystems and soil-water conservations. Additionally, the suitable area of R. pseudoacacia is predicted to shrink under projected future drying trends. In conclusion, vegetation suitability in the future planning and design of revegetation projects should be considered to effectively tackle the impacts of environmental degradation and climate change in the Loess Plateau.

The conversion of subtropical forest to tea plantation changes the fungal community and the contribution of fungi to N2O production.

The conversion of natural forests to tea plantations largely affects soil nitrous oxide (N2O) emissions and soil microbial communities. However, the impacts of this conversion on the contribution of fungi to N2O emission and on fungal community structure remain unclear. In this study, we determined the soil N2O emission rate, N2O production by fungi, associated fungal community diversity, and related ecological factors in chronological changes of tea crop systems (3, 36 and 105 years old tea orchards named T3, T36 and T105, respectively), and in an adjacent soil from a natural forest. The results indicate that the tea plantations significantly enhanced soil N2O production compared with the forest soil. Tea plantations significantly decreased soil pH and C/N ratio, but increased soil inorganic nitrogen (N). Furthermore, they increased the fungal contribution to the production of soil N2O, but decreased the bacterial counterpart. We also observed that fungal community and functional composition differed distinctly between tea plantations and forest. Additionally, most of the fungal groups in high N2O emission soils (T36 and T105) were identified as the genus Fusarium, which were positively correlated with soil N2O emissions. The variation in N2O emission response could be well explained by NO3--N, soil organic carbon (SOC), C/N, and Fusarium, which contributed to up to 97% of the observed variance. Altogether, these findings provide significant direct evidence that the increase of soil N2O emissions and fungal communities be attributed to the conversion of natural forest to tea plantations.