U.S. cereal rye winter cover crop growth database.

Winter cover crop performance metrics (i.e., vegetative biomass quantity and quality) affect ecosystem services provisions, but they vary widely due to differences in agronomic practices, soil properties, and climate. Cereal rye (Secale cereale) is the most common winter cover crop in the United States due to its winter hardiness, low seed cost, and high biomass production. We compiled data on cereal rye winter cover crop performance metrics, agronomic practices, and soil properties across the eastern half of the United States. The dataset includes a total of 5,695 cereal rye biomass observations across 208 site-years between 2001-2022 and encompasses a wide range of agronomic, soils, and climate conditions. Cereal rye biomass values had a mean of 3,428 kg ha-1, a median of 2,458 kg ha-1, and a standard deviation of 3,163 kg ha-1. The data can be used for empirical analyses, to calibrate, validate, and evaluate process-based models, and to develop decision support tools for management and policy decisions.

Tropical tree ectomycorrhiza are distributed independently of soil nutrients.

Mycorrhizae, a form of plant-fungal symbioses, mediate vegetation impacts on ecosystem functioning. Climatic effects on decomposition and soil quality are suggested to drive mycorrhizal distributions, with arbuscular mycorrhizal plants prevailing in low-latitude/high-soil-quality areas and ectomycorrhizal (EcM) plants in high-latitude/low-soil-quality areas. However, these generalizations, based on coarse-resolution data, obscure finer-scale variations and result in high uncertainties in the predicted distributions of mycorrhizal types and their drivers. Using data from 31 lowland tropical forests, both at a coarse scale (mean-plot-level data) and fine scale (20 × 20 metres from a subset of 16 sites), we demonstrate that the distribution and abundance of EcM-associated trees are independent of soil quality. Resource exchange differences among mycorrhizal partners, stemming from diverse evolutionary origins of mycorrhizal fungi, may decouple soil fertility from the advantage provided by mycorrhizal associations. Additionally, distinct historical biogeographies and diversification patterns have led to differences in forest composition and nutrient-acquisition strategies across three major tropical regions. Notably, Africa and Asia's lowland tropical forests have abundant EcM trees, whereas they are relatively scarce in lowland neotropical forests. A greater understanding of the functional biology of mycorrhizal symbiosis is required, especially in the lowland tropics, to overcome biases from assuming similarity to temperate and boreal regions.

Assessment of hydrological water balance in Lower Nzoia Sub-catchment using SWAT-model: towards improved water governace in Kenya.

Kenya's catchments has both natural and disturbed environments. Within these environments, there has been interaction between hydrological, physical and ecological characteristics. Therefore, impacts of Land Use Land Cover (LULC) change on surface and sub - surface hydrology needs to be well understood due to the increasing population competing for scarce natural resources such as water, trees and forest land. The water balance components' spatial and temporal dynamics in relationship to the LULC change between 2003 and 2018 in the Lower Nzoia Sub - Catchment (LNSC) in Kenya was therefore assessed. Landsat data with 30 m (m) spatial resolution was used in understanding LULC dynamics of the study area using Supervised Classification Approach (Interactive Classification Method) in ArcGIS 10.5. After landsat image classification, key water balance components including; surface runoff (SURFQ), lateral flow (LATQ), groundwater recharge (BASEQ), deep acquifer recharge (DEEPQ), evapotranspiration (ET) and groundwater revap (REVAP) for years 2003 and 2018 were estimated using SWAT model in ArcSWAT. The overall accuracies for 2003 and 2018 classified images were 75.9% and 98.9% respectively which are showing good values. The results of the study showed that agricultural land coverage reduced from 83.1% in 2003 to 78.6% in 2018. Rangeland on the hand increased from 6.3% to 9.8% while urban/built - up area increasing from 10.6% to 11.6%. The annual water balance components from the LULC distribution of the two time periods shows that ET reduced, SURFQ increased, BASEQ reduced, DEEPQ reduced, LATQ reduced and REVAP reduced. At catchment level, results show that 2018 had a higher water balance than 2003 which can partly be explained by land cover decrease. The relationship between rainfall distribution, Land Surface Temperature (LST) and LULC change were further compared. At the same time, the study found out that there is limited focus to date on rural communities climate adaptive capacity. Hence, water institutions in the sub - catchment such as Water Resources Authority (WRA) are yet to fully mainstream adaptive capacity into their organizational structure and policies.

Global trends in nature's contributions to people.

Declining biodiversity and ecosystem functions put many of nature's contributions to people at risk. We review and synthesize the scientific literature to assess 50-y global trends across a broad range of nature's contributions. We distinguish among trends in potential and realized contributions of nature, as well as environmental conditions and the impacts of changes in nature on human quality of life. We find declining trends in the potential for nature to contribute in the majority of material, nonmaterial, and regulating contributions assessed. However, while the realized production of regulating contributions has decreased, realized production of agricultural and many material commodities has increased. Environmental declines negatively affect quality of life, but social adaptation and the availability of substitutes partially offset this decline for some of nature's contributions. Adaptation and substitutes, however, are often imperfect and come at some cost. For many of the contributions of nature, we find differing trends across different countries and regions, income classes, and ethnic and social groups, reinforcing the argument for more consistent and equitable measurement.

The value of manure - Manure as co-product in life cycle assessment.

Livestock production is important for food security, nutrition, and landscape maintenance, but it is associated with several environmental impacts. To assess the risk and benefits arising from livestock production, transparent and robust indicators are required, such as those offered by life cycle assessment. A central question in such approaches is how environmental burden is allocated to livestock products and to manure that is re-used for agricultural production. To incentivize sustainable use of manure, it should be considered as a co-product as long as it is not disposed of, or wasted, or applied in excess of crop nutrient needs, in which case it should be treated as a waste. This paper proposes a theoretical approach to define nutrient requirements based on nutrient response curves to economic and physical optima and a pragmatic approach based on crop nutrient yield adjusted for nutrient losses to atmosphere and water. Allocation of environmental burden to manure and other livestock products is then based on the nutrient value from manure for crop production using the price of fertilizer nutrients. We illustrate and discuss the proposed method with two case studies.