Improved Land Management Research Articles

Efficiency of Vegetables Produced in Glasshouses: The Impact of Data Envelopment Analysis (DEA) in Land Management Decision Making

Glasshouse farming is one of the most intensive types of production of agricultural products. Via this process, consumers have the ability to consume mainly off-season vegetables and farmers are able to reduce operational risks, due to their ability to control micro-climate conditions. This type of farming is quite competitive worldwide, this being the main reason for formulating and implementing assessment models measuring operational performance. The methodology used in this study is Data Envelopment Analysis (DEA), which has wide acceptance in agriculture, among other sectors of the economy. The production protocols of four different vegetables—cucumber, eggplant, pepper, and tomato—were evaluated. Acreage (m2), crop protection costs (€), fertilizers (€), labor (Hr/year), energy (€), and other costs (€) were used as inputs. The turnover of every production unit (€) was used as the output. Ninety-eight agricultural holdings participated in this survey. The dataset was obtained by face-to-face interviews. The main findings verify the existence of significant relative deficiencies (including a mean efficiency score of 0.87) as regards inputs usage, as well as considerably different efficiency scores among the different cultivations. The most efficient of these was the eggplant production protocol and the least efficient was that used for the tomato. The implementation of DEA verified its utility, providing incentives for continuing to use this methodology for improving land management decision making.

Intelligent Spectroscopy System Used for Physicochemical Variables Estimation in Sugar Cane Soils.

The current condition of soils is a major area of interest due to the lack of certainty in their physicochemical properties, which can guarantee the quality and the production of a specific crop. Additionally, methodologies to improve land management must be implemented in order to address the consequences of many environmental issues. To date, many techniques have been implemented to improve the accuracy—and more recently the speed—of analysis, in order to obtain results while in the field. Among those, Near Infrared (NIR) spectroscopy has been widely used to achieve the objectives mentioned above. Nevertheless, it requires particular knowledge, and the cost might be high for farmers who own the fields and crops. Thus, the present work uses a system that implements capacitance spectroscopy plus artificial intelligence algorithms to estimate the physicochemical variables of soil used to grow sugar cane. The device uses the frequency response of the soil to determine its magnitude and phase values, which are used by artificial intelligence algorithms that are capable of estimating the soil properties. The obtained results show errors below 8% in the estimation of the variables compared to the analysis results of the soil in laboratories. Additionally, it is a portable system, with low cost, that is easy to use and could be implemented to test other types of soils after evaluating the necessary algorithms or proposing alternatives to restore soil properties.

Feeding Ecology and Prey Selection by Wintering Long-Eared Owls Asio otus in Mediterranean Agrosystems

The diet composition and dietary patterns of the Long-eared Owl Asiootus were studied in Mediterranean agrosystems in central Crete (Greece) over the winters of 2009–2015. Overall, 2,819 prey items were recovered from 1,207 pellets, belonging to six taxa of mammals, 22 taxa of birds and four taxa of insects. Small mammals were the most common prey species, accounting for 75.8% by frequency and 79.7% by biomass, followed by birds (23.2% and 20.1%); the latter being rather an island component compared to continental regions. The House Mouse Mus musculus was the most important prey species in the owl's diet (56.3%) ahead of the Wood Mouse apodemus sylvaticus (9.51%) and the Black Rat Rattus rattus (7.9%). The species proved to be a significant rodent predator in olive groves and vineyards during winter months, selecting Wood Mouse and young Black Rat more than expected. Long-eared Owl feeding ecology studies could lead to improved land management and agricultural practices in the rural landscapes of the Mediterranean.

Determinants of Potato Marketed Surplus Among Smallholder Farmers in Sekela District, West Gojjam Zone of Amhara Region, Ethiopia

For Sekela Woreda smallholder potato producers, potato has significant contribution for consumption at home which increase food security and in generating cash income. Therefore, enhancing potato producers’ access to market and linking them to most beneficial outlets is a key issue needed in the study area. This paper was aimed to identify factors affecting marketed surplus potato farmers using survey data collected from randomly selected 130 farmers from six kebeles were randomly and proportionately sampled to collect both secondary and primary sources. Descriptive statistics was used for characterizing farmers and econometrics analysis was used for identifying determinants of marketed surplus. The result of econometric analysis from OLS marketed surplus model revealed that distance to the nearest market, use of improved seed, frequency of extension contact, area of land allocated for potato and yield of potato significantly determined quantity of potato supplied to the market. Based on the finding the government and other stakeholders need to focus on strengthening improved seed access, strengthening rural-urban infrastructure, expanding market access, improving land management practices and yield through strengthening extension service in order to accelerate market chain development. Keywords: Marketed surplus, Potato, Multiple linear regression DOI : 10.7176/FSQM/83-06

Determinants of Potato Marketed Surplus among Smallholder Farmers in Sekela District, West Gojjam Zone of Amhara Region, Ethiopia

For Sekela Woreda smallholder potato producers, potato has significant contribution for consumption at home which increase food security and in generating cash income. Therefore, enhancing potato producers’ access to market and linking them to most beneficial outlets is a key issue needed in the study area. This paper was aimed to identify factors affecting marketed surplus potato farmers using survey data collected from randomly selected 130 farmers from six kebeles were randomly and proportionately sampled to collect both secondary and primary sources. Descriptive statistics was used for characterizing farmers and econometrics analysis was used for identifying determinants of marketed surplus. The result of econometric analysis from OLS marketed surplus model revealed that distance to the nearest market, use of improved seed, frequency of extension contact, area of land allocated for potato and yield of potato significantly determined quantity of potato supplied to the market. Based on the finding the government and other stakeholders need to focus on strengthening improved seed access, strengthening rural-urban infrastructure, expanding market access, improving land management practices and yield through strengthening extension service in order to accelerate market chain development. Keywords: Marketed surplus, Potato, Multiple linear regression DOI : 10.7176/FSQM/83-06

Analysis of Farmers’ Perception on the Impact of Land Degradation Hazard on Agricultural Land Productivity in Jeldu District in West Shewa Zone, Oromia, Ethiopia

Land degradation is increasing in severity and extent in many parts of the world. Success in arresting land degradation entails an improved understanding of its causes, process, indicators and impacts. Various scientific methodologies have been employed to assess land degradation globally. However, the use of local community knowledge in elucidating the causes, process, indicators and effects of land degradation has seen little application by scientists and policy makers. Land degradation may be a physical process, but its underlying causes are firmly rooted in the socio-economic, political and cultural environment in which land users operate. Analyzing the root causes and effects of land degradation from local community knowledge, perception and adapting strategies perspective will provide information that is essential for designing and promoting sustainable land management practices. The main objective of this study was to analyze the perceptions of farmers’ on the impact of land degradation hazard on agricultural land productivity decline associated with soil erosion and fertility loss. The study used a multistage sampling procedure to select sample respondent households. The sample size of the study was 120 household heads and 226 farm plots managed by these farmers. The primary data of the study were collected by using semi-structured Interview, focus group discussions and field observation. Both descriptive statistics and econometric techniques were used for data analysis. Descriptive results show that 57percent of the respondents were perceived the severity and its consequence on agricultural land productivity. The following indicators of soil erosion and fertility loss were generally perceived and observed by farmers’ in the study area: gullies formations, soil accumulation around clumps of vegetation, soil deposits on gentle slopes, exposed roots, muddy water, sedimentation in streams and rivers, change in vegetation species, increased runoff, and reduced rooting depth. The direct human activities which were perceived to be causing land degradation in the study area include: deforestation and clearing of vegetation, overgrazing, steep slope cultivation and continuous cropping. The farmers’ possibility of perceiving the impact of land degradation hazard on agricultural land productivity was primarily determined by institutional, psychological, demographic and by bio-physical factors. Farmers who perceive their land as deteriorating and producing less than desired, tend to adopt improved land management practices. On the other hand, farmers who perceive their land to be fertile tend to have low adoption of conservation practices. In order to overcome this land degradation and its consequent effects, the study recommended a need for the government to enforce effective policies to control and prevent land degradation and these policies should be community inclusive /participatory founded up on indigenous and age-honored knowledge and tradition of farmers' natural resource management as well as introduced scientific practices.

Soil composition and plant nutrients at the interface between crops and saline wetlands in arid environments in NE Spain

In arid and semiarid environments, saline wetlands are both high-value habitats threatened by landscape transformations, and a constraint to agricultural production. There is a lack of knowledge about nutrients distribution in intermittently flooded environments subjected to soil and water salinity. The aim of this work was to characterize soil and plant nutrient status along soil transects at the interface between agricultural land and saline wetlands. These aspects were studied in Guallar and Gallocanta, two Ramsar saline wetlands in NE Spain that represent arid and semiarid conditions, respectively. Soils were characterized for nitrogen (N) and phosphorous (P) status; crop and natural vegetation nutrient status was measured with P Nutrition Index (PNI) and Nitrogen Nutrition Index (NNI). Soil salinity (EC1:5) increases towards the halophyte areas, reaching 5.4 dS m−1 in Guallar and 3.7 dS m−1 in Gallocanta. On average, the soils are loams or sandy loams. Carbonate-rich soils are common (39% mean calcium carbonate equivalent) and some soils in Guallar have a high gypsum content (up to 72%). The soils have a low to moderate cation exchange capacity regardless of soil salinity, with a maximum of 14 cmol+ kg−1 in the soil with the highest organic matter content (3.8%). Overall, cereal soils show total P and N contents within the normal range for agricultural soils, although the available P is above the requirements for cereals, up to 67 mg kg−1. The difference in soil nutrients between cropped and halophyte land is more noticeable when it comes to total and available P content than for N levels. The relatively high nutrient content in some halophyte soils and the total and available P gradients along the soil transects, reflect downslope nutrient movement towards the lake. Halophyte soils can accumulate between 11% and 71% of the available P found in cropped soils. No relationship was found between the soil nutrient content and that of plants, nor between these two parameters and soil salinity. NNI and PNI indicate non-limiting nutrient status for cereals grown in Gallocanta and nutrient limitation in Guallar, probably related to the high gypsum content, and/or soil salinity. Studying the plant available nutrient content in arid and saline soils, at the interface between halophytes and crops, is crucial for improving land management strategies and reconciling production and conservation in protected saline habitats.

Soil moisture dynamics under Caragana korshinskii shrubs of different ages in Wuzhai County on the Loess Plateau, China

ABSTRACTSoil moisture is a key factor affecting vegetation growth and survival in arid and semi-arid regions. Knowledge of deep soil moisture dynamics is very important for guiding vegetation restoration and for improving land management practices on the water-limited Loess Plateau. Temporal changes and vertical variations in deep soil moisture (at soil depths of 0–600cm) combined with soil moisture availability were monitored in situ under Caragana korshinskii shrubs of different ages (named CK-10a, CK-20a and CK-35a) in the Loess hilly region during the growing season of 2013. The soil moisture content (SMC) under C. korshinskii shrubs of different ages was highly consistent with the seasonal precipitation variations and generally decreased as follows: CK-10a>CK-20a>abandoned land>CK-35a. The SMC varied greatly over time during the growing season (P<0.01), decreasing from April to May and then slowly increasing with some fluctuation from June to October. The SMC drastically decreased with depth from 0–300cm and then gradually increased with some fluctuation from 300–600cm. A critical turning point and transition zone connecting the shallow and deep soil moisture occurred at 200–300cm. Therefore, the soil profile was divided into active, secondary active and relatively steady soil layers in terms of soil moisture. The SMC fluctuated at depths of 0–100cm and 300–400cm and was relatively stable in the deeper soil layers. The amount of available soil moisture gradually decreased as the forest stand age increased, especially at CK-35a, where most of the soil moisture was unavailable for plant use. In addition, our study indicates that a large-scale restoration strategy with pure shrubland or woodland may not be suitable for soil moisture recovery in arid environments.

МОДЕЛИРОВАНИЕ ВРЕМЕННЫХ РЯДОВ ДЛЯ ПРОИЗВОДСТВА ПШЕНИЦЫ И ДОЛЯ СТАВКИ САМОДОСТАТОЧНОСТИ В БУДУЩЕМ: ДВОЙНОЕ ЭКСПОНЕНЦИАЛЬНОЕ ПРОГНОЗИРОВАНИЕ

The article proposes a time series model for forecasting the annual production and consumption of wheat in Egypt, based on data and economic indicators for the period from 1995 to 2015. The main objective of this work is to predict future trends in wheat production and consumption and use several prediction methods to analyze the development of the industry in Egypt until 2030. The study was conducted to select a suitable model for predicting these processes among three methods that depend on the values of three accuracy measures (MAPE, MAD and MSD) using the moving average model, the exponential smoothing model and the double exponential model. As a result, it was revealed that the double exponential model is the most suitable model for forecasting the future trend of wheat production and consumption due to smaller values of prediction errors. Recommendations were also formulated to improve food security until 2030, which are presented in order to improve land management and productivity, reduce agricultural waste and create a strategic wheat stock to address local supply problems.

Quantifying urban land expansion dynamics through improved land management institution model: Application in Ningxia-Inner Mongolia, China

It is of great importance to investigate mechanism of urban expansion as to policy-making and implementation of urban planning in China. The purpose of this study is to carry out a thorough investigation on quantifying dynamic process of urban land expansion through an improved Land Management Institution model (LMI), which was further applied in Ningxia-Inner Mongolia region, China. Therefore, an improved LMI model was developed by introducing the varying panel approach which can well determine the major contributors of spatial differences of urban land expansion and quantify the evolution of land management institution. Through this investigation, following findings were achieved. Firstly, the improved LMI model could efficiently quantify and determine spatial differences of endogenous factors of urban land expansion, and the land management institution evolution. The land management institution evolution presented a path dependence with a stable trajectory, which meant urban land expansion were well coincided with the evolution of land management institution. Secondly, the improved LMI model application in Ningxia-Inner Mongolia region disclosed that urban land expansion had an obvious negative effects of lock-in phase characters in land management institution evolution. Marginal effects of major influencing factors of urban land expansion contributed greatly to the differences of urban land expansion in terms of different sectors and regions. Finally, dynamics analysis of urban land expansion in this study area suggested that its urbanization had similar urbanization patterns with cities in elsewhere of China, and meanwhile it presented distinct characters. The massive conversion of land use has stimulated high-speed economic growth in the short term at the expense of eco-environment in the long term. It is suggested that governments at all levels should pay more attention to land management institution reform, industrial adjustment, technological innovation as to realize sustainable urbanization.

Short Communication: Presence of arbuscular mycorrhiza in maize plantation land cultivated with traditional and improved land management

Ishaq L. 2018. Short Communication: Presence of arbuscular mycorrhiza in maize plantation land cultivated with traditional and improved land management.Trop Drylands 2: 20-24. Arbuscular mycorrhizas (AM) are one of key fungtional soil biota that can greatly contribute to crop productiviy and agricultural sustainability. Their presences could be influenced by soil condition such as land management, and the sporulation of the fungal forming mycorrhiza could be affected by season ie. rainy and dry season. Previously, it was found that the abundance of AM fungi was higher under maize cropping with traditional land management (no tillage, no input of agrochemicals) than that under maize copping system with more modern land management (tillage, agrochemical input), when the soils were sampled at rainy season. As the presence of AM fungi could be influenced by climate factor ie. rain/season, the present study was carried out to examine the abundance and diversity of AM fungi in maize plantation land cultivated with traditional and improved land management in the dry season. At each land management system, three locations of study were purposively selected, and at each location within the cropping system, three soil samples were collected. A total of 9 soil samples representing each land management system were evaluated. The variables observed included AM fungal spore density (expressed as the number of AM fungal spores per 100 g of soil) and biodiversity of AM fungi (expressed as relative abundance of AM fungal spore). It was found that the density of AM fungal spore under maize cropping system with traditional land management was 203.55 per 100g, whereas only 84.91 spores per 100 g soil were found under maize cropping system with improved land management, supporting the previous finding. Despite only six AM fungal spores morphotypes were observed under maize plantation land of both traditional and improved land management, the abundance of the morphotype was different between the two land management systems. The study needs to be extended at a broader location and time to get more representative information on the impact of land management on the abundance of AM fungi in tropical agriculture.

Soil organic carbon pool changes in relation to slope position and land-use in Indian lower Himalayas

The increase in the atmospheric abundance of CO2 has raised interest in the potential of soils to sequester carbon (C), which inter alia depends on antecedent C level. While inventories of soil organic carbon (SOC) have been developed for different ecosystems at field or global scales, studies at hill-slope level where SOC redistributes by erosion remain scarce. In addition, quantitative information on the variation in SOC stocks and organic matter quality within hill-slopes would allow to make more realistic estimations of the C sequestration potential of landscapes while suggesting improved land management. The main objective of this study was to evaluate the impact of slope position and land-use (grassland versus cropland) on SOC stocks and organic matter quality (proportion of aggregate associated C and labile pools; water extractable, WEOC; hot water soluble, HWC; potassium permanganate oxidizable, KMnO4-C; microbial biomass, MBC). A total of 108 soil samples from the 0–0.15 m layer were collected from 4 slope positions (forested hilltops, middle slope with bare soils, backslopes under grasslands, cropped bottomlands) at nine catenas with 3 replicates per position. The greatest SOC stocks were found at hilltops and backslopes with respectively 10.1 ± 0.64 and 10.1 ± 0.57 Mg C ha−1. SOC stocks decreased by 17% to 8.4 ± 0.65 Mg C ha−1 in bottomlands and by 58% to 4.2 ± 0.26 Mg C ha−1 at backslopes. The soil organic matter from the hilltops showed the greatest proportion of recalcitrant components (62%) followed by the backslope and bottomland positions with ~42%, and middle slope position with 9%. In addition to showing a greater occurrence of labile C fractions, bare and eroded backslope soils were also depleted in water soluble C (WEOC and HWC), KMnO4-C and microbial biomass C. The results showed that there is considerable potential for C sequestration at middle and backslope position through land rehabilitation by either planting trees or vegetation by grass.

Selenium Distribution for Soils Derived from Mancos Shale in Gunnison and Uncompahgre River Basins, West-Central Colorado

ABSTRACTSelenium (Se) is an essential micronutrient for humans and animals and can be toxic when present in high concentrations in soil and water. Many soils in Gunnison and Uncompahgre River Basins in West-Central Colorado are formed from deposits derived mainly from weathered Mancos shale that have high concentration of Se and salts. Elevated concentrations of Se and salts were detected in streams and rivers in this area. The objectives were to determine the amount and distribution of different forms of Se and relationships with physical and chemical properties for soils derived from Se-rich Mancos shale. The information may help to improve land management practices and minimize the environmental impact on natural water resources. A total of 48 topsoil samples and soils from horizons in 9 pedons were investigated. The total and water-soluble Se and other elements as well as physical and chemical properties were determined in soils. The total Se ranged from 330 to 5,673 µg/kg with a mean of 2,224 µg/kg. The water-soluble Se ranged from a minimum of 4.95 µg/kg to a maximum of 2,415 µg/kg and a mean of 338 µg/kg. A highly significant correlation was detected between the total and water-soluble Se in soils. Both the total organic carbon (TOC) and CaCO3% had significant positive correlations with the total Se. A highly significant correlation was also found between the water-soluble Se and electric conductivity (EC), as well as with the water-soluble chloride, sulfate, nitrate, molybdenum, and sodium in soils. For the pedons tested, in general, both the total and water-soluble Se increased with depth. However, the water-soluble Se concentrations were greater in shallow than deep pedons where most Se was removed from soils with drainage water. It could be concluded that Se leaching from topsoils and that dissolving from Se-rich parent materials would be a major source of elevated Se concentrations in streams/rivers for the West-Central Colorado area. To minimize the impact on water quality, an appropriate land/water management practices should be followed to minimize Se leaching from soils derived from Mancos shale.

Indicator-based assessment of post-fire recovery dynamics using satellite NDVI time-series

Fire disturbance severely modifies ecosystem structure and functioning, and therefore predicting post-fire responses is pivotal to improve land management. Indicators that efficiently link post-fire recovery with a timely decision on landscape management can play a key role in the governance of fire risk. We describe a framework to evaluate post-fire recovery based on remotely-sensed measures of relative vegetation recovery, calculated from satellite NDVI time-series. Three indicators are proposed: the novel Cumulative Relative Recovery Index (CRRI), measuring the (mid-long term) extent and completeness of recovery; the Recovery Trend Index (RTI), measuring the steepness of the mid-term post-fire recovery trend; and the Half Recovery Time index (HRT), a measure of the short-term recovery rate. We used Random Forest (RF) models to predict the observed recovery patterns and ranked the predictive importance of several candidate explanatory factors. The performance of RF models ranged from good (CRRI, RTI) to moderate (HRT). Three sets of predictive variables consistently ranked higher: fire traits, landscape composition, and post-fire climatic conditions. The relative contribution of individual variables was different across recovery indicators. These results show that proposed indicators seem to capture different facets of the post-fire recovery process. The short-term recovery indicator (HRT) was linked to landscape composition and post-fire climate. Thus, HRT expresses the speed of initial recovery, related to differences in fire-response traits of vegetation and to climatic conditions immediately following fire. The mid-term recovery indicator (RTI) was mainly influenced by fire traits and post-fire climatic conditions. This indicator captures multiple interacting effects that shape the recovery process related to fire severity, vegetation type and post-fire conditions. Finally, the long-term recovery indicator (CRRI) was clearly more influenced by fire attributes related to severity than by vegetation type and structure or by post-fire climatic conditions. Overall, our results suggest that a combination of biotic processes (driven by plant life-history traits) and abiotic filters (e.g., post-fire climate) determine the early post-fire recovery process. Conversely, the mid to long-term recovery response (expressing its completeness) is driven by the depletion of resilience capacity and by the amount of change in vegetation structure and functioning modulated by spatial differences in fire severity. Our results strongly suggest that an indicator-based approach grounded on satellite time-series of vegetation indices can effectively cover various facets of post-fire recovery. This will improve the monitoring and prediction of post-fire recovery dynamics, with valuable applications in fire hazard management and post-fire ecosystem restoration and monitoring.

Ecohydrologic Connections in Semiarid Watershed Systems of Central Oregon USA

An improved understanding of ecohydrologic connections is critical for improving land management decisions in water-scarce regions of the western United States. For this study, conducted in a semiarid (358 mm) rangeland location in central Oregon, we evaluated precipitation-interception-soil moisture dynamics at the plot scale and characterized surface water and groundwater relations across the landscape including areas with and without western juniper (Juniperus occidentalis). Results from this study show that juniper woodlands intercepted up to 46% of total precipitation, altering soil moisture distribution under the canopy and in the interspace. Results indicate that precipitation reaching the ground can rapidly percolate through the soil profile and into the shallow aquifer, and that strong hydrologic connections between surface and groundwater components exist during winter precipitation and snowmelt runoff seasons. Greater streamflow and springflow rates were observed in the treated watershed when compared to the untreated. Streamflow rates up to 1020 L min−1 and springflow rates peaking 190 L min−1 were observed in the watershed where juniper was removed 13 years ago. In the untreated watershed, streamflow rates peaked at 687 L min−1 and springflow rates peaked at 110 L min−1. Results contribute to improved natural resource management through a better understanding of the biophysical connections occurring in rangeland ecosystems and the role that woody vegetation encroachment may have on altering the hydrology of the site.

Vulnerability to contamination by phosphorus in a zero-order basin with a high density of pigs and a history of slurry addition: extrapolation of an index

The application of phosphorus (P)-index methodology to assess the risk of water pollution from agriculture in river basins usually takes time and expends a great amount of resources. This study adapted the P-index methodology using digital mapping of key basin risk criteria for P loss in reference areas to evaluate the wider vulnerability to P loss in a zero-order basin with an intense concentration of pigs and with a history of pig slurry additions to the soil. The P content of eleven reference areas, where ten areas have received various applications of pig slurry and one area has no history of addition, was extrapolated to a zero-order basin using principal component analysis and analysis of hierarchical groupings. Estimated loss of soil and the distance between the P source and the watercourse were mapped using satellite images and in situ evaluations. The methodology of extrapolating was well correlated with a survey of P concentrations in land runoff and provides the potential to improve land management of those areas that are most vulnerable. Principal component analysis and hierarchical clustering analysis proved to be useful tools for the separation of areas with different slurry application times. Our results suggest that the P loss risk could be reduced through the adoption of soil conservation techniques such as reduced-tillage incorporating slurry and crop residue management to provide adequate soil protection, reduce the impact of raindrops and reduce erosion risk and transport of chemical pollutants to water bodies.

Looking to nature for solutions

Completely stopping fossil fuel use may not be enough to avoid dangerous climate change. Recent research on the mitigation potential of conservation, restoration, and improved land management demonstrates that natural solutions can reduce emissions and remove atmospheric CO2 while safeguarding food security and biodiversity.

Natural climate solutions

Better stewardship of land is needed to achieve the Paris Climate Agreement goal of holding warming to below 2 °C; however, confusion persists about the specific set of land stewardship options available and their mitigation potential. To address this, we identify and quantify "natural climate solutions" (NCS): 20 conservation, restoration, and improved land management actions that increase carbon storage and/or avoid greenhouse gas emissions across global forests, wetlands, grasslands, and agricultural lands. We find that the maximum potential of NCS-when constrained by food security, fiber security, and biodiversity conservation-is 23.8 petagrams of CO2 equivalent (PgCO2e) y-1 (95% CI 20.3-37.4). This is ≥30% higher than prior estimates, which did not include the full range of options and safeguards considered here. About half of this maximum (11.3 PgCO2e y-1) represents cost-effective climate mitigation, assuming the social cost of CO2 pollution is ≥100 USD MgCO2e-1 by 2030. Natural climate solutions can provide 37% of cost-effective CO2 mitigation needed through 2030 for a >66% chance of holding warming to below 2 °C. One-third of this cost-effective NCS mitigation can be delivered at or below 10 USD MgCO2-1 Most NCS actions-if effectively implemented-also offer water filtration, flood buffering, soil health, biodiversity habitat, and enhanced climate resilience. Work remains to better constrain uncertainty of NCS mitigation estimates. Nevertheless, existing knowledge reported here provides a robust basis for immediate global action to improve ecosystem stewardship as a major solution to climate change.

Streamflow and Sediment Yield Prediction for Watershed Prioritization in the Upper Blue Nile River Basin, Ethiopia

Inappropriate use of land and poor ecosystem management have accelerated land degradation and reduced the storage capacity of reservoirs. To mitigate the effect of the increased sediment yield, it is important to identify erosion-prone areas in a 287 km2 catchment in Ethiopia. The objectives of this study were to: (1) assess the spatial variability of sediment yield; (2) quantify the amount of sediment delivered into the reservoir; and (3) prioritize sub-catchments for watershed management using the Soil and Water Assessment Tool (SWAT). The SWAT model was calibrated and validated using SUFI-2, GLUE, ParaSol, and PSO SWAT-CUP optimization algorithms. For most of the SWAT-CUP simulations, the observed and simulated river discharge were not significantly different at the 95% level of confidence (95PPU), and sources of uncertainties were captured by bracketing more than 70% of the observed data. This catchment prioritization study indicated that more than 85% of the sediment was sourced from lowland areas (slope range: 0–8%) and the variation in sediment yield was more sensitive to the land use and soil type prevailing in the area regardless of the terrain slope. Contrary to the perception of the upland as an important source of sediment, the lowland in fact was the most important source of sediment and should be the focus area for improved land management practice to reduce sediment delivery into storage reservoirs. The research also showed that lowland erosion-prone areas are typified by extensive agriculture, which causes significant modification of the landscape. Tillage practice changes the infiltration and runoff characteristics of the land surface and interaction of shallow groundwater table and saturation excess runoff, which in turn affects the delivery of water and sediment to the reservoir and catchment evapotranspiration.

Monitoring thermal springs to improve land management decision-making, Sierra Nevada, California

The Sierra National Forest administers Mono Hot Springs and other nearby geothermal features, a concentration of more than a dozen springs, pools, and seeps in the high Sierra Nevada, California. The Native American Mono Tribe traditionally uses Mono Hot Springs for spiritual purposes, while simultaneously, the Mono Hot Springs Resort holds a special use permit for some of the geothermal waters. To support environmental assessments for area management, the Sierra National Forest studied thermal spring chemistry and temperature, evaluating potential use conflicts. An initial multi-year monitoring of eleven representative thermal springs was followed a decade later by another multi-year sampling of the same springs, providing insight into the geothermal character of Mono Hot Springs. Measured water temperatures ranged from 44.5° C to 24.3° C and pH 8.0 to 7.03, depending upon the thermal spring, higher pH values correlating with lower temperatures. Thermal spring temperatures varied seasonally with higher temperatures in springtime and lower ones in autumn. pH did not exhibit a coherent seasonal variation. Mono Hot Spring temperature decreased and pH increased during the decade-long study period, with even greater longer-term temperature change evidenced at nearby Mono Crossing. Silica and cation geothermometry at Mono Hot Springs suggests that the geothermal waters reached equilibrium with 74-79° C rock at depth at estimated pH 5-6. The spatial distribution of neighboring thermal springs, regional seismicity, and mapped faults suggests that Mono Hot Springs rises along faults running nearly north-south, connecting to Mammoth Mountain and Long Valley, California, 30 km to the north.