722 research outputs found
Measuring Ethiopian farmers' vulnerability to climate change across regional states:
"This study analyzes the vulnerability of Ethiopian farmers to climate change based on the integrated vulnerability assessment approach using vulnerability indicators. The vulnerability indicators consist of the different socioeconomic and biophysical attributes of Ethiopia's seven agriculture-based regional states. The different socioeconomic and biophysical indicators of each region collected have been classified into three classes, based on the Intergovernmental Panel on Climate Change's (IPCC 2001) definition of vulnerability, which consists of adaptive capacity, sensitivity, and exposure. The results indicate that the relatively least-developed, semiarid, and arid regions—namely, Afar and Somali—are highly vulnerable to climate change. The Oromia region—a wide region characterized both by areas of good agricultural production in the highlands and midlands and by recurrent droughts, especially in the lowlands—is also vulnerable. The Tigray region, which is characterized by recurrent drought, is also vulnerable to the negative impacts of climate change in comparison with the other regions. Thus, investing in the development of the relatively underdeveloped regions of Somali and Afar, irrigation for regions with high potential, early warning systems to help farmers better cope in times of drought, and production of drought-tolerant varieties of crops and species of livestock can all reduce the vulnerability of Ethiopian farmers to climate change." from authors' abstractClimate change, Vulnerability, adaptive capacity, regional states of Ethiopia,
Climate variability and maize yield in South Africa: Results from GME and MELE methods
"This paper investigates the impact of climate variability on maize yield in the Limpopo Basin of South Africa using the Generalized Maximum Entropy (GME) estimator and Maximum Entropy Leuven Estimator (MELE). Precipitation and temperature were used as proxies for climate variability, which were combined with traditional inputs variables (i.e., labor, fertilizer, seed, and irrigation). We found that the MELE fits the data better than the GME. In addition, increased precipitation, increased temperature, and irrigation have a positive impact on yield. Furthermore, results of the MELE show that the impact of precipitation on maize yield is stronger than that of temperature, meaning that the impact of climate variability on maize yield could be negative if the change increases temperature but reduces precipitation at the same rate and simultaneously. Moreover, the impact of irrigation on yield is positive but with a lower elasticity coefficient than that of precipitation, which supposes that irrigation may only partially mitigate the impact of reduced precipitation on yield. " from authors' abstractYield function, maize, Generalized maximum entropy, Maximum entropy Leuven estimator, Climate variability, Climate change,
Assessing household vulnerability to climate change: The case of farmers in the Nile Basin of Ethiopia
Vulnerability to climate extremes, Nile Basin of Ethiopia, Minimum daily income, Climate change,
Factors affecting the choices of coping strategies for climate extremes: The case of farmers in the Nile Basin of Ethiopia
This study adopted the multinomial logit model to analyze factors affecting the choice of coping strategies in response to climate extreme events for the Ethiopian Nile River Basin. Results from the multinomial logit model show that different socioeconomic and environmental factors affect coping with climate extreme events. Factors that positively influence coping include education of the head of household, gender of household head being male, farm income, livestock ownership, access to extension for crop and livestock production, farmer-to-farmer extension, temperature, ownership of radio, and better-quality house. Thus, to increase coping with covariate shocks, such as climate extreme events, policies should encourage income generation and asset holding (especially livestock), both of which will support consumption smoothing during and immediately after harsh climatic events. Moreover, government policies should focus on developing institutions that enhance access to education and extension services.climate extremes, coping, Nile Basin, multinomial logit model,
Analyzing the determinants of farmers' choice of adaptation methods and perceptions of climate change in the Nile Basin of Ethiopia:
"This study identifies the major methods used by farmers to adapt to climate change in the Nile Basin of Ethiopia, the factors that affect their choice of method, and the barriers to adaptation. The methods identified include use of different crop varieties, tree planting, soil conservation, early and late planting, and irrigation. Results from the discrete choice model employed indicate that the level of education, gender, age, and wealth of the head of household; access to extension and credit; information on climate, social capital, agroecological settings, and temperature all influence farmers' choices. The main barriers include lack of information on adaptation methods and financial constraints. Moreover, the analysis reveals that age of the household head, wealth, information on climate change, social capital, and agroecological settings have significant effects on farmers' perceptions of climate change." from authors' abstractAdaptation, Perception on climate change, Agriculture, Climate change, Nile Basin of Ethiopia,
EC193 Revised 1952 Anhydrous Ammonia, A Good Nitrogen Fetilizer
Extension Circular 193 Revised 1952 Anhydrous Ammonia as a good nitrogen fertilizer
Modeling water resources management at the basin level: review and future directions
Water quality / Water resources development / Agricultural production / River basin development / Mathematical models / Simulation models / Water allocation / Policy / Economic aspects / Hydrology / Reservoir operation / Groundwater management / Drainage / Conjunctive use / Surface water / GIS / Decision support systems / Optimization methods / Water supply
Lizards lack speed-accuracy trade-offs in a quantitative foraging task when unable to sample the reward.
To make decisions, animals gather information from the environment in order to avoid costs (e.g., reduced survival) and increase benefits (e.g., foraging success). When time is limited or information is insufficient, most animals face a speed-accuracy trade-off (SAT) - they have to balance the benefits of making quick decisions against the costs of inaccurate decisions. Here, we investigated the relationship between decision accuracy and decision speed in gidgee skinks (Egernia stokesii) performing a food-based spontaneous quantity discrimination task. Rather than a SAT we found a speed-accuracy alignment; lizards made decisions that were fast and accurate, rather than inaccurate. Furthermore, we found only within-, but no between-individual, differences in decision making indicating behavioural plasticity in the absence of individual decision styles. Finally, latency to choice was highly repeatable, more so than choice accuracy. Previous work has shown that learning, the costs of a bad decision and task difficulty frequently result in SATs. The lack of a SAT in our lizards might be a direct consequence of our simple testing methodology which prevented learning by not allowing lizards to consume the chosen quantity. To fully understand how SATs develop, different methodologies that control the costs and benefits of decisions should be compared
Evolutionary trade-offs between testes size and parenting in Neotropical glassfrogs.
In males, large testes size signifies high sperm production and is commonly linked to heightened sperm competition levels. It may also evolve as a response to an elevated risk of sperm depletion due to multiple mating or large clutch sizes. Conversely, weapons, mate or clutch guarding may allow individuals to monopolize mating events and preclude sperm competition, thereby reducing the selection of large testes. Herein, we examined how paternal care, sexual size dimorphism (SSD), weaponry and female fecundity are linked to testes size in glassfrogs. We found that paternal care was associated with a reduction in relative testes size, suggesting an evolutionary trade-off between testes size and parenting. Although females were slightly larger than males and species with paternal care tended to have larger clutches, there was no significant relationship between SSD, clutch size and relative testes size. These findings suggest that the evolution of testes size in glassfrogs is influenced by sperm competition risk, rather than sperm depletion risk. We infer that clutch guarding precludes the risk of fertilization by other males and consequently diminishes selective pressure for larger testes. Our study highlights the prominent role of paternal care in the evolution of testes size in species with external fertilization
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