International Journal of Ecology

Global warming is a serious world problem where earth’s temperature has been reported to increase over the years; the aquatic ecosystems are also not the exceptions. But, the effects of this phenomenon on the aquatic ecosystems are not well understood. This study aims to understand the influence of surface temperature on the population density of Limnothrissa miodon in Lake Kariba. We constructed a mathematical model on the population dynamics of Limnothrissa miodon with nutrients, phytoplankton, zooplankton, and Hydrocynus vittatus. Lake surface water temperature was modelled by a cosine function, and the parameters were estimated from data fitting. Numerical simulations were used to determine the stability of the nonautonomous model. Numerical simulation results of the nonautonomous model showed a stable periodic orbit for varying initial conditions, and therefore, instability. Numerical techniques were used to investigate the influence of surface water temperature on Limnothrissa miodon. Results from the model with fitted lake surface water temperature data showed that a shift in the optimal temperature for phytoplankton growth from C to C, corresponding to dominance of Cyanophyceae over Chlorophyceae, resulted in a decline in the population density of Limnothrissa miodon. Numerical results showed that the population density of Limnothrissa miodon declines after an optimum temperature of C for phytoplankton growth. Numerical simulation results suggested that warming of the lake may lead to a decline in Limnothrissa miodon population density in Lake Kariba.

Wetlands are valuable resources that provide a variety of functions for local populations, including environmental, hydrological, and socioeconomic benefits. Despite the importance of wetlands to humanity, they have been largely degraded and even lost in many countries including Ethiopia because they are wrongly regarded as wastelands. Some wetland conservation policies were designed not based on the perceptions of the people residing around the wetlands and lack of attention to communal areas. It is because of this gap that a quantitative analysis of physicochemical soil quality analysis and the local community’s perceptions was carried out with the overall goal of analyzing the degradation status of Kadar-Basaso wetland and community perceptions. A cross-sectional research approach was used with a purposeful soil sampling from/in 6 plots sized 50 m × 50 m and >100 m apart along two transect lines, and 200 household heads chosen randomly from three villages(Basaso, Shallo, and Nano Robe) bordering the wetland. Soil sampling, questionnaires, focus group discussion, and key informant interviews were used to collect data and then examined quantitatively and qualitatively. The result shows that the Kadar-Basaso wetland was moderately degraded. The physicochemical analysis of the soil reveals that the pH was acidic, indicating the presence of acidic waste effluents. In addition, the electric conductivity was salt-free, cation exchange capacity were found to be low, the organic matter was relatively low, potassium levels vary very little, and Phosphorous variation was minimal. Expansion of farmland and Overgrazing were the most damaging elements affecting wetland biodiversity. From the analysis, it was noted that communities’ attitudes influence human activities on the wetland. The study recommends that the government and wetland management authorities must establish strategies to minimize deterioration in the area and offer better infrastructure for both livestock keepers and farmers to improve the long-term usage of wetlands. The best management strategies should be devised for all sizes, types, and all site wetlands.

The study aimed to estimate the physical and monetary values for nontimber forest products (NTFP) of the Surra government plantation in the upper Hare-Baso rivers catchment of Gamo highlands, southwestern Ethiopia. The Surra government plantation was established in the mid-1980s and consisted of C. lusitanica, E. globulus, and P. radiata tree species, which were planted side by side. Because of food insecurity, forest proximity communities/inhabitants relied on extracting NTFP such as litter and fodder for income and livestock feed despite none of them being physically and monetarily accounted for. The plot method and stock change approach were applied to determine sample plots and collect litter data, respectively, while the active market price was used to account for monetary correspondences. Fodder data were acquired via integration of animal unit month (AUM), livestock carrying capacity, animal unit equivalent (AUE/TLU), quality of pasture (poor), and proper use factor (30%). Its monetary price data were collected from the local market. The gross total production of litter and grass/fodder was 158,614.90 kg and 284,076 kg per/year, respectively, while the corresponding monetary values were ETB 206,169.40 and ETB 255,669, respectively. However, the “proper use factor”-based physical value of fodder/grass was 85,224 kg per/year, and its corresponding monetary value was ETB 76,701. The average physical value (volume) of grass production/year during the wet and dry seasons was 56.67 kg and 96.67 kg, and its mean monetary price/kg was ETB 1.4 and 1.2, respectively. It was concluded that the fodder/grass data collected via the integrated approach reduced the accounting errors, and the data were more precise. Accounting for the economic values of litter and fodder embedded in the market price upscaled the accounting quality and was more indicative of ground facts. Therefore, this study contributed a fresh accounting approach to the field of NTFP accounting.

This study estimated the technical efficiency of small-scale trawling in the Mekong Delta using a translog stochastic frontier production function model. Primary data were collected by interviewing the small-scale trawling vessels from January 2020 to May 2021 in the four coastal provinces (Soc Trang, Bac Lieu, Ca Mau, and Kien Giang) of the Mekong Delta. The results showed that the average technical efficiency of the surveyed fishermen was approximately 68.8%. Small-scale trawling vessels could increase their production by 31.2% if they operated at full technical efficiency. The captain’s fishing experience, vessel size, the number of nets on a boat, cooperation for inputs, supplies, and problem-solving, fishing registration, operation distance, and the fishing grounds were the main factors influencing the technical efficiency. To improve the technical efficiency of the trawling industry, it is necessary to focus on training the captains in fishing techniques, upgrading and converting large-scale vessels, and linking the market channels for consuming the caught fishery products.

Echinops giganteus A. Rich. is an aromatic and medicinal plant of the Asteraceae family exploited in Cameroon under the access and benefit sharing (ABS) standard. Despite its importance, little information exists on the ecology of E. giganteus. The aim of the present study was to contribute to a better understanding of its ecology for sustainable management in the Western Highlands of Cameroon. Occurrence data as well as stationary ecological information were collected in the field and from different databases. Bioclimatic data were extracted from the WorldClim database and processed using DIVA-GIS and Maxent software. The Braun-Blanquet quadrat method was used for the phytosociological study. Results showed that the distribution of E. giganteus in its wild state is restricted to sub-Saharan Africa. This distribution is likely conditioned by altitude (1000 m–2600 m), light, temperature, and rainfall. The bioclimatic variables that best explained this distribution were the mean annual temperature (Bio1: 38.8%) and the precipitation of the coldest quarter (Bio19: 24.9%), and their favorable ranges were between 2°C–32°C and 300 mm–1800 mm, respectively. E. giganteus is a heliophilic plant that prefers well-drained substrates and would not have a requirement for organic matter. The floristic analysis of the E. giganteus community identified 68 plant species in 59 genera and 28 botanical families, with the most represented family being the Asteraceae (49%). The average species richness per quadrat was 8 species, dominated by herbs. Species consistent with E. giganteus were Aspilia africana (Pers.) C. D. Adams and Imperata cylindrica (L.) P. Beauv. Chamaephytes and Phanerophytes were dominant among the biological types, while the phytogeographic types were dominated by Pantropical species (38.23%). The most represented diaspore types and modes of dissemination were pogonochores (35.85%) and anemochores (55.38%).

Crop damage is a major form of human-primate conflict that not only affects the livelihoods of farmers living close to forest areas but also threatens nonhuman primate conservation. This study aimed to investigate the causes of crop loss and foraging by nonhuman primates in southwest Ethiopia. For the purpose of gathering data, we used a questionnaire and direct observation. We employed simple random sampling techniques to select villages and respondents. From the nine selected villages, a total of 130 household samples were identified for the questionnaire. The primates responsible for crop damage were olive baboons and grivet monkeys. Maize, barley, teff, potatoes, sorghum, and other crops were among those foraged by the nonhuman primate species. Farmland close to the woodland boundary suffered more damage than farmland further away. The total amount of maize damaged by the olive baboons and grivet monkeys in the selected kebeles varied significantly. The majority of the respondents used guarding, and a few of them used scarecrows to protect crops from damage by primates. The highest crop damage occurred in the Atiro Tigre and Arigno Gefere villages, while the lowest occurred in the Sedecha villages. The flowering stage of the maize suffered the most, and the seedling stage suffered the least, from grivet monkeys foraging. The growth of crops that are less edible to nonhuman primates, especially on the forest edges, would lessen crop damage.