生态学报最新文献

At present, water pollution is a widespread threat, specifically in emerging and developing nations, such as India. An effort was made to evaluate the spatial and seasonal status of water quality in Munroe Island, Kerala, India using various multivariate statistical methods from October 2020 to September 2021. The values of nineteen environmental variables namely water temperature, pH, electrical conductivity, turbidity, total dissolved solids, dissolved oxygen, free carbon dioxide, biochemical oxygen demand, chemical oxygen demand, total alkalinity, total hardness, salinity, nitrate, phosphate, silicate, sodium, potassium, calcium, and magnesium were calculated following standard methodology. Various environmental variables, namely temperature, pH, electrical conductivity, total dissolved solids, biochemical oxygen demand, chemical oxygen demand, total hardness, total alkalinity, sodium, potassium, calcium, and magnesium were higher in pre-monsoon followed by post-monsoon and monsoon seasons. Some other variables such as dissolved oxygen, nitrate silicate, and phosphate were higher in monsoon than premonsoon and postmonsoon seasons. Moreover, multivariate statistical tools were employed to assess spatial and temporal difference in water quality to find contamination sources and analyze results.

The outcomes of the present investigation indicated that, the Kallada River and the Ashtamudy estuary has significant influence on the environmental quality of Munroe Island along with various anthropogenic disturbances. Numerous environmental disturbances begin from S₂ and drastically rise at S₄ because of some harmful organic and inorganic contaminators. Thus, efforts are required in order to prevent the pollution levels at the Munroe Island.

The carrying capacities of resources and the environment are important criteria for measuring sustainable regional development. Adjusting the layout structure of regional agricultural production is an effective measure to improve resource and environmental carrying capacities. In this study, the carrying capacities of multiple crops, livestock and poultry breeding, and fisheries were investigated in Guangdong province. The water resource potential of pineapple cultivation in Guangdong is large; rice, peanuts, bananas, and vegetables also have the potential to increase; potatoes, longan, litchi, and sugarcane need to be adjusted in some areas to adapt to the carrying capacity of local water resources; and citrus needs to be reduced urgently. The overall scale of animal husbandry has no more growth potential, and the main production areas in northern Guangdong and western Guangdong are overloaded. Zhanjiang should reasonably expand the scale and strengthen the supply capacity of livestock and poultry; the Pearl River Delta (PRD) should change breeding methods as soon as possible; and Shaoguan, Shantou, and Jieyang should be encouraged to reasonably expand the scale of livestock and poultry breeding and improve production efficiency. Fisheries should focus on supporting the development of intensive, efficient, and clean aquaculture in the coastal areas of eastern and western Guangdong, moderately increasing the scale of freshwater aquaculture in inland and mountainous ecological fishing areas, and accelerating the transformation of urban fishing areas in the PRD into multi-functional fisheries. This study will provide a theoretical reference for the layout of agricultural regional productivity in Guangdong's “14th Five-Year Plan”, and will be particularly useful to guarantee sustainable food supply in the Guangdong-Hong Kong-Macao Greater Bay Area.

The composition, structure, and patterns of vegetation undergo a noticeable shift along the elevational gradient, and this is regulated by various abiotic variables, primarily the elevation and edaphic characteristics. The present study investigated the change in community characteristics of woody vegetation along a vertical gradient from 2800 m till 4000 m in parts of upper Bani Wildlife Sanctuary in Jammu and Kashmir. In all, 40 woody species were recorded including 11 trees and 29 shrubs with a distinctive hump shaped pattern that becomes steeper with the rising elevation. Quercus semecarpifolia Sm. and Betula utilis D.Don. exhibited a wide elevational range (3000–3500 m asl), eventually forming the climatic climax along southern and northern aspects. The diversity and phytosociological attributes peaked at intermediate elevation with $\overline{H}$=1.74 recorded for trees and $\overline{H}$=2.48 observed for shrubs. The average density and basal cover for trees and shrubs ranged between 75.50 Nha⁻¹ & 20.09 m²ha⁻¹ and 69.31 Nha⁻¹ & 4.50 m²ha⁻¹, respectively. The species turnover rate was recorded high in case of trees (0.11–0.77) and low for shrubs (0.17–0.29). A modest density of 114 seedlings ha⁻¹ and 249 saplings ha⁻¹ was recorded across the forest types. The low seedling (0.22) and sapling (0.48) per tree ratio indicated a low regeneration performance anticipating a very slow upslope movement of the tree line. This may result in population decline of a few select species in future, necessitating effective monitoring and management intervention for which these findings will be helpful.

Pesticides have widespread use and their toxic residues have been reported in vegetables, thereby residual analysis of pesticides in agricultural produce has become increasingly essential. In this study, effect of malathion application at different doses (0.005–0.1%) was assessed on germination, seedling growth, and photosynthetic pigments in fenugreek. Result outcomes revealed that higher malathion concentrations triggered antagonistic effects on fenugreek growth parameters and photosynthetic pigments. The persistence pattern of malathion in fenugreek herb after application at different doses (0.03%, 0.05%, 0.1%) was also determined by UHPLC. Results corroborated that the initial deposit of malathion in fenugreek was 16.28, 21.131, and 31.45 μg/g at 0.03%, 0.05%, 0.1% application doses, respectively. Consumable safety time was observed to be 3, 3, and 5 days after application, which was sufficient to reduce malathion residues to below MRL. Health risk assessment presented that % contribution to ADI of malathion through dietary consumption of fenugreek ranged from 29.7 to 133% in children and 12.6 to 74.2% in adults. Despite the fact that HRI values were < 1, children were determined to be at greater risk due to the concentration of malathion detected in samples. Therefore, current finding highlights the importance of vigilant pesticide monitoring and health risk assessment.

Aim

The objective of this research was to analyze the association between evaluated level of species disturbance between sites as well as determine the abundance and diversity of invasive alien species and the physicochemical parameters of soil samples with the view to determining the impact of mining on the distribution of invasive species.

Method

Four Land use types: active mining, abandoned mining, farmland and relatively undisturbed forest were selected as sampling sites for the study. Two 20 m by 20 m sampling plots were randomly selected in each land use types. Plants were identified to assess the floristic composition, the level of colonization of invasive species, and the diversity of the plant species. Soil chemical and physical properties in sites were analysed and plant-soil relationship was determined by means of Canonical correspondence analysis (CCA) and Principal Component Analysis (PCA).

Result

Diversity analysis showed that the active mining site was the least diverse and abandoned mining site the most diverse. The characteristics of the populations of the invasive plant species in the mining sites were weeds (10%), shrubs (60%), and climbers (30%). Distribution of invasive species was influenced by the four land use types (active mining, abandoned mining, farming and relatively undisturbed forest). Solanum torvum, Panicum brevifolium, Centrosema pubescens, Commelina erecta were found to be associated with active mining site. Abandoned mining and farming sites had similar composition of invasive species. Soil analysis showed significant difference between total nitrogen, available phosphorus, organic carbon and CEC between undisturbed forest and the active mining sites. Canonical correspondence analysis showed that active mining site was associated with increasing acidity, Na⁺ and bulk density and characterised by plant species such as Solanum torvum, Panicum brevifolium, Centrosema pubescens, Commelina erecta while undisturbed site was associated with increasing available P, Ca²⁺, total N, Organic C, CEC and Mg²⁺ and characterised by species such as Cola hispida, Lecaniodiscus cupanoides, Bahia nitida, Mirodesmis puberula, Monodora tenuifolia. Principal component analysis identified Organic C, Total N and Ca²⁺ as the most important physico-chemical factors responsible for variations observed in the study.

Conclusion

The study concluded that land use has significant effect on soil and is a driver for low plant diversity and introduction of invasive plant species.

Phosphorus availability from rock phosphate (RP) can be improved through composting with organic manure and phosphate-solubilizing microorganisms in the soil to improve phosphorus status and plant growth in alkaline and calcareous soils of Pakistan. As a result, an experiment was carried out to determine the impact of arbuscular mycorrhizal fungi (AMF) species as biofertilizers on Mentha arvensis when rock phosphate and organic manure (FYM) levels were varied (0%, 50%, and 100%). In M. arvensis, plant growth performance, mycorrhizal dependence values, oil output, mineral, and nutritional analysis, infection, and spore density were evaluated. The experiment was designed with eight RCBD treatments and five replications. Compared to non-inoculated plants, the growth responses of M. arvensis to AM inoculation with rock phosphate and organic manure were pronounced. Mycorrhizal dependencies increased with increasing levels of rock phosphate and organic manure, which were 40.82% and 46.92%, respectively. The results showed that M. arvensis produced a higher percentage of essential oil for AMF inoculation at higher and lower levels of rock phosphate and organic manure. In terms of nutrient uptake by mycorrhizal plants, there were a significant improvement in macro (P, N, K, Mg) and micronutrients (Fe, Cu, and Zn) in all tested mycorrhizal plants compared to non-treated plants. The nutritional value of M. arvensis rises with the amount of fertilizer added. Results proved that as fertility levels rise, the number of spores (150 to 190/100 g of soil) and the percentage of association (70.51 to 95.23%) increase in Mentha arvensis. The findings imply that inoculating plants with AMF might increase phosphorus solubility from rock phosphate and organic manure. Local rock phosphate and organic manure may be used to reduce reliance on expensive commercial synthetic fertilizers while also increasing crop yields.

The microbial community plays an important role in A. cepa productivity and soil fertility. In this study, we applied chemical (A2) and endophyte-based fertilizer (B) to A. cepa; where the use of B successfully improved productivity by the number of tubers and chlorophyll content compared to control (A1) and A2. We aimed to investigate how those fertilizers manipulate the rhizosphere bacterial community in A. cepa. The 16S-metagenomic analysis was conducted to investigate the bacterial community of the samples by amplifying the V3-V4 region. The application of A2 and B potentially enhanced the abundance of rhizosphere bacteria compared to the A1, possibly due to the increase in nutrient availability. Beta-diversity analysis showed that the B fertilizer did not highly change the bacterial community of indigenous rhizosphere bacteria, whereas the A2 fertilizer did. The endophytes themselves did not also greatly affect the original rhizosphere bacteria because they may enter the plant tissue and release the metabolites inside the plant host. The NGS data showed that the genus Aquicella was the most abundant in the rhizosphere treated with B and A1. Aquicella was discovered to boost plant resilience to contaminants by enhancing plant nutrition availability and encouraging plant root growth. Interestingly, Acidobacteria and Gemmatimonadetes decreased their population in the treatments of A2 or B. Overall, the use of B has a higher impact on plant productivity and soil properties without highly changing the composition of the bacterial community in the rhizosphere. Yet our metagenomic data support the hypothesis of phylogenetical conservation of bacterial communities concerning particular ecological conditions.