Acta Ecologica Sinica最新文献

Mangrove forests harbour some of the highest carbon densities of any ecosystem, yet their decline has resulted in potential carbon dioxide (CO₂) emissions. The emission of CO₂ due to the loss of above-ground biomass (AGB) of the Sundarbans mangrove ecosystem was calculated using the ArcMap and ERDAS software. Hence, classification of the Satellite images between 1990 and 2020 of the Indian portions of the Sundarbans was done.

The total loss of mangrove area in the Indian part of Sundarbans is 138.4 km² in the last 30 years. Around 57% of the total loss is due to erosion, 22% is converted to fallow lands, and the remainder is transformed into different landforms for human use. The AGB loss has led to the potential CO₂ emission of 2028.4 ± 713.7 Gg, which costs $101.42 million in terms of the social cost of carbon (SCC).

The stability analysis of the system showed that the fluctuations during the high tidal surges of cyclone ‘Aila’ that struck the coastline of the Bay of Bengal, resulted in the decrease of mangrove covers and acted as a driving force behind the depletion of ‘blue carbon’ of the Sundarbans.

The goal of this study was to see how much genetic and environmental interaction affects essential oil yield and patchouli alcohol content and find superior genotypes over the years of patchouli's unique aroma in India. The tests were carried out for one year in 2013–2014 (initial evaluation trial) and then for three years in 2015–2016, 2016–2017, and 2017–2018 (major yield assessment trials). The fourteen patchouli genotypes and one commercial variety (CIM- Samarth) were studied in an RBD design with three replications. A pooled analysis of variance was performed across the environments/years for the eleven economic attributes. The results showed that most of the attributes had significant differences. In all three environments/years, genetic correlations between economic traits played a critical role in genetic improvement, for example, the traits X3-vs-X4, X3-vs-X5, and X4-vs-X5. As a result, according to correlations throughout the selective environments/years, picking these features will be favorable. Furthermore, the heritability in a broad sense (h2BS) was expressed as a percentage. The scores for all ten attributes ranged from 87.13 to 99.25%. The genetic advance over mean (GAM) percent, which ranged from 13.42 to 162.83%, was equally fascinating. The four winning genotypes for essential oil yield, G/PATC-11, G/PATC-1, G/PATC-2, and G/PATC-5, and the lines G/PATC-1, G/PATC-4, G/PATC-9, and G/PATC-11 for patchouli alcohol percent), were explained by biplot analysis as stable and higher-yielding genotypes. The percentage of ar-curcumene in stable genotypes with a distinct fragrance ranged from 8.60 to 8.71% in G/PATC 4, G/PATC 11, G/PATC 14, and G/PATC 1. Ar-curcumene has been found for the first time in the patchouli (Pogostemon cablin (Blanco) Benth) species. As a result, it may be prudent to cultivate these stable genotypes on a big scale in India.

Biological assessment of the freshwater habitats aims to characterize and monitor the conditions of the aquatic resources. Assessment of species assemblage in these habitats will indicate the possible variations in the resource exploitation and trophic interactions. Macroinvertebrates are the best indicators of aquatic ecosystem and play an important role in freshwater ecosystem functioning through nutrient cycling, primary production, decomposition and biological control of mosquitoes.

Observations revealed that the prey individuals of order Diptera were found to be highest (51.16%), however the cumulative predatory taxa including Coleoptera, Odonata, Hemiptera and Orthoptera accounted to 67.02% The values of diversity indices varied significantly across different sampling spots justifying the usage of those wetlands and potentiality of them towards conservation biological control. Based on the biotic index, rice fields at Panskura ranked ‘Good’ to ‘Fair’ while all others ranked ‘Fair’ or ‘Poor’.Irrespective of the classes and orders, the representative individuals were observed in high numbers during the post monsoon and the winter months which may be attributed to the fact that with the volume of water, the space available for the insects increases, thereby promoting population expansion and releasing the crowding effect. The result of three way factorial ANOVA on the number of macroinvertebrates considering the spots, sites and sampling months as explanatory variables, revealed significant differences across all the interactions. A correspondence of the taxonomic diversity with the functional role of the aquatic predatory insects of the order Coleoptera, Hemiptera and Odonata is well established, through their links with multiple prey species including mosquito and chironomid larvae. In an assorted species assemblage of both predator and prey species, conservation biological control may require habitat extension and modification to allow increment of niche width to sustain diverse species in the habitats. Therefore to comment on the chances of the potentials of conservation biological control, monitoring of the macroinvertebrate community becomes imperative.

The supply of shrimp ponds water sources in this research utilizes water input from the waters of the Banyuasin River Estuary, which brings in heavy metal pollutant particles due to anthropogenic pressure. The potential for accumulation of heavy metals can occur in gastropods which are bioindicators of the pond environment. In this study, we present data on gastropods abundance and community structure concerning environmental physicochemical factors and heavy metal accumulation. Sampling was carried out in November 2021 at five observation stations spread over three shrimp ponds. The collection of gastropod samples used two methods based on achievement targets. The gastropod ecology index calculated the abundance, diversity (H′) values of heavy metals analyzed, namely Pb, Hg, Cu, and Cd. Wet digestion with an acid solution of HNO₃ and HClO was performed before measuring the concentration on the Atomic Absorption Spectrophotometer (Shimadzu AA-7000). Furthermore, all data on environmental variables were analyzed by principal components analysis (PCA) to determine the leading variable group for each station. A cluster was formed based on the Bray-Curtis similarity analysis. The results of the gastropod ecology index as a bioindicator showed moderate and low diversity (H′) and evenness (J) values, while dominance (D) was high and moderate. From two species analyzed for heavy metals, Nerita violacea and Telescopium telescopium contained Pb, Hg, and Cu concentrations, but no Cd levels were detected, including in water and sediment. Accumulation of heavy metals in shrimp ponds is not only due to the mass movement of tidal water, some of which contribute, namely the location of the inlet and outlet waterways and the position of the land to the main canal source. In general, these results indicate that the environmental conditions of the pond have accumulated heavy metal pollutants, but its whereabouts cannot be ascertained all the time. These results are sufficient to describe the current situation but need further study its impact on aquaculture production.

Understanding the impact of anthropogenic activities on various ecosystem matrices is fundamental to the application of biotic assessment. Here we explored the spatial changes of macroinvertebrate community structure under varying physicochemical gradients in Adoka Stream at Eziani Town, Southeast Nigeria. The water and macroinvertebrate samples were obtained from three stations positioned along the stretch of the stream with station 1 taken as a reference to others. We adopted Principal Component Analysis (PCA) and Canonical Correspondence Analysis (CCA) to analyse the monitored dataset comprising of 16 parameters with the aim to identify the important physicochemical parameters, and further evaluated the relationship between physicochemical parameters and macroinvertebrates assemblages. The PCA in first two rotated components (RCs) showed that turbidity, EC, NO₃, PO₄, SO₄, Cl, BOD₅, COD, DO, pH, and HCO₃ explained 57% of variance in the water quality dataset and associated macroinvertebrates assemblage. Based on the CCA, temperature, pH, turbidity, EC, NO₃, SO₄, DO, HCO₃, Ca, and Mg were important to predicting changes of macroinvertebrates assemblage structure in the stream. The observed variations of the water quality were reflected on macroinvertebrate assemblage across the stations. High abundance, taxa richness and pollution sensitive taxa of Trichoptera were obtained for station 1 with good water quality while stations 2 and 3 with significant influence from anthropogenic activities which resulted to degrading water quality had low abundance and taxa richness as well as dominance of pollution-tolerant taxa of Diptera groups. Dolophilodes urceolus and Leptonema natalense were the dominant taxa of the trichopterans while individuals of taxa Chironomus transvaalensis, Paraphaenocladius sp., and Pentaneura nilotica dominated the dipterans. In conclusion, our results provided useful information that supports the protocol for biotic assessment and also baseline data on physicochemical conditions and macroinvertebrate composition of the stream.

Many researchers have adopted the use of indicator species to detect changes in the environment and predict future ecological modifications. Irrespective of the popularity of indicator species concept among scientists in recent times, there is less studies on the use of mega semi-aquatic mammals as indicator species, especially in Africa. This study determined the ecological role of Hippopotamus amphibius and how the mammal respond to environmental changes in an aquatic ecosystem, focusing on changes in biological diversity (fish and phytoplankton) and environmental factors (temperature, pH, dissolved oxygen, conductivity, total dissolved solids, hydrogen isotope, and oxygen isotope) by comparing pools harboring H. amphibius and pools without H. amphibius at the Bui National Park, Ghana. The results show that H. amphibius play an important ecological role by indicating high productivity in aquatic ecosystem and serving as influencers of the aquatic food web at Bui National Park. The results found significantly higher concentrations of dissolved oxygen in H. amphibius pools than pools without H. amphibius. Significantly higher diversity of fish and phytoplankton species were recorded in pools with H. amphibius. Common fish species identified during this study include, Oreohromis niloticus, Labeo coubie, Alestes dentex and Labeo senegalensis. Phytoplankton communities were dominated by Chlorophyceae (37.26%), Cyanophyceae (25.21%), and Bacillariophyceae (21.53%). The study results also showed that H. amphibius are sensitive to changes in depth of water, preferring areas with shallow pools. Managerial options for H. amphibius populations require strong support because of their socio-ecological benefits including potential ecosystem effects, increasing fishing and tourism value at the Bui National Park.

Zinc (Zn) deficiency in soil is an important restriction for the production of crops and a well-known human health issue. In semi-arid and arid regions of the world, deficiency of zinc is very common due to an increase in fixation and decrease in solubility. Zinc deficiency is a growing health concern, with 20.6% of children having zinc concentrations below 60 g/dL. Geographically there is a very close relationship between zinc deficiency in soil and humans which represents the soaring necessity for zinc biofortification in crops. Zinc biofortification of crops can be a cost-effective and long-term strategy for combating zinc insufficiency and preventing morbidity in the target population. The use of organic amendments is very good to overcome this problem by increasing the process of nutrient delivery and improving crop growth and productivity. Food crops that have been biofortified, including grains, beans, vegetables, and fruits, can provide enough micronutrients for the target population. Aside from the challenges, biofortified crops have a promising future in combating hunger.

Activity patterns of raptors may vary through the day and influence their detectability which may further affect their abundance estimate. In this study, we exhibit the effect of time-of-day bias (survey time), in different seasons (summer vs winter) and landscape feature (cultivated land, wasteland, flooded vegetation, desert, human habitation, grassland, barren land) on the detection and abundance of diurnal raptors in the arid region of Rajasthan, India. We used 50 transects, using the roadside point count method between March 2019 and February 2020 and recorded 3927 observations of 35 species belonging to 14 sub-family. To evaluate the effect of predictive variables, i.e., time-of-day, season and landscape features on abundance estimate of each species of raptors, the Generalised Linear Model (GLM) was used. Chi-square test (χ2) was used to assess the relationship between each species abundance and the period of day. The effect of time-of-day bias on abundance estimate was significant in case of Red headed falcon (χ2 = 6.60, p < 0.001), Steppe eagle (χ2 = 7.89, p < 0.001), and Black wing kite (χ2 = 26.46, p < 0.001), while it was not significant for Shikra (χ2 = 0.306, p = 0.97), Long legged buzzard (χ2 = 0.42, p = 0.93) and Pallid harrier (χ2 = 0.115, p = 0.12). We did not observe any significant relationship between time-of-the day bias and abundance of raptors in different seasons and landscape features for any raptor species. Raptors showed variation in activity patterns with respect to the activity of their prey species and foraging strategies. The road count method for raptor surveys is widely used, but very few studies have undertaken and considered time-of-day bias in abundance estimate. This study can help bridge this gap and design a suitable method for survey raptors.