Influence of Multi-Layered Structure of Vadose Zone on Ecological Effect of Groundwater in Arid Area: A Case Study of Shiyang River Basin, Northwest China

The natural vegetation in arid areas of northwest China is strongly dependent on the availability of groundwater. Significantly, capillary water plays an essential role in regulating the ecological groundwater level in the multilayered structure of the vadose zone. The soil-column test and field survey in the lower reaches of the Shiyang River Basin were conducted to investigate the influence of the multi-layered structure of the vadose zone on maintaining the ecological effect of groundwater. Based on the field survey, the results show that the depth of groundwater is 3.0 m, and the rising height of capillary water is 140 cm. In the soil-column test, the height of the wetting front of the column was 125 cm. During the water releasing test, the water held by the vadose zone was 182.54 mm, which would have maintained Haloxylon’s survival in a growing season. Therefore, the multi-layered structure of the vadose zone extends the ecological groundwater depth and consequently enhances the ecological function of groundwater. Importantly, with a lower groundwater level, the clay soil layer within the rising height range of the original capillary water would hold more water and maintain a higher water content for a certain period to supply surface vegetation.

Assessment of Eco-Economic Effects of Urban Water System Connectivity Project

As one of the large ecological infrastructures, urban water system connectivity project is an important part of urban ecosystem construction. It has a variety of effects, such as conserving biodiversity, enriching urban landscape and increasing land value. It is helpful for the scientific planning and construction of the project to systematically evaluate the effects. However, due to the complex and various effects of urban water system connectivity project, there is no complete effect system and quantitative method. In this paper, the composition and mechanism of positive and negative effects of ecological economics of urban water system connectivity project were deeply analyzed to improve the composition system of eco-economic effects. At the same time, the emergy theory was used to put forward the quantification method of eco-economic effect system. Taking the urban water system connectivity project in Xuchang as an example, it’s ecological, social and economic effects were evaluated. The result showed that the average eco-economic effect of the project is 57.8 million dollars/year. Economic effect and ecological effect are significant, accounting for 88.83% and 9.77% of total effect, respectively. The former is mainly due to land value increment, and the latter is principally owing to biodiversity conservation. It showed that the water system connectivity project in Xuchang can promote the economic development of the surrounding areas and create a good ecological environment, which will bring huge eco-economic effect to the region.

Longevity of Ulmus pumila L. in protective afforestation on semi-desert lands of the Astrakhan Zavolzhye

The article provides a predictive assessment of longevity of Ulmus pumila L. stands in the Astrakhan Zavolzhye. The effi and expediency of renewable logging for rejuvenation and increasing the longevity of plantings in the semi-desert were confi The classifi of ecotopes of the Astrakhan Zavolzhye on suitability for cultivation of protective and shadow elm plantings on pasture lands was developed and presented. In the Caspian region, Ulmus pumila became widespread in forest reclamation of semi-desert lands in the 1950s. Since then, till the beginning of the 1990s, Bogdinskaya research agroforestry experimental station laid on the sandy massifs about 1 thousand hectares of Ulmus pumila L. plantings, which currently amounts to 1824 %. The long-term practice of using protective shade Ulmus pumila umbrellas has shown their signifi ecological effect on functioning pastures. The aim of the research was to develop an improved technology for creating long-lived protective shade stands of Ulmus pumila on degraded pastures of the Astrakhan Zavolzhye. The research was carried out using generally accepted methods of stand forest taxation by A.P. Anuchin (1961), 1. Bitvinskas (1974) and A.S. Manaenkov (2001). Soil conditions were studied by drilling sounding to 3 m depth. The results of the research revealed that the longevity of wood species in the dry-steppe zone was determined mainly by two factors: productive moisture in the soil and salinity level. The most favorable growing conditions for Ulmus pumila were unsalted (to a depth of at least 3 m) brown sandy soils, sandy loam soils, dark-colored swale soils with periodic redistributed accumulation of moisture. In arid conditions of the Astrakhan Zavolzhye in island plantations (group of trees, umbrellas, 0.51 ha parts of forest area) and optimal growing conditions without logging and reforestation, Ulmus pumila lives up to 6070 years.

Protozoa populations are ecosystem engineers that shape prokaryotic community structure and function of the rumen microbial ecosystem

Unicellular eukaryotes are an integral part of many microbial ecosystems where they interact with their surrounding prokaryotic community—either as predators or as mutualists. Within the rumen, one of the most complex host-associated microbial habitats, ciliate protozoa represent the main micro-eukaryotes, accounting for up to 50% of the microbial biomass. Nonetheless, the extent of the ecological effect of protozoa on the microbial community and on the rumen metabolic output remains largely understudied. To assess the role of protozoa on the rumen ecosystem, we established an in-vitro system in which distinct protozoa sub-communities were introduced to the native rumen prokaryotic community. We show that the different protozoa communities exert a strong and differential impact on the composition of the prokaryotic community, as well as its function including methane production. Furthermore, the presence of protozoa increases prokaryotic diversity with a differential effect on specific bacterial populations such as Gammaproteobacteria, Prevotella and Treponema. Our results suggest that protozoa contribute to the maintenance of prokaryotic diversity in the rumen possibly by mitigating the effect of competitive exclusion between bacterial taxa. Our findings put forward the rumen protozoa populations as potentially important ecosystem engineers for future microbiome modulation strategies.

Aerial and Optical Images-Based Plant Species Segmentation Using Enhancing Nested Downsampling Features

Plant species, structural combination, and spatial distribution in different regions should be adapted to local conditions, and the reasonable arrangement can bring the best ecological effect. Therefore, it is essential to understand the classification and distribution of plant species. This paper proposed an end-to-end network with Enhancing Nested Downsampling features (END-Net) to solve complex and challenging plant species segmentation tasks. There are two meaningful operations in the proposed network: (1) A compact and complete encoder–decoder structure nests in the down-sampling process; it makes each downsampling block obtain the equal feature size of input and output to get more in-depth plant species information. (2) The downsampling process of the encoder–decoder framework adopts a novel pixel-based enhance module. The enhanced module adaptively enhances each pixel’s features with the designed learnable variable map, which is as large as the corresponding feature map and has n×n variables; it can capture and enhance each pixel’s information flexibly effectively. In the experiments, our END-Net compared with eleven state-of-the-art semantic segmentation architectures on the self-collected dataset, it has the best PA (Pixel Accuracy) score and FWloU (Frequency Weighted Intersection over Union) accuracy and achieves 84.52% and 74.96%, respectively. END-Net is a lightweight model with excellent performance; it is practical in complex vegetation distribution with aerial and optical images. END-Net has the following merits: (1) The proposed enhancing module utilizes the learnable variable map to enhance features of each pixel adaptively. (2) We nest a tiny encoder–decoder module into the downsampling block to obtain the in-depth plant species features with the same scale in- and out-features. (3) We embed the enhancing module into the nested model to enhance and extract distinct plant species features. (4) We construct a specific plant dataset that collects the optical images-based plant picture captured by drone with sixteen species.

Assessment of the Heavy Metals Pollution and Ecological Risk in Sediments of Mediterranean Sea Drain Estuaries in Egypt and Phytoremediation Potential of Two Emergent Plants

Environmental pollution and its eco-toxicological impacts have become a large and interesting concern worldwide as a result of fast urbanization, population expansion, sewage discharge, and heavy industrial development. Nine heavy metals (Pb, Cd, Fe, Mn, Zn, Ni, Cu, Cr, and Co) were evaluated in 20 sediment samples from the estuaries of four major drains along the Mediterranean shoreline (Nile Delta coast) to determine the possible ecological effect of high heavy metal concentrations as well as roots and shoots of two common macrophytes (Cyperus alopecuroides and Persicaria salicifolia). For sediment, single- and multi-elemental standard indices were used to measure ecological risk. Data revealed high contents of heavy metals, for which the mean values of heavy metals in sediment followed a direction of Fe > Mn > Co > Zn > Cu > Ni > Cr > Pb > Cd, Fe > Mn > Co > Ni > Zn > Cu > Cr > Pb > Cd and Fe > Mn > Zn > Co > Cu > Ni > Cr > Pb > Cd for drains stream, estuaries, and Mediterranean coast, respectively. Mn, Cr, Zn, and Pb were found to be within Canadian Soil Quality Guidelines (CSQGD) and U.S. Environmental Protection Agency Guidelines (US-EPA) limitations, except for Zn and Pb in drain streams, which were above the US-EPA limits, whereas Cd, Co, Cu, and Ni indicated a high ecological risk index. This high quantity of contaminants might be linked to unabated manufacturing operations, which can bio-accumulate in food systems and create significant health issues in people. C. alopecuroides root demonstrated a more efficient accumulation of all metals than the shoot system. For most heavy metals, C. alopecuroides had the highest root BAF levels with the exception of Ni and Pb in P. salicifolia. As a result, C. alopecuroides might be employed as a possible phytoextractor of these dangerous metals, while P. salicifolia could be used as a hyper-accumulator of Ni and Pb. The policymaker must consider strict rules and restrictions against uncontrolled industrial operations, particularly in the Nile Delta near water streams.

Research on Ecological Effects of Reservoir Dam Project

Ecological effects of dam and reservoir development is a new concept proposed in recent years. It refers to the ecological impact and ecological consequences in the dam construction and operation process, which not only including the positive ecological effects, but also the negative. Ecological effect analysis is a kind of analysis which pointed at the influence of the water conservancy projects built on the living environment, the impact of the wild animals and plants, the effect of natural law, the impact of the economic growth. Based on the analysis of previous research results, this paper summarizes the connotation and characteristics of the ecological effects of the reservoir and dam project, and analyzes the ecological effects of the reservoir and dam project from the aspects of Hydrology, water environment, biology, climate, etc., this paper summarizes the connotation and characteristics of the ecological effect of the reservoir dam project, and provides the scientific basis for whether the hydraulic engineering should be retained or whether the function should be improved.

Effect of Copper On Bioconcentration of Benzotriazole Ultraviolet Stabilizers (BUVSs) in Common Carp (Cyprinus Carpio)

Benzotriazole ultraviolet stabilizers (BUVSs) have received increasing attention due to their widespread usage, ubiquitous detection and their adverse ecological effect. However, information about the bioaccumulation potential of BUVSs and their joint exposure with heavy metals remains scarce. In this study, we investigated the bioaccumulation kinetics of 6 frequently reported BUVSs in common carp under different Cu concentration for 48 d, and their tissue-specific distribution patterns (liver, kidney, gill, and muscle tissues) were also evaluated. The bioconcentration factors (BCFs) and half-lives (t1/2) in the tissues ranged from 5.73 (UV-PS) to 1076 (UV-327), and 2.19 (UV-PS) to 31.5 (UV-320) days, respectively. The tissue-specific concentration and BCF values followed the order of liver > kidney > gill > muscle with or without Cu exposure. An increase in BCF with rising Cu concentration was observed, which is caused by the decreased depuration rate (k2) in more than half of treatment groups. These results indicated that BUVSs accumulated in fish and provides important insight into the risk assessment of this group of chemicals.

Farmland Changes and Their Ecological Impact in the Huangshui River Basin

The Huangshui River Basin (HRB) is the main grain production and key implementation region of the “Grain for Green Program” (GGP) of Qinghai Province, and has experienced a quick urbanization during the last 20 years. Therefore, identifying the farmland change and its ecological effects is significant for farmland and ecological protection in the HRB. To this end, this study analyzed the farmland change between 2000 and 2018, based on 1 m spatial resolution farmland data visually interpreted from Google Earth high-resolution images, and then estimated its ecological impact based on the Normalized Difference Vegetation Index (NDVI) data of MODIS, using an ecological impact index of farmland change. The study found that: (1) The farmland area in the HRB decreased from 320.15 k ha in 2000 to 245.01 k ha in 2018, reduced by 23.47% or 1.48% per year, as mainly caused by ecological restoration and built-up land occupation; (2) from 2000 to 2018, the natural environment showed a greening trend in the HRB, with the mean NDVI increasing by 0.74% per year; (3) the farmland changes had a positive ecological effect, contributing 6.67% to the regional increase in the NDVI, but had a negative impact on grain production; (4) it is suggested to strengthen farmland protection by strictly controlling the urban land occupation and over-conversion of farmland in the HRB.