Factor Of Global Environmental Change Research Articles

Rethinking the effects of micro/nanoplastics from the global environmental change and systematic perspective: An aquatic environmental system-based comprehensive assessment approach of micro/nanoplastic impacts

The study on micro/nanoplastic pollution should embrace complexity. Here, we aim to develop an aquatic environmental system-based comprehensive assessment approach of micro/nanoplastic impacts (ACAM) to evaluate the effects of micro/nanoplastics on aquatic ecosystems from the global environmental change (GEC) and systematic perspective. A case study for freshwater systems in Saskatchewan, Canada was conducted to evaluate the comprehensive effects of multiple GEC factors (polystyrene-nanoplastics (PS-NPs), N, P, salinity, dissolved organic matter (DOM), pH, hardness) on Asterococcus superbus based on ten ecologically relevant endpoints. It is found that at the cellular level, PS-NPs and N had an antagonistic interaction on microalgal growth in the Saskatchewan freshwater ecosystem; at the molecular level, the PS-NP-induced changes in lipid composition in microalgae were regulated by P, DOM, and pH. The significance ranking of factor effects suggested that instead of PS-NPs pollution, the fluctuations in pH level, DOM and N concentrations should be paid attention to first in Saskatchewan. Under the combined impact of PS-NPs and other GEC factors, microalgae at station 14 (Qu'Appelle River near highway 56) might have the minimum growth rate with [−0.048, 0.094] d-1 in Saskatchewan. These findings demonstrate the efficacy of the developed ACAM in a more comprehensive and context-specific assessment of MNP risks, providing new insight for the management of MNP pollution.

Ecosystem Health Responses of Urban Agglomerations in Central Yunnan Based on Land Use Change.

Land use change in urban agglomerations is gradually becoming a major cause and a key factor of global environmental change. As a consequence of the interaction between land use and ecological processes, the transformation in natural ecosystem structure and function with human activity disturbances demands a systematic assessment of ecosystem health. Taking the Central Yunnan urban agglomeration, undergoing transition and development, as an example, the current study reveals the typical land use change processes and then emphasizes the importance of spatial heterogeneity of ecosystem services in health assessment. The InVEST model-based ecosystem service assessment is incorporated into the ecosystem health evaluation, and hotspot analysis is performed to quantitatively measure the ecosystem health response degree to land use according to spatial latitude. The study had three major findings: First, the urban land expansion in the urban agglomeration of central Yunnan between 1990 and 2020 is the most significant. Further, the rate of the dynamic change of urban land is 16.86%, which is the highest among all land types. Second, the ecosystem health of the central Yunnan urban agglomeration is improving but with obvious spatial differences, showing a trend of increasing from urban areas to surrounding areas, with the lowest ecosystem health level and significant clustering in the areas where the towns are located. The ecosystem health level is mainly dominated by the two classes of ordinary and well grades, and the sum of the two accounts for 63.35% of the total area. Third, the process of land transfer, mutual transfer between forest and grassland, and conversion from cropland to forest land contributed the most to the improvement of ecosystem health across the study area. Furthermore, the conversion from cropland and grassland to urban land is an important cause of the sustained exacerbation of ecosystem health. Significantly, the study provides a scientific reference for maintaining ecosystem health and formulating policies for macro-control of land in the urban agglomerations of the mountain plateau.

Identifying contributions of climatic and atmospheric changes to autumn phenology over mid-high latitudes of Northern Hemisphere

Variations in autumn phenology (i.e., the end of growing season, EOS) in recent decades have been suggested to be the dynamic response of terrestrial ecosystems to global environmental change. However, predicting EOS change with climate variation is still challenging, given that there are several environmental factors that can affect EOS apart from warming. In this study, EOS over the Northern Hemisphere (>30°) was calculated by three different extracting methods using the Normalized difference vegetation index (NDVI) records from the Global Inventory Modeling and Mapping Studies third generation (GIMMS3g) during 1982 to 2015. We used partial correlation and partial least-squares regression (PLSR) analyses to investigate the EOS variations in response to five global environmental change factors, including temperature, precipitation, insolation, atmospheric CO2 and nitrogen (N) deposition. We found that about 58.5% (13.6% were significant) of the study area showed earlier EOS trends and 41.5% (10.3% were significant) with later EOS. Warming played a critical role in regulating EOS. The cumulative precipitation during the preseason had the greatest positive impact on EOS in arid/semiarid regions. Sufficient insolation could contribute to the delayed EOS over high latitudes. Compared with climatic factors, EOS also showed high sensitivity to changes in the atmospheric factors, and the dominant control of atmospheric CO2 and N deposition on EOS was found at 25–30% of the areas. Our results confirmed the dominant role of climatic factors in regulating EOS, but other global environmental cues, for instance, elevated atmospheric CO2 concentration and increased atmospheric nitrogen (N) deposition should also be included in the autumn phenological model to further understand the carbon and N cycles of terrestrial ecosystems with climate change.

Soil organic matter as affected by the conversion of natural tropical rainforest to monoculture rubber plantations under acric ferralsols

Land-use change (LUC) in the tropics, such as the exponential rate of conversion of natural habitats into intense monocultures focusing on cash-crop cultivation, is a major causal factor of global environmental change. To understand the effects of LUC on soil organic matter (SOM) stability and the dynamics of C and N within SOM fractions, we measured the C and N content and δ13C and δ15N in fractions of different aggregate- and density-size of acric ferralsols in tropical rainforests and rubber plantations. The proportion of macroaggregates, heavy and light fractions significantly decreased after LUC. The results showed that, in general, conversion of tropical rainforest to rubber plantation significantly decreased the C and N content in bulk soil and the aggregate- and density-size to 20 cm soil depth. The decrease in C and N content in bulk soil was mainly driven by decreasing C and N associated with macroaggregates and light fractions, which accounted for > 50%. We found significant correlations among mean weight diameter, aggregate-, and density-size fractions C, N, and C/N ratios. The conversion of tropical rainforest to rubber plantation significantly enriched soil δ13C while depleting δ15N. Enrichment of δ13C in rubber plantations could be explained by the mixing of old and fresh C. We conclude that, C and N dynamics within SOM fractions were greatly affected by LUC and the δ13C and δ15N signature confirms the changes in SOM stability after forest conversion. We suggest that planting intercrops within rubber monocultures may improve SOM accumulation, soil aggregation, and C and N sequestration.

How Will Global Environmental Changes Affect the Growth of Alien Plants?

Global environmental changes can create novel habitats, promoting the growth of alien plants that often exhibit broad environmental tolerance and high phenotypic plasticity. However, the mechanisms underlying these growth promotory effects are unknown at present. Here, we conducted a phylogenetically controlled meta-analysis using data from 111 published studies encompassing the responses of 129 alien plants to global warming, increased precipitation, N deposition, and CO2 enrichment. We compared the differences in the responses of alien plants to the four global environmental change factors across six categories of functional traits between woody and non-woody life forms as well as C3 and C4 photosynthetic pathways. Our results showed that all four global change factors promote alien plant growth. Warming had a more positive effect on C4 than C3 plants. Although the effects of the four factors on the functional traits of alien plants were variable, plant growth was mainly promoted via an increase in growth rate and size. Our data suggest that potential future global environmental changes could further facilitate alien plant growth.

Plant diversity drives soil microbial biomass carbon in grasslands irrespective of global environmental change factors.

Soil microbial biomass is a key determinant of carbon dynamics in the soil. Several studies have shown that soil microbial biomass significantly increases with plant species diversity, but it remains unclear whether plant species diversity can also stabilize soil microbial biomass in a changing environment. This question is particularly relevant as many global environmental change (GEC) factors, such as drought and nutrient enrichment, have been shown to reduce soil microbial biomass. Experiments with orthogonal manipulations of plant diversity and GEC factors can provide insights whether plant diversity can attenuate such detrimental effects on soil microbial biomass. Here, we present the analysis of 12 different studies with 14 unique orthogonal plant diversity×GEC manipulations in grasslands, where plant diversity and at least one GEC factor (elevated CO2 , nutrient enrichment, drought, earthworm presence, or warming) were manipulated. Our results show that higher plant diversity significantly enhances soil microbial biomass with the strongest effects in long-term field experiments. In contrast, GEC factors had inconsistent effects with only drought having a significant negative effect. Importantly, we report consistent non-significant effects for all 14 interactions between plant diversity and GEC factors, which indicates a limited potential of plant diversity to attenuate the effects of GEC factors on soil microbial biomass. We highlight that plant diversity is a major determinant of soil microbial biomass in experimental grasslands that can influence soil carbon dynamics irrespective of GEC.

Impacts of urban sprawl on species richness of plants, butterflies, gastropods and birds: not only built-up area matters

Urban growth is a major factor of global environmental change and has important impacts on biodiversity, such as changes in species composition and biotic homogenization. Most previous studies have focused on effects of urban area as a general measure of urbanization, and on few or single taxa. Here, we analyzed the impacts of the different components of urban sprawl (i.e., scattered and widespread urban growth) on species richness of a variety of taxonomic groups covering mosses, vascular plants, gastropods, butterflies, and birds at the habitat and landscape scales. Besides urban area, we considered the average age, imperviousness, and dispersion degree of urban area, along with human population density, to disentangle the effects of the different components of urban sprawl on biodiversity. The study was carried out in the Swiss Plateau that has undergone substantial urban sprawl in recent decades. Vascular plants and birds showed the strongest responses to urban sprawl, especially at the landscape scale, with non-native and ruderal plants proliferating and common generalist birds increasing at the expense of specialist birds as urban sprawl grew. Overall, urban area had the greatest contribution on such impacts, but additional effects of urban dispersion (i.e., increase of non-native plants) and human population density (i.e., increases of ruderal plants and common generalist birds) were found. Our findings support the hypothesis that negative impacts of urban sprawl on biodiversity can be reduced by compacting urban growth while still avoiding the formation of very densely populated areas.

Spatial and Temporal Change of Land Use and its Impact on Water Quality of Poyang Lake Region

As an important influencing factor of global environmental change, land use change has always been the hot issues of geography study. Taking Poyang Lake region as an example the relationship between land use and ecological protection was expounded. Analyzed the comprehensive summarize to the Land use change, retrospected the development history of the Land use change, and also analyzed and depicted the current research field. The exploitation and conservation of the Poyang Lake international importance wetland are of importance for the ecologic environment in Jiangxi province.This paper is to summarize the status of land use change in the Poyang lake region refer to those research results before,finally some effective solutions were proposed.

RETRACTED ARTICLE: Environmental Impact Assessment of Industrial Structure Change in a Rural Region of China

As the embodiment of human activities, the change of regional industrial structure is an essential driving factor of global environmental change. Consequently, the research on the change of regional industrial structure and associated effects on the environment is one of the key issues of researches on sustainable development, human-environment relationship, and regional response to global environment change. However, compared to the flourish of researches on environmental impact assessment of industrial departments, few studies have been conducted to assess the environmental impact of regional industrial structure. In this study, based on a synthetic analysis of environmental disturbances of different industrial departments, the environmental impact coefficient of industrial department associated with the index of environmental impact of industrial structure was constructed, so as to make a quantitative assessment of environmental impact of the change of regional industrial structure. And the results of the case study in Lijiang City, a rural region of China, have showed that there are two obvious changes of industrial structure in the study area from 1992 to 2003, associated with a continuous decreasing of the index of environmental impact of industrial structure, which indicated a positive environmental effects of the change of regional industrial structure.