Semi-natural Ecosystems Research Articles

Unpacking public perceptions of carbon sequestration and storage in urban greenery: Implications for the social acceptability of carbon-oriented nature-based solutions

Research investigating how urban greenery contributes toward carbon sequestration and storage (CSS) is mushrooming, and evidence-based design, management, and planning approaches are increasingly guiding the implementation of carbon-oriented nature-based solutions (NBS) in cities. However, the long-term success of NBS will largely depend on their social acceptability to residents, which in-turn is informed by their perceptions of the environmental issues at stake. In this study, we investigate residents’ perceptions of CSS in urban greenery and examine its influence on social acceptability of carbon-oriented NBS. We administered a survey containing nine hypothetical carbon-oriented NBS policies, and open-ended descriptions of the perceptions of CSS in urban greenery to 1,600 adult residents in Helsinki, Finland. Findings show that residents’ perceptions of CSS are primarily built on ecological dimensions (i.e., ecology of carbon and the carbon cycling in natural and semi-natural ecosystems) rather than socio-political ones (i.e., how humans, social, and political systems influence carbon cycling and dynamics in urban greenery). This finding shows an informational and perceptual gap among the public on how to design, manage, and plan urban greenery for CSS. We observed that females and those with higher levels of education and access to forest and natural areas tended to be more comfortable and familiar with CSS and believed urban greenery was effective in CSS. Lastly, we observed that socio-political and ineffectiveness CSS perceptual dimensions were more strongly related to social acceptability of carbon-oriented NBS. We conclude by discussing how public perceptions of CSS can enhance the social acceptance of carbon-oriented NBS, and we put forward strategies to integrate transformative learning about these NBS into urban greenery.

Identifying appropriate reference ecosystems based on soil indicators to evaluate postmining reclamation: A multivariate framework

ABSTRACTLarge-scale mining operations, such as those associated with iron extraction, disturb soils and vegetation and create the need for effective rehabilitation practices. The Iron Quadrangle region of southeastern Brazil is one of the world’s biodiversity hotspots; however, iron mining activities threaten many natural and seminatural ecosystem types in which many rare/protected species occur. The Iron Quadrangle has four main ecosystem types: Atlantic Forest (AF), ferruginous rupestrian grassland with dense vegetation (FRG-D); ferruginous rupestrian grassland with sparse vegetation (FRG-S); and quartzite rupestrian grassland (QRG). To support rehabilitation and monitoring plans, we evaluated reference areas and identified soil and vegetative attributes that best differentiated between these four ecosystems. We measured thirty-four physical, chemical, and biological soil properties and two vegetation parameters and, using a multivariate analysis, detected: 1) correlations between properties and 2) differences between areas. We identified twelve properties that best differentiated the areas (in order from most to least relevant): nickel content; exchangeable aluminum; clay content; above-ground vegetation volume; aluminum saturation; particle density; bulk density; arsenic content; zinc content; lead content, fine sand plus silt content; and fine sand content. Soil physicochemical properties proved to be more sensitive to differences in ecosystem type, and in particular, parameters related to fertility and the presence of metals and semi-metals differentiated the AF from the FRG-D and FRG-S. Soil physical properties, including fine sand and silt content, were most important for differentiating QRG from the other ecosystems, possibly resulting from the exposure of quartzite material to erosive processes. This study demonstrates the importance of identifying appropriate reference areas for post-mining reclamation.

Landscape structure influences grassland productivity through plant functional diversity

Agriculture intensification led to the gradual destruction of semi-natural habitats and landscape simplification in the North-Western Europe. All these profound changes affected plant assemblages, especially in semi-natural ecosystems such as grasslands. They could have negative effects on the plant diversity and the related ecosystem functions, such as primary productivity. At the landscape scale this biodiversity-productivity relationship still have to be tested in real-world systems. It could have important economic implications concerning fodder production. We used a large-scale sampling design (30 landscape windows – 1 ×1 km) to quantify landscape structure variables (semi-natural habitat amounts and landscape heterogeneity), grassland plant taxonomic diversity and functional diversity calculated from multidimensional functional spaces (functional richness, evenness, dispersion), and grassland productivity (mean, temporal stability, spatial variability) derived from satellite image time-series. Taxonomic dissimilarity, functional evenness and functional dispersion of grassland plant assemblages were related to semi-natural habitat amount. Functional evenness and dispersion decreased with grassland amount whereas taxonomic dissimilarity and functional evenness increased with hedgerow amount. Only taxonomic and functional richness depended on landscape heterogeneity, and with a positive relationship. Grassland plant assemblages with a higher functional evenness presented a higher and more stable mean productivity. In addition to the direct effect of landscape heterogeneity on plant productivity, we demonstrated plant trait-mediated effect of landscape structure on mean and temporal stability of grassland productivity at the landscape scale. Landscape management, especially through the conservation of hedgerows can help maintain high and resilient production of fodder in the future as a result of their positive effects on plant functional diversity.

Ultisols with Unique Soil Properties and their Implications in Carbon Enhancement Strategies for Indian Tropical Soils

Million years old Ultisols, developed as an end stage of advance soil weathering on base-poor rock systems under forest and plantation crops of the Indian sub-continent, are enriched with organic carbon (OC). Despite their remarkable acid chemical reaction, they show an upward increase in extractable bases (EB) and base saturation (BS) in the pedon, and on some occasion BS > 35% in surface horizons. Recent research suggests that the litter falls from forest species provide bases on soil surface, which causes similar depth distribution of EB and BS in Andisols of Nilgiri Hills of humid tropical southern India, developed on pre-weathered lateritic materials consisting primarily of Fe and Al oxides/ hydroxides. Under similar humid tropical (HT) climate in protected rain forest, million years old OC rich soils of Andaman and Nicobar Islands, developed on base-poor rock systems, have similar chemical and clay mineralogical properties of Ultisols except however their EB and BS, which are more than 10% and much above 50%, respectively and therefore, they are acidic Alfisols. Formation of Alfisols on the Island is a unique example on the formidable role of vegetation in soil formation, suggesting that if inland Ultisols are kept under natural protected forest ecosystem, they may phase towards Alfisols thereby facilitating OC sequestration and perform other ecosystem functions. The preservation of natural or semi-natural ecosystems is thus essential to raise the OC stocks of soils, which would help to gain various ecological benefits.

Moderate sheep grazing increases arthropod biomass and habitat use by steppe birds

Open semi-natural ecosystems have been historically shaped by anthropogenic land-use, and the abandonment or intensification of these activities implied a detrimental alteration of their landscapes. Extensive sheep grazing has gradually decreased during the 20th century in Mediterranean steppes, triggering changes across all taxa. Here, we address the effect of sheep grazing on both arthropod biomass and space use by insectivorous steppe birds, using an endangered passerine as a model species. We found that biomass of different arthropod groups peaked at intermediate levels of grazing, and that both short-term grazing (affecting arthropod biomass) and long-term grazing (affecting vegetation structure) explain space use by insectivorous birds, whereas only long-term processes are decisive for bird territory establishment. Our results emphasise the role of sustained moderate grazing intensity in the conservation of steppe biodiversity. In the current decline context of extensive sheep grazing, agricultural policies should prioritise these practices to ensure the persistence of open semi-natural ecosystems

Agroforestry Ecosystem Structure and the Stability Improvement Strategy in Control of Karst Desertification

Agroforestry systems (AFS) are priority semi-natural ecosystems in fragile ecological zones. The complexity and diversity of their species structure play a crucial role in maintaining AFS stability. To explore the optimization of improvement strategies in AFS’ structure and stability for control of karst desertification (KD), in this study, we chose typical desertification control areas in the southern China karst region. The study included homegarden (HG), agrisilviculture (ASV), and multipurpose woodlots (MWLs) as three AFS. We quantified the AFS’ structural characteristics using descriptive statistics and spatial structure parameters. We used the fuzzy integrated evaluation method with structural and functional indicators as guidelines, and stand structure, plant species diversity, soil fertility, and environmental factors as first-level evaluation indicators. The entropy weight method calculates the weights of indicators at all levels. The fuzzy comprehensive evaluation method establishes an evaluation index system to evaluate the grading of AFS’ stability. The results showed that: (i) The species composition of the AFS in the KD control areas had a simple structure, the overall diversity level was low, and the diversity level of herbaceous plants was better than that of woody plants. (ii) The overall distribution curves of diameter at breast height (DBH), tree height (TH), and crown width (CW) of woody plants in the AFS in the KD control areas were slight to the left, with a single-peaked pattern, mostly randomly and unevenly distributed in space, with a low degree of tree species isolation and relatively weak stand stability. (iii) There was variability in the stability classes of different types of AFS, overall reflecting the ranking HG > ASV > MWLs. (iv) When structural optimization was applied, corresponding measures can be taken according to farmers’ wishes for different types of AFS and their primary business purposes. The improvement of stability depends mainly on the utility of the structural optimization applied coupled with positive human interference (for example, pruning, dwarfing, and dense planting). This study provides a scientific reference for maintaining the stability of AFS and promoting service provision.

The Effect of Plant Diversity and Soil Properties on Soil Microbial Biomass and Activity in a Novel Ecosystem

Plant–microbial relations have not yet been fully disclosed in natural or seminatural ecosystems, nor in novel ecosystems developing spontaneously on post-coal mine heaps. The aim of this study was to determine which factor, biotic (plant taxonomic diversity vs. plant functional diversity) or abiotic (physicochemical substrate parameters), affects the biomass of soil microbial communities the most, as well as soil in situ respiration in novel ecosystems. The study was carried out on unreclaimed plots selected according to four different combinations of taxonomic and functional plant diversity. Additionally, plots on a reclaimed heap served as a comparison between the two management types. The biomass of several soil microbial groups was analysed using phospholipid fatty acids profiles. We detected that soil microbial biomass was more impacted by abiotic parameters (explaining 23% of variance) than plant diversity (explaining 12% of variance). Particularly, we observed that substrate pH was the most important factor shaping microbial community biomass, as shown in the RDA analysis. The highest microbial biomass was found in plots with low taxonomic and functional diversity. This finding can be explained by the fact that these plots represented a more advanced phase of vegetation development in the early stages of plant succession.

Plant selection for pollinator restoration in seminatural ecosystems

Individual plant species play valuable roles in meeting restoration goals for pollinators. However, the selection of plant species for pollinator restoration is rarely informed using empirical evidence and is usually developed in agroecosystems, which experience frequent human interventions to ensure plant success as compared to seminatural ecosystems. We highlight concepts and future research needs to design planting mixes that fulfill the ecological requirements of pollinators in seminatural ecosystems. Native plants that are attractive to pollinators, increase the stability of pollination services, and provide consistent floral resources across the landscape and growing season should be prioritized in pollinator restoration projects in seminatural ecosystems. Furthermore, condensing criteria of desirable plant traits into a composite score can aid managers in selecting plant species that meet restoration goals. Developing restoration strategies for pollinators on seminatural lands is important for preserving organisms essential for biodiversity maintenance and ecosystem function.

Investigation of land cover (LC)/land use (LU) change affecting forest and seminatural ecosystems in Istanbul (Turkey) metropolitan area between 1990 and 2018

This study was conducted to examine the land cover (LC)/land use (LU) change affecting forest and seminatural ecosystems and the spatio-temporal development of urban expansion between 1990 and 2018 in the city of Istanbul, where urbanization is the most intense in Turkey. For this purpose, using Corine Land Cover (1990, 2000, 2006, 2012, and 2018) dataset, the land cover of the area was determined in 5 different classes (artificial surface, agriculture, forest, water bodies, water), maps were produced, and tabular data were created. The changes in LC/LU between 1990 and 2018 were determined according to the Puyravaud land cover change rate and hot spot analysis methods. According to our findings, we determined that urbanization in Istanbul expanded the most in the east-west direction, and the agricultural and forest areas gradually decreased by 3.02% and 6.66% respectively; urban areas increased at the same rate of 9.69%. It is predicted that this change will continue increasing until 2030 when the forecasting method is applied in the field. It has been determined that the most important reasons for this situation are local government policies, population growth, and economic development initiatives applied in the area. As a result, it has emerged that measures should be taken based on sustainability and naturalness approaches to design urban development plans and to protect natural areas on a large scale, in order to limit possible LC/LU conversion from natural structure to urbanization in the area.

New indicators for delineating priority regions for ecosystem conservation based on the criterion of cost-effectiveness

Natural and semi-natural ecosystems are increasingly threatened by human activities and their conservation conflicts with the ever-increasing spatial demands of human habitation and food production. Identifying the regions in most need of specific ecosystem conservation measures is an urgent problem in order to address this sustainability issue. However, the ambiguous definitions and methods of delineating these regions have led to difficulties in decision-making. To solve this problem of identifying priority regions, we developed new indicators (the marginal profit in terms of supplied ecosystem services and the area of land required to host permitted human activities) and rules for the determination of variable thresholds. Based on the criterion of cost-effectiveness, the concept of marginal profit was introduced and two variable thresholds were determined for its delineation: (i) the largest marginal profit with the highest efficiency and (ii) a marginal profit equal to zero as the potential upper limit. Taking four counties in the water conservation region of Beijing, China as case study areas, the proposed method was applied and tested. The results showed different spatial variations in water conservation services between the four counties, demonstrating the spatially distinct importance of services, which is strongly related to their priorities for conservation. Using the variable strategy, our new indicators and method were able to quantify these spatial characteristics and select particular areas with high-value ecosystem services for delineating priority regions for conservation. Compared to the non-variable threshold with a fixed target, our variable thresholds realized differentiated targets in the four different counties with smaller areas of land conserved for more ecosystem services. The developed indicators also avoided the likelihood of unreasonable outcomes from the use of a fixed target, which, although it could use more land, it would pay for fewer ecosystem services. Our results show the effectiveness of our developed indicators and overall method, which is easily operable and provides differentiated outcomes for priority regions for ecosystem conservation, leading to more informed decision-making.

Mapping the planet’s critical natural assets

Sustaining the organisms, ecosystems and processes that underpin human wellbeing is necessary to achieve sustainable development. Here we define critical natural assets as the natural and semi-natural ecosystems that provide 90% of the total current magnitude of 14 types of nature’s contributions to people (NCP), and we map the global locations of these critical natural assets at 2 km resolution. Critical natural assets for maintaining local-scale NCP (12 of the 14 NCP) account for 30% of total global land area and 24% of national territorial waters, while 44% of land area is required to also maintain two global-scale NCP (carbon storage and moisture recycling). These areas overlap substantially with cultural diversity (areas containing 96% of global languages) and biodiversity (covering area requirements for 73% of birds and 66% of mammals). At least 87% of the world’s population live in the areas benefitting from critical natural assets for local-scale NCP, while only 16% live on the lands containing these assets. Many of the NCP mapped here are left out of international agreements focused on conserving species or mitigating climate change, yet this analysis shows that explicitly prioritizing critical natural assets and the NCP they provide could simultaneously advance development, climate and conservation goals.

Evaluating the effectiveness of basin management using agricultural land for ecosystem-based disaster risk reduction

Flood risk reduction is a crucial global issue. Structural measures against floods have an upper limit on their function; thus, when the magnitude of floods exceeds this upper limit, few functions can prevent damage. Non-structural measures such as ecosystem-based strategies for disaster risk reduction (Eco-DRR) are attracting growing interest. In this study, I test the effectiveness of flood mitigation on agricultural land, which is a semi-natural ecosystem, using both municipality and watershed data from 9 years of statistical records on flood damage to test the relationship between flood frequency and land use patterns with terrain conditions in both municipalities and watersheds. I also conduct a simulation in which agricultural land use is reduced to compare the effectiveness of flood mitigation between the two scales. The results indicate that both paddy fields and dry farmland located in a water storage zone are effective in reducing flood frequency. In addition, this function is greater for watersheds than for municipalities. Thus, the conservation of agricultural land in which water storage zones are located could enhance Eco-DRR for flooding, especially in watersheds. I conclude that combining structural and non-structural measures—namely, Eco-DRR—is the most effective flood mitigation strategy for watersheds.

Critical Climate Periods Explain a Large Fraction of the Observed Variability in Vegetation State

Previous studies have suggested that a major part of the observed variability in vegetation state might be associated with variability in climatic drivers during relatively short periods within the year. Identification of such critical climate periods, when a particular climate variable most likely has a pronounced influence on the vegetation state of a particular ecosystem, becomes increasingly important in the light of climate change. In this study, we present a method to identify critical climate periods for eight different semi-natural ecosystem categories in Hungary, in Central Europe. The analysis was based on the moving-window correlation between MODIS NDVI/LAI and six climate variables with different time lags during the period 2000–2020. Distinct differences between the important climate variables, critical period lengths, and direction (positive or negative correlations) have been found for different ecosystem categories. Multiple linear models for NDVI and LAI were constructed to quantify the multivariate influence of the environmental conditions on the vegetation state during the late summer. For grasslands, the best models for NDVI explained 65–87% variance, while for broad-leaved forests, the highest explained variance for LAI was up to 50%. The proposed method can be easily implemented in other geographical locations and can provide essential insight into the functioning of different ecosystem types.

Soil C/N ratio is the dominant control of annual N2O fluxes from organic soils of natural and semi-natural ecosystems

Globally, organic soils of natural and semi-natural ecosystems have been considered as an important source of atmospheric nitrous oxide (N2O), a powerful greenhouse gas. However, we have little understanding of how and to what extent the magnitude of N2O emissions from such soils is mediated by variation in environmental controls. This knowledge is critical for scaling up the results of measurements from local to regional or global scales. Here we report on two-year field measurements of N2O fluxes from various alpine land use/cover types at 24 sites across an altitudinal gradient in a catchment on the eastern Tibetan Plateau. We found that annual N2O emissions varied between 0.05 and 1.39 kg N ha−1 yr−1, with non-growing season contributing 11–60% to these annual budgets. Our field results, together with published data from 43 studies on organic soils globally (natural and semi-natural ecosystems) showed that across all datasets, annual N2O fluxes were more closely related to the soil C/N ratio. Weaker relationships were found to the mean water table depth (WTD) and soil total N content. In contrast to the general assumption that soil N2O emissions may consistently increase with a narrowing of the organic soil C/N ratio, we found strong indications that the relationship of annual N2O fluxes to soil C/N ratio followed an optimum Gaussian curve, with a threshold at a C/N ratio of about 18–19. Moreover, there was a tendency towards high N2O emissions for sites with a mean annual WTD > 0.15 m, indicating a potential risk for increased N2O emissions from global organic soils under water table drawdown driven by climate drying or peatland drainage. Overall, our results suggest that the soil C/N ratio could be used as an indicator to better constrain the contribution of organic soils to N2O emissions from landscape at global scales.

Advances in mining restoration

This special issue is a compilation of studies arising from the activities of the 5‐year Australian Research Council Industrial Transformation Training Centre for Mine Site Restoration. Research conducted by the Centre involved disciplines often overlooked or under‐resourced in the mining industry including restoration genetics, seed technology and enablement, rare species management, and restoration ecophysiology. These studies then formed the context for development of an additional focus on mining closure policy development. The programs highlight the critical importance of ensuring that the seed supply chain, plant growth media, and restoration technologies are fit‐for‐purpose, that native fauna are considered in the life‐of‐mine and, how collectively, investment in these types of programs can inform effective mine closure planning. Though Australian‐based, the principles and outcomes of the research are applicable to international mining activities operating in natural or seminatural ecosystems or regions of high biodiversity.

Biodiversity of Bulgaria: Characteristics, protection and trends

Bulgaria is a medium-sized country located in the eastern part of the Balkan Peninsula. It hosts a rich mycota, flora and fauna, and quite well preserved natural and semi-natural ecosystems. This is mostly due to the country's geographic position between the temperate and subtropical zones, the complex geological history, and the big topographic variety. The high species diversity and endemism determine the high conservation value of Bulgarian biodiversity. The Bulgarian flora consist of more than 4,100 species, including more than 45 species of ferns, 250 species of mosses, and 2,800 higher plant species. The animals established in the country belong to 28 phyla and 75 classes. Vertebrates (858 species) comprise 2.7% of the Bulgarian fauna: 242 fishes and fish-like taxa; 24 amphibians; 40 reptiles; 452 birds; and 101 mammal species. Invertebrates account for more than 31,000 species. Over the past 25 years the number of known animals in the country has increased by over 4,500 species: from 29,000 in 1996 to 33,545 species in 2020. The total number of endemic animals is about 1,400 (4.2%). In some groups, the percentage of endemism is very high (95.5% of snails from the family Hydrobiidae and 71% of Clausiliidae; 53.6% of Diplopoda; 50.0% of terrestrial Isopoda). The richest endemic areas in Bulgaria are mostly in the mountains: Rila Mt.- 268, Pirin Mt. - 220, Western Stara Planina Mt. - 184, Western Rhodopes Mts - 183, and the Central Stara Planina Mt. – 181. Molecular data for Bulgarian animals is still insufficient, although Bulgaria ranks among the top 10 European countries in the proportion of the DNA-barcoded animal taxa; sequence coverage of animal specimens in Barcode of Life data System (BOLD) amounts to approximately 36,000 sequences from more than 7,100 Barcode index numbers (BINs). Bulgaria is part of large-scale initiatives of the European research infrastructure such as the Distributed System of Scientific Collections (DiSSCo) and the MOBILISE COST Action, with mass digitization of museum collections currently underway. Legislation to protect nature in Bulgaria dates back to the end of the 19th century and covers forestry (1890), the protection of certain species (1890's) and hunting (1897). Organized civil movements resulted in the establishment of the Union of Nature Protection (1928), the designation of several nature reserves (1933), and the first National Park (1934). More specific regulation followed with Ordinance for the Protection of Nature (1936). The Red Data Book of Bulgaria was published as early as 1984 (vol. 1, Plants) and 1985 (vol. 2, Animals), with a second updated edition in 2011. Bulgaria is also among the first countries to prepare a National Strategy for Biodiversity Protection (1993, adopted in 1998) following the Convention on Biological Diversity (CBD) process. Since then, several national plans for protection of biodiversity have been adopted including assessments of the threats, objectives, and measures for their achievement. According to recent references, such as the Red Data Book (Beshkov 2011) and the Article 17 reports of 2014 and 2020, the main threats to biodiversity in Bulgaria at the beginning of the 21st century have been human induced degradation: fragmentation and loss of habitats; industrial, agricultural and household waste pollution; direct exploitation of biological resources; genetic ingression and invasive alien species; and global climate change effects. A set of drivers for the loss of biodiversity is related to agriculture and land management, including the whole spectrum from intensification to the abandonment of traditional land, and wetland management practices.

Mapping the ecological resilience of Atlantic postglacial heathlands.

Anthropogenic heathlands are semi-natural ecosystems with a unique cultural and biodiversity value, considered worthy of preservation across most of the world. Their rate of loss, however, is alarming. Currently, we know little about the heathlands' actual span of resilience affordances and their association with abiotic and anthropogenic factors, including how much additional intervention they need to persist. Consequently, we are missing out on vital knowledge for conservation, management and the historical persistence of heathlands.This paper develops a method to assess the ecological resilience affordances of Atlantic postglacial heaths in the absence of human management. We use 12 existing cases of heathland succession to establish a four-step resilience grade for each site, which we regress onto a series of explaining factors and use it in predicting heath resilience across postglacial Atlantic Northern Europe.We find that temperature, humidity, elevation and sandiness have a positive correlation with high heathland resilience. Our predictive mapping shows an uneven distribution of ecological heath resilience across Atlantic Northern Europe within an area of 1,000 × 1,200 km of 5 × 5 km resolution.Historic heathland distributions far exceed areas that afford high heath resilience, suggesting that heath distribution and persistence depend on both abiotic and anthropogenic factors. Policy implications: The map predicting the ecological resilience of Atlantic postglacial heaths can be used by managers working towards heath preservation and restoration to prioritize conservation efforts and to plan management practices across Atlantic Northern Europe. Together with the predictive model, it provides an important initial screening tool to assess heathland resilience in the absence of management as well as the impact of atmospheric nitrogen. The results are equally relevant for scholars who are interested in humans' role in increasing and decreasing ecosystem resilience. Our predictive method can be applied in other regions across the world by adding regionally specific variables.

Novel Ecosystems in the Urban-Industrial Landscape–Interesting Aspects of Environmental Knowledge Requiring Broadening: A Review

Human activity is affecting and transforming the natural environment, changing the ecosystem mosaic and natural biogeochemical processes in urban-industrial landscapes. Among the anthropogenic ecosystems, there are many present features of Novel Ecosystems (NE), e.g., the de novo created habitats on post-mineral excavation sites. The biological nature of the functional mechanisms of Novel Ecosystems is mostly unknown. In natural and semi-natural ecosystems, biodiversity is considered as the primary element influencing ecosystem processes and functioning. The preliminary studies conducted on post-mineral excavation sites have shown that, in poor oligotrophic habitats, the species composition of the assembled vascular plants is non-analogous, distinctive, and not found in natural and semi-natural habitats. This paper aims to present the gaps between scientific identification of the biological mechanisms driving ecosystem processes and functioning (including the expanding areas of Novel Ecosystems created de novo). Among the identified gaps, the following issues should be listed. The detailed identification and understanding of the processes and biodiversity-dependent functioning of Novel Ecosystems is crucial for proper environmental management, particularly when facing the challenges of ecological constraints and of global change. The ecology of Novel Ecosystems is a social and economic issue because of the relationships with densely populated urban-industrial areas.

Inhibition of Elevated Atmospheric Carbon Dioxide to Soil Gross Nitrogen Mineralization Aggravated by Warming in an Agroecosystem.

The response of soil gross nitrogen (N) cycling to elevated carbon dioxide (CO2) concentration and temperature has been extensively studied in natural and semi-natural ecosystems. However, how these factors and their interaction affect soil gross N dynamics in agroecosystems, strongly disturbed by human activity, remains largely unknown. Here, a 15N tracer study under aerobic incubation was conducted to quantify soil gross N transformation rates in a paddy field exposed to elevated CO2 and/or temperature for 9 years in a warming and free air CO2 enrichment experiment. Results show that long-term exposure to elevated CO2 significantly inhibited or tended to inhibit gross N mineralization at elevated and ambient temperatures, respectively. The inhibition of soil gross N mineralization by elevating CO2 was aggravated by warming in this paddy field. The inhibition of gross N mineralization under elevated CO2 could be due to decreased soil pH. Long-term exposure to elevated CO2 also significantly reduced gross autotrophic nitrification at ambient temperature, probably due to decreased soil pH and gross N mineralization. In contrast, none of the gross N transformation rates were affected by long-term exposure to warming alone. Our study provides strong evidence that long-term dual exposure to elevated CO2 and temperature has a greater negative effect on gross N mineralization rate than the single exposure, potentially resulting in progressive N limitation in this agroecosystem and ultimately increasing demand for N fertilizer.

Arthropod fauna of Thymelaea hirsuta in the Egyptian western desert, with a special reference to Olpium kochi

BackgroundNatural and semi-natural ecosystems in the Egyptian Western Desert are in serious danger of being degraded or lost through overgrazing, and overcutting of dominant vegetation, shrubs and trees and tourism activities. The study shows the effect of Man's use during 1990 and recently in 2018 led to desertification.ResultsThymelaea hirsuta (L.) (Thymelaeceae) was an important component (shrubs) in the natural ecosystems of the Egyptian Western Desert that harbors rich arthropod fauna all the year around. The spiders, pesudocorions (Arachnida: Araneae), and insects associated with this shrub were monthly sampled in 1990 at two different protected sites. One is on a very nice coastal ridge, semi-arid site, and the other is in the inland depression, arid site. The sites had distinctive characteristic of populations of non-insect predatory arthropods responding to habitat characteristics. The insects, spiders and pseudoscorpions occurred throughout the year in both sites. However, on the less arid site, the pronounced insect population occurred in winter months while the non-insect was relatively higher in summer months. On the more arid site, the highest insect population was in winter and the non-insect population was higher in autumn. The false-scorpion Olpium kochi Simon (Arachnida, Pseudoscorpionida, Olpiidae), a native rare predator to the Saharan fauna, was very common and its activity reflects its effective predatory role in both sites. In 2017–2018, several visits to the above sites showed that they were completely degraded and most of figs, olive, palm trees and dominant vegetations were removed. The survived shrub populations were very far from each other, sparse very low number and are very poor in arthropod fauna. Thus, several visits were essential to be paid just to collect enough numbers of O. kochi. The life-cycle of O. kochi is through egg-stage and three nymphal instars. There was no active feeding period by the end of each of these stages. Adults can live for 2–4 months. The developmental period takes 10 to 14 months/generation. Cannibalism tendency was among nymphs, but was very rare among fed or starved adults.ConclusionsThe study sites were seriously degraded with irreversible changes. The nice cost ridge was completely degraded and lost by removing the leading dominant vegetations and fruit trees and replacing building houses. Houses replaced most of the site in the inland depression for more desertification.