The effect of nitrogen deposition on the species richness of acid grasslands in Denmark: a comparison with a study performed on a European scale

The effect of atmospheric nitrogen deposition on the species richness of acid grasslands was investigated by combining data from a large Danish monitoring program with a large European data set, where a significant non-linear negative effect of nitrogen deposition had been demonstrated (Stevens et al., 2010). The nitrogen deposition range in Denmark is relatively small and when only considering the Danish data a non-significant decrease in the species richness with nitrogen deposition was observed. However, when both data sets were combined, then the conclusion of the European survey was further corroborated by the results of the Danish monitoring. Furthermore, by combining the two data sets a more comprehensive picture of the threats to the biodiversity of acid grasslands emerge; i.e., species richness in remnant patches of acid grassland in intensively cultivated agricultural landscapes is under influence not only from nitrogen deposition, but also from current and historical land use.     

Loss of plant species richness and habitat connectivity in grasslands associated with agricultural change in Finland

The drastic loss of seminatural grasslands and the decrease in species diversity in Europe during the 20th century are closely linked to social-economic factors. Development in agricultural production drives land-use changes, and thus controls the capacity of landscapes to maintain biodiversity. In this study, we link agricultural production changes to landscape fragmentation and species diversity. Our results show that the termination of grazing on seminatural grassland caused significant changes in landscape structure and a decline in the number of vascular plant species. The decline of grazed grasslands has been driven mainly by farm-level economic efficiency and profitability interests, which have been connected with agricultural policy measures. Since 1995, when Finland joined the European Union, the area of grazed patches in our study area has again increased as a result of a support scheme for the management of seminatural grasslands.     

The littoral zone in the Three Gorges Reservoir, China: challenges and opportunities

For flood control purpose, the water level of the Three Gorges Reservoir (TGR) varies significantly. The annual reservoir surface elevation amplitude is about 30 m behind the dam. Filling of the reservoir has created about 349 km² of newly flooded riparian zone. The average flooding period lasts for more than 6 months, from mid-October to late April. The dam and its associated reservoir provide flood control, power generation, and navigation, but there are also many environmental challenges. The littoral zone is the important part of the TGR, once its eco-health and stability are damaged,which will directly endanger the ecological safety of the whole reservoir area and even the Yangtze River Basin. So, understanding the great ecological opportunities which are hidden in littoral zone of TGR (LZTGR) and putting forward approaches to solve the environmental problems are very important. LZTGR involves a wide field of problems, such as the landslides, potential water pollution, soil erosion, biodiversity loss, land cover changes, and other issues. The Three Gorges dam (TGD) is a major trigger of environmental change in the Yangtze River. The landslides, water quality, soil erosion, loss of biodiversity, dam operation, and challenge for land use are closely interrelated across spatial and temporal scales. Therefore, the ecological and environmental impacts caused by TGD are necessarily complex and uncertain. LZTGR is not only a great environmental challenge but also an ecological opportunity for us. In fact, LZTGR is an important structural unit of TGR ecosystem and has special ecosystem services function. Vegetation growing in LZTGR is therefore a valuable resource due to accumulation of carbon and nutrients. Everyone thinks that the ecological approach to the problem is needed. If properly designed, dike–pond systems, littoral woods systems, and re-created waterfowl habitats will have the capacity to capture nutrients from uplands and obstruct soil erosion. Ecological engineering approaches can therefore reduce environmental impacts of LZTGR and optimize ecological services. In view of the current situation and existing ecological problems of LZTGR, according to function demands such as environmental purification, biodiversity conservation, and vegetation carbon sink enhancement, we should explore the eco-friendly utilization mode of resources in LZTGR. Ecological engineering approaches might minimize the impacts or optimize the ecological services. Natural regeneration and ecological restoration in LZTGR are valuable for soil erosion decrease, pollutant purification, biodiversity conservation, carbon sink increase, and ecosystem health maintenance in TGR.     

Ecological recovery of vegetation on a coke-factory soil: role of plant antioxidant enzymes and possible implications in site restoration

The present paper investigated the short-term colonization by plants of a highly degraded soil in field conditions. The objectives were to identify, through phytosociological analysis, the plant species able to grow on such polluted areas and to characterize pollutant effects at different biological levels through analyses of plant oxidative status, plant growth or community indexes of richness and biodiversity. Our results showed that among the plants present in the uncontaminated surrounding area, only few species were able to colonize the polluted soil. These species were typical of the first years of grassland successions. Ecological indexes proved that the polluted soil vegetation presented a lower degree of species richness and biodiversity than the control area. These discrepancies were partly explained by pollutant phytotoxicity. Indeed, for several species including Erigeron canadensis and Oenothera biennis, we observed toxic effects of the polluted soil on plant height and biomass. Moreover, at the cellular level, changes in antioxidant enzyme activities (SOD, CAT, APX, GPX and GRD) and lipid peroxidation level (MDA) were observed. Such biochemical changes seemed to play an important role on plant sensitivity/tolerance to pollutants and thus to render them more or less competitive for colonization of such disturbed areas.     

Impacts of eutrophication on diatom life forms and species richness in coastal waters of the Baltic Sea

Increased nutrient and sediment loading can affect the functioning and biodiversity of coastal ecosystems. Lacking long-term monitoring data, paleolimnological techniques enable the estimation of habitat and diversity change through time. Using these methods we assessed the effects of eutrophication on diatom community structure and species richness over the past ca. 200 years in coastal waters of the Gulf of Finland. The abundance of planktonic diatoms has increased markedly because of increased eutrophication and turbidity. The loss of benthic habitats resulted in a clear decrease in diatom species richness after a threshold of 400-600 microg L(-1) total dissolved nitrogen; no unimodal pattern between diversity and productivity was observed in our data. The urban sites displayed a marked decrease in species richness starting in the late 19th century with increased urbanization. A clear recovery was visible after the cessation of point source loading by the mid-1980s at two sites, whereas at the third site no recovery was detected because of diffuse loading from the large catchment. Changes in the rural sites were minor and did not start until the 1940s.     

Differentiating the effects of climate and land use change on European biodiversity: A scenario analysis

Current observed as well as projected changes in biodiversity are the result of multiple interacting factors, with land use and climate change often marked as most important drivers. We aimed to disentangle the separate impacts of these two for sets of vascular plant, bird, butterfly and dragonfly species listed as characteristic for European dry grasslands and wetlands, two habitats of high and threatened biodiversity. We combined articulations of the four frequently used SRES climate scenarios and associated land use change projections for 2030, and assessed their impact on population trends in species (i.e. whether they would probably be declining, stable or increasing). We used the BIOSCORE database tool, which allows assessment of the effects of a range of environmental pressures including climate change as well as land use change. We updated the species lists included in this tool for our two habitat types. We projected species change for two spatial scales: the EU27 covering most of Europe, and the more restricted biogeographic region of ‘Continental Europe’. Other environmental pressures modelled for the four scenarios than land use and climate change generally did not explain a significant part of the variance in species richness change. Changes in characteristic bird and dragonfly species were least pronounced. Land use change was the most important driver for vascular plants in both habitats and spatial scales, leading to a decline in 50–100% of the species included, whereas climate change was more important for wetland dragonflies and birds (40–50 %). Patterns of species decline were similar in continental Europe and the EU27 for wetlands but differed for dry grasslands, where a substantially lower proportion of butterflies and birds declined in continental Europe, and 50 % of bird species increased, probably linked to a projected increase in semi-natural vegetation. In line with the literature using climate envelope models, we found little divergence among the four scenarios. Our findings suggest targeted policies depending on habitat and species group. These are, for dry grasslands, to reduce land use change or its effects and to enhance connectivity, and for wetlands to mitigate climate change effects.     

Spitsbergen landscape under 20th century climate change: Sørkapp Land

A reaction of the European Arctic landscape to a climate change on the scale of a typical middle-sized region is outlined. A wide scope of the methods was used, first of all field mapping and observations. Glaciers are important in the S?rkapp Land landscape because they cover the majority of its territory and undergo quick recessions as a result of the 20th century warming. Glacial recession influence intensively: relief with Quaternary deposits, waters, animals, vegetation and soils. The most important landscape changes in the 20th century are: uplift of the equilibrium line altitude on glaciers by 100-200 m; large glacial recession in both surface and volume; significant decrease of the land area due to recession of tidewater glaciers; lengthening of the coastline, and especially of glacial cliffs; development of the land water network; start of the plant succession in areas abandoned by glaciers. No isostatic uplift has taken place in S?rkapp Land since the Little Ice Age.     

Establishment of reference conditions for nutrients in an intensive agricultural watershed,Eastern China

Nutrient enrichment from nonpoint source pollution is one of the main causes of poor water quality and biotic impairment in many streams and rivers worldwide. The establishment of reference nutrient conditions in a river system is an essential but difficult task for water quality control. In the present study, the reference concentrations of total nitrogen (TN) and total phosphorus (TP) were estimated in an intensive agricultural watershed, the Cao-E River system of Eastern China. Based on a 3-year water quality monitoring data in the river system, three approaches were adopted to establish the reference concentrations of TN and TP, those are the 75th percentile of frequency distribution of nutrient concentrations in reference streams, the 25th percentile of frequency distribution of nutrient concentration in general streams (including reference and non-reference streams) and regression modeling. Results showed that the nutrient reference concentrations were slightly different from different approaches. By the three approaches, the average reference concentrations for TN and TP in the study system were 1.73?±?0.13 mg l^?1 and 55.23?±?4.77 μg l^?1 with CV of 7.39 % and 8.63 %, respectively. Accordingly, the reference concentrations for TN and TP were recommended to be 1.70 mg l^?1 and 55 μg l^?1, respectively. In the mountainous and intensive agricultural watershed, the major anthropogenic impacts to river water quality were the urban area percentage cover, cropland area with slopes 0–8°, and livestock and poultry waste loads density. These variables could account for 89.7 % and 80.3 % of the total variations for TN and TP concentration, respectively.     

Land use influences macroinvertebrate community composition in boreal headwaters through altered stream conditions

Land use is known to alter the nature of land–water interactions, but the potential effects of widespread forest management on headwaters in boreal regions remain poorly understood. We evaluated the importance of catchment land use, land cover, and local stream variables for macroinvertebrate community and functional trait diversity in 18 boreal headwater streams. Variation in macroinvertebrate metrics was often best explained by in-stream variables, primarily water chemistry (e.g. pH). However, variation in stream variables was, in turn, significantly associated with catchment-scale forestry land use. More specifically, streams running through catchments that were dominated by young (11–50 years) forests had higher pH, greater organic matter standing stock, higher abundance of aquatic moss, and the highest macroinvertebrate diversity, compared to streams running through recently clear-cut and old forests. This indicates that catchment-scale forest management can modify in-stream habitat conditions with effects on stream macroinvertebrate communities and that characteristics of younger forests may promote conditions that benefit headwater biodiversity.     

Climate Change and Agricultural Development: Adapting Polish Agriculture to Reduce Future Nutrient Loads in a Coastal Watershed

Currently, there is a major concern about the future of nutrient loads discharged into the Baltic Sea from Polish rivers because they are main contributors to its eutrophication. To date, no watershed-scale studies have properly addressed this issue. This paper fills this gap by using a scenario-modeling framework applied in the Reda watershed, a small (482 km²) agricultural coastal area in northern Poland. We used the SWAT model to quantify the effects of future climate, land cover, and management changes under multiple scenarios up to the 2050s. The combined effect of climate and land use change on N-NO₃ and P-PO₄ loads is an increase by 20–60 and 24–31 %, respectively, depending on the intensity of future agricultural usage. Using a scenario that assumes a major shift toward a more intensive agriculture following the Danish model would bring significantly higher crop yields but cause a great deterioration of water quality. Using vegetative cover in winter and spring (VC) would be a very efficient way to reduce future P-PO₄ loads so that they are lower than levels observed at present. However, even the best combination of measures (VC, buffer zones, reduced fertilization, and constructed wetlands) would not help to remediate heavily increased N-NO₃ loads due to climate change and agricultural intensification.     

Elemental analysis and nutritional value of edible Trifolium (clover) species

Trifolium species, commonly known as clover species, have a cosmopolitan distribution and, as such, are used in many different traditional systems of medicine and consumed by many communities all over the world. In this study, the elemental distribution and nutritional value of five edible Trifolium species, namely, Trifolium africanum, Trifolium burchellianum, Trifolium repens, Trifolium dubium and Trifolium pratense were investigated to evaluate the potential of these plant species to alleviate malnutrition, thereby contributing toward the fight against food insecurity. Trifolium species were found to be a rich alternate source of essential nutrients with concentrations of elements being in decreasing order of Ca > Mg > Fe > Mn > Zn > Se > Cu > Cr > Pb > Ni > Co > Cd > As and with adequate levels of lipids (4.2 to 8.6%), proteins (35.1 to 45.4%) and carbohydrates (26.7 to 47.0%). Trifolium species were found to be rich in Se (contributing greater than 516% toward its RDA) with T. dubium having a concentration of 0.53 mg 10 g^?1, dry mass, which is higher than Brazil nuts. T. pratense was found to be the most suitable species for human consumption due to it having low levels of toxic metals (As, Cd and Pb) while being rich in macro- and micro-elements, especially Fe (7.84 mg 10 g^?1, dry mass) and Se (0.36 mg 10 g^?1, dry mass).     

Improved land cover and emission factors for modeling biogenic volatile organic compounds emissions from Hong Kong

This paper describes a study of local biogenic volatile organic compounds (BVOC) emissions from the Hong Kong Special Administrative Region (HKSAR). An improved land cover and emission factor database was developed to estimate Hong Kong emissions using MEGAN, a BVOC emission model developed by Guenther et al. (2006). Field surveys of plant species composition and laboratory measurements of emission factors were combined with other data to improve existing land cover and emission factor data. The BVOC emissions from Hong Kong were calculated for 12 consecutive years from 1995 to 2006. For the year 2006, the total annual BVOC emissions were determined to be 12,400 metric tons or 9.82 × 10⁹ g C (BVOC carbon). Isoprene emission accounts for 72%, monoterpene emissions account for 8%, and other VOCs emissions account for the remaining 20%. As expected, seasonal variation results in a higher emission in the summer and a lower emission in the winter, with emission predominantly in day time. A high emission of isoprene occurs for regions, such as Lowest Forest-NT North, dominated by broadleaf trees. The spatial variation of total BVOC is similar to the isoprene spatial variation due to its high contribution. The year to year variability in emissions due to weather was small over the twelve-year period (?1.4%, 2006 to 1995 trendline), but an increasing trend in the annual variation due to an increase in forest land cover can be observed (+7%, 2006 to 1995 trendline). The results of this study demonstrate the importance of accurate land cover inputs for biogenic emission models and indicate that land cover change should be considered for these models.     

Feral swine disturbance at important archaeological sites

Feral swine are well known as environmentally destructive invasive animals in many areas around the world, where they degrade native habitats, harm rare plant and animal species, damage agricultural interests, and spread disease. We provide the first quantification of their potential as agents of disturbance at archaeological sites. Our study was conducted in south-central Florida at Avon Park Air Force Range, a base comprising over 40,000 ha and containing many archaeological sites. To determine the identifiable prevalence of feral swine disturbance, we examined 36 sites registered with the Florida State Historic Preservation Office and also eligible for inclusion in the National Register of Historic Places (NRHP). Moreover, we evaluated the extent of swine disturbance at a prehistoric site of extraordinary significance to Florida’s prehistory, “Dead Cow.” Fifteen of the 36 NRHP-eligible sites (42 %) had some level of swine disturbance, including 14 of 30 (47 %) sites known to have artifacts within 20 cm of the surface (well within swine rooting depths). At the Dead Cow site, we documented disturbance at 74 % of shovel test points. Sites with shallow artifact depositions appeared highly vulnerable to disturbance by feral swine, threatening destruction of artifact stratigraphy and provenience. Our observations likely are a minimal representation of accumulated damage. These irreplaceable sites tell the area’s land use story across the millennia. That they are under threat from feral swine should serve broad notice of potential threats that feral swine may pose to archaeological sites globally, making effective swine management imperative for site protection.     

In search for a compromise between biodiversity conservation and human health protection in restoration of fly ash deposits: effect of anti-dust treatments on five groups of arthropods

Recently, fly ash deposits have been revealed as a secondary refuge of critically endangered arthropods specialised on aeolian sands in Central Europe. Simultaneously, these anthropogenic habitats are well known for their negative impact on human health and the surrounding environment. The overwhelming majority of these risks are caused by wind erosion, the substantial decreasing of which is thus necessary. But, any effects of anti-dust treatments on endangered arthropods have never been studied. We surveyed communities of five arthropod groups (wild bees and wasps, leafhoppers, spiders, hoverflies and orthopteroid insects) colonising three fly ash deposits in the western Czech Republic. We focused on two different anti-dust treatments (~70 and 100 % cover of fly ash by barren soil) and their comparison with a control of bare fly ash. Altogether, we recorded 495 species, including 132 nationally threatened species (eight of them were considered to be extinct in the country) and/or 30 species strictly specialised to drift sands. Bees and wasps and leafhoppers contained the overwhelming majority of species of the highest conservation interest; a few other important records were also in spiders and orthopteroids. Total soil cover depleted the unique environment of fly ash and thus destroyed the high conservation potential of the deposits. On the other hand, partial coverage (with ~30 % of bare fly ash) still offered habitats for many of the most threatened species, as we showed by both regression and multivariate analyses, with a decrease of wind erosion. This topic still needs much more research interest, but we consider mosaic-like preservation of smaller spots of fly ash as one of the possible compromises between biodiversity and human health.     

Characterizing Long-Term Land Use/Cover Change in the United States from 1850 to 2000 Using a Nonlinear Bi-analytical Model

We relate the historical (1850–2000) spatial and temporal changes in cropland cover in the conterminous United States to several socio-economic and biophysical determinants using an eco-region based spatial framework. Results show population density as a major determinant during the nineteenth century, and biophysical suitability as the major determinant during the twentieth century. We further examine the role of technological innovations, socio-economic and socio-ecological feedbacks that have either sustained or altered the cropland trajectories in different eco-regions. The cropland trajectories for each of the 84 level-III eco-regions were analyzed using a nonlinear bi-analytical model. In the Eastern United States, low biophysically suitable eco-regions, e.g., New England, have shown continual decline in the cropland after reaching peak levels. The cropland trajectories in high biophysically suitable regions, e.g., Corn Belt, have stabilized after reaching peak levels. In the Western United States, low-intensity crop cover (<10 %) is sustained with irrigation support. A slower rate of land conversion was found in the industrial period. Significant effect of Conservation Reserve Program on planted crop area is found in last two decades (1990–2010).     

Wet deposition of the seeding agent after weather modification activities

Weather modification activities are performed mostly by cloud seeding. Some operational projects have been conducted for more than a half century and cover planetary scales. These activities have led to large amounts of seeding agents being deposited on the ground in precipitation. The main intent of this paper is to identify the spatial pattern of silver iodide deposits after hail suppression. The spatial pattern of silver iodide deposits is determined using the weather modification project measurements from seeding agent reports, two weather radars and 316 launching sites during a 5-year period. The estimated spatial distribution of the deposits is not uniform, with the maximum silver iodide amount located in the southern part of the study area (up to 140 μg m^?2). Our results are comparable with the measurements performed by chemical analyses during other cloud seeding experiments. The maximum location coincides well with that of the maximum seeded hailstorm precipitation frequency. A new method for identifying the spatial pattern of wet-deposited material has been established. The location with the maximum amount is found. This method would be important as a means of placing samplers and monitoring at the representative sites because those are where most weather modification projects would be performed in the future.     

Spontaneous revegetation vs. forestry reclamation in post-mining sand pits

Vegetation development of sites restored by two different methods, spontaneous revegetation and forestry reclamation, was compared in four sand pit mining complexes located in the southern part of the Czech Republic, central Europe. The space-for-time substitution method was applied to collect vegetation records in 13 differently aged and sufficiently large sites with known history. The restoration method, age (time since site abandonment/reclamation), groundwater table, slope, and aspect in all sampled plots were recorded in addition to the visual estimation of percentage cover of all present vascular plant species. Multivariate methods and GLM were used for the data elaboration. Restoration method was the major factor influencing species pattern. Both spontaneously revegetated and forestry reclaimed sites developed towards forest on a comparable timescale. Although the sites did not significantly differ in species richness (160 species in spontaneously revegetated vs. 111 in forestry reclaimed sites), spontaneously revegetated sites tended to be more diverse with more species of conservation potential (10 Red List species in spontaneous sites vs. 4 Red List species in forestry reclaimed sites). These results support the use of spontaneous revegetation as an effective and low-cost method of sand pit restoration and may contribute to implementation of this method in practice.     

Philippine protected areas are not meeting the biodiversity coverage and management effectiveness requirements of Aichi Target 11

Aichi Target 11 of the Convention on Biological Diversity urges, inter alia, that nations protect at least 17 % of their land, and that protection is effective and targets areas of importance for biodiversity. Five years before reporting on Aichi targets is due, we assessed the Philippines’ current protected area system for biodiversity coverage, appropriateness of management regimes and capacity to deliver protection. Although protected estate already covers 11 % of the Philippines’ land area, 64 % of its key biodiversity areas (KBAs) remain unprotected. Few protected areas have appropriate management and governance infrastructures, funding streams, management plans and capacity, and a serious mismatch exists between protected area land zonation regimes and conservation needs of key species. For the Philippines to meet the biodiversity coverage and management effectiveness elements of Aichi Target 11, protected area and KBA boundaries should be aligned, management systems reformed to pursue biodiversity-led targets and effective management capacity created.     

Long-term persistence of seeded grass species: an unwanted side effect of ecological restoration

Spoil heaps are the visible footprint of hydropower production, particularly in vulnerable alpine environments. Speeding up vegetation development by seeding commercial grass species has been a common restoration practice for the last 50 years, but we lack information on whether seeded species decline and allow native plant cover to develop. We visually estimated cover of native vascular plants and five seeded grass species (Agrostis capillaris, Festuca ovina, Festuca rubra, Schedonorus pratensis and Phleum pratense) on eight spoil heaps at different elevations (boreal–alpine zone) in western Norway. Spoil heap vegetation was censused twice (9–20 and 24–36 years after spoil heap construction); the undisturbed surrounding vegetation was also censused on the second occasion. Total cover on the spoil heaps showed some increase, but remained far below that in surrounding areas. Cover of seeded grass species in the surroundings was low (but not negligible), indicating suboptimal establishment ability. Seeded species usually covered less than 20 % of the spoil heaps, and only F. rubra, F. ovina and A. capillaris contributed substantially. Proportional cover indicated better initial establishment by seeded species, but their cover decreased between the censuses on all but the highest located spoil heap. The persistence of seeded grass species is problematic, and despite the decrease in proportional cover, they are likely to persist for decades on spoil heaps, posing a risk of invasion of surrounding areas. We therefore recommend replacing the practice of seeding with more appropriate restoration measures.     

Relating land use patterns to stream nutrient levels in red soil agricultural catchments in subtropical central China

Land use has obvious influence on surface water quality; thus, it is important to understand the effects of land use patterns on surface water quality. This study explored the relationships between land use patterns and stream nutrient levels, including ammonium-N (NH₄ ⁺-N), nitrate-N (NO₃ ^?-N), total N (TN), dissolved P (DP), and total P (TP) concentrations, in one forest and 12 agricultural catchments in subtropical central China. The results indicated that the TN concentrations ranged between 0.90 and 6.50 mg L^?1 and the TP concentrations ranged between 0.08 and 0.53 mg L^?1, showing that moderate nutrient pollution occurred in the catchments. The proportional areal coverages of forests, paddy fields, tea fields, residential areas, and water had distinct effects on stream nutrient levels. Except for the forest, all studied land use types had a potential to increase stream nutrient levels in the catchments. The land use pattern indices at the landscape level were significantly correlated to N nutrients but rarely correlated to P nutrients in stream water, whereas the influence of the land use pattern indices at the class level on stream water quality differentiated among the land use types and nutrient species. Multiple regression analysis suggested that land use pattern indices at the class level, including patch density (PD), largest patch index (LPI), mean shape index (SHMN), and mean Euclidian nearest neighbor distance (ENNMN), played an intrinsic role in influencing stream nutrient quality, and these four indices explained 35.08 % of the variability of stream nutrient levels in the catchments (p<0.001). Therefore, this research provides useful ideas and insights for land use planners and managers interested in controlling stream nutrient pollution in subtropical central China.