Integrating economic and biophysical data in assessing cost-effectiveness of buffer strip placement

The European Union Water Framework Directive (WFD) requires Member States to set water quality objectives and identify cost-effective mitigation measures to achieve "good status" in all waters. However, costs and effectiveness of measures vary both within and between catchments, depending on factors such as land use and topography. The aim of this study was to develop a cost-effectiveness analysis framework for integrating estimates of phosphorus (P) losses from land-based sources, potential abatement using riparian buffers, and the economic implications of buffers. Estimates of field-by-field P exports and routing were based on crop risk and field slope classes. Buffer P trapping efficiencies were based on literature metadata analysis. Costs of placing buffers were based on foregone farm gross margins. An integrated optimization model of cost minimization was developed and solved for different P reduction targets to the Rescobie Loch catchment in eastern Scotland. A target mean annual P load reduction of 376 kg to the loch to achieve good status was identified. Assuming all the riparian fields initially have the 2-m buffer strip required by the General Binding Rules (part of the WFD in Scotland), the model gave good predictions of P loads (345-481 kg P). The modeling results show that riparian buffers alone cannot achieve the required P load reduction (up to 54% P can be removed). In the medium P input scenario, average costs vary from ￡38 to ￡176 kg P at 10% and 54% P reduction, respectively. The framework demonstrates a useful tool for exploring cost-effective targeting of environmental measures.     

A simple model to assess nitrogen and phosphorus contamination in ungauged surface drainage networks: application to the Massaciuccoli Lake Catchment, Italy

Modeling is a common practice to evaluate factors affecting water quality in environmental systems impaired by point and nonpoint losses of N and P. Nevertheless, in situations with inadequate information, such as ungauged basins, a balance between model complexity and data availability is necessary. In this paper, we applied a simplified analytical model to an artificially drained floodplain in central-western Italy to evaluate the importance of different nutrient sources and in-stream retention processes and to identify critical source areas. We first considered only a set of chemical concentrations in water measured from February through May 2008 and from November 2008 through February 2009. We then broadened available data to include water discharge and hydraulic-head measurements to construct a hydrogeological model using MODFLOW-2000 and to evaluate the reliability of the simplified method. The simplified model provided acceptable estimates of discharge (ranging from 0.03-0.75 m s) and diffuse nutrient inputs from water table discharge and in-stream retention phenomena. Estimates of PO-P and total P retention (ranging from 1.0 to 0.6 μg m s and from 1.18 to 0.95 μg m s for PO-P and total P, respectively) were consistent with the range of variability in literature data. In contrast, the higher temporal variability of nitrate concentrations decreased model accuracy, suggesting the need for more intensive monitoring. The model also separated the dynamics of different reaches of the drainage network and identified zones considered critical source areas and buffer zones where pollutant transport is reduced.     

Investigation of an Escherichia coli environmental benchmark for waterborne pathogens in agricultural watersheds in Canada

Canada's National Agri-Environmental Standards Initiative sought to develop an environmental benchmark for low-level waterborne pathogen occurrence in agricultural watersheds. A field study collected 902 water samples from 27 sites in four intensive agricultural watersheds across Canada from 2005 to 2007. Four of the sites were selected as reference sites away from livestock and human fecal pollution sources in each watershed. Water samples were analyzed for Campylobacter spp., Salmonella spp., Escherichia coli O157:H7, Cryptosporidium spp., Giardia spp., and the water quality indicator E. coli. The annual mean number of pathogen species was higher at agricultural sites (1.54 ± 0.07 species per water sample) than at reference sites (0.75 ± 0.14 species per water sample). The annual mean concentration of E. coli was also higher at agricultural sites (491 ± 96 colony-forming units [cfu] 100 mL(-1)) than at reference sites (53 ± 18 cfu 100 mL(-1)). The feasibility of adopting existing E. coli water quality guideline values as an environmental benchmark was assessed, but waterborne pathogens were detected at agricultural sites in 80% of water samples with low E. coli concentrations (<100 cfu 100 mL(-1)). Instead, an approach was developed based on using the natural background occurrence of pathogens at reference sites in agricultural watersheds to derive provisional environmental benchmarks for pathogens at agricultural sites. The environmental benchmarks that were derived were found to represent E. coli values lower than geometric mean values typically found in recreational water quality guidelines. Additional research is needed to investigate environmental benchmarks for waterborne pathogens within the context of the "One World, One Health" perspective for protecting human, domestic animal, and wildlife health.     

Transport and retention of Cryptosporidium parvum oocysts in sandy soils

A series of miscible-displacement experiments was conducted to examine the retention and transport behavior of oocysts in natural porous media. Three soils and a model sand were used that differed in physical and geochemical properties. Transport behavior was examined under various treatment conditions to help evaluate retention mechanisms. Significant retention of oocysts was observed for all media despite the fact that conditions were unfavorable for physicochemical interactions with respect to DLVO theory. The magnitude of retention was not influenced significantly by alterations in solution chemistry (reduction in ionic strength) or soil surface properties (removal of soil organic matter and metal oxides). On the basis of the observed results, it appears that retention by secondary energy minima or geochemical microdomains was minimal for these systems. The porous media used for the experiments exhibited large magnitudes of surface roughness, and it is suggested that this surface roughness contributed significantly to oocyst retention.     

Winter Soil Respiration from Different Vegetation Patches in the Yellow River Delta, China

Vegetation type and density exhibited a considerable patchy distribution at very local scales in the Yellow River Delta, due to the spatial variation of soil salinity and water scarcity. We proposed that soil respiration is affected by the spatial variations in vegetation type and soil chemical properties and tested this hypothesis in three different vegetation patches (Phragmites australis, Suaeda heteroptera and bare soil) in winter (from November 2010 to April 2011). At diurnal scale, soil respiration all displayed single-peak curves and asymmetric patterns in the three vegetation patches; At seasonal scale, soil respiration all declined steadily until February, and then increased to a peak in next April. But, the magnitude of soil respiration showed significant differences among the three sites. Mean soil respiration rates in winter were 0.60, 0.45 and 0.17 μmol CO(2) m(-2) s(-1) for the Phragmites australis, Suaeda heteroptera and bare soil, respectively. The combined effect of soil temperature and soil moisture accounted for 58-68 % of the seasonal variation of winter soil respiration. The mean soil respiration revealed positive and linear correlations with total N, total N and SOC storages at 0-20 cm depth, and plant biomass among the three sites. We conclude that the patchy distribution of plant biomass and soil chemical properties (total C, total N and SOC) may affect decomposition rate of soil organic matter in winter, thereby leading to spatial variations in soil respiration.     

Clonal Re-Introduction of Endangered Plant Species: The Case of German False Tamarisk in Pre-Alpine Rivers

The scope of re-introduction as a measure for plant species protection is increasing, but as long as no standardized methods are available, species-specific assessments are necessary to determine whether seeds, adult plants or plant fragments should be used. The endangered German False Tamarisk (Myricaria germanica), which occurs on gravel bars along pre-alpine rivers, is difficult to grow from seeds. Thus, propagation of stem cuttings was investigated as an alternative method. Experiments were conducted in a greenhouse and a field site with three treatments: cutting length 5 or 10 cm, vertical burial 5 or 10 cm, and water level low or high. Plants grown in the greenhouse were transplanted to the River Isar to test establishment of rooted cuttings on gravel bars. The cuttings in the greenhouse showed high survival (34-96 %). Survival and biomass production were greatest for 10-cm cuttings buried at 10-cm depth, while only one of the 5-cm cuttings survived at this depth, and no significant effect of variation in water level was observed. None of the cuttings transplanted to field sites survived, most likely because of drought stress and competition. We conclude that for re-introduction of Myricaria germanica rooted cuttings can be easily produced in large quantities, while transplantation to near-natural environments has to be improved to reduce mortality.     

Finding Space for Participation: Fisherfolk Mobility and Co-Management of Lake Victoria Fisheries

The literature on fisheries co-management is almost silent on the issue of the movement of fisherfolk within fisheries, although such movement must have implications for the effectiveness of co-management. The introduction of co-management often involves the formation of new structures that should enable the participation of key stakeholder groups in decision-making and management, but such participation is challenging for migrating fishers. The article reports on a study on Lake Victoria, East Africa, which investigated the extent of movement around the lake and the implications of movement for how fishers participate and are represented in co-management, and the implications of the extent and nature of movement for co-management structures and processes. The analysis draws on the concept of space from the literature on participation in development and on a framework of representation in fisheries co-management in addressing these questions. The created space is on an 'invited' rather than open basis, reflecting the top-down nature of implementation and the desire to secure participation of different occupational groups, as well as women in a male-dominated sector. The more powerful boat owners dominate positions of power within the co-management system, particularly as the levels of co-management, from sub-district to national, are traversed. The limited power and resources of boat crew are exacerbated by the degree and nature of movement around the lake, making effective participation in co-management decision-making a challenge.     

Simulating Land-Cover Change in Montane Mainland Southeast Asia

We used the conversion of land use and its effects (CLUE-s) model to simulate scenarios of land-cover change in Montane mainland southeast Asia (MMSEA), a region in the midst of transformation due to rapid intensification of agriculture and expansion of regional trade markets. Simulated changes affected approximately 10 % of the MMSEA landscape between 2001 and 2025 and 16 % between 2001 and 2050. Roughly 9 % of the current vegetation, which consists of native species of trees, shrubs, and grasses, is projected to be replaced by tree plantations, tea, and other evergreen shrubs during the 50 years period. Importantly, 4 % of this transition is expected to be due to the expansion of rubber (Hevea brasiliensis), a tree plantation crop that may have important implications for local-to-regional scale hydrology because of its potentially high water consumption in the dry season.     

Organic Farming Benefits Local Plant Diversity in Vineyard Farms Located in Intensive Agricultural Landscapes

The majority of research on organic farming has considered arable and grassland farming systems in Central and Northern Europe, whilst only a few studies have been carried out in Mediterranean agro-systems, such as vineyards, despite their economic importance. The main aim of the study was to test whether organic farming enhances local plant species richness in both crop and non-crop areas of vineyard farms located in intensive conventional landscapes. Nine conventional and nine organic farms were selected in an intensively cultivated region (i.e. no gradient in landscape composition) in northern Italy. In each farm, vascular plants were sampled in one vineyard and in two non-crop linear habitats, grass strips and hedgerows, adjacent to vineyards and therefore potentially influenced by farming. We used linear mixed models to test the effect of farming, and species longevity (annual vs. perennial) separately for the three habitat types. In our intensive agricultural landscapes organic farming promoted local plant species richness in vineyard fields, and grassland strips while we found no effect for linear hedgerows. Differences in species richness were not associated to differences in species composition, indicating that similar plant communities were hosted in vineyard farms independently of the management type. This negative effect of conventional farming was probably due to the use of herbicides, while mechanical operations and mowing regime did not differ between organic and conventional farms. In grassland strips, and only marginally in vineyards, we found that the positive effect of organic farming was more pronounced for perennial than annual species.     

Farm Crops Depredation by European Bison (Bison bonasus) in the Vicinity of Forest Habitats in Northeastern Poland

European bison, the largest mammal in Europe, after being exterminated in the wild and then restored during the 20th century is still listed by the International Union for Conservation of Nature (IUCN Red List of Threatened Species) as a species vulnerable to extinction. However, the increasing number of European bison, through creation of new and expansion of existing populations strongly increases the risk of human-bison conflict in the near future. We analyzed the depredation of farm crops by bison and the factors influencing the level of damage in the vicinity of two forest areas inhabited by bison in northeastern Poland. Between 2000 and 2010, the total cost of compensation was 196,200. The level of damage and amount of compensation was increasing from year to year in both forests and correlated with the number of bison. The majority of damage (57?% of cases) was recorded in winter (December-March). Snow depth and temperature did not influence the frequency of damage. The incidences of damage increased with decreasing distance from the woodland patches, therefore, 69?% of cases in Bia?owie?a Forest, and 80?% in Knyszyn Forest were recorded closer than 0.5?km from nearest woodland patch. The majority of the crops damaged by bison were cereals (61?%) but also hay (20?%) and rape (13?%). When compared to the availability of crops, bison strongly selected rape and rye in both regions. This study is the first addressing the increasing problem of human-bison conflict in re-introduced populations and analyzing long-term data on crop depredation. Such situations probably occur in the majority of growing and expanding bison populations, however, it has not yet to be monitored and is rather neglected in post-Soviet countries.