Agricultural Conversion Research Articles

Changes in vegetation persistence across global savanna landscapes, 1982–2010

We present a global analysis of the changing face of vegetation persistence in savanna ecosystems by boreal seasons. We utilized nearly 30 years of monthly normalized difference vegetation index data in an innovative time-series approach and developed associated statistical significance tests, making the application of continuous vegetation metrics both more rigorous and more useful to research. We found that 8,000,000–11,000,000 km2 of savanna have experienced significant vegetation decline during each season, while 20,000,000–23,000,000 km2 have experienced an increase in vegetation persistence during each season, relative to the baseline period (1982–1985). In addition, with the exception of the March–April–May season, which is mixed, the pattern of significant vegetation persistence in the Northern Hemisphere is almost exclusively positive, while it is negative in the Southern Hemisphere. This finding highlights the increasing vulnerability of the Southern Hemisphere savanna landscapes; either resulting from changing precipitation regimes (e.g., southern Africa) or agricultural pressures and conversions (e.g., South America).

The Dynamics, Ecological Variability and Estimated Carbon Stocks of Mangroves in Mahajamba Bay, Madagascar

Mangroves are found throughout the tropics, providing critical ecosystem goods and services to coastal communities and supporting rich biodiversity. Globally, mangroves are being rapidly degraded and deforested at rates exceeding loss in many tropical inland forests. Madagascar contains around 2% of the global distribution, >20% of which has been deforested since 1990, primarily from over-harvest for forest products and conversion for agriculture and aquaculture. While historically not prominent, mangrove loss in Madagascar’s Mahajamba Bay is increasing. Here, we focus on Mahajamba Bay, presenting long-term dynamics calculated using United States Geological Survey (USGS) national-level mangrove maps contextualized with socio-economic research and ground observations, and the results of contemporary (circa 2011) mapping of dominant mangrove types. The analysis of the USGS data indicated 1050 hectares (3.8%) lost from 2000 to 2010, which socio-economic research suggests is increasingly driven by commercial timber extraction. Contemporary mapping results permitted stratified sampling based on spectrally distinct and ecologically meaningful mangrove types, allowing for the first-ever vegetation carbon stock estimates for Mahajamba Bay. The overall mean carbon stock across all mangrove classes was estimated to be 100.97 ± 10.49 Mg C ha−1. High stature closed-canopy mangroves had the highest average carbon stock estimate (i.e., 166.82 ± 15.28 Mg C ha−1). These estimates are comparable to other published values in Madagascar and elsewhere in the Western Indian Ocean and demonstrate the ecological variability of Mahajamba Bay’s mangroves and their value towards climate change mitigation.

The Effects of Restoration Age and Prescribed Burns on Grassland Ant Community Structure.

North American grassland environments are endangered as a result of degradation and conversion for agriculture and housing. Efforts to manage and restore grasslands have traditionally focused on monitoring plant communities to determine restoration success, but the incorporation of animal communities may provide important benchmarks of ecosystem function and restoration. Ants play many roles in maintaining ecosystem health in temperate grasslands, but relatively little is known about how ant communities respond to restoration. We studied the role that restoration age and prescribed burns have on ant communities in two types of Illinois grasslands, prairies and savannas, and identify indicator species of restoration success. Grassland environments included remnants and restorations that varied in age from newly restored sites, to sites that have been under restoration for >15 yr. We demonstrate that prairie and savanna ant communities are distinct, but respond to restoration in a similar manner. Three distinct prairie ant assemblages were identified based on the age of restoration of a site-sites <3 yr old, sites that have been under restoration >5 yr, and remnant prairies. Four distinct savanna ant assemblages were identified based on the age of restoration of a site-sites <3 yr old, sites 5-15 yr old, sites >15 yr old, and remnant savanna environments. After accounting for restoration age, time since last burn in both prairie and savannas does not explain community composition or species richness. Several ant species in both prairies and savannas have predictable changes in incidence that indicate their suitability for use as indicator species.

The effects of forest conversion to oil palm on ground‐foraging ant communities depend on beta diversity and sampling grain

Beta diversity – the variation in species composition among spatially discrete communities – and sampling grain – the size of samples being compared – may alter our perspectives of diversity within and between landscapes before and after agricultural conversion. Such assumptions are usually based on point comparisons, which do not accurately capture actual differences in total diversity. Beta diversity is often not rigorously examined. We investigated the beta diversity of ground-foraging ant communities in fragmented oil palm and forest landscapes in Sabah, Malaysia, using diversity metrics transformed from Hill number equivalents to remove dependences on alpha diversity. We compared the beta diversities of oil palm and forest, across three hierarchically nested sampling grains. We found that oil palm and forest communities had a greater percentage of total shared species when larger samples were compared. Across all grains and disregarding relative abundances, there was higher beta diversity of all species among forest communities. However, there were higher beta diversities of common and very abundant (dominant) species in oil palm as compared to forests. Differences in beta diversities between oil palm and forest were greatest at the largest sampling grain. Larger sampling grains in oil palm may generate bigger species pools, increasing the probability of shared species with forest samples. Greater beta diversity of all species in forest may be attributed to rare species. Oil palm communities may be more heterogeneous in common and dominant species because of variable community assembly events. Rare and also common species are better captured at larger grains, boosting differences in beta diversity between larger samples of forest and oil palm communities. Although agricultural landscapes support a lower total diversity than natural forests, diversity especially of abundant species is still important for maintaining ecosystem stability. Diversity in agricultural landscapes may be greater than expected when beta diversity is accounted for at large spatial scales.

Scenario-based land cover change modeling and its implications for landscape pattern analysis in the Neka Watershed, Iran

Land cover changes and urbanization cause destruction of natural habitats and threaten biodiversity. Land cover modeling is one of the most important procedures for evaluating this trend. This study was performed with the objective of comparing multi-layer perceptron (MLP) artificial neural network with logistic regression (LR) in predicting land cover change and quantifying future landscape change using landscape metrics in the Neka River Basin, a small part of the eastern Hyrcanian forest, in northern Iran. For this purpose, first, change analysis was carried out using satellite imagery, from 1987 to 2011. Then, transition potential modeling was conducted using MLP and LR in 5 different scenarios. A Relative Operating Characteristic (ROC) analysis was carried out to detect the degree of correlation between variables and transitions in LR. In addition, the accuracy rate for assessing the transition potential modeling using MLP was employed. Land cover change prediction was conducted using prediction for 2011 and 2017. The accuracy assessment model was determined by comparing the actual land cover map of 2011 with the predicted land cover map of 2011. Landscape indices for 1987, 2001, 2006, 2011, and 2017 were calculated and analyzed using Fragstats to determine the impact of land cover change on landscape fragmentation. The result showed that during 1987–2001, agriculture was the main contributor to the increased built-up area. The most important transition was the conversion of agriculture to orchard and residential, between 2001 and 2006. Forest regenerated from orchard and agricultural lands, between 2006 and 2011. The maximum and minimum amounts of Cramer's V were obtained for the empirical likelihood to change variable and distance from the river. Overall kappa obtained in the best scenario based on LR was 88%. Furthermore, the prediction results showed that major deforestation will occur in surrounding forest areas and most residential development is in the outskirts of the town of Neka. Increased fragmentation in the landscape will continue in 2017, more shape complexity will be observed, and habitats of the Neka Basin will become more diverse and abundant. The results of this study provide useful information for Reducing Emission from Deforestation and Forest Degradation (REDD) project.

An International Union for Conservation of Nature risk assessment of coastal lowland rainforests of the Wet Tropics Bioregion, Queensland, Australia

AbstractLowland rainforest communities are among the most threatened across South‐east Asia as a result of ease of access, suitability for agriculture and proximity to population centres along the coast and to ports for export of timber, minerals and agricultural produce. In Australia, coastal lowland rainforest occupies a narrow band between the marine‐influenced littoral communities and the forests of the coastal ranges and uplands in the Wet Tropics Bioregion of north‐east Queensland. As the coastal lowlands were already highly fragmented, and subject to ongoing conversion for agriculture and urbanization, they were excluded from the World Heritage listing of the Wet Tropics of Queensland in 1988. Littoral rainforest and broad‐leaved tea‐tree swamps in the coastal zone have both recently been protected under Commonwealth environmental protection legislation; meanwhile, the remnant coastal lowland rainforest faces continued threats from extreme events, climate change, land management activities and introduced species. In a risk assessment based on IUCN guidelines, coastal lowland rainforest was assessed as endangered due to restricted distribution (full extent of the community encompassed by a minimum complex polygon less than 20 000 km2) in conjunction with qualitative evidence of disruption to biotic interactions. A second criterion related to the historic decline in geographic distribution (60% decline in distribution since 1750) would correspond to a condition of vulnerable. Coastal lowland rainforest on alluvial soils has been particularly impacted, and a 75% decline in distribution since 1760 would correspond to a condition of endangered for this subtype. We had insufficient data to address the remaining IUCN Red List criteria for ecosystems, but point to published studies which address these criteria at the subregional level, and make suggestions for future data collection, monitoring and analyses which may support future reviews or proposals for enhanced protection within an Australian legislative context.

Twenty‐five years of change in southern African passerine diversity: nonclimatic factors of change

We analysed more than 25 years of change in passerine bird distribution in South Africa, Swaziland and Lesotho, to show that species distributions can be influenced by processes that are at least in part independent of the local strength and direction of climate change: land use and ecological succession. We used occupancy models that separate species' detection from species' occupancy probability, fitted to citizen science data from both phases of the Southern African Bird Atlas Project (1987-1996 and 2007-2013). Temporal trends in species' occupancy probability were interpreted in terms of local extinction/colonization, and temporal trends in detection probability were interpreted in terms of change in abundance. We found for the first time at this scale that, as predicted in the context of bush encroachment, closed-savannah specialists increased where open-savannah specialists decreased. In addition, the trend in the abundance of species a priori thought to be favoured by agricultural conversion was negatively correlated with human population density, which is in line with hypotheses explaining the decline in farmland birds in the Northern Hemisphere. In addition to climate, vegetation cover and the intensity and time since agricultural conversion constitute important predictors of biodiversity changes in the region. Their inclusion will improve the reliability of predictive models of species distribution.

Increasing Demand for Natural Rubber Necessitates a Robust Sustainability Initiative to Mitigate Impacts on Tropical Biodiversity

Strong international demand for natural rubber is driving expansion of industrial-scale and smallholder monoculture plantations, with >2 million ha established during the last decade. Mainland Southeast Asia and Southwest China represent the epicenter of rapid rubber expansion; here we review impacts on forest ecosystems and biodiversity. We estimate that 4.3–8.5 million ha of additional rubber plantations are required to meet projected demand by 2024, threatening significant areas of Asian forest, including many protected areas. Uncertainties concern the potential for yield intensification of existing cultivation to mitigate demand for new rubber area, versus potential displacement of rubber by more profitable oil palm. Our review of available studies indicates that conversion of forests or swidden agriculture to monoculture rubber negatively impacts bird, bat and invertebrate biodiversity. However, rubber agroforests in some areas of Southeast Asia support a subset of forest biodiversity in landscapes that retain little natural forest. Work is urgently needed to: improve understanding of whether land-sparing or land-sharing rubber cultivation will best serve biodiversity conservation, investigate the potential to accommodate biodiversity within existing rubber-dominated landscapes while maintaining yields, and ensure rigorous biodiversity and social standards via the development of a sustainability initiative.

Response of avian diversity to habitat modification can be predicted from life-history traits and ecological attributes

Habitat conversion for agriculture is a major driver of global biodiversity loss, partly because of homogeneity within agri-ecosystems. Anthropogenic landscapes can also increase habitat heterogeneity and primary productivity, however, augmenting regional biodiversity, as species that exploit resources associated with human activities expand their ranges into novel ecological regions. We used birds as a model in the Kruger to Canyons Biosphere, South Africa, to ask whether agriculture can add habitat components and bird species complementary to those already present, and whether habitat variables and bird functional traits can be used to identify bird species most likely to respond to such habitat changes. We surveyed birds and measured habitat structure in 150 fixed-radius point counts each in natural habitat and mango orchards, and assessed relationships between habitat variables and bird functional traits. Despite mango orchards having greater vertical height structure because of tall (average 20 m) Casuarina windbreaks, they were missing the low-scrub (1–2 m woody cover) component of natural vegetation. We found that species whose life-history traits and ecological attributes were associated with structures missing from mango orchards were correspondingly absent from the orchards, which translated into the exclusion of 35 % of the bird species; bird assemblages within mango orchards were only a subset of those found in natural habitat. These findings suggest that knowledge of habitat structure, along with species’ functional traits can provide a predictive framework for effects that anthropogenic habitats may have on regional biodiversity, and allow management to reduce negative effects.

Agricultural conversion of floodplain ecosystems: Implications for groundwater quality

With current trends of converting grasslands to row crop agriculture in vulnerable areas, there is a critical need to evaluate the effects of land use on groundwater quality in large river floodplain systems. In this study, groundwater hydrology and nutrient dynamics associated with three land cover types (grassland, floodplain forest and cropland) were assessed at the Cedar River floodplain in southeastern Iowa. The cropland site consisted of newly-converted grassland, done specifically for our study. Our objectives were to evaluate spatial and temporal variations in groundwater hydrology and quality, and quantify changes in groundwater quality following land conversion from grassland to row crop in a floodplain. We installed five shallow and one deep monitoring wells in each of the three land cover types and recorded water levels and quality over a three year period. Crop rotations included soybeans in year 1, corn in year 2 and fallow with cover crops during year 3 due to river flooding. Water table levels behaved nearly identically among the sites but during the second and third years of our study, NO3–N concentrations in shallow floodplain groundwater beneath the cropped site increased from 0.5 mg/l to more than 25 mg/l (maximum of 70 mg/l). The increase in concentration was primarily associated with application of liquid N during June of the second year (corn rotation), although site flooding may have exacerbated NO3–N leaching. Geophysical investigation revealed differences in ground conductivity among the land cover sites that related significantly to variations in groundwater quality. Study results provide much-needed information on the effects of different land covers on floodplain groundwater and point to challenges ahead for meeting nutrient reduction goals if row crop land use expands into floodplains.

Weather Constrains the Influence of Fire and Grazing on Nesting Greater Prairie-Chickens

Grasslands are highly imperiled as a result of widespread conversion for agriculture and alteration from human development. Remaining grasslands are susceptible to mismanagement, development and fragmentation, and variable weather associated with global climate change. Understanding the response of declining grassland species to these challenges will be important for informed conservation and management. We assessed Greater Prairie-Chicken (Tympanuchus cupido) survival and nest site selection in tallgrass prairie characterized by interacting fire and grazing disturbance and oil and gas infrastructure. We found that Greater Prairie-Chicken survival was most affected by weather variability (expressed in our models as solar radiation) while most other variables had little influence. Focal disturbance did not affect survival directly, but vegetation height, which is greatly influenced by fire and grazing processes, was positively associated with nest survival. Greater Prairie-Chickens chose nesting locations that maximized time post fire while minimizing tree cover and distance to leks. Future conservation efforts for Greater Prairie-Chickens should focus on variable fire regimens that create areas of residual biomass to increase vegetation height and potentially reduce the effects of solar radiation while decreasing woody vegetation that is avoided by nesting females. However, even the best management practices may prove to be futile in the southern Great Plains if climate change continues to create unfavorable nest survival conditions. Management that creates and maintains suitable nesting sites through the use of interacting fire and grazing should maximize the potential for high reproduction in years when local weather variables are favorable.

Woody Plant-Cover Dynamics in Argentine Savannas from the 1880s to 2000s: The Interplay of Encroachment and Agriculture Conversion at Varying Scales

Woody plant-cover dynamics can alter the provisioning of ecosystem services that humans rely on. However, our understanding of such dynamics today is often limited by the availability of reliable and detailed land-cover information in the past, before the onset of remote sensing technologies. In this study, we carefully extracted information from historical maps of the Caldenal savannas of central Argentina in the 1880s to generate a woody cover map that we compared to a 2000s dataset. Over about the last 120 years, woody cover increased across approximately 12,200 km2 (14.2% of the area). During the same period, about 5,000 km2 of the original woody area was converted to croplands and around 7,000 km2 to pastures, about the same total land area as was affected by encroachment. A smaller area, fine-scale analysis between the 1960s and the 2000s revealed that tree cover increased overall by 27%, shifting from open savannas to a mosaic of dense woodlands along with additional agricultural clearings. Statistical models indicate that woody cover dynamics in this region were affected by a combination of environmental and human factors. Over about the last 120 years, increases in woody plant cover have stored significant amounts of C (95.9 TgC), but not enough to compensate for losses from conversions to croplands and pastures (166.7 TgC), generating a regional net loss of 70.9 TgC. C losses could be even larger in the future if, as predicted, energy crops such as switchgrass, would trigger a new land-cover change phase in this region.

Migratory bird species benefit from traditional agricultural gardens in arid South Sinai

In temperate and tropical regions agricultural conversion of natural habitat typically has negative impacts upon the diversity and functional complexity of bird communities. In arid environments however, the irrigation associated with agricultural can lead to an increase in local abundances of plant and insect resources, so has the potential to benefit bird communities. South Sinai is a key migratory corridor for many birds making the annual journey from wintering sites in Africa to breeding sites in Europe. We assess the importance of traditional Bedouin agricultural gardens for both resident and migratory species by comparing the density and functional composition of birds within the irrigated gardens to those in the unmanaged desert habitat. Estimated bird densities were significantly higher within the gardens than the unmanaged habitat, with a higher estimated species richness within the gardens. Functional composition of bird communities differed between the two habitats, with gardens supporting a higher proportion of insectivorous and migratory birds in addition to the resident desert species that were associated with the unmanaged habitat. Migratory species were almost entirely absent from the unmanaged habitat, suggesting that this region may not be used as a migratory stop-off if not for the presence of traditional agricultural gardens.

Human health risk assessment of soil dioxin/furans contamination and dioxin-like activity determined by ethoxyresorufin-O-deethylase bioassay.

The major objective of this study was to evaluate the human health risks of agricultural land use conversion to other purposes in Hong Kong, based on the levels of polychlorinated dibenzo-p-dioxin and polychlorinated dibenzofuran (PCDD/Fs) and determined dioxin-like activity in soil using ethoxyresorufin-O-deethylase (EROD) bioassay. Hazard quotient showed soils of open burning site (OBS) and electronic waste open burning site (EW (OBS)) exert a relatively higher non-cancer risk on adults (50.9 and 8.00) and children (407 and 64.0) via the pathway of accidental ingestion of soil particles than other types of land use. In addition, the levels of 17 PCDD/Fs congeners in OBS and EW (OBS) soils indicated high and moderate (1654 and 260 in one million people) cancer risks through the above pathway. Furthermore, the biologically derived TCDD concentrations (TEQbio) were also significantly correlated to the chemically derived toxic equivalent concentrations of dioxin-like chemicals (TEQcal (sum of chemically derived 2,3,7,8-TeCDD toxic equivalent concentrations (TEQPCDD/F) and chemically derived dioxin-like PAHs toxic equivalent concentrations (TEQPAH)) (r = 0.770, p <0.05). PCDD/Fs (95.4 to 99.9%) were the major stressor to the TEQcal in the soil samples, indicating higher concentrations of PCDD/Fs derived from chemical analyses may reflect a higher potency of inducing EROD activity.

Aboveground Forest Biomass and Litter Production Patterns in Atlantic White Cedar Swamps of Differing Hydroperiods

Ecosystems dominated by Chamaecyparis thyoides (Atlantic White Cedar) are critically endangered due to hydrologic alterations associated with ditching, logging, development, and agricultural conversion. Few studies have related structural and functional characteristics of this plant community to water tables, yet hydrologic management options may be critical to establish a peat-based seed refugium and allow Atlantic White Cedar self-maintenance in this ecosystem. In this study, we assessed aboveground forest biomass, litter production, and depth to water table at a mature (60–70 y) and an intermediate (20–35 y) age-class stand in two national wildlife refuges, Alligator River (AR) and Great Dismal Swamp (DS) in North Carolina. We calculated forest biomass from morphometric data gathered within randomized study plots. We made monthly litter collections at each study plot from November 1998 to April 2000; litter was sorted by species and type for the first 12 months. Wells installed at each study plot recorded water-table levels, which were at or near the surface at AR but >30 cm below the soil surface at DS throughout the study. Although Atlantic White Cedar was a dominant species at all sites, community structure differed between refuges. Total aboveground biomass was similar among age classes; however, Atlantic White Cedar stem density was greater and mean diameter at breast height was lower at AR. Mean annual litter production was higher at AR sites for each age class despite a persistently high water table. We conclude that the rates of primary production associated with high water tables at AR represent favorable conditions for Atlantic White Cedar self-maintenance.

Contrasting vulnerability of drained tropical and high‐latitude peatlands to fluvial loss of stored carbon

AbstractCarbon sequestration and storage in peatlands rely on consistently high water tables. Anthropogenic pressures including drainage, burning, land conversion for agriculture, timber, and biofuel production, cause loss of pressures including drainage, burning, land conversion for agriculture, timber, and biofuel production, cause loss of peat‐forming vegetation and exposure of previously anaerobic peat to aerobic decomposition. This can shift peatlands from net CO2 sinks to large CO2 sources, releasing carbon held for millennia. Peatlands also export significant quantities of carbon via fluvial pathways, mainly as dissolved organic carbon (DOC). We analyzed radiocarbon (14C) levels of DOC in drainage water from multiple peatlands in Europe and Southeast Asia, to infer differences in the age of carbon lost from intact and drained systems. In most cases, drainage led to increased release of older carbon from the peat profile but with marked differences related to peat type. Very low DOC‐14C levels in runoff from drained tropical peatlands indicate loss of very old (centuries to millennia) stored peat carbon. High‐latitude peatlands appear more resilient to drainage; 14C measurements from UK blanket bogs suggest that exported DOC remains young (&lt;50 years) despite drainage. Boreal and temperate fens and raised bogs in Finland and the Czech Republic showed intermediate sensitivity. We attribute observed differences to physical and climatic differences between peatlands, in particular, hydraulic conductivity and temperature, as well as the extent of disturbance associated with drainage, notably land use changes in the tropics. Data from the UK Peak District, an area where air pollution and intensive land management have triggered Sphagnum loss and peat erosion, suggest that additional anthropogenic pressures may trigger fluvial loss of much older (&gt;500 year) carbon in high‐latitude systems. Rewetting at least partially offsets drainage effects on DOC age.

LCA Study of Oleaginous Bioenergy Chains in a Mediterranean Environment

This paper reports outcomes of life cycle assessments (LCAs) of three different oleaginous bioenergy chains (oilseed rape, Ethiopian mustard and cardoon) under Southern Europe conditions. Accurate data on field practices previously collected during a three-year study at two sites were used. The vegetable oil produced by oleaginous seeds was used for power generation in medium-speed diesel engines while the crop residues were used in steam power plants. For each bioenergy chain, the environmental impact related to cultivation, transportation of agricultural products and industrial conversion for power generation was evaluated by calculating cumulative energy demand, acidification potential and global warming potential. For all three bioenergy chains, the results of the LCA study show a considerable saving of primary energy (from 70 to 86 GJ·ha−1) and greenhouse gas emissions (from 4.1 to 5.2 t CO2·ha−1) in comparison to power generation from fossil fuels, although the acidification potential of these bioenergy chains may be twice that of conventional power generation. In addition, the study highlights that land use changes due to the cultivation of the abovementioned crops reduce soil organic content and therefore worsen and increase greenhouse gas emissions for all three bioenergy chains. The study also demonstrates that the exploitation of crop residues for energy production greatly contributes to managing environmental impact of the three bioenergy chains.

Current and future economic performance of first and second generation biofuels in developing countries

Net Present Value (NPV) and total production cost calculations are made for first and second generation biofuels in 74 settings, covering 5 fuel output types, 8 feedstock types, 12 countries and 8 combinations of agricultural management systems between 2010 and 2030. Yields are assumed to increase due to better crop management and improved varieties. High NPVs (meaning profitable production) are calculated for cassava (up to 16,000$/ha) and palm production (up to almost 7000$/ha). But cassava can also have a negative NPV which indicates that the project investment is not without risk. The calculated NPVs for jatropha range from −900 to 2000$/ha, while for sugarcane and soy the NPV is always positive, (2500–5000$/ha and 200–3000$/ha respectively) and therefore profitable. Total production costs in 2010 are estimated to vary from 5 to 45$/GJ for 1st generation feedstocks in 2010, and from around 10–35$/GJ in 2020, compared to 20–30$/GJ for fossil fuels. Argentina and Malaysia are the regions with the lowest production costs for biofuel (soy and palm biodiesel for 11–15$/GJ and 8–23$/GJ respectively), although potential for cost reduction exists in other regions. Production costs of 2nd generation biofuels are estimated to be 17–26$/GJ in 2020 and 14–23$/GJ in 2030. Poplar based synfuel production in Ukraine has the lowest costs (14–17$/GJ) and rice straw based bioethanol the highest (23–26$/GJ) – for both the short and long term. The time between investment and benefits, as well as the size of investment and the alternative commodity markets, varies with the type of feedstock. The choice of feedstock therefore depends on the local agricultural system, and the preferences and means of the local farmers. Key to the competitive production of 2nd generation fuels is the optimisation of the conversion process, which dominates overall production costs (with 35–65% of total costs). Also important is the efficient organisation of supply chain logistics, especially for the low energy density feedstocks such as wheat straw – requires densification early in the chain. Key factors in the economic analysis are: labour costs and requirements, agricultural efficiency, conversion cost and biomass yields. Acquiring accurate location specific data is essential for detailed analyses.

Habitat Selection by White Storks Breeding in a Mosaic Agricultural Landscape of Central Poland

ABSTRACT The number of White Storks (Ciconia ciconia) has been decreasing in many parts of Europe at least since the middle of the 20th century. Intensification of agriculture and continuous conversion of natural habitats, such as wetlands, into agricultural landscapes have been recognized as the most important determinants of dramatic reductions in population sizes of this species. For this reason, providing quantitative estimates of habitat requirements may allow us to identify the key biota which should be prioritized for conservation. The aim of this study was to investigate White Storks' habitat selection in a mosaic agricultural landscape in central Poland. We found that territories associated with large river valleys were highly preferred by first-arriving storks. We also recorded lower intensity of brood reduction and higher reproductive success of storks breeding in such territories. Thus, it seems likely that location of nests close to river valleys provided easy access to rich food resources as...

Silver nanoparticle/PDMS nanocomposite catalytic membranes for H2S gas removal

The removal of H2S gas molecules from an environment with other gas species is an important technological challenge for a number of applications. In this work, we developed a nanocomposite catalytic membrane made of polydimethylsiloxane (PDMS) with different weight concentrations of silver (Ag) nanoparticles to reactively remove H2S from CH4 and CO2 gas streams. PDMS was chosen as a model base polymer as Ag nanoparticles could be well dispersed into its matrix. At a small Ag nanoparticles loading of 1%, the catalytic membranes were able to remove more than 60% of H2S gas molecules. The characterization revealed that the exposure to H2S gas molecules transformed the Ag nanoparticles into a catalytic nanocompound made of Ag and Ag2S. The nanocompound then catalytically decomposed H2S, while it had much smaller effect on CO2 and almost no effect on CH4 gas species. The presented nanocomposite system demonstrates the ability to efficiently remove H2S from mixed gas streams and offers a plethora of environmental, agricultural, biotechnology and energy conversion applications.