Agricultural land use and Skylark Alauda arvensis: a case study linking a habitat association model to spatially explicit change scenarios

We present the results of spring and winter surveys of birds using 22 willow short‐rotation coppice (SRC) fields and 22 paired arable or grassland controls over a 5 year period in central and northern England. The study sites were linked to the first commercial wood‐fuelled electricity plant in Yorkshire and were managed commercially. We use the findings of this study, in the context of other work on birds in energy crops, to suggest how birds may be affected by commercial cropping of SRC or energy grasses on UK farmland. For willow SRC, most existing farmland species were not completely displaced by SRC cropping. Even farmland specialists such as Skylark Alauda arvensis used cut SRC fields. Some species characteristic of scrub and wood‐type habitats were attracted onto farmland by SRC. Birds were more abundant in hedgerows next to SRC than in those adjoining arable or grass. The interior of large SRC plots contained fewer birds than the edge‐zone (< 50 m). In winter, the same resident species occured in SRC as the summer, plus winter migrants such as Snipe Gallinago gallinago and Fieldfare Turdus pilaris. Overall, more individuals and species were recorded in and around SRC than equivalent arable or grassland throughout the year. Yellow Wagtail Motacilla flava and certain locally occurring farmland specialists may be displaced by SRC plantations. Equivalent census data for energy grasses in the UK are not available. The impact of large regional energy crop developments on birds is not known. We do not know if species commonly recorded in these crops survive and breed well so population effects are unknown. However SRC crops are often weedy and insect rich and hence have potential as foraging habitats in summer and winter. The scope for agri‐environment schemes to include energy crops is discussed.

The purpose of this paper is to identify the potential changes in agricultural land use in Poland as a consequence of implementing the European Green Deal, including its potential economic effects. The study covered crops of key importance to Polish agriculture, cultivated in a total area of 8.2 million ha, which accounts for more than 60% of land in good agricultural condition. The analyses were based on average values for 2016–2020 and used three scenarios for EGD implementation by 2030 (no EGD; partial implementation of the EGD; full implementation of the EGD). Each analysis took account of changes in the area of land under conventional, organic and precision farming systems. The study found that EGD requirements can be met by implementing the precision farming system, especially for intensive farming schemes like rape and sugar beet. Organic farming should be used either for extensively farmed cereals like oat or for fruits which are sold at higher prices when farmed organically. Another finding is that the full implementation of the EGD could decrease the production volume of key Polish crops by 13%, which can have important social impacts, such as increased prices of food products or a deterioration of food security.

The rich biodiversity of the Central European farmland is to a large extent directly dependent on human management decisions. Diverse and dynamic biocoenoses have developed in mutual interactions with farming practices, and have been an integral part of agricultural land ever since the Neolithic. In the middle of the 20th century, when synthetic biocides, mineral fertilisers and more powerful machinery became widely available, an unprecedented, steady and rapid erosion of farmland biodiversity commenced. Despite political declarations of intentions to slow biodiversity loss, pressure on farmland biodiversity has been further increasing in recent years. In the face of climate change and to reduce the dependency on limited fossil fuels, the subsidy-driven bioenergy boom is increasing the demand for arable land to cultivate the required feedstocks. Only few scientific publications have yet addressed the consequences of the rapid expansion of energy cropping on farmland plant diversity. This thesis aimed to contribute to filling this gap, by recording the habitat conditions (field management, light regime, soil chemical properties) and the plant diversity in different energy cropping systems (maize for anaerobic digestion, oilseed rape for biodiesel and poplar/willow short rotation coppices (SRC) for wood chip combustion). Subsequently, the energy cropping systems were compared to conventionally managed food/fodder crops (winter-sown wheat and barley) and to winter cereal fields managed extensively according to an agri-environmental scheme (AES). The results show clearly that the underlying root causes of the strong decline in arable plant diversity extent far beyond energy cropping. We found the arable plant assemblages in the field interior to be extremely impoverished in energy maize and oilseed rape fields as well as in conventionally managed winter-sown wheat or barley (on average 3–6 species 100 m-²). The mean nitrogen fertilisation rate (195 kg N ha-1 yr-1) and herbicide use intensity (HI = 1.8) were shown to be similarly high for maize and winter wheat. Excessive phosphorus fertilisation (on average 96 kg P2O5 ha-1 yr-1) was, however, discerned as a threat to plant diversity which mainly applies to maize production. Maize was also found to be more shading (11% PAR transmissivity vs. 19% in winter cereals) and consequently less species rich at the field margins than winter cereals (11 and 15 species 100 m-2 respectively). Across study regions, the arable plant communities of conventionally managed fields were typically dominated by the same set of only 5–10 common weedy species. We found (summer-sown) maize stands to offer habitats to a slightly different set of arable plant species than fields cultivated with winter-sown crops. A balanced mixture of maize, oilseed rape and winter cereals at the landscape scale consequently offers habitats to a wider range of arable plant species than any of these crops alone. Habitat conditions on extensively managed fields cultivated according to an AES were, however, found to be much more heterogeneous and suitable for a far greater range of species, including rare and threatened taxa (on average 21 species in the interior and 33 species 100 m-2 at the field margins). Our models also demonstrate that moderate reductions in herbicide use intensity or fertilisation while staying within the range of currently practiced conventional farming techniques can hardly be expected to reliably halt the decline in arable plant diversity. Novel, regionally adapted approaches and extensively managed arable habitats are urgently needed. The plant diversity of SRC was found to decline strongly with plantation age. Young, low-input SRCs showed a community composition similar to early successional fallow land. Contrarily, 5–8 year old densely planted SRCs were found to be dominated by a set of few generalist, nitrophilous species. They were more shading (1–4% PAR transmissivity) and only slightly more species rich (8–19 species 75 m-2) than annual energy crops, despite not being fertilised or treated with herbicides for several years. The planting of 5–20 m wide SRC strips dividing larger fields with annual crops, can nevertheless be recommended in structurally impoverished, intensively managed agricultural landscapes, particularly if measures to increase the variability of habitat conditions in the coppices are applied. To address the root causes of plant diversity loss on farmland it seems, however, additionally paramount to create a permanent network of extensively managed field sanctuaries to maintain viable source populations which can potentially disperse to the wider agricultural landscapes in the future. To effectively inform policy makers, future research on energy cropping and farmland plant diversity should broaden the focus from the field to the landscape scale and address remaining open questions with regard to the interactions of arable plant diversity with other taxonomic groups.

Estimating the pre-harvest greenhouse gas costs of energy crop production

Predicting the fate of French bird communities under agriculture and climate change scenarios

Complex aspects of climate change impacts on the cultivation of perennial energy crops in the Czech Republic

Energy crops in marginal areas: Scenario-based assessment through ecosystem services, as support to sustainable development

The implications for energy crops under China's climate change challenges

This study addresses the uncertainties related to potential changes in land use and management and associated impacts on hydrology and water quality resulting from increased production of biofuel from the conventional and cellulosic feedstock. The Soil Water Assessment Tool (SWAT) was used to assess the impacts on regional and field scale evapotranspiration, soil moisture content, stream flow, sediment, and nutrient loadings in the Ohio River Basin. The model incorporates spatially and temporally detailed hydrologic, climate and agricultural practice data that are pertinent to simulate biofuel feedstock production, watershed hydrology and water quality. Three future biofuel production scenarios in the region were considered, including a feedstock projection from the DOE Billion‐Ton (BT2) Study, a change in corn rotations to continuous corn, and harvest of 50% corn stover. The impacts were evaluated on the basis of relative changes in hydrology and water quality from historical baseline and future business‐as‐usual conditions of the basin. The overall impact on water quality is an order of magnitude higher than the impact on hydrology. For all the three future scenarios, the sub‐basin results indicated an overall increase in annual evapotranspiration of up to 6%, a decrease in runoff up to 10% and minimal change in soil moisture. The sediment and phosphorous loading at both regional and field levels increased considerably (up to 40–90%) for all the biofuel feedstock scenario considered, while the nitrogen loading increased up to 45% in some regions under the BT2 Study scenario, decreased up to 10% when corn are grown continuously instead of in rotations, and changed minimally when 50% of the stover are harvested. Field level analyses revealed significant variability in hydrology and water quality impacts that can further be used to identify suitable locations for the feedstock productions without causing major impacts on water quantity and quality.

Plant cover plays an essential role in the maintenance and balance of the hydrological cycle, performing functions in the control of water availability, which guarantee flow permanence. The use of mathematical models is an alternative to represent the hydrological system and help in the understanding of phenomena involving the variables of the water cycle, in order to anticipate and predict impacts from potential changes in land use. In the present study, the hydrological model SWAT (Soil and Water Assessment Tool) was used to analyse the dynamics of flow and water flow in the Pará River Basin, Minas Gerais, Brazil, aiming to evaluate the impact caused by changes in land use in water availability. The adjusted model was assessed by the coefficient of efficiency of Nash-Sutcliffe (between -0.057 to -0.059), indicating high correlation and coefficient of residual mass (0.757 to 0.793) and therefore a satisfactory fit. An increase of about 10% in the basin flow was estimated, as a function of changes in land use, when simulating the removal of the original 'Cerrado' vegetation and of the seasonal semideciduous forest for pasture implementation in 38% of the basin.

Lignocellulosic energy crops can produce substantial amounts of biomass for energy purposes, but their introduction implies land-use changes as they are mainly cultivated in agriculturally dominated landscapes. This thesis presents a land-use analysis of lignocellulosic energy crops in the agricultural landscape in Sweden, specifically aiming to i) assess different energy crops’ regarding production, location and climatic profiles, ii) characterise and define the surrounding agricultural landscape, and iii) study the overall land-use changes derived from the establishment of energy crops in the country. The analysis is based on empirical data from commercial fast-growing tree plantations (willow, poplar, and hybrid aspen) and energy grasses (reed canary grass) at multiple spatial scales from field to landscape level, during the period 1986-2018. At field level, there is a trend for smaller and more regular fields dedicated to energy crops, with cultivation patterns moving towards more productive lands, reflecting an intensification in the land-use management. Willow was initially established mainly on fallow lands, but many plantations were subsequently replaced by cereals due to changes in global cereal prices. In the case of grasses, this pattern was similar, although changes appeared later and not so markedly. At landscape level, energy crops significantly diversify the agricultural landscape, as fast-growing tree plantations are largely introduced in cereal areas and grasses in forest-dominated landscapes. The methods and analysis of this thesis contribute to a better understanding of land-use changes associated to energy crops, and help define their contribution to diversifying the agricultural landscape.

Lowland Farmland Birds III: Delivering Solutions in an Uncertain World. A report on the BOU’s Annual Conference held at the University of Leicester, 31 March–2 April 2009

Although forest conservation activities, particularly in the tropics, offer significant potential for mitigating carbon (C) emissions, these types of activities have faced obstacles in the policy arena caused by the difficulty in determining key elements of the project cycle, particularly the baseline. A baseline for forest conservation has two main components: the projected land-use change and the corresponding carbon stocks in applicable pools in vegetation and soil, with land-use change being the most difficult to address analytically. In this paper we focus on developing and comparing three models, ranging from relatively simple extrapolations of past trends in land use based on simple drivers such as population growth to more complex extrapolations of past trends using spatially explicit models of land-use change driven by biophysical and socioeconomic factors. The three models used for making baseline projections of tropical deforestation at the regional scale are: the Forest Area Change (FAC) model, the Land Use and Carbon Sequestration (LUCS) model, and the Geographical Modeling (GEOMOD) model. The models were used to project deforestation in six tropical regions that featured different ecological and socioeconomic conditions, population dynamics, and uses of the land: (1) northern Belize; (2) Santa Cruz State, Bolivia; (3) Paraná State, Brazil; (4) Campeche, Mexico; (5) Chiapas, Mexico; and (6) Michoacán, Mexico. A comparison of all model outputs across all six regions shows that each model produced quite different deforestation baselines. In general, the simplest FAC model, applied at the national administrative-unit scale, projected the highest amount of forest loss (four out of six regions) and the LUCS model the least amount of loss (four out of five regions). Based on simulations of GEOMOD, we found that readily observable physical and biological factors as well as distance to areas of past disturbance were each about twice as important as either sociological/demographic or economic/infrastructure factors (less observable) in explaining empirical land-use patterns. We propose from the lessons learned, a methodology comprised of three main steps and six tasks can be used to begin developing credible baselines. We also propose that the baselines be projected over a 10-year period because, although projections beyond 10 years are feasible, they are likely to be unrealistic for policy purposes. In the first step, an historic land-use change and deforestation estimate is made by determining the analytic domain (size of the region relative to the size of proposed project), obtaining historic data, analyzing candidate baseline drivers, and identifying three to four major drivers. In the second step, a baseline of where deforestation is likely to occur–a potential land-use change (PLUC) map—is produced using a spatial model such as GEOMOD that uses the key drivers from step one. Then rates of deforestation are projected over a 10-year baseline period based on one of the three models. Using the PLUC maps, projected rates of deforestation, and carbon stock estimates, baseline projections are developed that can be used for project GHG accounting and crediting purposes: The final step proposes that, at agreed interval (e.g., about 10 years), the baseline assumptions about baseline drivers be re-assessed. This step reviews the viability of the 10-year baseline in light of changes in one or more key baseline drivers (e.g., new roads, new communities, new protected area, etc.). The potential land-use change map and estimates of rates of deforestation could be re-done at the agreed interval, allowing the deforestation rates and changes in spatial drivers to be incorporated into a defense of the existing baseline, or the derivation of a new baseline projection.

Land use and its dynamics have attracted considerable scientific attention for their significant ecological and socioeconomic implications. Many studies have investigated the past changes in land use, but efforts exploring the potential changes in land use and implications under future scenarios are still lacking. Here we simulate the future land use changes and their impacts on ecosystem services in Northeast China (NEC) over the period of 2000–2050 using the CLUE–S (Conversion of Land Use and its Effects at Small regional extent) model under the scenarios of ecological security (ESS), food security (FSS) and comprehensive development (CDS). The model was validated against remote sensing data in 2005. Overall, the accuracy of the CLUE–S model was evaluated at 82.5%. Obtained results show that future cropland changes mainly occur in the Songnen Plain and the Liaohe Plain, forest and grassland changes are concentrated in the southern Lesser Khingan Mountains and the western Changbai Mountains, while the Sanjiang Plain will witness major changes of the wetlands. Our results also show that even though CDS is defined based on the goals of the regional development plan, the ecological service value (ESV) under CDS is RMB 2656.18 billion in 2050. The ESV of CDS is lower compared with the other scenarios. Thus, CDS is not an optimum scenario for eco-environmental protection, especially for the wetlands, which should be given higher priority for future development. The issue of coordination is also critical in future development. The results can help to assist structural adjustments for agriculture and to guide policy interventions in NEC.

We compared birds in a group of established and well‐managed miscanthus (Miscanthus x giganteus) fields in Somerset and East Devon, southwestern England, with plots of short rotation coppice (SRC) willow, arable crops and grassland in two winters and one summer. Following early spring cutting, 19 miscanthus fields grew taller, initially produced greater cover and were less weedy than SRC. As stubble in May, the miscanthus contained broadly similar species at similar densities to arable and grassland comparison plots. By July, at 2‐m‐tall, miscanthus held higher densities of birds but of fewer species, most of them characteristic of woodland and scrub. SRC, previously identified as being a beneficial crop for many birds, always contained more species and individuals than miscanthus. Throughout each of two winters, 15 miscanthus plots remained unharvested and contained more wood/scrub species such as Blackbirds Turdus merula, tits, Reed Buntings Emberiza schoeniclus and Woodcock Scolopax rusticola than the comparison plots, which held more corvids and Skylarks Alauda arvensis amongst others. Similar overall mean densities of birds in the miscanthus and the comparison plots masked relatively low density variance in miscanthus and very high variance in the comparison plots. Unharvested miscanthus crops grown in place of habitat types supporting flocks of wintering birds would displace these flocks. Miscanthus plantations with open patches attracted more finches and waders in winter. The two previous studies of birds in miscanthus in the UK found more species and more individuals than we did in summer and winter. Both these studies documented high levels of weediness and patchy crop growth. In the context of this previous work our data suggest that bird use of miscanthus in summer and winter is likely to be variable, affected by region, weediness, crop structure and patchiness. While large‐scale cropping of SRC in England is likely to have a positive overall impact on a suite of common farmland and woodland birds, our data suggest that miscanthus in the southwest of England may have an approximately neutral effect. However, some open farmland specialist species may be lost when planting either crop.