Low-intensity Farming Practices Research Articles

Farm management and landscape context shape plant diversity at wetland edges in the Prairie Pothole Region of Canada.

Evaluating the impacts of farming systems on biodiversity is increasingly important given the need to stem biodiversity loss, decrease fossil fuel dependency, and maintain ecosystem services benefiting farmers. We recorded woody and herbaceous plant species diversity, composition, and abundance in 43 wetland-adjacent prairie remnants beside crop fields managed using conventional, minimum tillage, organic, or perennial cover (wildlife-friendly) land management in the Prairie Pothole Region. We used a hierarchical framework to estimate diversity at regional and local scales (gamma, alpha), and how these are related through species turnover (beta diversity). We tested the expectation that gamma richness/evenness and beta diversity of all plants would be higher in remnants adjacent to perennial cover and organic fields than in conventional and minimum tillage fields. We expected the same findings for plants providing ecosystem services (bee-pollinated species) and disservices (introduced species). We predicted similar relative effects of land management on alpha diversity, but with the expectation that the benefits of organic farming would decrease with increasing grassland in surrounding landscapes. Gamma richness and evenness of all plants were highest for perennial cover, followed by minimum tillage, organic, and conventional sites. Bee-pollinated species followed a similar pattern for richness, but for evenness organic farming came second, after perennial cover sites, followed by minimum tillage and conventional. For introduced species, organic sites had the highest gamma richness and evenness. Grassland amount moderated the effect of land management type on all plants and bee-pollinated plant richness, but not as expected. The richness of organic sites increased with the amount of grassland in the surrounding landscape. Conversely, for conventional sites, richness increased as the amount of grassland in the landscape declined. Our results are consistent with the expectation that adopting wildlife-friendly land management practices can benefit biodiversity at regional and local scales, in particular the use of perennial cover to benefit plant diversity at regional scales. At more local extents, organic farming increased plant richness, but only when sufficient grassland was available in the surrounding landscape; organic farms also had the highest beta diversity for all plants and bee-pollinated plants. Maintaining native cover in agroecosystems, in addition to low-intensity farming practices, could sustain plant biodiversity and facilitate important ecosystem services.

The importance of landscape heterogeneity and vegetation structure for the conservation of the Ortolan Bunting Emberiza hortulana

Summary Over the last decades, European farmland birds have strongly declined, mainly driven by agricultural intensification. The Ortolan Bunting Emberiza hortulana has suffered one of the most severe declines among farmland specialists. In order to maintain viable populations of the species in the long run, there is a vital need for evidence-based conservation measures. The main goal of this study was to detect the key drivers of breeding-territory selection and mating success of the species in an agricultural landscape in central Europe. We found that the landscape structure within the territories of Ortolan Bunting breeding pairs strongly varied from the overall habitat availability in the study area on both the territory and home-range scales. However, the environmental conditions also differed between the territories of breeding pairs and those of unpaired males. While landscape structure played an important role in breeding-territory selection, it had only weak effects on mating success. In contrast, crop type and vegetation height at potential nesting sites were important drivers of mating success. Overall, our study revealed that Ortolan Bunting has very complex breeding-habitat requirements. Only heterogeneous agricultural landscapes where (1) suitable song posts, (2) appropriate nesting sites, and (3) sufficient foraging habitats occur in close proximity are suitable for breeding. According to the findings of our study, agri-environmental schemes should primarily facilitate low-intensity farming practices that promote landscape heterogeneity, provide suitable nesting sites, and sustain a high abundance of invertebrate prey in farmlands.

Factors modulating home range and resource use: a case study with Canarian houbara bustards

BackgroundThe home range of an animal is determined by its ecological requirements, and these may vary depending on many intrinsic and extrinsic factors, which are ultimately driven by food resources. Investigating the effects of these factors, and specifically how individuals use food resources within their home ranges is essential to understand the ecology and dynamics of animal populations, and to establish conservation measures in the case of endangered species. Here, we investigate these questions in the Canarian houbara bustard, an endangered subspecies of African houbara endemic to the Canary Islands.MethodsWe analysed GPS locations of 43 houbaras in 2018–2021, using solar GSM/GPRS loggers provided with accelerometers. We assessed (1) the variation in their home range and core area with kernel density estimators in relation to several intrinsic and extrinsic factors and (2) their foraging habitat selection.ResultsHome ranges were smallest during the breeding season (November–April), when rains triggered a rapid growth of herbaceous vegetation. Displaying males and nesting females had smaller home ranges than individuals not involved in reproduction. Both sexes used almost exclusively non-cultivated land, selecting low density Launaea arborescens shrublands, pastures and green fallows as foraging habitats. Heavier males used smaller home ranges because they spent more time displaying at a fixed display site, while heavier females moved over larger areas during the mating period, probably visiting more candidate mates. During the non-breeding season (May–October), both sexes showed larger home ranges, shifting to high density shrubland, but also partly to cultivated land. They selected sweet potato fields, green fallows, alfalfas, orchards and irrigated fields, which offered highly valuable food resources during the driest months of the year.ConclusionsOur study shows how Canarian houbara, originally a desert-dwelling species that uses mostly shrublands and pastures, has developed the necessary adaptations to benefit from resources provided by current low intensity farming practices in the study area. Maintaining appropriate habitat conditions in the eastern Canary islands should constitute a key conservation measure to prevent the extinction of this endangered houbara subspecies.

The ambiguous role of agri-environment-climate measures in the safeguarding of High Nature Value Farming Systems: The case of the Montado in Portugal

The preservation of High Nature Value farmland (HNVf) is essential for meeting many of the new European Union (EU) Green Deal targets, as they correspond to production systems which respect the preservation of natural resources and support multiple ecosystem services. However, most of the farming systems on which HNVf rely cannot survive without support from public policies. Typically, these are low intensity and low agrochemical input systems, such as the Montado in southern Portugal, a silvo-pastoral land use system adapted to the Mediterranean constraints encountered in the region. Agri-environment-climate measures (AECM) within the EU Common Agricultural Policy, despite their multiple objectives, provide great potential for supporting the conservation of HNVf. However, for this to happen, the measures in place must ensure the maintenance of the low intensity farming practices that led to the HNV status of these systems in the first place. Using an extensive cattle production system in a Montado area as a case study, this paper assesses whether if the implementation of the AECM for Integrated production and the AECM for Organic production, are indeed supporting a less intensive management of this multifunctional land use system and, thus, its HNV. These are two well-known horizontal measures, which can be applied across all farmland and are therefore of major relevance in promoting environmental performance of farming across the EU. The results of our study show that overall, none of these AECM is promoting less intensive management practices in Montado areas, and they therefore do not contribute to the conservation of their natural value. Furthermore, the results underline the importance of grazing management to understand the ongoing changes in many Montado areas. Lastly, the results also show that horizontal AECM are barely able to provide consistent environmental benefits in systems with a high level of complexity as found in silvo-pastoral systems.

Polycultures, pastures and monocultures: Effects of land use intensity on wild bee diversity in tropical landscapes of southeastern Mexico

The conservation of pollinator diversity is fundamental to maintaining sustainable agricultural systems and food security. Some agricultural systems support pollinator diversity, while others may lead to their decline. Previous studies have evaluated the impacts of agricultural intensification on pollinators in temperate climates regions, but in tropical regions these impacts have been evaluated by only very few studies. We conducted a study in southeastern Mexico, in order to understand the effects of three agricultural systems on bee diversity in a tropical landscape. We compared 18 sites at two different scales (plot scale and landscape scale). We found a link between agricultural system intensity level at the plot scale and forest proportion at the landscape scale: land use intensity was low at both scales in 7 polycultures, low at plot scale and high at landscape scale in 4 pastures, and high at both scales in 7 monocultures. We collected bees at all sites, and found an overall high bee richness, with a total of 127 species. Bee richness was compared across agricultural systems using diversity accumulation curves with iNEXT package. Both polycultures and pastures had significantly higher richness as monocultures. We constructed bee species guilds according to ecological and life-history traits (i.e. size, sociality and nesting) and found that whatever the trait considered, the species richness in the different agricultural systems was most often affected in the same way than the complete community richness. Our results show, for the first time in tropical conditions that agricultural systems with low-intensity farming practices and forested landscape allow the preservation of a significantly higher diversity of bees than agricultural systems with high-intensity farming practices and highly deforested landscape. Considering that bee diversity is key to maintaining crop productivity, these findings can help scientists, policy-makers, and community members design policies that support both agricultural production and biodiversity conservation in the tropics.

The Importance of Common Grazing Lands for the Sustainable Management of Natura 2000 Areas in Bulgaria

Common grazing is a traditional practice in Bulgaria. After land restitution in the post-socialist land reform, common grasslands are owned by municipalities or the state and are rented out for grazing to livestock breeders. The introduction of EU CAP area-based payments have led to a series of legal changes in common land regulations so that they are made eligible for support. At the same time, the EU nature conservation legislation requires that Natura 2000 zones are designated in a way that protects all species and habitats of European importance. Due to the historically low-intensity farming practices, it is estimated that the majority of grasslands in Natura 2000 areas in Bulgaria are common grasslands. This paper aims to analyse the available data about regional distribution of common grasslands and to assess their importance for the sustainable management of Natura 2000 zones based on their eligibility for CAP direct payments. The method used is data analysis and GIS spatial representation of both municipal and state common grasslands in Natura 2000 zones across the 28 administrative districts in Bulgaria. Based on the findings of this research work, we demonstrated that common grasslands have an important share in the territorial scope of Natura 2000 sites and can provide substantial financial support for ensuring their sustainable management.

Hydroperiod and Traditional Farming Practices Drive Plant Community Composition on Unregulated Atlantic Floodplain Meadows

The River Shannon, Ireland, among the last unregulated rivers in western Europe, has extensive floodplains and supports rare and endangered species and habitats, of ecological and cultural importance. Unregulated floodplains result in community composition responding directly to natural fluctuations in water level. This study assesses how hydrological factors and farming practices effect flood meadow plant communities. Three main plant communities were identified, forming an uninterrupted ecotone, along a gradient of dry to wet. Habitats of European conservation interest (Lowland Hay Meadows and Molinia Meadows) were well represented. Hydroperiod, calculated using microtopographical measurements, was the primary factor determining community composition and was negatively correlated with elevation and plant species richness. The botanical continuum comprised a range of insect-pollinated species, demonstrating the role of floodplains in providing pollinator services. Climate change projections indicate more prolonged winter flooding in the future, signifying potential range shifts for these plant species and communities; highlighting the need for appropriate conservation measures in the surrounding landscape. Low-intensity farming practices, with minimal fertiliser use and regular hay-mowing, played an essential, secondary role in maintaining plant species diversity. Retaining the floodplain topography, its associated hydrological regime and low-intensity farming practices, are necessary to maintain species diversity and ecosystem services.

Reshaping agri-environmental subsidies: From marginal farming to large-scale rewilding

Despite continued discussion about market distortions and environmental impacts, agricultural subsidies continue to be a key component of European Union policy. About 10% of the agro-forestry subsidies are targeted at supporting agri-environment schemes, and at supporting farming in Less Favoured Areas (LFA) such as mountain regions. One of the main justifications for these agri-environmental subsidies towards marginally productive land is that they promote the conservation of biodiversity by maintaining low-intensity farming practices. Here, we critically examine this assumption and argue instead for a two-tier approach to Europe's agri-environmental policy based on inherent land fertility and spatial scale: (i) at a local, single-farm scale, fertile agricultural land should preferentially be intensively but sustainably farmed with a focus on high yields, (ii) while simultaneously and at larger, regional scales, less-productive land, and especially protected areas, may be ecologically restored into ‘wild’ and resiliently functioning ecosystems. As such, agri-environmental subsidies towards fertile land should support the implementation of measures that benefit biodiversity while allowing, and even helping, the achievement of high agricultural yields. In contrast, agri-environmental and LFA subsidies towards marginal land and protected areas should also promote rewilding and the management of natural succession. In order for this approach to be successful, a higher proportion of the Common Agricultural Policy subsidies would need to be allocated to environmental goals.

Phylogenetic structure of Xanthomonas determined by comparison of gyrB sequences

Previously, we have produced a phylogeny of species type strains from the plant-pathogenic genus Xanthomonas based on gyrB sequences. To evaluate this locus further for species and infraspecies identification, we sequenced an additional 203 strains comprising all the pathovar reference strains (which have defined plant hosts), 67 poorly characterized pathovars, currently classified as Xanthomonas campestris, and 59 unidentified xanthomonads. The well-characterized pathovars grouped either in clades containing their respective species type strain or in clades containing species related to Xanthomonas axonopodis. The Xanthomonas euvesicatoria, Xanthomonas perforans and Xanthomonas alfalfae species complex, Xanthomonas fuscans and Xanthomonas citri were discriminated as X. axonopodis-related clades and comprised a large proportion of unidentified strains as well as 80 pathovars representing all the X. axonopodis pathovars and many poorly characterized pathovars, greatly increasing the plant host ranges of the constituent species. Most xanthomonads from these three large clades were isolated from a taxonomically diverse range of plant hosts, including many weed species, from field systems in India, suggesting that these lineages became established and diversified in agricultural areas in this region. The majority of these xanthomonads had minimal sequence diversity, consistent with rapid and highly extensive pathovar diversification that has occurred in relatively recent times. Low-intensity farming practices may have provided conditions conducive to pathovar development, and evidence for pathovar diversification within other regional angiosperm floras is discussed. The gyrB locus was sufficiently discriminating to identify diversity within many species. Seven branches or clades were sufficiently distinct to be considered as potential novel species. This study has provided a comprehensive xanthomonad classification framework and has firmly established gyrB sequencing as a rapid and efficient identification tool.

Low-Intensity Farming Systems in the Conservation of the Countryside

The historical role of agriculture in creating semi-natural vegetation is still not fully appreciated by many ecologists, conservationists, policy-makers or the general public. Nor is the fact that for many European landscapes and biotopes of high nature conservation value, the only practicable, socially acceptable and sustainable management involves the continuation of low-intensity farming. Consequently, too much emphasis is placed on attempting to ameliorate damaging effects of agricultural management rather than supporting ecologically sustainable low-intensity farming practices. More than 50% of Europe's most highly valued biotopes occur on low-intensity farmland. However, most of this farmland has no environmental policy directly affecting it; most management decisions are taken by farm businesses and determined primarily by European and national agricultural officials. As a result, there continues to be intensification or abandonment of traditional practices, changes which are equally damaging to the nature conservation value. However, the nature conservation importance of low-intensity farming systems is gradually being recognized. Reforms and reviews of agriculture policy are providing a variety of potential opportunities for maintaining such systems. Unfortunately, initiating change through policy is a slow process. There is therefore also a pressing need to look for other opportunities to maintain surviving systems and, where poss-. ible, to reinstate those recently lost. Although these systems may be considered low-intensity in terms of chemical inputs and productivity, they are usually high-intensity in terms of human labour. Therefore, the processes that make the low-intensity farmed countryside biologically rich and diverse must be understood, but at the same time mechanisms to make life easier and more rewarding for the people who work such farmland must be found. Ecologists and conservationists should think less of'remnants of habitat being left amongst farmland' and more of a farmland biotope for which optimum management practices need to be developed. At the same time the current emphasis on site-based conservation should be complemented by strategic initiatives that promote wise management of the wider countryside.