Consequence Of Agricultural Intensification Research Articles

Soil, climate, time and site factors as drivers of soil structure evolution in agricultural soils from a temperate-boreal region

The evolution of soil structure in agricultural soils is driven by natural and anthropogenic factors including inherent soil properties, climate and soil management interventions, all acting at different spatial and temporal scales. Although the causal relationships between soil structure and these individual factors are increasingly understood, their relative importance and complex interactive effects on soil structure have so far not been investigated across a geo-climatic region.Here we present the first attempt to identify the relative importance of factors that drive the evolution of soil structure in agricultural soils as well as their direction of effect with a focus on the temperate-boreal zone. This was done using a random forest (RF) approach including soil, climate, time, and site factors as covariates. Relative entropy, as quantified by the Kullback-Leibler (KL) divergence, was used as a quantitative index of soil structure, which is derived from the particle-size distribution and soil water retention data, and integrates the effects of soil structure on pores from the micrometre-scale to large macropores. Our dataset includes 431 intact topsoil and subsoil samples from 89 agricultural sites across Sweden and Norway, which were sampled between 1953 and 2017. The relative importance of covariates for the evolution of soil structure was identified and their non-linear and non-monotonic effects on the KL divergence were investigated through partial dependence analysis. To reveal any differences between topsoils (0–30 cm; n = 174) and subsoils (30–100 cm; n = 257), the same analysis was repeated separately on these two subsets.The covariates were able to explain on average more than 50% of the variation in KL divergence for all soil samples and when only subsoil samples were included. However, the predictions were poorer for topsoil samples (≈ 35%), underlining the complex dynamics of soil structure in agricultural topsoils. Parent material was the most important predictor for the KL divergence, followed by clay content for all soil samples and sampling year for only subsoil samples. Mean annual air temperature ranked third and annual precipitation ranked fourth for subsoil samples. However, it remains unclear whether the effects of climate factors are direct (e.g., freezing and thawing, wetting and drying, rainfall impact) or indirectly expressed through interactions with soil management. The partial dependence analysis revealed a soil organic carbon threshold of around 3% below which soil structure starts to deteriorate. Besides this, our results suggest that subsoil structure in the agricultural land of Sweden deteriorated steadily during the 1950′s to 1970′s, which we attribute to traffic compaction as a consequence of agricultural intensification. We discuss our findings in the light of data bias, laboratory methods and multicollinearity and conclude that the approach followed here gave valuable insights into the drivers of soil structure evolution in agricultural soils of the temperate-boreal zone. Theses insights will be of use to inform soil management interventions that address soil structure or soil properties and functions related to it.

Agricultural intensification increases farmers' income but reduces food self‐sufficiency and bee diversity: Evidence from southeast Mexico

AbstractThe tropical region of Hopelchén, southeastern Mexico, is a place of high contrasts in terms of the agricultural intensity of production systems and landscape configuration: It presents enormous areas of conserved forest and at the same time the highest rate of deforestation in Mexico. The consequences of agricultural intensification in this region are the subject of our research. We surveyed 80 farmers, whom we grouped into seven types, and developed an index of agricultural intensity based on sowing intensity, frequency of pesticide application and frequency of tractor use. We evaluated the economic potential and added value for farmers, such as food security and self‐sufficiency, as well as bee diversity in the agricultural intensification gradient. Our results show that agricultural intensification generates higher added value, but not economic potential, and does not necessarily lead to higher food security. However, it does negatively affect bee diversity and pollination potential, which compromises the sustainable development of the region.

Infantile scurvy as a consequence of agricultural intensification in the 1st millennium BCE Etruria Campana

The 1st millennium BCE in Italy was a time of agricultural intensification of staple cereal production which shaped sociocultural, political, and economic spheres of pre-Roman groups. The lifeways and foodways of the Etruscans, the greatest civilization in western Europe before Roman hegemony, are traditionally inferred from secondary written sources, funerary archaeology, archaeobotany, and zooarchaeology. However, no direct data extrapolated from the study of human skeletal remains are available to evaluate the extent to which agricultural intensification and decreased dietary diversity impacted health and the expression of skeletal indicators of metabolic disease. Macroscopic and radiological analyses were conducted on an archaeological skeletal sample of non-adults (n = 29) recovered from Pontecagnano (southern Italy) dating to the Orientalizing period (730–580 BCE). This allowed us to identify five cases of scorbutic non-adults and to assign diagnostic values to skeletal lesions of scurvy that have not been previously described in the literature. The onset of scurvy in the examined sample is related to the increased reliance of Etruscans on crops lacking vitamin C in this period of agricultural intensification. The skeletal expression of scurvy varied among the non-adults, with differences in location and disease severity; these were interpreted considering the age-at-death of the individuals coupled with feeding behaviors and interindividual variability.

Landscape-scale connectivity and fragment size determine species composition of grassland fragments

As a consequence of agricultural intensification and habitat fragmentation since the mid-20th century, biological diversity has declined considerably throughout the world, particularly in Europe. We assessed how habitat and landscape-scale heterogeneity, such as variation in fragment size (small vs. large) and landscape configuration (measured as connectivity index), affect plant and arthropod diversity. We focused on arthropods with different feeding behaviour and mobility, spiders (predators, moderate dispersal), true bugs (mainly herbivores and omnivores with moderate dispersal), wild bees (pollinators with good dispersal abilities), and wasps (pollinators, omnivores with good dispersal abilities). We studied 60 dry grassland fragments in the same region (Hungarian Great Plain); 30 fragments were represented by the grassland component of forest-steppe stands, and 30 were situated on burial mounds (kurgans). Forest-steppes are mosaics of dry grasslands with small forests in a matrix of plantation forests. Kurgans are ancient burial mounds with moderately disturbed grasslands surrounded by agricultural fields. The size of fragments ranged between 0.16–6.88 ha (small: 0.16–0.48 ha, large: 0.93–6.88 ha) for forest-steppes and 0.01–0.44 ha (small: 0.01–0.10 ha and large: 0.20–0.44 ha) for kurgans. Fragments also represented an isolation gradient from almost cleared and homogenous landscapes, to landscapes with relatively high compositional heterogeneity. Fragment size, connectivity, and their interaction affected specialist and generalist species abundances of forest-steppes and kurgans. Large fragments had higher species richness of ground-dwelling spiders, and the effect of connectivity was more strongly positive for specialist arthropods and more strongly negative for generalists in large than in small fragments. However, we also found a strong positive impact of connectivity for generalist plants in small kurgans in contrast to larger ones. We conclude that besides the well-known effect of enhancing habitat quality, increasing connectivity between fragments by restoring natural and semi-natural habitat patches would help to maintain grassland biodiversity.

Traditional small waterbodies as key landscape elements for farmland bird conservation in Mediterranean semiarid agroecosystems

Farmland bird populations are declining worldwide as a consequence of agricultural intensification, and the loss of singular landscape elements has been suggested as one of the main drivers. This scenario of agroecosystem simplification is even more exacerbated in arid and semiarid regions, where traditional small waterbodies (SWB) are rapidly vanishing due to groundwater overexploitation and the declining extensive pastoralism. Here, we used data from breeding bird surveys at SWB and adjacent control sites to assess for the first time the landscape-scale contribution of three types of traditional SWB for supporting farmland bird communities in the most arid region of continental Europe. Four community metrics were calculated for each SWB: species richness, abundance, diversity and proportion of conservation-concern species. In general, a high proportion (71% on average) of the local breeding bird communities used SWB, irrespective of the SWB type. Cattle ponds supported a greater abundance and proportion of threatened species, whereas drinking troughs were used by more diversified bird communities. Traditional artificial pools showed intermediate values for all community metrics. Our results support that in semiarid regions any type of traditional man-made SWB, if properly designed and managed, can play a pivotal role in supporting farmland bird communities at landscape scale. Despite their ecological importance, traditional SWB are often overlooked from agri-environment schemes, and their role for supporting farmland biodiversity is rarely considered. Therefore, effective SWB management and conservation measures should be implemented in the framework of the new reform of the European Common Agricultural Policy and other similar eco-schemes in order to halt the decline of farmland biodiversity. • Traditional small waterbodies (SWB) provide pivotal services to a large proportion (71 %) of the farmland bird communities. • Different types of traditional SWB are equally important to support local bird communities in Mediterranean agroecosystems. • Some environmental and SWB-related structural variables are particularly important to explain among-type differences in bird metrics. • Cattle ponds support a greater abundance and ratio of threatened species, whereas drinking troughs are species-richest. • Agri-environment schemes should promote the creation and nature-friendly management of small waterbodies in farmlands.

Status, trends, and future dynamics of freshwater ecosystems in Europe and Central Asia

ABSTRACTThis review is part of the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES) report on Europe and Central Asia (ECA) and provides a critical assessment of issues facing decision-makers, including freshwater biodiversity and ecosystem trends as well as drivers of change. Freshwater systems are well established as the most threatened ecosystem type in the ECA region, with the quantity and quality of habitats and abundance of many species rapidly declining. Only about half (53%) of the EU's rivers and lakes achieved good ecological status in 2015 (as defined by the Water Framework Directive in terms of the quality of the biological community), and many lakes, ponds, and streams are disappearing as a consequence of agricultural intensification and inefficient irrigation and urbanisation, combined with climate change. The situation regarding freshwater biodiversity remains highly critical in ECA as many species remain threatened with extinction, including >50% of known species for some groups (e.g., molluscs, amphibians). Drivers of ECA freshwater taxa include the destruction or modification of their habitat, including water abstraction, which affects ∼89% of all amphibian threatened species and ∼26% of threatened freshwater invertebrate species. Of particular concern is the lack of data for freshwater invertebrates. Current status is available for only a minority of species, and the impact of alien invasive species is often unknown, especially in Central Asia. Based on current freshwater biodiversity trends, it is highly unlikely that ECA will achieve either the respective Aichi biodiversity targets by 2020 (i.e., targets 2 to 4, 6 to 12, and 14) or Target 1 of the Biodiversity Strategy.

Partnering for nature conservation: NGO-farmer collaboration for meadow bird protection in the Netherlands

In order to reverse the trend of continuous decline in species diversity and abundance in agricultural landscapes, various governance arrangements have been implemented that promote, organise and finance nature conservation by farmers. The scientific literature predominantly focuses on agri-environment schemes (AES), i.e. publicly funded financial compensation schemes for farmers who implement prescribed conservation measures. Less attention has been paid to governance arrangements initiated by actors outside the public domain. This paper analyses a unique partnership between a nature conservation NGO – BirdLife Netherlands (BLN) – and a network of about 130 dairy and cattle farmers, aimed at meadow bird protection in the Netherlands. Meadow birds breed in large numbers in the Netherlands, mainly on farmland, but their numbers have been declining as a consequence of agricultural intensification, urbanisation and predation, amongst other things. Established in 2010, the partnership is gradually evolving from bilateral cooperation between BLN and individual farmers into a network. Based on desk research, interviews and five focus group sessions with almost 40 representatives of the partnership, we conclude that the main (perceived) achievements include: a large contribution to awareness of and recognition for the important role and efforts of farmers in meadow bird protection among citizens, politicians, policy-makers and companies in agri-food chains; a modest contribution to improving conservation efforts by participating farmers; and a modest contribution to their knowledge about conservation of meadow birds. The main success factors are the alignment of interests and complementarity of the partners and motivation derived from meeting peers. The partnership clearly complements AES in terms of its functions.

Effects of higher‐tier agri‐environment scheme on the abundance of priority farmland birds

AbstractAgri‐environment schemes (AES) are the main policy mechanism available for reversing the widespread declines of European farmland biodiversity. We assessed the impact of AES land management on the abundance of bird species whose populations have declined as a consequence of agricultural intensification. The AES involved the deployment of a whole‐farm package of wildlife‐friendly land management options covering an average of 7% of the farmed area. The study was conducted across three English regions and focused on species of conservation concern and on a wider suite of farmland birds comprising the UK Government's Farmland Bird Indicator (FBI). Changes in avian abundance on AES farms were compared with those measured across the wider farmed landscape as part of a national bird monitoring scheme. Twelve out of 17 priority species, and the FBI, showed more positive changes in abundance on AES farms in at least one region. Eight species exhibited sustained responses to AES management in at least one region, and eight species exhibited a temporary enhancement in abundance in at least one region. Temporary responses to AES management followed a large scale failure of key AES options to establish during successive wet and cold summers, and involved species known to depend on the habitats provided by these options. In order to offset ongoing declines of FBI species in the wider farmed countryside of 2.3–4.1% per annum, we estimate 26–33% of FBI populations would need to be subject to AES‐type management. This study demonstrates the potential for AES land management to substantially enhance the abundance of priority farmland birds and highlights the need for option packages that are resilient to the impacts of variable weather conditions.

A matter of pipes: Wryneck Jynx torquilla habitat selection and breeding performance in an intensive agroecosystem

The Wryneck Jynx torquilla has undergone one of the largest bird species’ declines in Europe as a consequence of agricultural intensification; however, in some regions it still occurs in intensively managed permanent crops (e.g. vineyards). Considering the conservation status of the Wryneck and the increasing extent and intensification of permanent crops over Europe, investigating the habitat selection and use of nesting sites of this species in these ecosystems is urgently required. With this aim, we studied territory-scale habitat selection in a Wryneck population inhabiting a vineyard-dominated landscape without conservation measures for this species (e.g. nest box supplementation) in northeast Italy, and provide a preliminary assessment of its breeding biology. We evaluated the effect of land cover, management, and nest site availability on Wryneck occurrence in 44 territories and an equal number of control plots. In the year following this evaluation, Wryneck nests were surveyed in a subset of simple landscapes (<20% of semi-natural habitats). All nest boxes and holes provided by pipe beams supporting traditional pergola vineyards were checked twice during the breeding season. According to the territory model, Wrynecks did not select particular habitat types, but established territories in sunny areas in which pergola vineyards were more abundant than spalliera ones, the former having a higher availability of pipe holes, and in simpler landscapes. Breeding attempts in pipes were few and all failed during egg deposition; conversely, 39% of the few available nest boxes were occupied with an overall breeding success of 57%. Of the eggs laid, 36% resulted in fledged juveniles. Although pipes provide potential nesting sites and positively affect territory settlement, they finally resulted in breeding failure, thus potentially exacerbate the impact of intensive agricultural management on the species (i.e. a pattern indicating an ecological trap). Nest boxes may supply safer breeding sites for Wrynecks; however, a wider assessment of reproductive outcomes following nest box supplementation should be carried out.

Evaluation of Ecological Criteria of Biofuel Certification in Germany

The share of biofuels has increased significantly over the last decade, which has lead to several negative impacts on the environment. As a solution, several governments worldwide have promoted the use of certification systems, which have been implemented and in some cases have even been established as mandatory regulations. Due to the focus of the public debate, standard-setting has mainly been limited to developing and newly industrializing countries. Hence, the issues of environmental impacts as a consequence of agricultural intensification in Germany has been given little attention, and the question whether existing biofuel certification systems sufficiently cover ecological issues remains. In order to answer this question, this study performs a benchmarking analysis of selected certification systems, whereby their ability to ensure ecological sustainability is evaluated and compared. The assessment reveals that the currently existing national ordinances, like Cross Compliance, are in many aspects insufficient to ensure sustainability. Contrarily, they often deter necessary discussions to tackle these issues.

Using Next-Generation Sequencing to Contrast the Diet and Explore Pest-Reduction Services of Sympatric Bird Species in Macadamia Orchards in Australia.

Worldwide, avian communities inhabiting agro-ecosystems are threatened as a consequence of agricultural intensification. Unravelling their ecological role is essential to focus conservation efforts. Dietary analysis can elucidate bird-insect interactions and expose avian pest-reduction services, thus supporting avian conservation. In this study, we used next-generation sequencing to analyse the dietary arthropod contents of 11 sympatric bird species foraging in macadamia orchards in eastern Australia. Across all species and based on arthropod DNA sequence similarities ≥98% with records in the Barcode of Life Database, 257 operational taxonomy units were assigned to 8 orders, 40 families, 90 genera and 89 species. These taxa included 15 insect pests, 5 of which were macadamia pests. Among the latter group, Nezara viridula (Pentatomidae; green vegetable bug), considered a major pest, was present in 23% of all faecal samples collected. Results also showed that resource partitioning in this system is low, as most bird species shared large proportion of their diets by feeding primarily on lepidopteran, dipteran and arachnids. Dietary composition differed between some species, most likely because of differences in foraging behaviour. Overall, this study reached a level of taxonomic resolution never achieved before in the studied species, thus contributing to a significant improvement in the avian ecological knowledge. Our results showed that bird communities prey upon economically important pests in macadamia orchards. This study set a precedent by exploring avian pest-reduction services using next-generation sequencing, which could contribute to the conservation of avian communities and their natural habitats in agricultural systems.

Recently created man-made habitats in Doñana provide alternative wintering space for the threatened Continental European black-tailed godwit population

Over the last decades the Continental European population of black-tailed godwits, Limosa limosa limosa, has shown steep declines as a consequence of agricultural intensification on the breeding grounds. Although numbers have also declined in their traditional wintering areas in West-Africa, in the Doñana wetlands of southwestern Spain high nonbreeding numbers have persisted. Here we provide a long-term (35year, 1977–2011) analysis of godwit numbers in Doñana. In fact, from the mid 1990s there has been a steep increase in numbers so that the fraction of godwits along this flyway that winters in Doñana increased from 4% in the late 1980s to 23% in 2011. These changes were not correlated with climatic conditions in Spain, nor in Sahel, but they were associated with changes in habitat availability – mainly an increase in man-made artificial wetlands. Commercial fish-farms and rice fields provide alternative habitats to the original seasonal marshlands for daytime roosting (mainly in the fish ponds) or nocturnal foraging (probably rice fields in addition to fish ponds). For migrating waterbirds, degradations of natural wetlands can thus be compensated by man-made alternative habitats. As the availability especially of such man-made areas is highly sensitive to short-term political/economic driven decision-making, they should be given greater consideration in global conservation plans.

Genetic diversity and complementary sex determination (CSD) in Dolerus aeneus (Hymenoptera, Symphyta): implications for the conservation of an ecologically-important sawfly

Graminivorous sawfly numbers have declined steadily over recent years as a consequence of agricultural intensification. In spite of these declines and the importance of sawflies (Hymenoptera, Symphyta) as a food source for threatened populations of farmland birds, sawfly conservation studies have been restricted to census-based research. This is largely due to certain aspects of the sawfly life-cycle which make adequate sampling of these insects difficult. However, genetic research provides a valuable insight into population structure that cannot be obtained by traditional ecological means, and one which is essential for the development of conservation management strategies. In this study, we investigate the population genetic structure of the graminivorous sawfly Dolerus aeneus, and conduct a preliminary study to determine whether complementary sex determination (CSD), which can produce sterile diploid males under inbreeding conditions, operates in this species. Our research suggests that fragmentation of sawfly habitat as a result of agri-intensification has not yet acted to isolate D. aeneus populations, although some genetic effects are apparent (inbreeding and low diversity compared with other solitary Hymenoptera). In addition, diploid males were detected which may have compromised fertility and could indicate that CSD is operative in D. aeneus. This study highlights the need for further genetic research in sawflies to assess population structure on a UK-wide scale and to assess the prevalence of diploid males in key species. We discuss our findings in wider context of the genetics of Hymenoptera and the conservation and management of farmland biodiversity.

Multi-criteria spatialization of soil organic carbon sequestration potential from agricultural intensification in Senegal

On the eve of the 15th climate negotiations conference in Copenhagen, the pressure to assess all climate mitigation options is mounting. In this study, a bio-physic model and a socio-economic model were designed and coupled to assess the carbon sequestration potential of agricultural intensification in Senegal. The biophysical model is a multiple linear regression, calibrated and tested on a dataset of long-term agricultural trials established in West Africa. The socio-economic model integrates both financial and environmental costs related to considered practice changes. Both models are spatially explicit and the resulting spatial patterns were computed and displayed over Senegal with a geographic information system. The national potential from large-scale intensification was assessed at 0.65-0.83 MtC. With regards to local-scaled intensification as local projects, the most profitable areas were identified in agricultural expansion regions (especially Casamance), while the areas that meet the current financial additionality criteria of the Clean Development Mechanism were located in the northern part of the Peanut Basin. Using the current relevant mode of carbon valuation (Certified Emission Reductions), environmental benefits are small compared to financial benefits. This picture is radically changed if "avoided deforestation", a likely consequence of agricultural intensification, is accounted for as the greenhouse gases sink capacity of projects increases by an average of a hundred-fold over Senegal.

Diet plasticity in blackcap (Sylvia atricapilla): The ability to overcome nutritional constraints imposed by agricultural intensification

We studied the consequences of agricultural intensification on the diet, nutritive balance, and body condition of an avian frugivore (blackcap, Sylvia atricapilla) that overwinters in southern Spain, and analysed dietary plasticity as an ability to overcome the effects of agricultural intensification. We considered two habitats with very different levels of land-use: Mediterranean shrublands dominated by wild olive trees, and highly managed olive orchards. We partitioned the diet into four basic components: olive fruits, non-olive fruits, arthropods, and non-fruit plant matter. Availability of these resources, which influenced diet composition and body mass, differed among habitats and reflected the degree of human land-use. Hedges in olive orchards increased the local fruit diversity, making the diet and body mass in olive orchards more similar to that of less altered habitats. Based on diet composition analysis in relation to energy, protein, and mineral intake, we suggest that blackcaps wintering in olive orchards select non-fruit plant matter (a rare item in other habitats) so as to balance their energy, protein, and mineral intakes. This is necessary because of the scarcity of resources other than olives in orchards. Moreover, such deficiency probably results in higher exploitation costs, which in turn may affect the birds’ physical condition. Remarkably, blackcap shows a high dietary plasticity among habitats during the autumn-winter period in southern Spain, which seems to help this species reside for part of the year in a large man-made region.