Consequences Of Agricultural Expansion Research Articles

Detection of the maned wolf, a cryptic and vulnerable species, through environmental DNA studies

The maned wolf (Chrysocyon brachyurus) is a vulnerable and ubiquitous species endemic to South America. Their populations are declining due to habitat loss as a consequence of agricultural expansion and exposure to anthropic threats such as road-kills, illegal hunting and diseases. In Argentina, there is a lack of information about its accurate distribution because its populations are sparse and the specimens are very difficult to observe due to its cryptic and lonely behavior, low population density, and type of habitat. In this article, we describe the results of the application of the environmental DNA methodology to carry out indirect monitoring of maned wolf specimens. The data obtained show that this technique is effective in detecting specimens of this mammal, which was verified through direct monitoring. This information represents an adjustment of the methods that can be applied in large-scale monitoring to study the structure and distribution of the maned wolf populations, as well as to obtain genetic data about this species, to design optimal conservation plans to preserve it in Argentina.

Consequences of land-use change in Brazil’s new agricultural frontier: A soil physical health assessment

In the so-called MATOPIBA region in northeastern Brazil, large areas of the Brazilian savannah (Cerrado biome) were converted to agricultural areas (e.g., soybean and cotton production) in recent years. However, little is known about the long-term impacts of this land-use change on soil physical properties and related soil functions. We carried out a field experiment in three consolidated agricultural areas (~23 years old) across a 1000-km transect within the MATOPIBA region to quantify land-use change effects from native vegetation (NV) to agricultural areas under no-tillage (NT) on soil physical properties and associated functions; and compare the obtained results with critical values from literature considered as thresholds for soil degradation. Soil samples were collected from paired plots (NV and NT) in each location at 0–5, 5–10, 10–20, and 20–30 cm soil depth to determine key soil physical properties related to soil texture, compaction, porosity, water storage, and structural stability. Additionally, a set of soil physical indicators was added into a soil physical quality index (SPQI) as an integrated and quantitative approach for evaluating changes in soil functions. Our results indicated that conversion from NV to agriculture under NT increased the compaction process and reduced total soil porosity, unbalancing the proportion between soil water and air storage to critical levels. Besides, water infiltration within the soil profile was strongly decreased. The land-use conversion further induced changes on soil aggregate stability, decreasing large macroaggregates (>2000 µm) and increasing small macroaggregates (250–2000 µm) and the silt/clay-sized fraction (<53 µm). The SPQI was reduced by ~33% in NT, indicating detrimental effects of agriculture expansion on soil functionality. Based on the SPQI, water availability and air diffusion were the soil functions most affected by land-use change. Our results provide a quantitative assessment of soil physical properties and soil function changes as a consequence of agricultural expansion in the MATOPIBA region, indicating the need to improve NT practices towards alleviating soil compaction and improving soil structure. Best management practices are fundamental to restore soil functionality, ensuring crop yields and other ecosystem services.

Examining the sustainability and development challenge in agricultural-forest frontiers of the Amazon Basin through the eyes of locals

Abstract. The Amazon basin is the world's largest rainforest and the most biologically diverse place on Earth. Despite the critical importance of this region, Amazon forests continue inexorably to be degraded and deforested for various reasons, mainly a consequence of agricultural expansion. The development of novel policy strategies that provide balanced solutions, associating economic growth with environmental protection, is still challenging, largely because the perspective of those most affected – local stakeholders – is often ignored. Participatory fuzzy cognitive mapping (FCM) was implemented to examine stakeholder perceptions towards the sustainable development of two agricultural-forest frontier areas in the Bolivian and Brazilian Amazon. A series of development scenarios were explored and applied to stakeholder-derived FCM, with climate change also analysed. Stakeholders in both regions perceived landscapes of socio-economic impoverishment and environmental degradation driven by governmental and institutional deficiencies. Under such abject conditions, governance and well-integrated social and technological strategies offered socio-economic development, environmental conservation, and resilience to climatic changes. The results suggest there are benefits of a new type of thinking for development strategies in the Amazon basin and that continued application of traditional development policies reduces the resilience of the Amazon to climate change, whilst limiting socio-economic development and environmental conservation.

Impacts of Agricultural Expansion (1910s–2010s) on the Water Cycle in the Songneng Plain, Northeast China

Agricultural expansion is one of the primary land use changes on the Earth’s surface. The Songnen Plain in Northeast China is renowned for its Black Soil and is one of the most important agricultural regions of this country. In the last century, its population increased 20-fold and excessive areas of grassland were cultivated. Based on a series of decadal land use/land cover data sets in the plain (1910s–2010s), this study simulated the water balance in each decade using the Weather Research and Forecasting (WRF) model and assessed the water effects of centurial agricultural expansion. Six variables were simulated to explain the land-atmosphere interaction: precipitation, total evapotranspiration, canopy transpiration, canopy interception evaporation, land evaporation and land surface runoff and infiltration. Agreeing with historical climate reanalysis data, the simulated precipitation in the plain did not have a significant trend. However, the total evapotranspiration significantly increased in the study region. The canopy transpiration and interception evaporation increased and the runoff and infiltration decreased, both indicating a drought effect in soil. The drying trend varied spatially with the strongest pattern in the central plain where large areas of wetlands remain. As a consequence of agricultural expansion, the centurial drying process in the fertile Black Soil may put strong pressure on the crop productivity and food safety of this important agricultural region.

The Causes and Consequences of Agricultural Expansion in Matopiba

This paper examines the causes and consequences of the agricultural expansion in Matopiba (Brazil). It documents that agricultural expansion in this region is concentrated in municipalities in the Cerrado biome. Since the late 1990s, these municipalities experience larger increases in agricultural production than municipalities outside the biome. Thes municipalities also experience larger increases in GDP per capita and in the share of households with access to durable goods and to electricity over this period. These results suggest that agricultural expansion in Matopiba is associated with geographic factors and lead to improvements in economic development.

Mire initiation, climatic change and agricultural expansion over the course of the Late-Holocene in the Massif Central mountain range (France): Causal links and implications for mire conservation

Peat initiation during the Late-Holocene was studied in the eastern part of the Massif Central in France from the analysis of numerous conventional and AMS radiocarbon dates obtained in the basal layers of 83 mires, representative of old, thick deposits, but also of younger and marginal mire areas. Radiocarbon dates were calibrated to calendar years BP in order to generate probability distributions of calibrated radiocarbon dates. Only the oldest dates from each mire were used for this statistical analysis.It appears that the Late-Holocene was one of the two most intensive periods of peat initiation since the end of the glacial period. Peat initiation began around 4500cal. BP, following a complete halt in the formation of mires from 5300 to 4500cal. BP. By contrast, peat initiation increased significantly since 2400cal. BP. This history of Late-Holocene peat initiation is not in agreement with chronologies of climatic change in Western Europe. The hypothesis is that peat initiation during the last 4500 years was a consequence of agricultural expansion in the Massif Central in France, which is supported by pollen and archaeological data. Nevertheless, the possible role of climate in certain periods, for example during the Little Ice Age, is not discounted.In term of conservation, the demonstration of a human origin of certain mires leads to a new interest in these ecosystems, and provide a huge argument in order to protect them. Indeed, because of their existence, they testify to the history of agricultural expansion, and some mires are therefore the object of archaeological studies.

Analysis of spatio-temporal land cover changes for hydrological impact assessment within the Nyando River Basin of Kenya

The spatio-temporal changes in the land cover states of the Nyando Basin were investigated for auxiliary hydrological impact assessment. The predominant land cover types whose conversions could influence the hydrological response of the region were selected. Six Landsat images for 1973, 1986, and 2000 were processed to discern the changes based on a methodology that employs a hybrid of supervised and unsupervised classification schemes. The accuracy of the classifications were assessed using reference datasets processed in a GIS with the help of ground-based information obtained through participatory mapping techniques. To assess the possible hydrological effect of the detected changes during storm events, a physically based lumped approach for infiltration loss estimation was employed within five selected sub-basins. The results obtained indicated that forests in the basin declined by 20% while agricultural fields expanded by 16% during the entire period of study. Apparent from the land cover conversion matrices was that the majority of the forest decline was a consequence of agricultural expansion. The model results revealed decreased infiltration amounts by between 6% and 15%. The headwater regions with the vast deforestation were noted to be more vulnerable to the land cover change effects. Despite the haphazard land use patterns and uncertainties related to poor data quality for environmental monitoring and assessment, the study exposed the vast degradation and hence the need for sustainable land use planning for enhanced catchment management purposes.