Conversion Of Native Vegetation Research Articles

Modelling potential landscape sediment delivery due to projected soybean expansion: A scenario study of the Balsas sub-basin, Cerrado, Maranhão state, Brazil

In Brazil, agriculture expansion is taking place primarily in the Cerrado ecosystems. With the aim of supporting policy development and protecting the natural environment at relevant hotspots, a scenario study was conducted that concerned not only land-use change, but also the resulting effects on erosion and deposition. This coupled approach helped to evaluate potential landscape impacts of the land-use scenarios. In the study area, the Balsas sub-basin in Maranhão State, a model chain was used to model plausible future soybean expansion locations (CLUE-S model) and resulting sediment mobilization patterns (LAPSUS model) for a business-as-usual scenario. In the scenario, more erosion occurred in areas where the conversion of natural vegetation into soybean cultivation is likely to take place, but the generated sediments tended to accumulate mainly within the conversion areas, thus limiting the offsite effects of the increased erosion. These results indicated that when agricultural expansion is kept away from rivers, Cerrado conversion will have only a limited impact on the sediment loads of local rivers. Where land-use changes are most concentrated are coincident with areas where more new sediments are generated (higher erosion) and where more sediments are re-deposited.

Aggregate C depletion by plowing and its restoration by diverse biomass-C inputs under no-till in sub-tropical and tropical regions of Brazil

Encapsulation of soil organic carbon (SOC) within aggregates is one of the principal mechanisms for long-term C sequestration, macroaggregate formation and stabilization. Our objectives were to quantify the changes in aggregate size distribution, aggregate-C concentrations and stocks upon conversion of native vegetation (NV) to conventional plow-based tillage (CT), and to assess the rate of aggregation and SOC recovery with no-till (NT) under diverse biomass-C inputs. The study was conducted at both sub-tropical (Ponta Grossa – PG, State of Paraná) and tropical (Lucas do Rio Verde – LRV, State of Mato Grosso) sites in Brazil. The SOC content under NV was used as a baseline to evaluate the depletion rate under CT and the restoration rate under NT. A specific emphasis was given to the largest macroaggregate size class (8–19mm) because of its importance to protecting the recently deposited labile SOC. A discriminant analysis of principal components (DAPC) indicated that NV soil is modified by conversion to an arable land use and that, mechanical tillage, biomass input, and their interactions drastically influence the distribution of aggregate-size classes, aggregation indices, and SOC distribution within aggregates. At both sites, soil aggregation indices were positively impacted by NT and associated with SOC concentration in the labile fractions (e.g., total polysaccharides (TPS), hot water extractable organic C (HWEOC), particulate organic C (POC)). At the PG site, the 8–19mm aggregate size fraction was significantly affected by land use and tillage treatments and represented 54%, 43%, and 72%, under NV, CT, and NT in 0–20cm depth, respectively. Furthermore, the 8–19mm size fraction stored 55%, 45%, and 71% of the total SOC stock under NV (53.8MgCha−1), CT (28.5MgCha−1) and NT (51.2MgCha−1), respectively. At the LRV site, the 8–19mm aggregate size fraction decreased from 50% under Cerrado NV to 35% under CT, and ranged from 33% to 51% under diverse biomass-C input under NT in 0–20cm depth. The 8–19mm size fraction stored 52%, 37%, and 41% of the total SOC stock across all aggregate sizes under NV (25.4MgCha−1), CT (11.7MgCha−1), and NT (9.9–18.1MgCha−1), respectively. The difference in SOC stock among land uses is largely attributed to storage in the 8–19mm aggregate size class, indicating that NT cropping systems rebuilt the largest macroaggregates, which are crucial for stabilization of SOC.

Using Historical General Land Office Survey Notes to Quantify the Effects of Irrigated Agriculture on Land Cover Change in an Arid Lands Watershed

In arid regions of the world, the conversion of native vegetation to agriculture requires the construction of an irrigation infrastructure that can include networks of ditches, reservoirs, flood control modifications, and supplemental groundwater pumping. The infrastructure required for agricultural development has cumulative and indirect effects, which alter native plant communities, in parallel with the direct effects of land use conversion to irrigated crops. Our study quantified historical land cover change over a 150-year period for the Walker River Basin of Nevada and California by comparing direct and indirect impacts of irrigated agriculture at the scale of a 10,217 km2 watershed. We used General Land Office survey notes to reconstruct land cover at the time of settlement (1860–1910) and compared the settlement-era distribution of land cover to the current distribution. Direct conversion of natural vegetation to agricultural land uses accounted for 59 percent of total land cover change. Changes among nonagricultural vegetation included shifts from more mesic types to more xeric types and shifts from herbaceous wet meadow vegetation to woody phreatophytes, suggesting a progressive xerification. The area of meadow and wetland has experienced the most dramatic decline, with a loss of 95 percent of its former area. Our results also show Fremont cottonwood, a key riparian tree species in this region, is an order of magnitude more widely distributed within the watershed today than at the time of settlement. In contrast, areas that had riparian gallery forest at the time of settlement have seen a decline in the size and number of forest patches.

Exploring short-term leaf-litter decomposition dynamics in a Mediterranean ecosystem: dependence on litter type and site conditions

Plant litter decomposition plays an important role in the storage of soil organic matter in terrestrial ecosystems. Conversion of native vegetation to agricultural lands and subsequent land abandonment can lead to shifts in canopy structure, and consequently influence decomposition dynamics by alterations in soil temperature and moisture conditions, solar radiation exposure, and soil erosion patterns. This study was conducted to assess which parameters were more closely related to short-term decomposition dynamics of two predominant Mediterranean leaf litter types. Using the litterbag technique, we incubated leaf litter of Pinus halepensis and Rosmarinus officinalis in two Mediterranean land-uses with different degree of vegetation cover (open forest, abandoned agricultural field). Fresh local litter lost between 20 and 55% of its initial mass throughout the 20-month incubation period. Rosemary litter decomposed faster than pine litter, showing net N immobilization in the early stages of decomposition, in contrast to the net N release exhibited by pine litter. Parameters related to litter quality (N content or C:N) or land-use/site conditions (ash content, an index of soil deposition on litter) were found to explain the cross-site variability in mass loss rates for rosemary and Aleppo pine litter, respectively. The results from this study suggest that decomposition drivers may differ depending on litter type in this Mediterranean ecosystem. While rosemary litter was degraded mainly by microbial activity, decomposition of pine litter was likely driven primarily by abiotic processes like soil erosion.

Concluding remarks: overall impacts on biodiversity and future perspectives for conservation in the Pantanal biome

The Pantanal biome is characterised by seasonal flooding which determines specific ecosystem processes, with the occurrence of adapted plants and animals to the annual shrinking and expansion of habitats due to the seasonal hydrological regime. Biodiversity abundance varies during the dry and wet seasons. The Pantanal's biodiversity is a fundamental component of ecosystem services for human society, including nutrient cycling, fish production, ecotourism, carbon storage, flood control, among others, which are relevant to regional and global environmental consequences. The biome has been impacted by the conversion of natural vegetation into agricultural fields and pasture for cattle raising, with alteration and loss of natural habitats and biodiversity. Major negative impacts occur in uplands, with drastic deforestation of savanna vegetation, where main rivers feeding the Pantanal have their springs. This article discusses future needs and priorities for ecological research, in order to better understand the biome's natural system, to achieve conservation and sustainable use.

A conservation agenda for the Pantanal's biodiversity

The Pantanal's biodiversity constitutes a valuable natural resource, in economic, cultural, recreational, aesthetic, scientific and educational terms. The vegetation plus the seasonal productivity support a diverse and abundant fauna. Many endangered species occur in the region, and waterfowl are exceptionally abundant during the dry season. Losses of biodiversity and its associated natural habitats within the Pantanal occur as a result of unsustainable land use. Implementation of protected areas is only a part of the conservation strategy needed. We analyse biodiversity threats to the biome under seven major categories: 1) conversion of natural vegetation into pasture and agricultural crops, 2) destruction or degradation of habitat mainly due to wild fire, 3) overexploitation of species mainly by unsustainable fishing, 4) water pollution, 5) river flow modification with implantation of small hydroelectric plants, 6) unsustainable tourism, and 7) introduction of invasive exotic species.

Impact of pasture, agriculture and crop-livestock systems on soil C stocks in Brazil

Changes in land use can result in either sources or sinks of atmospheric carbon (C), depending on management practices. In Brazil, significant changes in land use result from the conversion of native vegetation to pasture and agriculture, conversion of pasture to agriculture and, more recently, the conversion of pasture and agriculture to integrated crop-livestock systems (ICL). The ICL system proposes a diversity of activities that include the strategic incorporation of pastures to agriculture so as to benefit both. In agricultural areas, for example, the implementation of ICL requires the production of quality forage for animals between crops as well as the production of straw to facilitate the sustainability of the no-tillage (NT) management system. The objective of this study was to evaluate the modifications in soil C stocks resulting from the main processes involved in the changes of land use in Amazonia and Cerrado biomes. For comparison purposes, areas under native vegetation, pastures, crop succession and ICL under different edapho-climatic conditions in Amazonia and Cerrado biomes were evaluated. This study demonstrated that the conversion of native vegetation to pasture can cause the soil to function either as a source or a sink of atmospheric CO 2, depending on the land management applied. Non-degraded pasture under fertile soil showed a mean accumulation rate of 0.46 g ha −1 year −1. Carbon losses from pastures implemented in naturally low fertile soil ranged from 0.15 to 1.53 Mg ha −1 year −1, respectively, for non-degraded and degraded pasture. The conversion of native vegetation to agriculture in areas under the ICL system, even when cultivated under NT, resulted in C losses of 1.31 in six years and of 0.69 Mg ha −1 in 21 years. The conversion of a non-degraded pasture to cropland (soybean/sorghum) released, in average, 1.44 Mg of C ha −1year −1to the atmosphere. The ICL system in agricultural areas has shown evidences that it always functions as a sink of C with accumulation rates ranging from 0.82 to 2.58 Mg ha −1 year −1. The ICL produces soil C accumulation and, as a consequence, reduces atmospheric CO 2 in areas formerly cultivated under crop succession. However, the magnitude of C accumulation in soil depends on factors such as the types of crops, the edapho-climatic conditions and the amount of time the area is under ICL.

Brazilian Law: Full Speed in Reverse?

Is it possible to combine modern tropical agriculture with environmental conservation? Brazilian agriculture offers encouraging examples that achieve high production together with adequate environmental protection ([ 1 ][1], [ 2 ][2]). However, these effective practices may soon lose ground to the conventional custom of resource overexploitation and environmental degradation. A revision to the Forest Act, the main Brazilian environmental legislation on private land, has just been submitted to Congress, and there is a strong chance that it will be approved. The proposed revision raises serious concerns in the Brazilian scientific community, which was largely ignored during its elaboration. The new rules will benefit sectors that depend on expanding frontiers by clear-cutting forests and savannas and will reduce mandatory restoration of native vegetation illegally cleared since 1965. If approved, CO2 emissions may increase substantially, instead of being reduced as was recently pledged in Copenhagen. Simple species-area relationship analyses also project the extinction of more than 100,000 species, a massive loss that will invalidate any commitment to biodiversity conservation. Proponents of the new law, with well-known ties to specific agribusiness groups, claim an alleged shortage of land for agricultural expansion, and accuse the current legislation of being overprotective of the environment in response to foreign interests fronted by green nongovernmental organizations. However, recent studies ([ 3 ][3]) show that, without further conversion of natural vegetation, crop production can be increased by converting suitable pastures to agriculture and intensifying livestock production on the remaining pasture. Brazil has a high potential for achieving sustainable development and thereby conserving its unique biological heritage. Although opposed by the Ministry of the Environment and most scientists, the combination of traditional politicians, opportunistic economic groups, and powerful landowners may be hard to resist. The situation is delicate and serious. Under the new Forest Act, Brazil risks suffering its worst environmental setback in half a century, with critical and irreversible consequences beyond its borders. 1. [↵][4] 1. D. Nepstad 2. et al ., Science 326, 1350 (2009). [OpenUrl][5][Abstract/FREE Full Text][6] 2. [↵][7] 1. C. R. Fonseca 2. et al ., Biol. Conserv. 142, 1209 (2009). [OpenUrl][8][CrossRef][9] 3. [↵][10] 1. G. Sparovek 2. et al ., Consideracoes sobre o Codigo Florestal brasileiro (“Luiz de Queiroz” College of Agriculture, University of Sao Paulo, Piracicaba, Brazil, 2010); [http://eco.ib.usp.br/lepac/codigo\_florestal/Sparovek\_etal_2010.pdf][11]. [1]: #ref-1 [2]: #ref-2 [3]: #ref-3 [4]: #xref-ref-1-1 View reference 1 in text [5]: {openurl}?query=rft.jtitle%253DScience%26rft.stitle%253DScience%26rft.issn%253D0036-8075%26rft.aulast%253DNepstad%26rft.auinit1%253DD.%26rft.volume%253D326%26rft.issue%253D5958%26rft.spage%253D1350%26rft.epage%253D1351%26rft.atitle%253DThe%2BEnd%2Bof%2BDeforestation%2Bin%2Bthe%2BBrazilian%2BAmazon%26rft_id%253Dinfo%253Adoi%252F10.1126%252Fscience.1182108%26rft_id%253Dinfo%253Apmid%252F19965742%26rft.genre%253Darticle%26rft_val_fmt%253Dinfo%253Aofi%252Ffmt%253Akev%253Amtx%253Ajournal%26ctx_ver%253DZ39.88-2004%26url_ver%253DZ39.88-2004%26url_ctx_fmt%253Dinfo%253Aofi%252Ffmt%253Akev%253Amtx%253Actx [6]: /lookup/ijlink/YTozOntzOjQ6InBhdGgiO3M6MTQ6Ii9sb29rdXAvaWpsaW5rIjtzOjU6InF1ZXJ5IjthOjQ6e3M6ODoibGlua1R5cGUiO3M6NDoiQUJTVCI7czoxMToiam91cm5hbENvZGUiO3M6Mzoic2NpIjtzOjU6InJlc2lkIjtzOjEzOiIzMjYvNTk1OC8xMzUwIjtzOjQ6ImF0b20iO3M6MjQ6Ii9zY2kvMzI5LzU5ODkvMjc2LjIuYXRvbSI7fXM6ODoiZnJhZ21lbnQiO3M6MDoiIjt9 [7]: #xref-ref-2-1 View reference 2 in text [8]: {openurl}?query=rft.jtitle%253DBiol.%2BConserv.%26rft.volume%253D142%26rft.spage%253D1209%26rft_id%253Dinfo%253Adoi%252F10.1016%252Fj.biocon.2009.02.017%26rft.genre%253Darticle%26rft_val_fmt%253Dinfo%253Aofi%252Ffmt%253Akev%253Amtx%253Ajournal%26ctx_ver%253DZ39.88-2004%26url_ver%253DZ39.88-2004%26url_ctx_fmt%253Dinfo%253Aofi%252Ffmt%253Akev%253Amtx%253Actx [9]: /lookup/external-ref?access_num=10.1016/j.biocon.2009.02.017&link_type=DOI [10]: #xref-ref-3-1 View reference 3 in text [11]: http://eco.ib.usp.br/lepac/codigo_florestal/Sparovek_etal_2010.pdf

Influência do manejo do solo nas propriedades químicas e físicas em topossequência na bacia do rio Araguaia, Estado do Tocantins

A conversão do Cerrado nativo em áreas de exploração agrícola pode modificar os processos de decomposição e síntese da matéria orgânica do solo e, assim, na disponibilidade de nutrientes. Objetivou-se avaliar as propriedades químicas e físicas do solo em topossequência caracterizada por apresentar uso com pastagem cultivada com Brachiaria brizantha ao lado do Cerrado nativo, na camada de 0- 15 cm de profundidade. O estudo foi realizado no município de Colmeia, Estado do Tocantins. Foram determinados 10 pontos de coleta (cinco para Cerrado nativo e cinco para pasto) para cada posição do relevo (topo, encosta e pedimento); em cada ponto amostral, foram coletados solos em três profundidades (0-5, 5-10 e 10- 15 cm), totalizando 90 amostras. Foram realizadas as seguintes análises químicas e físicas: C orgânico, P, K+, Ca2+, Mg2+, H + Al, pH e granulometria. O C orgânico não apresentou diferença (p > 0,05) entre os valores encontrados no Cerrado nativo e pastagem e as posições do relevo avaliadas. A conversão de Cerrado nativo para uso agropecuário reduziu os teores de P. Os teores de K trocável não foram alterados pela retirada da cobertura vegetal original. Observou-se aumento dos teores de areia quando se passou da meia-encosta para o pedimento.

Global scale DAYCENT model analysis of greenhouse gas emissions and mitigation strategies for cropped soils

Conversion of native vegetation to cropland and intensification of agriculture typically result in increased greenhouse gas (GHG) emissions (mainly N 2O and CH 4) and more NO 3 leached below the root zone and into waterways. Agricultural soils are often a source but can also be a sink of CO 2. Regional and larger scale estimates of GHG emissions are usually obtained using IPCC emission factor methodology, which is associated with high uncertainty. To more realistically represent GHG emissions we used the DAYCENT biogeochemical model for non-rice major crop types (corn, wheat, soybean). IPCC methodology estimates N losses from croplands based solely on N inputs. In contrast, DAYCENT accounts for soil class, daily weather, historical vegetation cover, and land management practices such as crop type, fertilizer additions, and cultivation events. Global datasets of weather, soils, native vegetation, and cropping fractions were mapped to a 1.9° × 1.9° resolution. Non-spatial data (e.g., rates and dates of fertilizer applications) were assumed to be identical within crop types across regions. We compared model generated baseline GHG emissions and N losses for irrigated and rainfed cropping with land management alternatives intended to mitigate GHG emissions. Reduced fertilizer resulted in lower N losses, but crop yields were reduced by a similar proportion. Use of nitrification inhibitors and split fertilizer applications both led to increased (~ 6%) crop yields but the inhibitor led to a larger reduction in N losses (~ 10%). No-till cultivation, which led to C storage, combined with nitrification inhibitors, resulted in reduced GHG emissions of ~ 50% and increased crop yields of ~ 7%.

Rapid decomposition of maize detritus in agricultural headwater streams

Headwater streams draining agricultural landscapes receive maize leaves (Zea mays L.) via wind and surface runoff, yet the contribution of maize detritus to organic-matter processing in agricultural streams is largely unknown. We quantified decomposition and microbial respiration rates on conventional (non-Bt) and genetically engineered (Bt) maize in three low-order agricultural streams in northwestern Indiana, USA. We also examined how substrate quality and in-stream nutrient concentrations influenced microbial respiration on maize by comparing respiration on maize and red maple leaves (Acer rubrum) in three nutrient-rich agricultural streams and three low-nutrient forested streams. We found significantly higher rates of microbial respiration on maize vs. red maple leaves and higher rates in agricultural vs. forested streams. Thus both the elevated nutrient status of agricultural streams and the lability of maize detritus (e.g., low carbon-to-nitrogen ratio and low lignin content) result in a rapid incorporation of maize leaves into the aquatic microbial food web. We found that Bt maize had a faster decomposition rate than non-Bt maize, while microbial respiration rates did not differ between Bt and non-Bt maize. Decomposition rates were not negatively affected by genetic engineering, perhaps because the Bt toxin does not adversely affect the aquatic microbial assemblage involved in maize decomposition. Additionally, shredding caddisflies, which are known to have suppressed growth rates when fed Bt maize, were depauperate in these agricultural streams, and likely did not play a major role in maize decomposition. Overall, the conversion of native vegetation to row-crop agriculture appears to have altered the quantity, quality, and predictability of allochthonous carbon inputs to headwater streams, with unexplored effects on stream ecosystem structure and function.

Padrões de autocorrelação espacial de índices de vegetação MODIS no bioma cerrado

Embora os índices de vegetação MODIS estejam sendo extensivamente investigados quanto ao seu potencial para o mapeamento e monitoramento biofísico do bioma Cerrado, em particular no que diz respeito à sazonalidade e fenologia da cobertura vegetal, pouco se sabe sobre o comportamento espacial desses índices em escalas regionais. Assim, neste estudo foram avaliados, à escala adotada em estudos de macroecologia (Resolução de 1º x 1º), os padrões de autocorrelação espacial do EVI (índice de vegetação realçado) e NDVI (índice de vegetação da diferença normalizada), utilizando-se índices I de Moran obtidos em diferentes classes de distância geográfica (correlogramas espaciais). Em média, os valores apresentados por esses índices são autocorrelacionados até uma distância aproximada de 800 km, que pode revelar um padrão de manchas afetado por variação ambiental e conversão da vegetação nativa. No entanto, esses padrões de similaridade espacial são principalmente influenciados pelo contraste sazonal encontrado no bioma Cerrado, bem como em função dos padrões de cobertura da terra e do tipo de índice considerado (i.e., EVI ou NDVI).

Pairwise comparison of soil organic particle-size distributions in native savannas and Eucalyptus plantations in Congo

Conversion of native vegetation into fast-growing tree plantations is known to affect soil organic matter (SOM): soil carbon (C) and nitrogen (N) content and their distribution in particle-size fractions can be modified in various ways depending on numerous factors, such as soil properties, SOM levels prior to conversion, climatic conditions, silvicultural practices and fire occurrence. Since 1978, 43,000 ha of clonal eucalyptus plantations have been established on sandy coastal plains under savannas near Pointe-Noire, Congo. We investigated the effects of afforestation on topsoil (0–10 cm) C and N through the analysis of their distribution in particle-size fractions using a pairwise experimental design that compared adjacent savannas and plantations. The studied plantations were of different ages (2–30-year-old stands) and differently affected by accidental fires. No significant difference in total topsoil C, N or C/N was observed between young plantations and savanna. In old plantations that had not been affected by fire, total topsoil C content was twice as high as in savanna ( p = 0.0016 ), on average, mostly involving fractions > 50 μ m. By contrast, total topsoil N did not differ significantly at these sites. In old plantations affected by fire, total topsoil C content did not differ significantly from that in savanna, but total topsoil N was 26 % lower in plantations than in savanna ( p = 0.0063 ), on average, and the decrease affected fractions < 200 μ m especially. Whatever the fire occurrence, total topsoil C/N was higher in old plantations than in savanna, in fractions > 20 μ m especially.

Climate Change and Moving Species: Furthering the Debate on Assisted Colonization

With global climate change looming large in the public psyche, the recent paper by McLachlan et al. (2007) and its popular accompaniment (Fox 2007) are timely indeed. Of course some conservation biologists will not wish to think about the prospect of actively moving species that are threatened with extinction by climate change. For them this would be almost analogous to handing out placebos in the midst of an epidemic and worse yet, these placebos may have serious unintended consequences if translocated species become invasive. They will probably argue that we should focus almost exclusively on two central roles for conservation biology: (1) facilitating natural range shifts by redoubling efforts to maintain or restore large-scale connectivity (Hunter et al. 1988; Hannah et al. 2002) and (2) working with our fellow environmental professionals to avoid carbon-management solutions that will have unacceptable consequences for biodiversity (e.g., by directing biofuel production away from sites that would involve the conversion of native vegetation into fuel farms; Cook & Beyea 2000). These two roles will be very demanding, but I believe we should allocate a small portion of our attention to the issue of assisted colonization that McLachlan et al. (2007) have brought to the fore. McLachlan et al. propose framing the debate around two considerations—perception of risk and confidence in ecological understanding—that can be construed to generate an axis or continuum from scientists who would strongly support assisted colonization to those who would oppose it. I think it is useful to advance this exercise by considering three issues that can also be construed as continua: species that are more or less acceptable to translocate, sites that are more or less acceptable for receiving translocations, and projects that are more or less acceptable because of their socioeconomic ramifications and feasibility. I have used the term assisted colonization in contrast to assisted migration used by McLachlan et al.

Monitoring land use change in the Lake Taupo catchment between 1975, 1990 and 2002 using satellite remote sensing data

Conversion of native vegetation into farmed grassland in the Lake Taupo catchment commenced in the late 1950s. The lake's iconic value is being threatened by the slow decline in lake water quality that has become apparent since the 1970s. Keywords: satellite remote sensing, nitrate leaching, land use change, livestock farming, land management

Transformations of soil macroinvertebrate populations after native vegetation conversion to pasture cultivation (Brazilian Cerrado)

This study describes the impact on soil fauna populations after conversion of native vegetation to pastures. The invertebrate edaphic macrofauna was evaluated in areas where pastures are being introduced and renewed in the Cerrado, savannah biome. Five sites were considered in a Ferralsol area: a native vegetation area of Cerrado (CE), the deforested Cerrado (DC) and three areas involving pastures:9-years old pasture of Brachiaria brizantha (Pa9), a renewed pasture with the same plant (PaB), and a renewed pasture with Brachiaria associated with a legume, Stylosanthes guianensis (PaS). Thirty-six samples, at random, spaced 20 m apart, were removed from each site. A soil volume of 25 × 25 × 10 cm was delimited at each sampling point. The macrofauna was separated from the soil manually and then identified and weighed. The old pasture presents a higher biomass than the Cerrado area. Mechanical tilling, in both the old pasture and the Cerrado, caused a marked decrease in macrofauna populations. The renewed pastures PaB and PaS showed less diversity, population density and biomass than the deforested Cerrado. Termites were more abundant in the old pasture than in the other areas, however, the Cerrado (CE) showed greater diversity of termite genera and a greater number of predators (Araneae, Scorpions and Pseudoscorpions).

Linking Landscape and Water Quality in the Mississippi River Basin for 200 Years

Two centuries of land use in the Mississippi River watershed are reflected in the water quality of its streams and in the continental shelf ecosystem receiving its discharge. The most recent influence on nutrient loading—intense and widespread farming and especially fertilizer use—has had a more significant effect on water quality than has land drainage or the conversion of native vegetation to cropland and grazing pastures. The 200-year record of nutrient loading to offshore water is reflected in the paleoreconstructed record of plankton in dated sediments. This record illustrates that the development of fair, sustained management of inland ecosystems is linked to the management of offshore systems. Land use in this fully occupied watershed is under the strong influence of national policies affecting all aspects of the human ecosphere. These policies can be modified for better or worse, but water quality will probably change only gradually because of the strong buffering capacity of the soil ecosystem.