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A Faixa de Fronteira possui restrições ao direito de propriedade. Cerca de 35% dos municípios paranaenses situam-se nessa região, imersos em insegurança jurídica, frequentes conflitos agrários e incertezas fundiárias. O artigo apresenta elementos de análise das dimensões da regularização fundiária rural nessa Faixa de Fronteira, por meio da sistematização de mapeamentos, levantamentos amostrais, documentais e estatísticos. Os resultados demonstram entraves para a Governança Fundiária dos imóveis do INCRA e da União Federal, atravessados por contingências históricas imobilizadoras de políticas públicas de regularização fundiária rural. Observa-se discrepâncias entre dados oficiais, posses e subdivisões, apontando para falta de sistema informatizado, recursos orçamentários escassos e reduzido número de servidores num cenário em que o aparato administrativo cria problemas para si mesmo. Os resultados obtidos apontam diversas possibilidades de pesquisa a fim de se conhecer quais as reais condições de não proprietários nessa Faixa em relação à ratificação e regularização de seus imóveis.

Deforestation of riparian areas is a major driver of biodiversity loss in aquatic ecosystems. Thus, we investigated the influence of forest cover and physical and chemical characteristics of streams on zooplankton communities in the southeastern Amazon. We addressed the following questions: (1) Are environmental factors (water physical and chemical characteristics and landscape variables) and dispersive processes (reflected in the spatial structure among sampling sites) efficient predictors of zooplankton communities in different hydrologic seasons? (2) Can zooplankton species be indicators of watersheds’ forest-cover levels? We sampled 15 streams located in nine rural settlements in northern Mato Grosso, Brazil, in the dry (August) and rainy (March) seasons of 2017. The forest-cover level had a significant effect on the physical and chemical characteristics (conductivity, dissolved oxygen, and temperature) of streams and also on the structure and composition of zooplankton communities, mainly of rotifers and testate amoebae. Areas with low vegetation cover had seasonal changes in species richness, individuals density, and zooplankton community structure. Environmental and spatial variables had no significant effect on the structure of zooplankton communities, which may indicate the strong influence of stochastic factors. Species from three zooplankton groups (rotifers, microcrustaceans, and testate amoebae) were indicators of forest-cover classes. This study provided valuable contributions to the conservation of riparian ecosystems and the use of biological indicators in environmental monitoring programs.

Solutions for ecological and economic problems posed by Hakea sericea invasions rely on scientific knowledge. We conducted a systematic review to analyze and synthesize the past and current scientific knowledge concerning H. sericea invasion processes and mechanisms, as well as monitoring and control techniques. We used ISI Web of Science, Scopus, and CAPES Periodicals to look for publications on the ecological and environmental factors involved in H. sericea establishment (question 1); responses of H. sericea to fire in native and invaded ecosystems (question 2); and H. sericea monitoring and control methods (question 3). We identified 207 publications, 47.4% of which related to question 1, mainly from Australia and South Africa, with an increasing trend in the number of publications on monitoring and modeling. The traits identified in our systematic review, such as adaptations to dystrophic environments, drought resistance, sclerophylly, low transpiration rates, high nutrient use efficiency, stomatal conductance and photosynthetic rates, strong serotiny, proteoid roots and high post-fire seed survival and seedling recruitment, highlighted that H. sericea is a successful invader species due to its long adaptive history mediated by an arsenal of ecophysiological mechanisms that place it at a superior competitive level, especially in fire-prone ecosystems. Integrated cost-effective control methods in selected areas and the incorporation of information on the temporal invasion dynamics can significantly improve invasion control and mitigate H. sericea impacts while maintaining the supply of ecosystem services in invaded areas.

Os Sistemas agroflorestais (SAFs) são sistemas de produção agrícola que atuem próximos a dinâmica da natureza. O objetivo desta pesquisa foi avaliar características químicas, físicas e microbiológicas de solos de SAF’s em três estágios sucessionais e em uma área controle (pastagem), localizadas em Brasília, Distrito Federal. O histórico da área foi elaborado a partir de informações coletadas em entrevista. Realizou-se análises químicas (pH, MO, C, N, C:N, P, K, Ca, Mg e Al), físicas (granulometria) e microbiológicas (glomalina facilmente extraível). Os dados foram analisados através de análise multivariadas e univariadas. A agrobiodiversidade vegetal foi de 19 espécies no SAF estabelecido, 11 no SAF em formação, 5 no SAF inicial e 2 na pastagem. Os SAFs estabelecido e em formação foram os que obtiveram o maior aumento progressivo de C, MO, K e Ca. Quanto maior o estágio sucessional, maior o grau de agregação e a distribuição dos agregados. Os solos de todos os SAFs e da pastagem apresentaram a glomalina, sendo sua maior concentração nos SAFs. Conclui-se que quanto maior o tempo de manejo, maiores serão as diferenças nas características químicas, físicas e microbiológicas do solo. A evolução temporal dos sistemas favorece para uma maior disponibilidade de nutrientes, aumento da atividade biológica e da capacidade de agregação, aumentando, consequentemente, a camada orgânica do solo, retendo mais carbono no sistema, gerando serviços ecossistêmicos e contribuindo para a atenuação dos efeitos danosos de processos agrícolas no solo e no ecossistema.

Compreender as dinâmicas territoriais de uso e ocupação da terra e as implicações políticas administrativas no processo de tomada de decisão sobre a questão climática no estado do Mato Grosso, Brasil consiste no objetivo deste estudo. Os autores, em pesquisa bibliográfica e estudos de campo realizaram uma investigação sobre o as decisões governamentais em temáticas ambientais recentes no estado e como as trajetórias de setores diversos influem nesta construção. Na primeira parte do texto há uma breve reconstrução do processo ocupacional estadual, sua dinâmica territorial em função da expansão do agronegócio e o fenômeno de desmatamento que já consumiu parte considerável das florestas. Na segunda parte, os autores se debruçam sobre entrevistas feitas em 2018 com gestores políticos, visando compreender a ligação do entrevistado com a temática ambiental, a percepção deles sobre a agenda ambiental mato-grossense no período de 2004 a 2015, como estes percebiam a interferência política na agenda ambiental e suas contradições e, por fim, uma abordagem exploratória sobre as diferentes iniciativas em curso na agenda ambiental local. Resulta do estudo uma leitura que dialoga com a abordagem da sociologia política em reconhecer um leque ampliado de instituições e atores no processo das decisões governamentais, mas que esbarra nos interesses do setor do agronegócio, que domina a política. Por mais que haja uma tentativa de organizações não governamentais e instâncias mistas de envolver a pauta ambiental no desenvolvimento mato-grossense, as ambiguidades ainda são bastante enfatizadas pelos entrevistados. L'objectif de cette étude est de comprendre la dynamique territoriale de l'utilisation et de l'occupation des terres et les implications politiques administratives dans le processus de prise de décision sur la question climatique dans l'État du Mato Grosso au Brésil. Les auteurs, dans des recherches bibliographiques et des études de terrain, ont mené une enquête sur les décisions gouvernementales dans les thèmes environnementaux récents dans l'État et comment les trajectoires des différents secteurs influencent cette construction. Dans la première partie du texte, il y a une brève reconstruction du processus d’occupation de l'État, de sa dynamique territoriale due à l'expansion de l'agro-industrie et au phénomène de déforestation qui a déjà consommé une partie considérable des forêts. Dans la deuxième partie, les auteurs se penchent sur des entretiens réalisés en 2018 avec des responsables politiques, dans le but de comprendre le lien de l'interviewé avec le thème environnemental, leur perception du programme environnemental du Mato Grosso de 2004 à 2015, comment ils ont perçu l'interférence politique sur l'agenda environnemental et ses contradictions et, enfin, une approche exploratoire des différentes initiatives en cours sur l'agenda environnemental local. L'étude résulte d'une lecture dialoguant avec l'approche de la sociologie politique en reconnaissant un large éventail d'institutions et d'acteurs dans le processus de décisions gouvernementales, mais qui se heurte aux intérêts du secteur agroalimentaire, qui domine la politique. Autant il y a une tentative par des organisations non gouvernementales et des organismes mixtes d'impliquer l'agenda environnemental dans le développement du Mato Grosso, les ambiguïtés sont encore fortement soulignées par les répondants. Understanding the territorial dynamics of land use and occupation and the administrative political implications in the decision-making process on the climate issue in the state of Mato Grosso – Brazil is the objective of this study. The authors, in bibliographic research and field studies conducted an investigation on governmental decisions in recent environmental issues in the state and how the trajectories of various sectors influence this construction. In the first part of the text there is a brief reconstruction of the occupational process of Mato Grosso, its territorial dynamics due to the expansion of agribusiness and the phenomenon of deforestation that has already consumed considerable part of the forests of the territory of the State. In the second part, the authors focus on interviews with political managers, aiming to understand the connection of the informant with the environmental theme, their perception of the environmental agenda Mato Grosso in the period from 2004 to 2015, as these perceived the Political interference in the environmental agenda and its contradictions and, finally, an exploratory approach to the different initiatives underway in the state's environmental agenda. It follows from the study a reading that dialogues with the approach of political sociology in recognizing an enlarged range of institutions and actors in the process of governmental decisions, but which is in the interests of the agribusiness sector, which dominates the local policy. As much as there is an attempt by non-governmental organizations and mixed instances to involve the environmental agenda in the Mato Grosso development, the ambiguities are still greatly emphasized by the informants.

Nesse estudo descrevemos a dinâmica de cobertura da terra e de estoques e emissoes brutas de carbono (C) em 55 assentamentos na Amazonia Legal, situados em 22 municipios do norte de Mato Grosso, entre julho de 2008 e julho de 2016 e discutimos suas implicacoes para politicas de mudancas climaticas. A estimativa de C foi baseada na mudanca da cobertura da terra, obtida por processamento de imagens Spot, Sentinel e Landsat e visitas de campo, e dados secundarios de valores medios de carbono por classe de vegetacao. Considerando a cobertura potencial da vegetacao, ou seja, a cobertura hipotetica antes da acao antropica na area, estimada pelo Instituto Brasileiro de Geografia e Estatistica, os 55 assentamentos eram originalmente cobertos por 685 mil ha de vegetacao nativa (103 Teragrama (Tg) de C). O desmatamento ate 2016 (ocorrido antes e depois de 2008) foi superior a 65% da area de cobertura nativa. A maior parte dele (77%) ocorreu ate 2008. Embora a restauracao de areas consolidadas (desmatadas antes de julho de 2008) nao seja obrigatoria, ela pode gerar receita com creditos de carbono, cotas de reserva ambiental, manejo florestal e agrosilvicultura. A area desmatada por assentamento ate 2008 teve forte relacao com a taxa de desmatamento por assentamento entre 2008 e 2016. Isso sugere que, os que desmataram muito ate 2008 tendem a continuar a desmatar. A taxa de desmatamento anual entre 2008 e 2016 foi de 12,7 mil hectares (ha). Caso permaneca a mesma, toda a vegetacao nativa da area tera sido suprimida em menos de duas decadas. Em geral, os assentamentos da modalidade de Projetos de Desenvolvimento Sustentavel tiveram menor desmatamento, o que indica que e possivel associar reforma agraria e desenvolvimento economico e social com a conservacao da floresta amazonica. Contudo, e preciso fortalecer as politicas voltadas para o pagamento de servicos ambientais e para os produtos da floresta em pe (manejo florestal de baixo impacto e de recursos nao madeireiros). Para isso, e essencial a integracao de esforcos do governo federal, estadual, municipal e do mercado.

Cabruca agroforestry systems play a crucial role as ecological corridors in biodiversity conservation on the south coast of Bahia. The decline in these agroecosystems due to land-use changes poses as a major threat to Atlantic Forest biodiversity conservation. Therefore, efficient agricultural extension actions towards the maintenance of these agroforestry systems are paramount. This research evaluated the process of construction and sharing of knowledge in agricultural extension practices toward agroecological management of the Cabruca in three agrarian reform settlements, and the challenges for the persistence of Cabruca in this region. We interviewed seven farmers and three extension agents from the Cabruca Institute. The study showed that most of the proposed practices adopted by farmers were already part of the traditional Cabruca management. The main limitations for the adoption of new practices were that they required increased labor, which is scarce and expensive. In fact, exodus and aging of the rural population remain major threats for long-term sustainability and persistence of Cabruca agroecosystems. Other limitations for organic management include the absence of differentiated price and marketing channels for organic cocoa and other products for the Cabruca social biodiversity. Although the process of construction and sharing of knowledge was participatory, overall community participation in the process was low. Extensionists should devise and implement innovative community engagement strategies to empower these small-scale farmer communities to ensure the persistence of Cabruca in the region and consolidate organic management of Cabruca agroecosystems.

Large-scale land governance and environmental monitoring are huge challenges for tropical countries with significant forest cover. In this discussion paper, we analyzed the conditions and achievements of the implementation of the Brazilian Rural Environmental Registry (CAR). CAR was an important breakthrough of the Native Vegetation Protection Law for environmental monitoring in Brazil. CAR is the mandatory and self-declaratory registry for rural properties. Owners must provide georeferenced delimitation of their property’s boundaries and legally protected areas, such as Areas of Permanent Preservation and Legal Reserves. We used the example of the State of Mato Grosso (transition between the two largest biomes in Brazil – Amazon and Cerrado) to discuss how CAR and its national information system (called SICAR) provide important inputs for land-use, environmental, economic, territorial, and food security policies. Future policies should include increasing investments and coordination between different sectors to integrate CAR and conservation efforts with agricultural production and sustainable management.

Many activities related to the expansion of food supply, energy and infrastructure result in great environmental impacts, whose most visible features are observed in the degradation of large areas. The present study demonstrates how the combined use of stonemeal technology and agroforestry systems can help to reverse such impacts, allying the recovery of degraded areas with agricultural and forest production. The study area is located in a hydroelectric reservoir affected by the siltation process and soil erosion in the hydrographic basin of the San Francisco River, Brazil. An Experimental Unit (EU) was set up in the Ecological Station of Pirapitinga (Tres Marias reservoir). The design of the EU was based on a factorial design, with seven treatments applied on six native tree species, with three replications (21 blocks). The germination and establishment data of each species were considered in the different treatments. The oxides concentration and fertility level of sediments were analyzed for the determination of the sampling points in the reservoir. The experiment and evaluation were conducted over six years, and the sediments analysis presented high levels of the essential macronutrients K2O, MgO and TiO2, while CaO and Na2O levels were significantly low, due to their high solubility and mobility. The P2O5 also showed equally low values. After two years, soil pH was balanced, especially in the blocks with mineral inputs. P, K, Ca and Mg concentrations were increased up to 5 times more than those of original soil of the EU, and the highest values were found in the remineralizer + sediment treatment. The use of geological material (e.g. mining waste) and organic compost was proved to be an adequate and sustainable technology to mitigate degradation processes. Besides, locally available sources of organic matter enhanced.

Understanding the relationships between Coffea arabica L. and the native tree community of secondary forests regrowing after the abandonment of coffee plantations is important because, as a non-native species in the Neotropics, coffee can outcompete native species, reducing diversity and forests ecosystem services. We aimed to answer three questions: 1) Does coffee regeneration in secondary forests differ between shaded and unshaded abandoned plantations?; 2) How is coffee basal area related to structural attributes, species diversity and composition of the native community?; and 3) Do the relationships between coffee and native community differ between tree and sapling components? We sampled the tree and sapling components in a seasonal tropical dry forest that were previously used as shaded and unshaded coffee plantations. Coffee was the most important species in the sapling component of shaded systems, but was almost absent in unshaded ones. Coffee basal area was negatively related with the native density and absolute species richness of the sapling component; and was negatively related with tree density, and positively related with the percentage of pioneer individuals of the native tree component. Our results indicate that coffee persists in secondary forest communities even after more than 70 years of shaded-coffee plantations were abandoned, potentially reducing density and diversity of native species. Despite limitations, which hinder more general conclusions on coffee invasiveness in Brazilian secondary tropical forests, our results indicate that coffee is a strong competitor in the studied secondary forests and provide important insights for future research on this topic.

Cerrado is the second largest biome in South America and accounted for the second largest contribution to carbon emissions in Brazil for the last 10 years, mainly due to land-use changes. It comprises approximately 2 million km2 and is divided into 22 ecoregions, based on environmental conditions and vegetation. The most dominant vegetation type is cerrado sensu stricto (cerrado ss), a savanna woodland. Quantifying variation of biomass density of this vegetation is crucial for climate change mitigation policies. Integrating remote sensing data with adequate allometric equations and field-based data sets can provide large-scale estimates of biomass. We developed individual-tree aboveground biomass (AGB) allometric models to compare different regression techniques and explanatory variables. We applied the model with the strongest fit to a comprehensive ground-based data set (77 sites, 893 plots, and 95,484 trees) to describe AGB density variation of cerrado ss. We also investigated the influence of physiographic and climatological variables on AGB density; this analysis was restricted to 68 sites because eight sites could not be classified into a specific ecoregion, and one site had no soil texture data. In addition, we developed two models to estimate plot AGB density based on plot basal area. Our data show that for individual-tree AGB models a) log-log linear models provided better estimates than nonlinear power models; b) including species as a random effect improved model fit; c) diameter at 30 cm above ground was a reliable predictor for individual-tree AGB, and although height significantly improved model fit, species wood density did not. Mean tree AGB density in cerrado ss was 22.9 tons ha-1 (95% confidence interval = ± 2.2) and varied widely between ecoregions (8.8 to 42.2 tons ha-1), within ecoregions (e.g. 4.8 to 39.5 tons ha-1), and even within sites (24.3 to 69.9 tons ha-1). Biomass density tended to be higher in sites close to the Amazon. Ecoregion explained 42% of biomass variation between the 68 sites (P < 0.01) and shows strong potential as a parameter for classifying regional biomass variation in the Cerrado.

Este estudo determinou o custo e o efeito de polímero hidrorretentor (hidrogel) na redução da mortandade de mudas de seis espécies florestais nativas do Cerrado, na recuperação de área degradada em Planaltina – Distrito Federal. Foram testados quatro tratamentos (com e sem hidrogel nas estações seca e chuvosa) em delineamento em blocos casualizados com quatro blocos e três repetições por bloco. ANOVA e teste de Tukey revelaram que o hidrogel reduziu significativamente a mortandade na estação seca, mas não teve efeito significativo na estação chuvosa. Considerando o custo de substituição de mudas mortas, o tratamento sem hidrogel foi mais caro que com hidrogel na estação seca. O plantio no final da estação seca com hidrogel representa alternativa viável para reduzir a mortandade de mudas via mitigação dos efeitos do estresse hídrico pós-transplante no final da estação seca, sem representar custo significativo adicional aos programas de recuperação de áreas degradadas de Cerrado. We determined the cost and effect of a water retention polymer (hydrogel) in reducing mortality of planted seedlings of six Cerrado forest species in the restoration of a degraded area in Planaltina county – Brazilian Federal District. We tested four treatments (hydrogel use and no hydrogel use in dry and rainy seasons) in a randomized block design, with four blocks and three replications per block. ANOVA and Tukey’s test revealed that hydrogel significantly reduced mortality in the dry season, and had no significant effect in the rainy season. Regarding the cost of dead seedlings replacement, the treatment without hydrogel was more expensive than the one with hydrogel in the dry season. Planting at the end of the dry season using hydrogel is a viable alternative in reducing mortality of seedlings via mitigation of water stress effects after transplantation, without significant additional cost to recovery programs of Cerrado degraded areas.

A Lei de Proteção da Vegetação Nativa (LPVN) gerou intenso debate na sociedade brasileira. Dentre as principais mudanças, destacam-se a flexibilização das Áreas de Preservação Permanente (APPs) e de Reserva Legal (RLs). Este estudo analisou, por meio de geoprocessamento, as modificações das RLs e APPs em um assentamento rural em Nova Venécia, Espírito Santo, após a aprovação da LPVN. Houve redução de 27,2 ha (56,82%) de áreas destinadas às APPs, dos quais 23,8 ha estão associados a cursos d’água e 3,4 ha a nascentes. Não houve mudança em relação às RLs, pois a cobertura florestal existente (187,99 ha) já era superior ao exigido pelo antigo código florestal. A forte redução na inexigência de recuperação de APPs pode causar impactos qualiquantitativos nos recursos hídricos, regulação dos agroecossistemas e dos serviços ecossistêmicos locais. Portanto, mecanismos de incentivo à recuperação florestal são fundamentais para garantir a manutenção dos serviços ecossistêmicos.

The aim of this study was to determine leaf decomposition rates and nutrient release in a cerrado sensu stricto under nitrogen (N), phosphorus (P) and N plus P additions. The experiment was carried out in an area located in the Ecological Reserve of the Instituto Brasileiro de Geografia e Estatistica, near Brasilia (15° 56’ S, 47° 53’ W). Between 1998 and 2006, 100 kg ha−1 year−1 of N (N treatment), P (P treatment) and N plus P (NP treatment) were applied to 16 225 m2 plots, arranged in a completely randomized design. Litterfall was collected at the end of dry season (September 2006) and oven dried (60 °C) for 72 h. Litter bags with 10 g of leaf litter were incubated in situ for 453 days to determine decomposition rate. Nitrogen and P concentrations and mass loss were measured during the incubation process. Decomposition rates of leaf litter in N plots did not differ in relation to those in control plots. Leaf litter decomposition rates increased in P (+ 18.6 %) and NP (+ 27.4 %) plots, where there was a greater N (in NP plots) and P (in P and NP plots) initial concentration in litter relative to the control plots (p < 0.05). Leaf litter in the N treatment had the highest N mass loss, and together with NP treatment, the smallest P mass loss. Nitrogen addition increased N mass loss, while the combined addition of N and P resulted in an immobilization of N in leaf litter. When the nutrients are supplied separately, there is greater mass loss of N with N addition, and greater mass loss of P with P addition compared to that observed when N and P are supplied together. The results indicate that if the availability of P is not increased proportionally to the availability of N, the losses of N are intensified during the decomposition process.

The aim of this study was to compare the diversity of the shrub-tree layer in fertilized and unfertilized plots in a cerrado stricto sensu area in Central Brazil. The experiment was conducted in 16 plots of 15 m × 15 m arranged in a completely randomized design with tree fertilization treatments (+ N, + P, + NP), and an unfertilized treatment (control) in the Ecological Reserve of the Instituto Brasileiro de Geografia e Estatistica (RECOR-IBGE), Federal District, near Brasilia. Treatments were applied from 1998 to 2006. Vegetation surveys were performed during January and July 2008 on all trees and shrubs with circumference > 5 cm at ground level. Indices of diversity of Shannon (H′), evenness of Pielou (J′) and similarity of Sorensen were calculated. Control plots contained 479 individuals of 47 species, belonging to 29 families. In the nitrogen (N) plots, 461 individuals were registered, belonging to 53 species and 34 families while 448 individuals of 54 species from 31 families were registered in phosphorus (P) plots and 336 individuals of 40 species, belonging to 24 families in nitrogen + phosphorus (NP) plots. The N (H′ = 3.20; J′ = 0.80) and NP (H′ = 2.89; J′ = 0.78) plots showed lower Shannon (H′) and Pielou (J′) indices relative to the control plots (H′ = 3.40; J′ = 0.88). The Sorensen floristic similarity was high between fertilized and control plots but decreased in the following order: P plots (0.81), N (0.78) and NP (0.76) plots. Fertilization shifted species density and dominance patterns in comparison to unfertilized plots. Nitrogen and NP addition decreased the evenness, species diversity and provided the least floristic similarity relative to the control plots. Density and dominance changes resulted in differences in species importance values among treatments. Simultaneous addition of N and P affected density, dominance, richness and diversity patterns more significantly than addition of N or P separately.

Coffee has major importance in tropical landscapes from agronomic, economic and ecological perspectives. Yet the conversion of shade-coffee into full sun monocultures has deep effect on the potential of those systems to conserve biodiversity and ecosystems services (such as pest control and pollination). Despite of this, effect of shade on production has not been sufficiently addressed, particularly in Brazil, the world major coffee producer. This study compared the performance of shaded coffee and full sun management in terms of productivity and production costs. The survey was conducted in Municipality of Mirante da Serra, in the Brazilian Amazon and eight coffee agroecosystems, four under shade and four under full sun were investigated. The results indicate that shaded systems have lower production costs requiring less working hours than sun plantations. The average production cost of shaded agroecosystems was 49.63%, while in systems under full sun, this value was 82.2%. Shaded and full sun productivity did not differ significantly, with higher variance in the former, showing that shaded systems are more heterogeneous. Shaded coffee agroecosystems presented an economically and environmentally viable alternative. The lower production cost enhances economic viability of these ecosystems in Amazon as well as in the rest of the tropics. Such efficiency may have influenced the persistence of these managements, despite the worldwide agriculture intensification tendency.

© 2012 Goulart et al., licensee InTech. This is an open access chapter distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Agricultural SystemS and the Conservation of Biodiversity and Ecosystems in the Tropics

This study investigated changes in diversity of shrub-tree layer, leaf decomposition rates, nutrient release and soil NO fluxes of a Brazilian savanna (cerrado sensu stricto) under N, P and N plus P additions. Simultaneous addition of N and P affected density, dominance, richness and diversity patterns more significantly than addition of N or P separately. Leaf litter decomposition rates increased in P and NP plots but did not differ in N plots in comparison to control plots. N addition increased N mass loss, while the combined addition of N and P resulted in an immobilization of N in leaf litter. Soil NO emissions were also higher when N was applied without P. The results indicate that if the availability of P is not increased proportionally to the availability of N, the losses of N are intensified.