Linear and spatial variability of eucalyptus dendrometric attributes correlated with the properties of a Typic Haplustox soil (Oxisol) in the Brazilian savannah

Effects of soil attributes using the geostatistical tool improves the interpretation of specific soil management. Thus, this study aimed to evaluate the physical, chemical, and microbiological properties of a Typical Haplustox (Oxisol), identifying those with the best linear and spatial correlation with eucalyptus (Eucalyptus spp.) vegetative growth. The experiment was conducted at the Teaching, Research, and Extension Farm (FEPE) of the Universidade Estadual Paulista (UNESP), Campus of Ilha Solteira. Thirty-five points spaced 13 meters apart were demarcated for analysis, which were distributed in 5 rows of 7 points each. From each point, 2 soil samples were collected from the 0-10 cm depth layer. The physical, chemical, and microbiological soil properties evaluated were: sand, silt, and clay contents; penetration resistance (PR), gravimetric moisture (GM), real density (RD), microbial biomass carbon (MBC), respirometry (CO2-C), metabolic quotient (qCO2), organic matter content (OM), and hydrogenionic potential (pH). The eucalyptus attributes assessed were: plant height (PH) and circumference at breast height (CBH). Each attribute was analyzed by descriptive statistics using the SAS software. Data frequency distribution was verified by the Shapiro Wilk method, and geospatial changes were analyzed by the GS+ software. The soil property that best explained the variability in eucalyptus dendrometric attributes was real density (RD). Except for RD, all properties did not show spatial dependence (i.e., pure nugget effect), which significantly represents eucalyptus vegetative performance.

Negative effects of ant-plant interaction on pollination: costs of a mutualism

The mutualism of ants and extrafloral nectary (EFN)-bearing plants is known to reduce rates of herbivory. However, ants may have negative impacts on other mutualisms such as pollination, constituting an indirect cost of a facultative mutualism. For instance, when foraging on or close to reproductive plant parts ants might attack pollinators or inhibit their visits. We tested the hypothesis that ants on EFN-bearing plants may negatively influence pollinator behavior, ultimately reducing plant fitness (fruit set). The study was done in a reserve at Brazilian savannah using the EFN-bearing plant Banisteriopsis malifolia (Malpighiaceae). The experimental manipulation was carried out with four groups: control (free visitation of ants), without ants (ant-free branches), artificial ants (isolated branches with artificial ants on flowers) and plastic circles (isolated branches with plastic circles on flowers). We made observations on flower visitors and their interactions, and measured fruit formation as a proxy for plant fitness. Our results showed that pollinators hesitated to visit flowers with artificial ants, negatively affecting pollination, but did not hesitate to visit flowers with plastic circles, suggesting that they recognize the specific morphology of the ants. Pollinators spent more time per flower on the ant-free branches, and the fruiting rate was lower in the group with artificial ants. Our results confirm an indirect cost in this facultative mutualism, where the balance between these negative and positive effects of ants on EFN-bearing plants are not well known.

Efficiency of fertilization with coated urea in the cultivation of cactus pear under rainfed conditions in Brazilian savannah

Cactus pear is an important species for animal feeding in the regions of dry climate. There is no information on the fertilization with coated urea in the cultivation of cactus pear under rainfed conditions in the savannah region. The aim of the current study was to evaluate the forage potential of Nopalea cochenillifera variety Doce in yellow latosol under rainfed conditions in the Brazilian savannah, comparing the fertilization with urea and coated urea in different levels. A randomized block design was adopted, in a 2 × 4 × 2 factorial scheme, with the factors corresponding to two sources of nitrogen (urea and urea coated with polymers, N+), four levels of nitrogen (0, 60, 120 and 240 kg/ha/year) and two harvests (year I and year II). The plants were evaluated after 1 year of growth, in each year of evaluation, regarding the characteristics of growth, production, chemical and mineral composition and nutritional value. The level of 240 kg/ha provided higher emission of cladodes per plant (17.33 and 18.17), respectively, for N+ and urea. The highest nitrogen use efficiency was found in the level of 60 kg N/ha (142 kg/ha/year). NFC values were 3.5 g/kg dry matter (DM) higher when the cactus pear was fertilized with urea in year I and 5.4 g/kg DM in year II. The use of conventional urea promoted better results of agronomic and nutritional characteristics of the cactus pear, under rainfed regime, when compared to the use of urea coated with polymers.

Brown-lacewings (Insecta: Neuroptera: Hemerobiidae) from Brazilian savannah in Central Brazil

In this study were documented the species of brown-lacewings (Neuroptera: Hemerobiidae) found at Parque Nacional da Chapada dos Veadeiros, in Alto Paraíso de Goiás, state of Goiás and at Parque Nacional Grande Sertão Veredas, in Chapada Gaúcha, state of Minas Gerais, both in Brazil, based on a survey carried out with Malaise traps between February 2018 and May 2019. During the samplings 60 specimens of hemerobiids were captured, being 26 of Nusalala tessellata (Gerstaecker, 1888), 13 of Nomerobius argentinensis González Olazo, 1990, eight of Sympherobius amazonicus Penny & Monserrat, 1985, six of Megalomus impudicus (Gerstaecker, 1888), five of Hemerobius hernandezi Monserrat, 1996, one Nomerobius cuspidatus Oswald, 1990 and one of Notiobiella sp. Nomerobius argentinensis and Nom. cuspidatus are reported by the first time to Brazil and H. hernandezi, M. impudicus, Notiobiella sp. and S. amazonicus to the state of Goiás, Brazil.

Classification Based on Rules for the Study of Cotton Productivity in the State of Mato Grosso

The advance of cotton farming in the Brazilian savannah boosted and made possible a highly technified, efficient and profitable production, elevating the country from the condition of cotton fiber importer in the 70s to one of the main exporters so far. Despite the increasing contribution of technologies such as transgenic cultivars, machines, inputs and more efficient data management, in recent years there has been a stagnation of cotton productivity in the State of Mato Grosso (MT). Data Mining (MD) techniques offer an excellent opportunity to assess this problem. Through the rules-based classification applied to a real database (BD) of cotton production in MT, factors were identified that were affecting and consequently limiting the increase in productivity. In the pre-processing of the data, we perform the attributes, selection, transformation and identification of outliers. Numerical attributes were discretized using automatic techniques: Kononenko (KO), Better Encoding (BE) and combination: KO + BE. In modeling the rule algorithms used were PART and JRip, both implemented in the WEKA tool. Performance was assessed using statistical metrics: accuracy, recall, cost and their combination using the I_FC index (created by the authors). Results showed better performance for the PART classifier, with discretization by the KO + BE technique, followed by binary conversion. The analysis of the rules made it possible to identify the attributes that most impact productivity. This article is an excerpt from an ICMC/USP Professional Master's Dissertation in Science carried out in São Carlos-SP/BR.

Landscape barriers to pollen and seed flow in the dioecious tropical tree Astronium fraxinifolium in Brazilian savannah

Gene flow studies provide information on gene exchange between populations, which is essential for developing genetic conservation strategies. Such analyses enable a better understanding of the life history and seed and pollen dispersal mechanisms of plant species. In this study, we investigate pollen and seed flow in a regenerant population of the pioneer species Astronium fraxinifolium in an area degraded during the construction of a hydroelectric dam. We mapped, sampled, sexed, and genotyped 386 individuals in the regenerant population (RP), as well as 128 adult trees located along two highways adjacent to the degraded area; one in Mato Grosso do Sul State (MS) and other in São Paulo State (SP). Parentage analyses was carried out for 370 individuals of the RP population, using as putative parents 348 individuals from RP and all 128 individuals sampled in MS and SP. Based on parentage analysis and eight microsatellite loci, our analyses revealed that for individuals of the RP with an identified father (pollen donor), 1.1% of the pollen was dispersed up to 532 m, while for those with an identified mother (seed donor), 0.5% of seeds were dispersed up to 4,782 m. However, a large proportion of pollen (76.5%) and seeds (57%) immigrated from trees outside the sampled populations. Pollen and seeds were dispersed through a pattern of isolation by distance. Genetic diversity was significantly similar between adults of both highway populations and individuals from RP, with significant levels of inbreeding detected only in RP. Our results demonstrate that the nearest trees contributed pollen and seeds for the recovery of the degraded area, indicating reproductive spatial isolation among the sampled populations due to the damming of the river. Such results help to understand the process of regeneration for A. fraxinifolium in regenerant populations to inform strategies for conservation and environmental recovery with this species.

Dinâmica de ocupação e passivos ambientais nos assentamentos rurais do município de Goiás-GO

Estudos sobre a influência de assentamentos rurais no processo de desmatamento são normalmente controversos. Alguns apontam uma aceleração desse processo, enquanto outros demonstram que nesses locais a dinâmica de uso do solo segue uma tendência regional. No Cerrado (a savana brasileira) esse é um fenômeno ainda pouco conhecido. Nosso objetivo foi analisar o uso e a cobertura do solo em assentamentos rurais do município de Goiás – região com grande destaque nacional –, com foco nas áreas de preservação permanente (APPs) de cursos d’água. Foram empregadas técnicas de geoprocessamento e classificação de imagens de satélites para quatro anos (1985, 1991, 1995 e 2018), com abrangência temporal de 33 anos. Para verificar o padrão do uso do solo em áreas dentro e fora de APPs, nos assentamentos rurais e no restante do município, foram empregadas análises de componentes principais. Os resultados indicam que as áreas com vegetação nativa reduziram em 33% e 34%, para os assentamentos e o restante do município, respectivamente. As classes ligadas às atividades agropecuárias tiveram aumento entre o ano inicial e final do estudo. A ocupação do solo por atividades agropecuárias, dentro das áreas de preservação permanente, teve uma maior redução nos assentamentos. Concluímos que as dinâmicas do uso e ocupação do solo nos assentamentos e no restante do município seguem uma tendência parecida, porém com um atendimento ao código florestal ligeiramente maior nos assentamentos, representando uma maior conservação relativa de áreas nativas do Cerrado. Dynamics of occupation and environmental liabilities in rural settlements in the municipality of Goiás, Goiás A B S T R A C TStudies are controversial about the influence of the implantation of rural settlements in the deforestation process, some point that there is an acceleration of this process, others already show that in these places the dynamics of land use follows a regional trend. In the Cerrado (the Brazilian savannah) this is still a little-known phenomenon. Our objective was to analyze land use and cover in rural settlements and for the municipality of Goiás, where they are located, with a focus on permanent preservation areas (APPs) of water courses. Geoprocessing and satellite image classification techniques were used for four years (1985, 1991, 1995 and 2018), with a time span of 33 years. To check the pattern of land use in areas inside and outside APPs, in rural settlements and in the rest of the municipality, principal component analyzes were used. The results show that the areas with native vegetation reduced by 33% and 34%, for the settlements and the rest of the municipality, respectively. The classes linked to agricultural activities had an increase between the initial and final year of the study. The occupation of the land by agricultural activities, within the areas of permanent preservation, had a greater reduction in the settlements. We conclude that the dynamics of land use and occupation in the settlements and in the rest of the municipality follow a similar trend, it cannot be said that the settlements are responsible for a greater deforestation of native areas of the Cerrado.Keywords: deforestation, Cerrado, geoprocessing, land use.

Assessing Wildfire Regimes in Indigenous Lands of the Brazilian Savannah-Like Cerrado

The Brazilian savannah-like Cerrado is classified as a fire-dependent biome. Human activities have altered the fire regimes in the region, and as a result, not all fires have ecological benefits. The indigenous lands (ILs) of the Brazilian Cerrado have registered the recurrence of forest fires. Thus, the diagnosis of these events is fundamental to understanding the burning regimes and their consequences. The main objective of this paper is to evaluate the fire regimes in Cerrado’s indigenous lands from 2008 to 2017. We used the Landsat time series, at 30 m spatial resolution, available in the Google Earth Engine platform to delineate the burned areas. We used precipitation data from a meteorological station to define the rainy season (RS), early dry season (EDS), middle dry season (MDS), and late dry season (LDS) periods. During 2008–2017, our results show that the total burned area in the indigenous lands and surrounding area was 2,289,562 hectares, distributed in 14,653 scars. Most fires took place between June and November, and the annual burned area was quite different in the years studied. It was also possible to identify areas with high fire recurrence. The fire regime patterns described here are the first step towards understanding the fire regimes in the region and establishing directions to improve management strategies and guide public policies.