Avaliação das propriedades químicas do solo submetido a diferentes sistemas de manejo em Igarapé- Açú (PA) / Evaluation of the chemical properties of a Latosol submitted to different management systems with and without vegetation burning in Igarapé- Açú (PA)

Nas últimas décadas, as atividades agrícolas vêm modificando a cobertura vegetal original de parte do território brasileiro. Ecossistemas naturais, como a floresta amazônica, vêm, há muito tempo, perdendo suas propriedades originais, devido à implantação de atividades agropecuárias ou extrativistas. Esse cenário se faz presente principalmente no território amazônico, onde a exploração agrícola ainda utiliza o fogo de forma indiscriminada para realizar o preparo do solo, caracterizado pela derrubada e queima das florestas primárias. A agricultura de corte e queima, na sua definição mais ampla, é qualquer sistema agrícola contínuo no qual clareiras são abertas para serem cultivadas por períodos mais curtos de tempo do que aqueles destinados ao pousio. Na região bragantina, o sistema tradicional de produção agrícola é baseado em roças de corte e queima da vegetação, e isso tem se mantido por séculos. Em Igarapé-Açu, a agricultura também é marcada pelo uso do fogo no sistema de derruba e queima. Assim, o objetivo deste trabalho foi avaliar o efeito do sistema de preparo solo com queima e sem queima da vegetação sobre as propriedades químicas em um Latossolo Amarelo no município de Igarapé – Açu, Pará. O estudo foi realizado no município de Igarapé-Açu, sob diferentes sistemas de manejo, as análises químicas foram feitas nos laboratórios da UFRA. E os resultados encontrados apontem que os maiores valores de pH foram encontrados em sistemas com queima da vegetação. Houve incremento nos teores de Ca, em virtude da queima. Logo, a queima influenciou diretamente sobre alguns atributos do solo.

An outline summary document of the current knowledge about prescribed vegetation burning impacts on ecosystem services compared to alternative mowing or no management

A lay summary of our discussion paper: A critical review of the IUCN UK Peatland Programme’s “Burning and Peatlands” position statement (https://link.springer.com/article/10.1007/s13157-021-01400-1). In short, we discuss the prescribed burning on blanket bog evidence base and its interpretation within a UK context - specifically in relation to the International Union for Conservation of Nature UK Peatland Programme "Burning and Peatlands” position statement published in 2020, and with reference to management alternatives (cutting and a cessation of management).

Fire history and the relationship with late Holocene anthropogenic activity in Tăul Mare peat bog in the Lăpuș Mts (Eastern Carpathians). Romania

<p>Predicted climate warming and increasing anthropogenic pressure on environmental resources are expected to increase wildfire risk in Central and Eastern Europe (including Romania) and thus may affect areas currently outside fire risk areas. Therefore, knowledge of the natural and anthropogenic variability of wildfire, as well as its long-term impacts on the environment can provide an important perspective and be used to enhance the environmental management of this region.</p><p>Our study aims to reconstruct fire history in relation to anthropogenic disturbances and climate variability, over the last 2000 years in a now forested but former mining area from Lăpuș Mts (Eastern Carpathians, Romania) based on an ombrotrophic peat sequence. To reconstruct past fire activity, we employed sedimentary macroscopic charcoal (counts and morphological characteristics), a widely used proxy for gaining insight into long-term fire history and vegetation burning. Ombrotrophic peat bogs are sensitive to local environmental changes and, given that the deposition of allochthonous material is exclusively atmospheric, they are ideal archives for recording charcoal fluxes resulted from vegetation burning. Past local soil/bedrock erosion and regional atmospheric pollution from (pre)historical mining were reconstructed on the basis of abiotic sediment properties such as elemental geochemistry, mineral magnetic characteristics, organic matter content and particle size. Published sources were used to extract information regarding regional climate variability and extra-local to regional vegetation history.</p><p>Results show that increases in macro-charcoal concentration, particularly the woody charcoal morphotype, were shortly followed by marked increases in heavy metal concentration and by enhanced soil and bedrock erosion, as inferred from geochemical, magnetic and grain-size proxies. This suggests increased local disturbance during intervals with mining activities and indicates the likelihood that humans used fire to clear the forests and open the access to the mining sites. Alternatively, humans could have deforested the landscape to obtain charcoal in kilns, for ore smelting. Such actions likely resulted in topsoil removal and exposed bedrock surfaces, which is supported by the increase in the concentration of detrital elements and small, topsoil-derived magnetic particles in our record. Over recent centuries, the recovery of the local environment is evident in the proxies, with low fire activity and decreased soil/bedrock erosion, which coincides with the abandonment of the mining sites. This multi-proxy study shows the impact of anthropogenic disturbances and the recovery of the local environment and can be used to predict future possible responses of the local environment to stressors.</p>

BROADLEAVED TREE TRUNKS CHARRING DURING FOREST FIRES WITHIN THE UKRAINIAN ROZTOCHYA

Introduction. On the territory of Ukrainian Roztochya and Male Polissya (Zhovkva part of Roztochya included) fires often occur in natural ecosystems – forest fires, meadow vegetation burning, stubble, landfills, and peatlands. Such fires, in addition to the destruction of property, cause significant emissions of incomplete combustion products and smoke into the air. Charring of broadleaved species, along with conifers, needs more detailed research, as the territory of the Ukrainian Roztochya is dominated by hornbeam-oak-pine, mixed oak, and beech forests.Aim. The object of the paper is to investigate the degree of tree trunks charring of the main forest-forming species in the Ukrainian Roztochya during forest fires based on experimental data.Research methods. Freshly cut trees were exposed to heating for 10 minutes, at periods of 1 minute, 3, and 5 minutes, checking the degree of damage to the trunk (charring, mm). Repeatability of the experiment – three times. Basing on received data the charring of broadleaved tree trunks in the Ukrainian Roztocze was determined. The flame temperature was measured by a GM1150A non-contact pyrometer. The level of burnout was measured by a ruler made following GOST 17435-72. A stopwatch was used to record the time of burning. Results and discussion. The experiments were performed in the fresh air under close-to-natural conditions. The fire source was an artificial open flame. Freshly cut tree trunks were installed vertically, right in the burning zone. Cutting residues, fallen dry leaves, straw, dry grass was used as flammable material. It was found that the lowest degree of charring is inherent to oak, which has burned by 38 mm during 10 minutes (with log thickness of 124 mm). Species such as hornbeam and maple completely burned out in 10 minutes (in diameters of 129 mm and 140 mm).Conclusions. Investigations of temperature effects on the main forest-forming species of the region have shown that they all differ in charring during forest fires. Three species grown in Ukrainian Roztochya were selected – hornbeam (Carpinus betulus), oak (Quercus robur), and maple (Acer platanoides). To prevent fires in forests, fire lanes should be planned with oak plantations on the edge of the forest.

Chemical attributes of soil in agroforestry systems is conditioned by the management system adopted

The aim of this study was to evaluate the influence of vegetation management on soil chemical attributes during the implementation of an agroforestry system in Pará, Brazil. Three treatments were evaluated - T1 Control (secondary vegetation - SF), T2 - Fire management system (FMS) and T3 - Management system without vegetation burning (MSWB). Soil samples were collected at 30 cm deep to analyze chemical attributes. The data were analyzed using Analysis of Variance - ANOVA, and the t-test. Treatment T2 caused the most changes in soil chemical attributes on the first analysis showing increased pH, increased levels of N, P, K, Ca, Sum of bases, CEC and percentage of base saturation, and decreased potential acidity of Al in the short term. However, in the second evaluations 48 months later, there was an inversion, in which a reduction of pH, the contents of N, P, K, Ca, Sum of bases and percentage of base saturation, as well as increased potential acidity and of the contents of Al of the soil were observed. For treatments T1 and T3, there were no substantial soil attributes changes during the first and second evaluations. Thus, soil chemical attributes were altered according to the type of management of secondary vegetation and evaluation period during the implementation of Agroforestry Systems.

Impact of Land-Use Change on Soil Carbon Dynamics in Tropical Peatland, West Kalimantan- Indonesia

The conversion of tropical peat forest to other land uses can reduce organic carbon (C) and stable C isotope (δ13C) of peat soil. This research aimed at analyzing the soil organic-C and δ13C of peatland with respect to maturity (fibric, hemic and sapric) in five types of peatland use, which included primary peat forest, secondary peat forest, shrubs, oil palm plantations, and cornfield in West Kalimantan. Analysis of peat soil samples includes organic C with Loss in ignition method and δ13C using an isotope ratio mass spectrometry(IRMS) method. Organic-C at fibric was higher than hemic and sapric, respectively (57.2%, 57.0%, 56.4%), meanwhile, organic-C was the highest on primary peat forest, followed by on secondary peat forest, oil palm plantation, cornfield, and shrubs, respectively 57.1%, 57.0%, 56.4%, 56.0%. The cause of increasing and decreasing organic C and δ13C due to land-use change due to changes in vegetation, burning during tillage, and age of organic matter of peat soil. This condition causes the opening of natural peat ecosystems and changes in anaerobic to aerobic conditions.

Impact of postburn jhum agriculture on soil carbon pools in the north-eastern Himalayan region of India

Land-use change, particularly soil organic carbon (SOC) loss induced by shifting cultivation (jhum) is a common land degradation issue in the hilly tracts of the humid tropics. The SOC concentration comprises different pools (labile and recalcitrant fractions), and each fraction responds to temporal dynamics of adopted management practices at varying magnitudes, such as deforestation followed by cultivation. However, information on the variation of different SOC pools due to cultural practices of vegetation burning and postburn agricultural practices (crop production) associated with shifting cultivation remains inadequate. In the present investigation, we examined the effect of burning and postburning cultivation on SOC pools across different forest fallow periods at Kolasib district, Mizoram state of the north-eastern Himalayan Region of India. Results revealed increase in the soil C stocks and total organic carbon (TOC) due to the increase in the length of fallow periods ranging from 3 to 23 years. The TOC decreased significantly compared with antecedent concentrations before vegetation burning. This was mostly attributed to the reduction in contribution of active pools (very labile and labile) to TOC from 69% to 60%. However, contribution of passive pools (less labile and nonlabile) to TOC concentration increased from 31% to 40%. Postburn cultivation also resulted in reduction of TOC as well as considerable variation in the proportion of different SOC pools to TOC concentration. Among the different pools of SOC, the very labile C pool was most sensitive to land-use change induced by shifting cultivation (phytomass burning and postburn cultivation). The labile SOC pools can act as a sensitive indicator for devising suitable location specific management practices for restoration of soil health through SOC dynamics in degraded jhum lands in hilly ecosystems.

Effect of an accidental fire on Anastrepha fruit fly (Diptera: Tephritidae) community in a conservation area of the Cerrado Biome

The effects of vegetation burning on populations and species composition of Anastrepha fruit flies in environments of the Cerrado are unknown. Thus, this study investigated the influence of fire on a community of fruit flies in two Cerrado environments, namely, typical Cerrado (savanna-like) and forested Cerrado. We collected species of Anastrepha, using McPhail traps weekly from 2 May 2011 to 30 April 2013. Collection data were analyzed using non-metric multidimensional scaling (NMDS) to characterize the patterns of variation in species composition, comparing the species abundance (numbers of individuals) before and after the fire event. The NMDS results showed an influence of both annual season and fire on the populations of fruit flies in the forested Cerrado, and a trend of population growth after the fire event in the typical Cerrado. The curves of species accumulation indicated a greater diversity of species in the post-fire than the pre-fire period, and the species diversity did not reach stabilization within the post-fire observation period. The diversity of habitats formed by burning and rapid regeneration of the flora after the fire could be responsible for the increase in species abundance and species richness of fruit flies in comparison with the pre-fire period.Efeito de um incêndio acidental na comunidade de Anastrepha (Diptera: Tephritidae) em uma área de conservação do Bioma de CerradoResumo. Os efeitos de queima da vegetação sobre as populações e a composição de espécies de moscas das frutas do gênero Anastrepha em ambientes do cerrado ainda são desconhecidos. Assim, este estudo investigou a influência do fogo em uma comunidade de moscas das frutas em dois ambientes de Cerrado: Cerrado típico e Cerradão. Foram coletadas espécies de Anastrepha, usando armadilhas McPhail semanalmente, no período de 2 maio de 2011 a 30 abril de 2013. Os dados das coletas foram analisados empregando-se escalonamento não-métrico multidimensional (NMDS) para caracterizar os padrões de variação na composição de espécies, comparando a abundância e diversidade das espécies antes e após o incêndio. Os resultados NMDS mostraram uma influência da época do ano e do fogo sobre as populações de moscas das frutas no Cerradão e uma tendência de crescimento da população após a passagem do fogo no Cerrado típico. Curvas de acumulação de espécies indicaram uma maior diversidade de espécies no período pós-fogo em comparação ao período anterior ao incêndio, e a diversidade de espécies não atingiu a estabilização dentro do período de observação após o incêndio. A diversidade de hábitats formados pela queimada e rápida regeneração da flora após tal incêndio pode ter sido responsável pelo aumento na abundância de indivíduos e riqueza de espécies de Anastrepha em comparação com o período anterior à passagem do fogo.