Suppression Of Vegetation Research Articles

Use of Applied Geotechnology for Analysis of the Permanent Preservation Area - APP of Bico da Pedra Lake, in the Municipality of Janaúba, MG

Urbanization in permanent preservation areas (APP) results in eutrophication of water bodies, water contamination and change in gene flow of the fauna and flora. Given the above, the purpose of this study was to analyze the permanent preservation areas of the Bico da Pedra Lake in the municipality of Janaúba, MG, using geotechnology. The methodology consisted of the use of Linear Spectral Mixture Model (LSMM) and the Bhattacharya unsupervised classification developed from the image of the Landsat-5TM satellite to identify the land use and vegetation in the Lake’s APP. Subsequently, we scanned the QuickBird satellite image at a constant scale of 1:5000 with the purpose of measuring the built-up areas located in the APP in the analysis. The results identified the presence of exposed soil and vegetation suppression in certain locations in the APP. The quantitative area of the APP was measured at 1768.89 ha, with the presence of 15% exposed soil, 32% sparse vegetation, 52% dense vegetation, and 1% non-classified area. We performed scanning for the presence of masonry buildings and farms; 79 of which are in the maximum level of flooding and 217 are in the APP. We concluded that the study obtained satisfactory results for the analysis and measurement of the area of permanent preservation area, allowing the identification of targets and vegetation accurately. Thus, it is inferred that this methodology can be applied in permanent preservation areas in separate locations aiming at monitoring and environmental supervision.

A novel field technique to assess ploidy in introduced Grass Carp (Ctenopharyngodon idella, Cyprinidae)

Invasions by Asian carps have become a high profile topic due to the threat they pose to native ecosystems and associated economies. One of four primary invasive Asian carp species, Grass Carp, Ctenopharyngodon idella (Cyprinidae), is commonly produced as triploid, sterile, individuals and stocked as a biological control for the suppression of unwanted aquatic vegetation. Illegal sale and transport of diploid fish can result in unwanted fertile populations. Current methods of determining ploidy of an individual require the use of laboratory equipment (Coulter Counter) and are not possible to perform under field conditions. Here we introduce a rapid, inexpensive technique to distinguish diploid fertile versus triploid sterile Grass Carp under field conditions using a compound microscope. We compared blood smears of known diploid and triploid Grass Carp individuals, finding that the frequency of abnormally shaped erythrocyte nuclei (dumbbell or teardrop shaped) is significantly higher in the latter. This difference is accompanied by larger cell and increased nuclear volumes, and it is significantly correlated with Coulter Counter values (the standard measure of ploidy used by the United States Fish and Wildlife Service). Additionally, we field tested our method on a managed, presumably triploid, standing stock of Grass Carp and found that all individuals tested exhibited proportions of abnormal nuclei typical of triploids. Finally, a blinded study was used to confirm diagnostic reliability of our visual assessment of ploidy. Examination of blood smears for abnormally shaped nuclei may become a powerful tool in the management of invasive Grass Carp.

Conflitos no uso da terra em Áreas de Preservação Permanente em um polo de produção de biodiesel no Estado do Pará

As Áreas de Preservação Permanente (APPs) desempenham um papel fundamental na manutenção dos principais fatores que regulam os processos hidrológicos e de conservação biológica. Na Amazônia, as APPs vêm sendo ocupadas com atividades econômicas de alto impacto ambiental que levam à supressão de vegetação, desrespeitando o regime legal desse tipo de área protegida. Este artigo analisa os conflitos de uso da terra dentro das áreas destinadas à preservação e propõe uma delimitação dessas áreas de acordo com o Código Florestal Brasileiro de 2012, no municipio de Moju, um dos mais importantes polos de produção de biodiesel do estado do Pará. A pesquisa utilizou imagem multiespectral de alta resolução do satélite RapidEye de 2010 para uma classificação supervisionada que determinou oito classes de cobertura e uso da terra, com especial atenção para a floresta, o cultivo agrícola e cultivo de óleo de palma (Elaeis guineensis). As terras alteradas do município perfazem 30,29% do total, sendo que 17,07% estão ocupadas pela pecuária. Somente 5,2% do território de Moju é legalmente definido como APP. Destas áreas, 29,3% se encontram em uso conflituoso, onde predomina a pastagem, presente em 15,6% das APPs do município. O cultivo de palma corresponde a apenas 0,63% da área da APP e a 2,17% do município. A aplicação das novas regras de recomposição de APPs pelo novo Código Florestal Brasileiro irá resultar em perda de 60,69% de área recuperada em APPs neste município.

Atributos físico-hídricos de um Argissolo amarelo sob floresta e savana naturais convertidas para pastagem em Roraima

O Estado de Roraima apresenta ampla diversidade pedológica e de ecossistemas, sendo gradativamente ocupados com pastagem, que dependendo do manejo podem estar associadas à degradação física do solo. Dentro desse contexto, este trabalho foi realizado com os objetivos de avaliar e comparar os atributos físico-hídricos de um Argissolo Amarelo sob os ecossistemas de savana e floresta natural, convertidos em pastagem para pecuária. Os tratamentos principais foram savana natural (SN), savana convertida em pastagem (SC), floresta natural (FN) e floresta convertida em pastagem (FC) e os tratamentos secundários foram as profundidades de amostragem do solo, 0-10, 10-20 e 20-40 cm. Os atributos avaliados foram: granulometria, densidade do solo (DS) e de partículas (DP), resistência à penetração (RP), porosidade total (PT), umidade gravimétrica (UG), capacidade de armazenamento de água (CAD) e matéria orgânica do solo (MOS). A DS foi superior nas duas áreas de Savana, não havendo diferença entre SC e SN em nenhuma das profundidades. A RP variou em função das áreas e da profundidade, verificando-se influência da conversão nesse atributo. A PT foi maior na FN e menor na SC; houve diminuição da porosidade com a profundidade. A CAD foi maior na FN apenas na profundidade de 0-10 cm. A MOS foi superior nas áreas de FN e FC. Portanto, a conversão dos ambientes naturais em pastagem provocou alterações significativas na RP, DS, CAD, PT e MOS, com maior expressividade nas áreas da FC em razão da supressão da cobertura vegetal natural, que tem na matéria orgânica o condicionador da qualidade físico-hídrica do solo. Na SC, por sua vez, a supressão da cobertura vegetal natural não provocou a mesma expressividade por causa dos teores significativamente inferiores de MOS.

Management of Vegetation by Alternative Practices in Fields and Roadsides

In attempts to reduce the amounts of conventional herbicides used, alternative practices are sought in the management of roadside vegetation. In this investigation, alternative herbicides (citric-acetic acids, clove oil, corn gluten meal, limonene, and pelargonic acid), flaming, and mulching were assessed in management of annual and perennial, herbaceous vegetation in field and roadside plots. Several formulations of alternative herbicides applied singly or repeatedly during the growing season were evaluated and compared with conventional herbicides (glyphosate and glufosinate ammonium) or with flaming or mulching. Citric-acetic acid formulations, clove oil, limonene, or pelargonic acid applied as foliar sprays immediately desiccated foliage, but the efficacy lasted for no longer than five weeks. Repeated applications were better than single applications of these herbicides in suppressing plant vegetative growth. Corn gluten meal imparted little or no early control and stimulated late-season growth of vegetation. A single flaming of vegetation gave no better control than the alternative herbicides, but repeated flaming strongly restricted growth. Mulching with wood chips or bark gave season-long suppression of vegetation. Glyphosate gave season-long inhibition of vegetation, but the efficacy of glufosinate ammonium waned as the growing season progressed. For season-long suppression of vegetation with alternative herbicides or flaming repeated applications will be required.

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Estrutura e florística de dois fragmentos de florestas aluviais no Vale do rio Paraíba do Sul, SP, Brasil

O Vale do rio Paraíba do Sul pode ser caracterizado pela supressão intensa de suas formações vegetais nativas adjacentes. Este trabalho buscou caracterizar a estrutura e a flora de fragmentos florestais remanescentes localizados em São José dos Campos (Eugênio de Melo - EM) e Tremembé (TR) e obter a listagem de espécies florestais de várzea inundável recomendada para recuperação de áreas degradadas da região. Cada área recebeu duas parcelas (50 × 20 m) onde foram incluídas árvores com diâmetro a 1,30 m de altura do solo ≥ 5 cm. Para a interpretação dos dados foram utilizados os parâmetros fitossociológicos usuais e análises multivariadas, assim como o índice de diversidade de Shannon (H') e de equabilidade de Pielou (E). A fitofisionomia em TR é mais heterogênea e complexa comparada à EM, cuja homogeneidade é expressa pelo predomínio de populações de Sebastiania commersoniana e Alchornea triplinervia.

Mosquitoes in degraded and preserved areas of the Atlantic Forest and potential for vector-borne disease risk in the municipality of São Paulo, Brazil

In order to assess the epidemiological potential of the Culicidae species in remaining areas of the Brazilian Atlantic Forest, specimens of this family were collected in wild and anthropic environments. A total of 9,403 adult mosquitoes was collected from May, 2009 to June, 2010. The most prevalent among species collected in the wild environment were Anopheles (Kerteszia) cruzii, the Melanoconion section of Culex (Melanoconion), and Aedes serratus, while the most common in the anthropic site were Coquillettidia chrysonotum/albifera, Culex (Culex) Coronator group, and An. (Ker.) cruzii. Mosquito richness was similar between environments, although the abundance of individuals from different species varied. When comparing diversity patterns between environments, anthropic sites exhibited higher richness and evenness, suggesting that environmental stress increased the number of favorable niches for culicids, promoting diversity. Increased abundance of opportunistic species in the anthropic environment enhances contact with culicids that transmit vector-borne diseases.

Monitoring of the urban stretch of Arroio dos Pereiras (Brazil): evaluation of physicochemical and biological parameters

The levels of pollution in water bodies are directly related to the health and welfare of the population that uses this water with different purposes. Events such as vegetation suppression, different uses (industrial, agricultural and domestic), sewage discharge, are some of the factors that mostly contribute to the depletion of such water resources, mainly in urban areas. The objective of this study was the physicochemical monitoring of the urban stretch Arroio dos Pereiras, located in Irati (Parana State, Brazil), in areas of low and medium human occupation. The relations between superface water quality and the use of urban soil in that region were also verified employing high resolution orbital images. The water quality parameters analyzed included pH, total solids, turbidity, dissolved oxygen (DO), biochemical oxygen demand (BOD), total and fecal coliforms (E. coli). The water in Arroio dos Pereiras presented, for most parameters, characteristics which were in accordance with the Brazilian Federal Legislation; however, total and fecal coliforms values were high above limits permitted by law, making the water unsuitable for use. The sewage discharge along the stretch evaluated was the main reason for the low quality of this water.

Fast restoration of grassland vegetation by a combination of seed mixture sowing and low-diversity hay transfer

Technical reclamation of grasslands is a powerful tool for conserving biodiversity in fragmented landscapes. Plant material transfer and sowing seeds of local provenance are used most frequently to recover grassland vegetation in former croplands. The joint application of these methods is rarely used, although it has the potential to gain a predictable and directed vegetation development with effective early weed suppression. We studied the effectiveness of combining low diversity seed sowing and hay-transfer in weed suppression and recovery of perennial grassland vegetation in Hortobágy Puszta, Central-Europe, by testing the following hypotheses: (i) lower weed cover and biomass is expected in vegetation recovered by the joint method of sowing and hay transfer than by seed sowing only. (ii) With sowing and additional hay transfer a higher rate of establishment of Festuca species is expected than with sowing only. Our results supported both hypotheses. We found that the additional application of hay significantly accelerated the development of perennial grassland vegetation and provided a higher weed suppression rate in the first year and onwards in most plots than seed sowing only. A higher establishment rate was detected both in the cover and the biomass of perennial grasses including Festuca species in all plots with hay addition than with sowing only. Our results suggest that a combination of hay transfer and low diversity sowing may provide a cost-effective alternative to the more costly high-density sowing and if proper sources for high-diversity hay are available, it may replace high-diversity seed mixtures.

Land Degradation Model Based on Vegetation and Erosion Aspects Using Remote Sensing Data

The study of land degradation in various geographic conditions in the world using remote sensing is still become a concern amongst researchers because it has been proven as one of the most effective ways. In Indonesia, East Kalimantan province is one of the experiencing land area degradation due to intensive exploitation of natural resouces since 1970. The degradation model proposed in this study is modeled using a combination of ASTER and Landsat ETM+ imagery, both taken on February 27, 2001. The model composed of both two aspects: erosion aspect and vegetation aspect. Vegetation aspect is a function of suppression of vegetation from Crippen and Blom method and spectral angle a of Spectral Angle Mapper (SAM) algorithm. The erosion aspect is calculated from erosion prediction and depends on the constant factors of b as well, and the latter is said as a function of Normalized Difference Vegetation Index (NDVI) value. Based on the validation using spectral based degradation map and Land Degradation Index of Chikhaoui et al, our model proves the ability to map land degradation, especially to better distinguish the classification of land degradation at very-slightly to very-severe intensity and the ability to differentiate water body, swamp or river.

Influence of herbaceous and woody competition on white pine regeneration in a uniform shelterwood

We investigated the effects of herbaceous and woody vegetation control on the survival and growth of planted and natural eastern white pine (Pinus strobus L.) seedlings through six growing seasons following a uniform shelterwood regeneration harvest on two independent sites. Subsequent to chain scarification, white pine seedlings were planted at 2-m spacing, augmenting natural regeneration (full stocking and >3000 seedlings per ha). Herbaceous vegetation control involved the suppression of grasses, forbs, ferns, and low shrubs, and was maintained for zero, two, or four growing seasons after planting. Woody control involved the removal of all tall shrubs and deciduous trees, and was conducted at the time of planting, at the end of the second or fifth growing seasons, or not at all. White pine seedling growth responded positively to increased duration of herbaceous vegetation control and negatively to delayed woody control. Maximum growth was not realized unless both types of vegetation were suppressed. During the first six growing seasons, the height growth of planted pine was more than twice that of naturally regenerating pine, regardless of tending regime. The study suggests that successful white pine regeneration may be achieved by thinning from below to allow 50% to 60% of full sunlight in the understory, followed by the proactive, early suppression of woody and herbaceous vegetation to maintain optimum light levels and reduce competition for soil moisture and nutrients.

Suppression of vegetation in multispectral remote sensing images

Vegetation cover is an impediment to the interpretation of multispectral remote sensing images for geological applications, especially in densely vegetated terrains. In order to enhance the underlying geological information in such terrains, it is desirable to suppress the reflectance component of vegetation. This article adapts the forced invariance technique proposed by Crippen and Blom (2001) for the suppression of the vegetation reflectance component in a densely vegetated study area in northern Zhejiang province, eastern China. The approach uses a three-step process that comprises: (i) masking of barren or sparsely vegetated areas using a normalized difference vegetation index (NDVI) mask in order to retain their original spectral information through the subsequent processing; (ii) applying a forced invariance technique to subtract the spectral response of vegetation only in vegetated areas; and (iii) combining the processed vegetated areas with the masked barren or sparsely vegetated areas followed by a histogram equalization to eliminate the differences in colour scales between these two types of area. An evaluation based on comparison with the geological map shows that the forced invariance technique results in significant enhancement of the geological information in the processed image.

A General Approach for Suppressing Vegetation in Optical Remotely Sensed Imagery

Vegetation coverage is always an obstacle in the lithological information extraction from optical remotely sensed imagery.Aimed at enhancing lithological and soil information in vegetation coverage area,this paper used a three-step(i.e.,masking,enforced variance,histogram equalization) general vegetation suppression approach.Four experiments were conducted by using different datasets in different locations,which included a Landsat ETM+ image in Hangzhou of Zhejiang,a Landsat ETM+ image in Funing of Yunnan,a Hyperion image in Rongtang of Jiangxi and a MODIS image in Guangdong.The results indicate the effectiveness of the proposed approach in suppressing vegetation in optical remote sensing images with different spatial and spectral resolutions.

Twenty years of intensive fertilization and competing vegetation suppression in loblolly pine plantations: Impacts on soil C, N, and microbial biomass

Silvicultural treatments of fertilization (F) and competing vegetation suppression (H) have continued to increase as demands for forest products have grown. The effects of intensive annual F and H treatments on soil C, N, microbial biomass, and CO 2 efflux were examined in a two-way factorial experiment (control, F, H, FxH) in late-rotation (20+ years) loblolly pine stands. This study is unique in testing the cumulative effects of continual H and repeated F treatments for the first 20 years of stand growth, an uncommon operational practice, and in having treatments replicated upon four different soil types in the state of Georgia, USA. Annual fertilization included applications of N, P, K and periodic additions of micronutrients while competing vegetation suppression was maintained for all non-pine vegetation with herbicides throughout the rotation. Measurements included total O-horizon (forest floor) organic matter, C, and N, and 0–10 cm mineral soil pH, C, N, microbial biomass C and N, and surface CO 2 efflux. Sample collections and analyses were conducted seasonally for 1.5 yrs. Competing vegetation suppression was associated with a decrease of total soil C, soil microbial biomass C and N, and soil surface CO 2 efflux, while increasing O-horizon C:N. The fertilization treatment greatly reduced soil microbial biomass C and N, soil pH, and O-horizon C:N, while increasing O-horizon mass, N content, and soil carbon. No significant interactions between F and H were found. The combination of F and H treatments acted additively to achieve the greatest loss of soil microbial biomass, which may possibly have negative implications for long-term soil fertility.

A case study in land and water regeneration to reduce the impact of climate change by soil bio-sequestration of atmospheric carbon

The whole of landscape regenerative processes are being studied to determine their effect upon carbon bio-sequestration in agricultural soils. The Mulwaree Ponds drainage system, south of Sydney, shows the effects of overgrazing by fine wool sheep over the past 160 years and the resultant loss of perennial groundcover causing nutrient leaching into Sydney's drinking water catchment. Natural Sequence Farming methods, in combination with the strategic application of composted, recycled, organic waste, will be trialled to measure: a) the increase in stable soil carbon content; b) the improvement in water infiltration and retention in agricultural soils; c) the increase in biodiversity and suppression of undesirable vegetation; d) the sustainability and profitability of low input farming practices. Land owned and managed by conventional farmers will be subjected to this innovative agricultural regime in the belief that former 'doubters' make the best 'believers'. This paper details the methodology involved in the demonstration site which will assist in arguments linking increased soil carbon levels to mitigation of the effects of climate change.

Assessment of grazing effect on sheep fescue ( Festuca valesiaca) dominated steppe rangelands, in the semi-arid Central Anatolian region of Turkey

In the semi-arid steppe rangelands of Central Turkey, Festuca valesiaca and Thymus sipyleus ssp rosulans have become the dominant species on degraded pastures. We hypothesized that decreases in species richness and abundance are correlated with increasing prevalence of these two species. Therefore, our objectives were to determine whether there are patterns in examined vegetation; how dominant species contribute to these patterns; and how patterns differ between grazed and ungrazed vegetation. We determined that protection from grazing increased species richness. Grazing significantly changed composition through decreasing total plant, forb, grass and F. valesiaca covers, while substantially increasing T. sipyleus cover. Topography, soil and grazing appear to impact the dominance of plant communities where F. valesiaca and T. sipyleus prevail. These two dominant species had a significant effect in shaping vegetation patterns. Based on regression analysis, alterations in species richness with changes in cover of forbs and shrubs were evident, and spatial heterogeneity of F. valesiaca and T. sipyleus indicated unstable vegetative patterns in heavily grazed pastures and successional changes in protected pastures. Our study results identify F. valesiaca and T. sipyleus as indicator species of vegetation suppression in condition assessments of degraded steppe rangelands.

Produção animal em pastagem natural e pastagem sobre-semeada com espécies de estação fria com e sem o uso de glyphosate

This study evaluated animal production of steers and pasture production of natural grassland and grassland overseeded with Italian ryegrass (Lolium multiflorum), white clover (Trifolium repens) and birdsfoot trefoil (Lotus corniculatus), with and without the use of glyphosate herbicide. Treatments consisted of: NG – natural grassland, with annual mowing; ING – natural grassland with overseeding, fertilizing and annual mowing; G1 – Same ING, but with glyphosate application in the first year; G3 – same as G1, with suppression of natural vegetation using herbicide in the second and third years; GF3 – same as G3, with doubled fertilizing in the three years. The experimental design consisted of completely randomized blocks with two replications. The results presented are from the third year of evaluation. For average daily weight gain, there were differences (p &le 0.1) among treatments and periods, varying from 0.214 kg animal-1 day-1 in NG to 1.406 for the treatments with introduction of species. Live weight gain per area varied from 84 to 410 kg of LW ha-1. The stocking rates varied from 283 to 679 kg of LW ha-1. The herbicide did not present effects on production; and introduction of cool season species by overseeding improved animal production in NG, resulting in higher animal performance per animal and per area.

Reversal of fortune: plant suppression and recovery after vole herbivory

It is not clear how plant species preferred as forage by rodents persist in prairie vegetation. To test permanence of suppression of wet-mesic prairie vegetation by vole (Microtus pennsylvanicus) herbivory in synthetic experimental communities, access treatments were reversed after 9 years of vole exclusion or access. Between 1996 and 2004, rye grass Elymus virginicus (Poaceae) and tick-trefoil Desmodium canadense (Fabaceae) achieved mean cover of up to 30 and 25%, respectively, in plots where voles were excluded, but disappeared from plots where voles had access. To determine whether these species remained vulnerable to vole herbivory as established adults, and to determine whether the species could recover if vole herbivory were removed, access treatments were reversed at the end of the 2004 growing season and monitored through 2007. Repeated measures ANOVA demonstrated dramatic vole suppression of established E. virginicus, but not D. canadense, indicating continuing vulnerability of the grass but not of the adult legume. Release from vole herbivory resulted in re-growth of rye, but not tick-trefoil, which was apparently suppressed by established vegetation. Two additional common planted species did not respond to treatment reversal, nor did 11 much less common planted species that comprised a minor portion of the vegetation. Dominant perennial black-eyed Susan Rudbeckia subtomentosa (Asteraceae) did not change in plant numbers by year or treatment, but expanded or contracted in stems per plant and cover as E. virginicus was suppressed or released by vole herbivory or its absence. Results indicate that preferred food plants may persist through capacity to quickly recover during periods of relative vole scarcity, or reach a refuge in maturity.

Seasonal soil and foliage nutrient dynamics of a juvenile loblolly pine plantation: Impacts of fertilizer formulation and vegetation suppression

Understanding soil and foliage nutrient dynamics can enhance effectiveness and sustainability of forest nutrition improvement practices. Monthly soil and foliage nutrient concentrations were measured in a juvenile loblolly pine ( Pinus taeda L.) plantation in southeastern Oklahoma, USA, in response to: untreated control, herbaceous vegetation suppression (VS), urea and diammonium phosphate (DAP), urea and DAP with VS, and coated urea fertilizer (CUF) with VS. Fertilization treatments persistently increased soil NO 3 − and foliage N concentrations. All fertilization treatments also reduced foliage P:N and K:N ratios below optimum levels, suggesting that the fertilizer treatments used in this study (which are conventionally applied to mid-rotation loblolly pine plantations of the region) did not adequately match the nutrient demands of this juvenile plantation. Herbaceous vegetation suppression prolonged soil and foliage N increases, prolonged declines in P:N ratios, and increased foliage B and P concentrations in the second year of the study. Fertilizer formulations yielded similar foliage and soil N and P concentrations.