Measuring botanical composition of grasslands.

Whalley, R. D. B.; Hardy, M.B.; Mannetje, L. ‘t; Jones, R. M.

doi:10.1079/9780851993515.0067

Cited by 38 publications

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“…A metodologia de amostragem utilizada foi a da estimativa direta da composição percentual, proposta por Whalley & Hardy (2000), considerando-se as percentagens de material verde (MV -folhas e colmos) e material morto (MM -folhas e colmos) por m². Sendo este um método subjetivo de seleção visual, foi realizado por três pessoas e no mesmo dia para as três espécies de braquiária.…”

Section: Methodsunclassified

Densidade populacional de Pratylenchus spp. em pastagens de Brachiaria spp. e sua influência na disponibilidade e na qualidade da forragem

et al. 2013

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Population density of Pratylenchus spp. in pastures of Brachiaria spp. and its influence on the forage availability and qualityThe aim of this work was to evaluate the population density of Pratylenchus brachyurus and Pratylenchus zeae associated with Brachiaria brizantha, B. decumbens and B. humidicola and their influence on forage availability and quality. The experiment was conducted in the Hisaeda Farm, Terenos, MS, Brazil. Soil, roots and plant aerial part were harvest, with ten replications each, in one square meter randomized sets encompassing three treatments: Good, Intermediary and Bad, visually characterized, considering the percentage of green material. P. brachyurus and P. zeae density were evaluated in soil and plant roots. Dry matter of green, dead and re-growth materials, plant nutritional status and forage quality were assessed in the aerial plant part. Soil fertility was determined in all harvested samples. Both nematode species were identified from all samples, with a larger number in the roots (between 87-311 P. brachyurus and 1-61 P. zeae.10 g -1 ) than in the soil (0-8 P. brachyurus and 1-39 P. zeae.200 cm -³), however, no significant differences were found in the number of specimens between treatments. Considering that these forage species are perennial and host Pratylenchus spp, there is a tendency to increase the population of these pathogens over time, becoming a serious phytosanitary problem. Objetivando avaliar a densidade populacional de Pratylenchus brachyurus e Pratylenchus zeae, associados à Brachiaria brizantha, B. decumbens e B. humidicola, e sua influência na disponibilidade e na qualidade da forragem, realizou-se este trabalho. O experimento foi conduzido na Agropecuária Hisaeda, em Terenos, MS. Coletaram-se amostras de solo, raízes e parte aérea, em dez repetições ao acaso, de 1 m² cada, dos seguintes tratamentos: Bom, Intermediário e Ruim, caracterizados visualmente, considerando-se a percentagem de material verde das plantas. As densidades de P. brachyurus e P. zeae foram avaliadas nas amostras de solo e raízes. Na parte aérea, avaliou-se a disponibilidade de matéria seca dos materiais verde, morto e da rebrota, estado nutricional das plantas e qualidade da forragem. A fertilidade do solo foi determinada em todas as unidades amostrais. Ambos os nematoides foram identificados em todas as amostras, com maior número nas raízes (entre 87-311 P. brachyurus e 1-61 P. zeae.10 g -1 ) que no solo (de 0-8 P. brachyurus a 1-39 P. zeae.200 cm -³), no entanto, não houve diferenças significativas, na quantidade de espécimes, entre os tratamentos. Considerando-se que essas forrageiras são perenes e hospedam Pratylenchus spp., há tendên-cia ao aumento da população desses patógenos, ao longo do tempo, podendo se tornar um sério problema fitossanitário. Palavras-chave:Brachiaria brizantha, B. decumbens, B. humidicola, Poaceae, Pratylenchus brachyurus, P. zeae.

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Section: Methodsunclassified

Densidade populacional de Pratylenchus spp. em pastagens de Brachiaria spp. e sua influência na disponibilidade e na qualidade da forragem

et al. 2013

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“…Each site was divided into three blocks, in each block six quadrats were established, the quadrats were fixed systematically along the block (beginning, middle and the end of the block). For each quadrat, all occurring plant species were recorded and the proportion of each species from the total dry weight biomass was visually estimated following a method of percentage ranking (Whalley and Hardy, 2000). Above-ground biomass (used as surrogate for the above-ground productivity) was measured for each quadrat by harvesting all plant material (>2 cm).…”

Section: Data Collectionmentioning

confidence: 99%

The Relationship Between Plant Diversity and Productivity in Natural and in Managed Grasslands

Assaf¹

2011

Appl Ecol Env Res

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Assaf et al.: The relationship between plant diversity and productivity in natural and in managed grasslands - Abstract. Despite the fact that several experiments have been conducted to explore the biodiversityproductivity relationship in synthesized and natural plant communities, the results obtained were contradictory and no clear consensus has been reached. Recent experiments that surveyed mature natural plant communities have investigated this relationship across environmental gradients, where biotic and/or abiotic factors are correlated with the observed diversity and productivity levels. We studied the effect of plant diversity on ecosystem productivity in agriculturally managed (managed at a low intensity with moderate level of disturbance) and natural (no history of management) grasslands at a within-site scale in order to minimize the confounding effect of environmental factors. We tested the effects of two diversity measures (species richness and species evenness) on productivity within-and across-sites scale. Our results indicated that this relationship was different between the natural and the managed grasslands and varied according to the diversity measure. Species richness only poorly explained the variation in productivity for the managed grasslands, while the variations in system productivity were better explained by species evenness. Interestingly, our results from the natural low productive, species poor grassland are in agreement with the results obtained from the recent experiments that artificially manipulated diversity levels and found an asymptotic increase in productivity along with increasing species richness. Our results provide additional evidence of the complex behavior that measures of species diversity that combine several aspects of diversity such as species evenness, species identity as well as the interactions among the species may be better determinants of the response of the ecosystem to biodiversity.

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“…Relative frequencies of occurrence, relative density and relative canopy cover were determined. The mean of these three values were considered as the importance value (IV) for each plant species in the study area (Whalley and Hardy, 2000;Franco-Lopez et al, 2001). Proportional IV (contribution of each species to the total IV) for each species was computed to be used in the determination of the similarity and preference indices.…”

Section: Methodsmentioning

confidence: 99%

“…Twenty two fixed transects (30m long) permanently established and distributed randomly were used to measure the botanical composition of the study area by the line-intercept method. At each linear transect individuals and species touching the tape or string were recorded and the lengths of the intercept occupied by them touching the line were recorded (Whalley and Hardy, 2000;Franco-Lopez et al, 2001). Relative frequencies of occurrence, relative density and relative canopy cover were determined.…”

Section: Methodsmentioning

confidence: 99%

Utilización Del Forraje Y Selección De La Dieta Por Cabras Pastando en Un Matorral Sarcocaulescente en El Noroeste De México

Armenta-Quintana¹,

Ramírez-Orduña²,

Ramírez-Lozano³

2011

RCHSCFA

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RESUMENEl agostadero sarcocaulescente es representativo del desierto Sonorense en Baja California Sur, México, de su flora, 92 % son arbustos y 23 % son especies endémicas, sin embargo, el impacto ecológico de la producción animal es desconocido. Los objetivos de este estudio fueron determinar y comparar durante dos años la preferencia y utilización de especies de plantas por caprinos en pastoreo. La colecta de datos de campo se llevó a cabo de junio de 2006, a junio de 2008. Los datos de composición botánica de la dieta y del área de estudio se emplearon para estimar los índices de preferencia y similitud. Se detectaron 78 especies, de las cuales los caprinos utilizaron 41; en cada muestreo, los animales utilizaron de 10 a 24 especies. El índice de similitud medio fue 26 % (16-32 %), la preferencia y la utilización fueron variables entre muestreos. La preferencia no estuvo acorde con la similitud. Este patrón de conducta alimenticia puede ser indicativo de una estrategia conservativa de utilización del forraje por los caprinos. ABSTRACTSarcocaulecent scrubland is representative of the Sonoran Desert of Baja California Sur, Mexico. In this area 92 % of its flora is shrubs and 23 % of these are endemic species, however, the ecological impact of animal production is unknown. The objectives of this study were to determine and to compare during two years the preference and use of plant species by grazing goats. Data field collections were done from June 2006 through June 2008. Botanical composition of diet and the study area data sets were used to estimate preference and similarity indices. In the studied site total plant species were 78 and goats utilized 41 throughout the study, in each collection date goats utilized 10 to 24 species. Mean similarity index was 26 % (16 to 32 %), both preference and utilization were highly variable between collection dates for each plant species. Preference by goats was not in accordance with similarity. This pattern of feeding behavior may indicate a conservative strategy of forage utilization by goats. PALABRAS CLAVE: Cabras enpastoreo, desierto sonorense, utilización de plantas, preferencia de forrajes, hábitos alimenticios KEY WORDS: Ranggoats, sonoran desert, plant utilization, forage preference, feeding behavior.

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Measuring botanical composition of grasslands.

Cited by 38 publications

References 0 publications

Densidade populacional de Pratylenchus spp. em pastagens de Brachiaria spp. e sua influência na disponibilidade e na qualidade da forragem

Densidade populacional de Pratylenchus spp. em pastagens de Brachiaria spp. e sua influência na disponibilidade e na qualidade da forragem

The Relationship Between Plant Diversity and Productivity in Natural and in Managed Grasslands

Utilización Del Forraje Y Selección De La Dieta Por Cabras Pastando en Un Matorral Sarcocaulescente en El Noroeste De México

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