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Efeito do plantio de Acacia mangium Willd. (Fabaceae) sobre a riqueza e diversidade arbórea em áreas de savana na Amazônia setentrionalSidney Araújo de Sousa 21 August 2014 (has links)
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Este estudo teve como objetivo estimar a riqueza e a diversidade arbórea em áreas de savana natural e em áreas convertidas em monocultivos de Acacia mangium na Amazônia Setentrional. Todas as plantas com diâmetro de base maior ou igual a 2 cm foram medidas em 25 parcelas longas e estreitas (250m x 2m) de 0,05 hectares distribuídas em uma área de 190 km2, sendo 8 parcelas em áreas de savana e 17 em plantios. Foram amostrados 1365 indivíduos de espécies arbóreas e arbustivas, sendo 829 indivíduos de A. mangium (60,7%) e 536 indivíduos (39,2%) de espécies nativas. No total, foram registradas 62 espécies arbóreas e arbustivas, sendo 8 espécies típicas de savana (12,9% do total de espécies), 34 espécies florestais (54,9%) e 20 espécies (32,2%) consideradas generalistas, por ocorrerem tanto em savana como em floresta. A maioria das espécies de savana (7) foram encontradas nos plantios de A. mangium, sugerindo que o tempo de estabelecimento dos plantios ainda não atingiu um limite de alterações microclimáticas para excluir todas as espécies de savana. Apenas a riqueza e a diversidade de espécies arbóreas florestais foram relacionadas positivamente com a área basal e a idade dos plantios de A. mangium, indicando que a exclusão do fogo e alterações microclimáticas estão propiciando mudanças abruptas na composição de espécies na área. A distância mais próxima às áreas nativas (floresta e savana) não explicou as variações de riqueza e diversidade de espécies arbóreas encontradas nos plantios. A conversão da savana em plantios florestais de A. mangium causa alterações bruscas na composição de espécies, propiciando a entrada de espécies arbóreas em áreas antes ocupadas por espécies de savana. Os resultados apresentados não permitem afirmar que os plantios florestais podem servir como áreas complementares para conservação da biodiversidade das savanas, tendo em vista as alterações causadas na composição de espécies. Futuros estudos devem focar em outros importantes componentes da biodiversidade das savanas amazônicas como ervas e gramíneas e sobre o efeito da permeabilidade e conectividade da paisagem. / This study aimed to estimate tree species richness and diversity in natural savannas and savannas converted to Acacia mangium plantations in northern Amazonia. All trees with base diameter greater than or equal to 2 cm were measured and identified using thin and long (250m x 2m) plots of 0.05 hectares (8 plots in savannas and 17 plots in Acacia plantations). We found 1365 individuals, 829 (60.7%) of which were of A. mangium, and the remaining 536 (39.2%) from native species. Typical savanna trees were represented by eight species (12.9%), while 34 species (54.9%) were forest species and 20 (32.2%) were habitat generalists. Most savanna species (7) were found in the understory of plantations. Only richness and diversity of forest species were positively related to plantations age and basal area, indicating that possibly fire exclusion and microclimatic changes are favoring the establishment of forest species in the plantation understory. The nearest distance from native forest and/or savanna patch did not explain the variation in richness and diversity of tree species found in the plantations. In conclusion, tree plantation promoted a deep change in species composition in the area, allowing the entrance of tree species not found before in local savannas. Although several savanna species were found in plantations, the results are not conclusive regarding a complementary role of forest plantations for conservation of savanna woody species in northern Amazonia. Future studies should focus on other components of biodiversity such as herbs and grasses and in determining the effects of connectivity and permeability of this landscape.
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Alternativas de manejo de pastagem natural submetida a pastoreio rotativo / Management alternatives in natural grassland submitted to rotational grazingGaragorry, Fabio Cervo 15 February 2012 (has links)
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / This study aimed to evaluate different alternatives for management of natural pasture.
Vegetation dynamics was evaluated for a period of six years in a natural pasture, submitted
along 16 years to fire and grazing treatments. Furthermore, we evaluated the production and
behavior of beef heifers from 12 to 18 months of age, maintained on natural pasture under two
grazing frequencies. In the first experiment, the treatments consisted of a combination of
burning factors (presence or absence) and grazing (presence or absence), in concave and
convex slope positions, in a completely randomized design with factorial arrangement of four
treatments and two topographic positions. Rotational grazing was used, with intervals
calculated by the thermal time (760 degree days) necessary for the emergence of four leaves
of Paspalum notatum and Andropogon lateralis. Burning was performed at the end of winter
in a bimodal fashion. The treatments excluded from disturbances had a behavior atypical due
to a burning caused by a lightning leading vegetation to a succession process. The grazed
treatments had a stable prevalence of Paspalum notatum, on concave slope and its association
with Andropogon lateralis, in convex slope. Natural grassland proved to be resilient to
burning and grazing. However, the use of burning and grazing on concave slope areas can
cause a reduction in vegetation diversity. In the second experiment, we evaluated the effect of
two defoliation intervals, 375 and 750 degree days (DD), on the productive performance of
beef heifers maintained on natural pasture under rotational grazing in the growing season of
2010 and 2011. The experimental design was completely randomized with two treatments and
three replications. We evaluated the forage mass, height, green material and dead material in
pasture. The performance measurements in animals were evaluated stocking rate, average
daily gain and gain/ha. The greatest height, mass of green material, dead material and forage
mass were observed in 750 DD treatment. Treatment with 375 DD presented a higher
percentage of green material in relation to herbage mass. The highest average daily gain and
gain per area were observed in the treatment 375 DD. The shortest interval between grazing
permits satisfactory performance in rearing of beef heifers, since the natural pasture is
managed with green material above 1500 kg DM/ha and grazing periods lower than three
days. In the third experiment were related parameters and performance of grazing animal and
its ingestive behavior. Ingestive behavior of heifers was measured as times of grazing,
ruminating and resting, bite rate, bites per feeding station, feeding stations per minute,
displacement rates by stations and time. The multiple regression equations had coefficients of
determination of 48, 68 and 89% for grazing time, average daily gain and gain/ha. The
average temperature, day of occupation, number of bites/min and bits per season were the best
predictors of ingestive behavior of beef heifers grazing on natural grassland. / Este trabalho teve por objetivo avaliar alternativas de manejo de pastagem natural. Foi avaliada a
dinâmica da vegetação por um período de seis anos de uma pastagem natural, submetida ao longo
de 16 anos a tratamentos de fogo e pastejo. Além disso, foram avaliadas a produção e o
comportamento de novilhas de corte dos 12 aos 18 meses de idade, mantidas em pastagem natural
sob duas frequências de desfolha. No primeiro experimento, os tratamentos foram constituídos da
associação dos fatores queima (presença ou ausência) e pastejo (presença ou ausência), nas
posições de encosta e baixada, num delineamento completamente casualizado com arranjo fatorial
de quatro tratamentos e duas posições topográficas. O pastejo foi rotacionado, com intervalos
calculados pela soma térmica acumulada (760 graus dia) necessária para o surgimento de quatro
folhas das espécies Paspalum notatum e Andropogon lateralis. A queima foi realizada ao final do
inverno de forma bimodal. Os tratamentos excluídos de distúrbios tiveram um comportamento
atípico devido a uma queima provocada por um raio levando a vegetação a um processo de
sucessão. Os tratamentos pastejados foram estáveis com um predomínio das espécies Paspalum
notatum, na encosta e de uma associação desta com Andropogon lateralis, na baixada. A
pastagem natural mostrou-se resiliente a queima e ao pastejo. Entretanto, o uso da queima e
pastejo, em áreas de encosta, pode causar redução na diversidade da vegetação. No segundo
experimento foi avaliado o efeito de dois intervalos entre desfolhas de 375 e 750 graus dia (GD),
sobre o desempenho produtivo de novilhas de corte mantidas em pastagem natural sob pastoreio
rotacionado, na estação de crescimento entre 2010 e 2011. O delineamento utilizado foi o
inteiramente casualizado com dois tratamentos e três repetições. Foram avaliados a massa de
forragem, altura, material verde e material morto na pastagem. As medidas de desempenho nos
animais foram a carga animal, ganho médio diário e ganho/ha. As maiores altura, massa de
material verde, material morto e massa de forragem total foram observados com 750 GD. No
tratamento com 375 GD foi observado maior percentual de material verde em relação à massa de
forragem. Os maiores ganho médio diário e ganho por área foram observados no tratamento 375
GD. O menor intervalo entre pastoreios permite desempenho satisfatório na recria de novilhas de
corte, desde que a pastagem natural seja manejada com material verde superior a 1500 kg de
MS/ha e com períodos de ocupação de no máximo três dias. No terceiro experimento, foram
relacionados os parâmetros da pastagem e de desempenho animal com o comportamento ingestivo
dos animais. O comportamento ingestivo das novilhas foi medido pelos tempos de pastejo, de
ruminação e de ócio, taxa de bocados, bocados por estação alimentar, estações alimentares por
minuto, taxas de deslocamento e tempo por estação. As equações de regressão múltipla
apresentaram coeficientes de determinação de 48, 68 e 89% para tempo de pastejo, ganho médio
diário e ganho/ha, respectivamente. A temperatura média, os dias de ocupação, número de
bocados/min e bocados por estação foram os melhores preditores do comportamento ingestivo das
novilhas de corte em pastagem natural.
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Floristic composition and environmental determinants of roadside vegetation in North England.Akbar, K.F., Hale, William H.G., Headley, Alistair D.D. 2011 January 1918 (has links)
No / The roadside vegetation in
some counties of north England (north and west
Yorkshire) was studied to determine the community
structure according to the British National
Vegetation Classification (NVC) and main
environmental factors influencing its composition.
The data from Phytosociological survey
(699 quadrats) and from the physico-chemical
analyses of 233 soil samples from 35 sites were
obtained. Both the classification (TWINSPAN &
MATCH) and ordination programs (Canonical
Correspondence Analysis) were used. The roadside
vegetation is mainly dominated by few grasses
(Arrhenatherum elatius, Festuca rubra, Dactylis
glomerata, Lolium perenne, Poa trivialis, Elymus
repens, Holcus lanatus) and their associated herbs
(Cirsium arvense, Heracleum sphondylium, Urtica
dioica). Five NVC Mesotrophic grassland communities
(Arrhenatheretum elatioris community
MG1, Lolium perenne-Cynosurus cristatus grassland
MG6, Lolium perenne leys MG7, Holcus lanatus-
Deschampsia cespitosa grassland MG9, Festuca
rubra-Agrostis stolonifera-Potentilla anserina
grassland MG11) and one Upland Festuca ovina-
Agrostis capillaris-Galium saxatile grassland, U4
were identified which in general, exhibited good
fit with the typical NVC units.
Altitude, pH, potassium, sodium and road
age were found to be the main variables affecting
the roadside vegetation. By relating the floristic
composition with ecological characteristics
of the roadside verges, three kinds of pattern of
variation are observed. The first pattern is related
to regional or geographical characteristics and
the second pattern of variation exists across the
width of the road verges showing a zonal pattern
of plant distribution. The third scale of pattern is
active at the local level including micro-environmental
conditions, e.g., local edaphic variables.
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From arable field to forest: Long-term studies on permanent plots / Vom Acker zum Wald: Dauerflächenuntersuchungen zur Sukzession auf AckerbrachenDölle, Michaela 23 September 2008 (has links)
No description available.
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A plant ecological study and management plan for Mogale's Gate Biodiversity Centre, GautengTuckett, Alistair Sean 12 1900 (has links)
The Mogale’s Gate Biodiversity Centre is a 3 060 ha reserve located within the Gauteng
province. The area comprises grassland with woodland patches in valleys and lower-lying
areas. To develop a scientifically based management plan a detailed vegetation study was
undertaken to identify and describe the different ecosystems present. From a TWINSPAN
classification twelve plant communities, which can be grouped into nine major communities,
were identified. A classification and description of the plant communities, as well as, a
management plan are presented. The area comprises 80% grassland and 20% woodland
with 109 different plant families. The centre has a grazing capacity of 5.7 ha/LSU with a
moderate to good veld condition. From the results of this study it is clear that the area makes
a significant contribution towards carbon storage with a total of 0.520 tC/ha/yr stored in all
the plant communities. / Environmental Sciences / M.Sc. (Environmental Management)
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Estudos florísticos e fitossociológicos em comunidades vegetais de restinga da Ilha do Cardoso, Cananéia, SP.Sugiyama, Marie 27 May 2003 (has links)
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TeseMS.pdf: 839878 bytes, checksum: ce4d6d134c72bc480b1a92a8bc4ca303 (MD5)
Previous issue date: 2003-05-27 / The present study evolved floristic composition, structure and regeneration dynamic
aspects of a restinga forest (pluvial sand coastal plain forest), at Ilha do Cardoso, in
Cananéia region, São Paulo State, Brazil. Three portions of restinga forest with
same physiognomic aspects were selected: restinga of Trilha para o Morro das
Almas (MA), Trilha Interpretativa (TI) and Estrada para a Captação (EC). Five
strata of forest were sampled in each portion: Tree, Tree/shrub, Shrub/herbaceous,
Herbaceous and Lianas. Each portion was analyzed individually and subsequently
were analyzed the entirely of the three portions and compared them. At Trilha para
o Morro das Almas were sampled 73 species, at Trilha Interpretativa 72, at
Estrada para a Captação 56 and totally sample 112, inside them 31 species were
common to three portions and 46 restrict only one of them. The three portions of a
forest were floristically similar, MA and TI had the highest Sørensen similarity
(70,3%), and TI and EC had the less Sørensen similarity (55,5%). When compared
the strata in general Tree/shrub and Shrub/herbaceous strata had the highest value
of Sørensen similarity, and the Tree and Herbaceous strata had the less similarity.
The highest diversity and equability were found in herbaceous strata, and the less in
tree strata. The plants of the three portions had majority of species with geographic
distribution in south and southeast Brazil regions, and the majority individuals and
species were secondary-climax category. The portions of studied forest were in
advanced stage of regeneration, and shade-tolerant species were favored. The
differences between three portions of a forest were due to natural process common
in tropical forests, where the substitution of one tree produce a mosaic of distinct
regenerative phases at community that differ in structure and floristic composition.
Differences in environment physical conditions, especially edaphic factors, and
distinct anthropic interventions are responsible too. / O presente estudo envolveu a composição florística, a estrutura e aspectos da
dinâmica de regeneração de floresta de restinga (floresta pluvial da planície
arenosa costeira), na Ilha do Cardoso, Cananéia, Estado de São Paulo, Brasil.
Foram selecionadas três áreas com fisionomias semelhantes: restinga da Trilha
para o Morro das Almas (MA), da Trilha Interpretativa (TI) e da Estrada para a
Captação (EC). Foram amostrados cinco estratos em cada uma delas: Arbóreo,
Arbóreo/arbustivo, Arbustivo/herbáceo, Herbáceo e Lianas. Cada uma das áreas foi
analisada individualmente e posteriormente fez-se uma análise conjunta
comparando as três áreas entre si. Na Trilha para o Morro das Almas foram
amostradas 73 espécies, na Trilha Interpretativa 72, na Estrada para a Captação 56
e na amostragem total 112, sendo que 31 espécies foram comuns às três áreas e
46 foram restritas à apenas uma delas. Pelo índice de Sørensen as três áreas são
floristicamente similares entre si, sendo que MA e TI apresentaram a maior
similaridade (70,3%) e TI e EC a menor similaridade (55,5%). Na comparação entre
os estratos de modo geral entre o arbóreo/arbustivo e o Arbustivo/herbáceo houve
maior similaridade de Sørensen e, entre o Arbóreo e o Herbáceo menor. A maior
diversidade florística e equabilidade couberam ao estrato herbáceo e as menores
ao arbóreo. Nas três áreas amostradas a maioria das espécies apresentaram
padrão de distribuição geográfica sul e sudeste do Brasil e, a maioria dos indivíduos
e das espécies pertencia à categoria sucessional secundária tardia. Os trechos de
floresta estudados estão em estágio avançado da sucessão e as espécies
tolerantes à sombra estão sendo favorecidas. As diferenças entre os três trechos
da floresta amostrados devem-se a processos naturais comuns nas florestas
tropicais, onde a substituição de árvores produz um mosaico de distintas fases
regenerativas na comunidade que diferem na estrutura e na composição floristica.
As diferenças nas condições físicas ambientais, especialmente fatores edáficos e,
as intervenções antrópicas diferenciadas também são responsáveis por essas
diferenças.
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A plant ecological study and management plan for Mogale's Gate Biodiversity Centre, GautengTuckett, Alistair Sean 12 1900 (has links)
The Mogale’s Gate Biodiversity Centre is a 3 060 ha reserve located within the Gauteng
province. The area comprises grassland with woodland patches in valleys and lower-lying
areas. To develop a scientifically based management plan a detailed vegetation study was
undertaken to identify and describe the different ecosystems present. From a TWINSPAN
classification twelve plant communities, which can be grouped into nine major communities,
were identified. A classification and description of the plant communities, as well as, a
management plan are presented. The area comprises 80% grassland and 20% woodland
with 109 different plant families. The centre has a grazing capacity of 5.7 ha/LSU with a
moderate to good veld condition. From the results of this study it is clear that the area makes
a significant contribution towards carbon storage with a total of 0.520 tC/ha/yr stored in all
the plant communities. / Environmental Sciences / M.Sc. (Environmental Management)
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Vegetation ecology of Drakensberg foothill moist grassland on Hlogoma Mountain, Underberg, KwaZulu-NatalBerruti, Sharron Marion 11 1900 (has links)
Hlogoma Mountain is a small inselberg surrounded by farms and commercial forestry in the Underberg district (KwaZulu-Natal) within the Gs10 Drakensberg Foothill Moist Grassland. As little is known about the vegetation on Hlogoma, a survey was undertaken to classify, map and describe the plant communities occurring on the inselberg. A total of 100 (16 m2) randomly stratified sample plots were placed in homogeneous vegetation units within the 117 ha study area. A TWINSPAN classification, refined by Braun-Blanquet procedures, resulted in the identification of two major communities, five communities, 12 sub-communities and four variants. All communities were described and a vegetation map constructed. Ordinations identified key environmental variables that have an impact on the vegetation at the study site. A plant species checklist was created and analysed for floristic composition; rarity and threatened species; medicinal plants; endemism; phenology; flower colour and elevation range; species richness and plant community biodiversity. A total of 467 species were identified, represented by 271 genera and 87 families. Four Red Data species and a new Aspidoglossum species were discovered. Two near-endemic genera, two endemic species and 88 near-endemic species belonging to the Drakensberg Alpine Centre were found on Hlogoma. This study showed that Hlogoma Mountain is an inselberg with high plant species richness and endemism, and is a refuge of conservation importance for biodiversity. / Environmental Sciences / M. Sc.(Environmental Science)
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Vegetation ecology of Egoli Granite Grassland on the farm Doornrandjie, GautengBezuidenhout, Antonia 12 1900 (has links)
A vegetation survey was conducted on the newly acquired farm portions of the farm
Doornrandje 386 JR, which are being incorporated into Gauteng Department of
Agriculture and Rural Development’s protected area expansion. This study provides
an ecological basis for establishing an efficient management programme for the
area. From a TWINSPAN classification, refined by Braun-Blanquet procedures, five
plant communities were identified. A classification and description of the major plant
communities is presented. Descriptions of the plant communities include
characteristic species, as well as prominent and less conspicuous species of the
tree, shrub, herb and grass strata. Floristic analyses of the vegetation and a
biodiversity comparison of the different plant communities found on the farm are also
undertaken. This study proves that the extended land incorporated into the Reserve contributes to the biological diversity of the study area. / Environmental Sciences / M. Sc. (Environmental Science)
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Vegetation ecology of Egoli Granite Grassland on the farm Doornrandjie, GautengBezuidenhout, Antonia 12 1900 (has links)
A vegetation survey was conducted on the newly acquired farm portions of the farm
Doornrandje 386 JR, which are being incorporated into Gauteng Department of
Agriculture and Rural Development’s protected area expansion. This study provides
an ecological basis for establishing an efficient management programme for the
area. From a TWINSPAN classification, refined by Braun-Blanquet procedures, five
plant communities were identified. A classification and description of the major plant
communities is presented. Descriptions of the plant communities include
characteristic species, as well as prominent and less conspicuous species of the
tree, shrub, herb and grass strata. Floristic analyses of the vegetation and a
biodiversity comparison of the different plant communities found on the farm are also
undertaken. This study proves that the extended land incorporated into the Reserve contributes to the biological diversity of the study area. / Environmental Sciences / M. Sc. (Environmental Science)
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