Caracterização e Avaliação da Flora e Vegetação no

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1 Objectives VIII Assessment of Ground Vegetation 5 Within the framework of intensive monitoring activities at Level II, vegetation assessment is important for two different reasons. Firstly, vegetation is a major component of forest ecosystems. Vegetation layers contain a large part of total forest biological diversity. They play a direct role in water or nutrient cycling, and strongly interact with other biotic components (insects, game, etc.). Vegetation has been also identified as a specific target for the calculation of critical loads/levels. Secondly, vegetation is a good bioindicator of environmental changes. Our current knowledge of the ecological niche of numerous plant species allows changes in underlying environmental factors to be deduced from vegetation changes. Thus, the long-term study of vegetation dynamics at selected locations will provide information on changes in other forest ecosystem variables (soil, microclimate, etc.). The two main objectives of the vegetation assessment are: • characterization of the current state of the forest ecosystems on the basis of their composition; • monitoring of the vegetation changes due to natural and anthropogenic environmental factors. The characterization will allow plots to be positioned within identifiable vegetation types. The aims of studies of vegetation dynamics are to describe, explain and model succession, by an analysis of pathways, causes and mechanisms of vegetation changes. 2 Sampling design Since there is a trade-off between the accuracy of species cover estimation and the area which can be surveyed, two different sampling designs may be used, which either lead to a more qualitative or to a more quantitative characterization: • in the first case, the dynamics are assessed by monitoring changes in the species composition of a large number of species over a large area, utilizing sampling units greater than 100 m 2 , with a low to medium accuracy in estimates of changes in cover for each of these species; • in the second case, the study concentrates on population dynamics (expansion or regression) on a smaller area. Small sampling units (in general under 10 m 2 ) are used for a more accurate estimation of species cover. The area selected for vegetation assessment must be representative for the plot, in order to allow the comparison with other parameters recorded on the same plot. Several sampling units can be used in order to obtain statistical replication. 2.1 Total area surveyed, number and shape of sampling units According to phytosociological usage, the minimal requirement is to sample almost all of the species at the plot level. In order to achieve comparability of results between countries, a common sampling area (CSA) of 400 m 2 , representative for the ground vegetation of the Level II plot, is mandatory. This area can be reached as the sum of smaller sub-plots within the Level updated 06/2002
6 VIII Assessment of Ground Vegetation 2 plot area. Data are to be submitted for the total CSA area, not per sub plot (aggregated data). NFCs should keep the results of separate sub-plots in their national databases. Countries are free to select the number and shape of the sampling units (i.e. the units on which the ground vegetation is assessed). However, it should be noted that rectangular designs allow more species to be found (Stohlgren, 1994). Information on ground vegetation shall be submitted as estimates of species coverage in percent (with a minimum of 0.01%). A proposal for transformation of different scales into percent coverage is given in Annex I. 2.2 Spatial location of the sampling units If sampling units are not contiguous, they should be placed as far apart as possible within the Level II plot or in its buffer zone in order to minimize spatial correlation between the sampling units within a plot. They should also exclude major heterogeneities at any scale of sampling (boulders and cliffs, tracks and paths, fire places, streams and ponds, ditches and channels, peaty pools). 2.3 Marking the sampling units A permanent marking system has to be installed for the sampling units. The precise method to be used is at the discretion of each country (boundary markers, buried metal stakes, etc.) but the material used should be inert. The presence of markers should be regularly checked. It is recommended that maps should be used for recording the spatial arrangement and exact locations of the sampling units. Such maps should use the most permanent system of coordinates possible. 2.4 Additional survey of species outside the sampling units If the sampling units do not cover the total Level II plot area, which is the general situation, a list of all additional species not encountered within the sampling units should be established, if possible. Such a list will help to interpret future vegetation changes within the sampling units and will be of additional interest regarding the biodiversity. 2.5 Compatibility with other surveys In all cases, the exact location of the vegetation plots has to be determined in that way that any conflict with other assessments will be avoided. During the installation of sampling units, areas already used for other intensive studies (e.g. soil studies or measurements of deposition) and the tracks leading to these areas have to be avoided. Adequate information (map, signs) must be provided to all survey teams in order to limit the intensity of vegetation trampling and soil compaction within the sampling units. updated 06/2002
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UNIVERSIDADE DE ÉVORA CURSO DE ENG
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AGRADECIMENTOS Ao Prof. Doutor Jos
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6. REFERÊNCIAS BIBLIOGRÁFICAS 73
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1.1. OBJECTIVOS CARACTERIZAÇÃO E
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VASCO ALMEIDA DA SILVA, OUTUBRO 200
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2. CARACTERIZAÇÃO BIOFÍSICA 2.1.
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CARACTERIZAÇÃO E AVALIAÇÃO DA F
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Diagramas ombrotérmicos das parcel
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2.4. BIOGEOGRAFIA 2.4.1. Conceitos
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3. METODOLOGIA CARACTERIZAÇÃO E A
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3.2.2. Análise numérica dos dados
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Page 39 and 40: Código: 350.003.999 Racomitrium he
Page 41 and 42: EC: Zona elevada da Serra do Gerês
Page 43 and 44: COMPOSITAE Aetheorhiza bulbosa (L.)
Page 45 and 46: Local: 9, 10 Código: 036.003.001 Q
Page 47 and 48: DG: Endémica da Península Ibéric
Page 49 and 50: Galium mollugo L. RUBIACEAE TF: Pro
Page 51 and 52: Código: 193.044.001 Cynosurus echi
Page 53 and 54: CARACTERIZAÇÃO E AVALIAÇÃO DA F
Page 65 and 66: Serra da Lousã CARACTERIZAÇÃO E
Page 73 and 74: 4.2.4. Classificação estatística
Page 75 and 76: 5. CONSIDERAÇÕES FINAIS CARACTERI
Page 87 and 88: ANEXO I - Manual on methods and cri
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Page 101 and 102: ANEXO III Preenchimento do formulá
Page 103 and 104: Local 3: Perímetro Florestal da Co
Page 105 and 106: Local 9: Serra da Padrela (Vila Pou
Page 107 and 108: Local 10: Serra da Estrela (Manteig
Page 111 and 112: VASCO ALMEIDA DA SILVA, OUTUBRO 200
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Page 137: file:///D|/DGF%20-%20POLUIÇÃO/TFC
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