| Registro completo |
| Provedor de dados: |
Ecology and Society
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| País: |
Canada
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| Título: |
From Satellite Imagery to Peatland Vegetation Diversity: How Reliable Are Habitat Maps?
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| Autores: |
Rochefort, Line; ;
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| Data: |
2002-12-09
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| Ano: |
2002
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| Palavras-chave: |
Landsat 7
Coarse filter
Error matrix
Habitat distinctiveness
Habitat variability
Mask procedure
Maximum likelihood classification
Peatland habitats
Plant species assemblages
Remote sensing
Supervised classification
Wetland conservation
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| Resumo: |
Although satellite imagery is becoming a basic component of the work of ecologists and conservationists, its potential and reliability are still relatively unknown for a large number of ecosystems. Using Landsat 7/ETM+ (Enhanced Thematic Mapper Plus) data, we tested the accuracy of two types of supervised classifications for mapping 13 peatland habitats in southern Quebec, Canada. Before classifying peatland habitats, we applied a mask procedure that revealed 629 peatlands covering a total of 18,103 ha; 26% of them were larger than 20 ha. We applied both a simple maximum likelihood (ML) function and a weighted maximum likelihood (WML) function that took into account the proportion of each habitat class within each peatland when classifying the habitats on the image. By validating 626 Global Positioning System locations within 92 peatlands, we showed that both classification procedures provided an accurate representation of the 13 peatland habitat classes. For all habitat classes except lawn with pools, the predominant classified habitat within 45 m of the center of the validation location was of the same type as the one observed in the field. There were differences in the performance of the two classification procedures: ML was a better tool for mapping rare habitats, whereas WML favored the most common habitats. Based on ordinations, peatland habitat classes were as effective as environmental variables such as humidity indicators and water chemistry components at explaining the distribution of plant species and performed 1.6 times better when it came to accounting for vegetation structure patterns. Peatland habitats with pools had the most distinct plant assemblages, and the habitats dominated by herbs were moderately distinct from those characterized by ericaceous shrubs. Habitats dominated by herbs were the most variable in terms of plant species assemblages. Because peatlands are economically valuable wetlands, the maps resulting from the new classification procedure presented here will provide useful information for land managers and conservationists.
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| Tipo: |
Peer-Reviewed Reports
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| Idioma: |
Inglês
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| Identificador: |
vol6/iss2/art16/
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| Editor: |
Resilience Alliance
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| Formato: |
text/html application/pdf
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| Fonte: |
Ecology and Society; Vol. 6, No. 2 (2002)
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