Landsat TM inventory and assessment of waterbird habitat in the southern altiplano of South America

Abstract

The diverse set of wetlands in southern altiplano of South America supports a number of endemic and migratory waterbirds. These species include endangered endemic flamingos and shorebirds that nest in North America and winter in the altiplano. This research developed maps from nine Landsat Thematic Mapper (TM) images (254,300 km 2 ) to provide an inventory of aquatic waterbird habitats. Image processing software was used to produce a map with a classification of wetlands according to the habitat requirements of different types of waterbirds. A hierarchical procedure was used to, first, isolate the bodies of water within the TM image; second, execute an unsupervised classification on the subsetted image to produce 300 signatures of cover types, which were further subdivided as necessary. Third, each of the classifications was examined in the light of field data and personal experience for relevance to the determination of the various habitat types. Finally, the signatures were applied to the entire image and other adjacent images to yield a map depicting the location of the various waterbird habitats in the southern altiplano. The data sets referenced with a global positioning system receiver were used to test the classification system. Multivariate analysis of the bird communities censused at each lake by individual habitats indicated a salinity gradient, and then the depth of the water separated the birds. Multivariate analysis of the chemical and physical data from the lakes showed that the variation in lakes were significantly associated with difference in depth, transparency, latitude, elevation, and pH. The presence of gravel bottoms was also one of the qualities distinguishing a group of lakes. This information will be directly useful to the Flamingo Census Project and serve as an element for risk assessment for future development.

Mapping and spatial characterization of Argentine High Andean peatbogs

“…This percentage is considerably smaller than other analyses in the same ecosystem type. For example, Boyle et al (2004) reported that approximately 4 % in a study area of 254,000 Km 2 partially overlapping (NW) with our study area was covered by peatbogs but their classification had very few ground truth points for validation (only two GT for the peatbogs class). We showed through an extra validation process that our method is a conservative measure of peatbogs' area (Table 2), but the underestimation of the peatbogs area is in the order of 15-20 %.…”

Precautionary rules for exotic trout aquaculture in fishless shallow lakes of Patagonia: minimizing impacts on the threatened hooded grebe (Podiceps gallardoi)

“…The variables incorporated in the model are easy to measure and can be acquired at low cost. In addition, remote sensors such as Landsat satellites would estimate some of these variables successfully (Mathew et al, 2003;Nelson et al, 2003;Boyle et al, 2005;Cozar et al, 2005). The integration of both information sources within a geographic information system provides an effective tool to extrapolate the results of this paper to the whole meseta, to evaluate hydrological regimes of individual lakes, and to delineate strategies in the face of rainbow trout culture expansion.…”

How are wetlands and biological interactions related to carnivore distributions at high altitude?

“…For example, Vilama is hypersaline whereas Polulus is brackish (Perovic and Caziani unpublished data), which were important factors for waterbird distribution (Boyle et al, 2004). Density of meteorological stations is particularly low in the high mountains of northwest Argentina (Hijmans et al, 2005) so the results of this study are limited, and a higher density of climate stations could increase our knowledge about this area.…”