Tuuli Toivonen

Prediction of total and rare plant species richness in agricultural landscapes from satellite images and topographic data

The diversity of future landscapes might depend on our ability to predict their potential species richness. The predictability of patterns of vascular plant species richness in a Finnish agricultural river landscape was studied using generalized linear modeling, floristic records from fifty-three0.25-km grid squares in the “core” study area, and environmental variables derived from Landsat TM images and a digital elevation model. We built multiple regression models for the total number of plant species and the number of rarities, and validated the accuracy of the derived models with a test set of 52 grid squares. We tentatively extrapolated the models from the core study area to the whole study area of 601u2009km2 and produced species richness probability maps using GIS techniques. The results suggest that the local ‘hotspots’ of total flora (grid squares with > 200species) are mainly found in river valleys, where habitat diversity is high and a semi-open agricultural-forest mosaic occurs. The ‘hotspots’ of rare species (grid squares with > 4 rare species) are also found in river valleys, in sites where extensive semi-natural grasslands and herb-rich deciduous forests occur on steep slopes. We conclude that environmental variables derived from satellite images and topographic data can be used as approximate surrogates of plant species diversity in agricultural landscapes. Modeling of biological diversity based on satellite images and GIS can provide useful information needed in land use planning. However, due to the potential pitfalls in processing satellite imagery and model-building procedures, the results of predictive models should be carefully interpreted.

Accessibility of lowland rain forests of Western Amazonia via rivers - An analysis using Landsat TM mosaic and GIS

In the present paper a mosaic of 130 Landsat TM satellite images is used to identify navigable rives in the Western Amazon region and to analyse the accessibility pattern of the area via the river network. The environmental heterogeneity of the Western Amazonia is enormous, and thus the potential for human use varies significantly. In sustainable land use planning accessibility of potential resources is of paramount importance. Most studies and zoning proposals neglect the issue of accessibility or ignore the river network. Our study concentrated on the accessibility in the Western Amazonian region shared by several countries. A Landsat TM mosaic was created over this area and waters were separated by rationing of TM bands 5 and TM, classification and manual corrections. With the 100-meter resolution used, navigable rivers could still be delineated. Grid-based model on the on the accessibility of peripheral areas around regional, provincial and local centres was created and the accessibility pattern of the entire region and within each country was analysed. Nearly entire Peruvian Amazon as well as the vicinities of the main course of the Amazon River were found the most accessible regions, whereas large parts of Colombian and Brazilian Amazon were poorly accessible.

Launching a new article type in Fennia: Data descriptions

The journals of the Geographical Society of Finland are launching a new article type: Data descriptions ( Datankuvauksia in Finnish, Beskrivningar av data in Swedish). The autumn issue of Terra (3/2014) pioneers the new article type. With this announcement we welcome manuscripts of this kind also to Fennia.