Michael J. Eden

Development Research: The Environmental Challenge

What do you do to start reading development research the environmental challenge? Searching the book that you love to read first or find an interesting book that will make you want to read? Everybody has difference with their reason of reading a book. Actuary, reading habit must be from earlier. Many people may be love to read, but not a book. Its not fault. Someone will be bored to open the thick book with small words to read. In more, this is the real condition. So do happen probably with this development research the environmental challenge.

Crop diversity in tropical Swidden cultivation: Comparative data from Colombia and Papua New Guinea

Abstract Traditional swidden or shifting cultivation in the tropics is commonly associated with mixed cropping, from which it is assumed to derive ecological advantages. However, considerable variation exists in the level of diversity of individual swidden communities. This is illustrated by the application of Simpson and Shannon indices to crop compositional data for such communities in the Colombian Amazon and in southwest Papua New Guinea. In these areas, both high-diversity and low-diversity swiddens are encountered, which are apparently of sustainable character. It is inferred that diverse crop communities do not have a monopoly on adaptation in swidden cultivation.

Traditional shifting cultivation and the tropical forest system.

The idea of shifting cultivation as a compositionally diverse, and thereby adaptive, agrosystem has been overemphasized. Other aspects of the system, particularly its successional characteristics, are beginning to receive due attention.

Geomorphology and land development in the Maraca area of northern Roraima, Brazil.

The geomorphological materials and forms of the Maraca area of Roraima, Brazil are described, an their sgnificance for land development examined. Significant contrasts are noted in areas presently under rainforest and savanna vegetation. Lateritic gravels and extensive shetwash accumulations in savanna areas constrast with incipient or absent plinthite development, few gravels and limited evidence of colluvium under rainforest. Terrain is in general relatively highly-dissected. Slope profiles are characterised, particularly within the savanna zone, by a relatively steep lower concavity. These contrasts are sharply-demarcated by the present savanna/rainforest bondary, unexpectedly in view of the generally accepted hypothesis of repeated contraction an expansion of Amazonian rainforest throughout the Pleistocene. It is concluded that geomorphological conditions in the Maraca area are not favorable for land develoment.

Soil physical and chemical properties of cultivated pasture on forest land, Roraima, Brazil

Soil conditions under pasture were examined in a range of sites representing the sequence of conversion of forest to pasture at two locations in the vicinity of Ilha de Maraca, Roraima. Comparisons were made with adjacent savana. Soil bulk densities shown to increase after forest clearance and soil chemical data indicate that the initial beneficial effects on nutrient supply of burning forest debris are rather short-lived. Very low levels of available phosphorus prevail in areas of savanna and cultivated pasture of all ages. Variations in the status of older cultivated pastures are mainly attributable to different grazing levelt.