Rates in rupees are valid in India & South Asia only / Les tarifs en roupies sont valables en Inde et en Asie du Sud seulement A vegetation map may be considered in different ways, for instance as a physiognomic map showing the present state of the vegetation, or as a land use survey map. A useful purpose of this kind of map is to show the possibilities of improving production. For this we must...

The ecological impacts of Hydrodictyon reticulatum blooms (1989-94) were studied at Lake Aniwhenua (a constructed lake) in North Island, New Zealand by collating fish, invertebrate and macrophyte data collected towards the end of a four year bloom period and following its decline. Hydrodictyon reticulatum had some localised impacts on the biota of the lake. Some macrophyte beds were smothered t...

Evolutionary branching occurs when frequency-dependent selection splits a phenotypically monomorphic population into two distinct phenotypic clusters. A prerequisite for evolutionary branching is that directional selection drives the population toward a fitness minimum in phenotype space. This article demonstrates that selection regimes leading to evolutionary branching readily arise from a wid...

The tenet that ecological opportunity drives adaptive diversification has been central to theories of speciation since Darwin, yet no widely accepted definition or mechanistic framework for the concept currently exists. We propose a definition for ecological opportunity that provides an explicit mechanism for its action. In our formulation, ecological opportunity refers to environmental conditi...

In a wide range of the central boundaries of the Iranian plateau, encompassing an important part of the arid areas in Asia, the phenomenon of desertification is a long his tory. In this arid and waterless expanse, living conditions are fully dependent on access to water due to the supremacy of the Kavirs and deserts. The most important and oldest ways of obtaining water have been Qanat or Kariz...

The Flora of Iran is very rich due to the diverse climatic and soil conditions in mdifferent ecological regions. Iran has around 10000 species of wild plant of which about 850 are considered being medicinally important. In the present work the phytochemistry of several Iranian medicinal plants and their possible usage will be discussed.