Biodiversity refers to the number and types of different species present within a biological ecosystem. It is defined as the “totality of genes, species and ecosystems of a region.” The biodiversity of any biological system is indicative of the health of biological system. It ensures that any hazard, man made or naturally occurring diseases affecting one or more species does not affect the entire biological system and thus is necessary for selective evolution and survival of various life forms in diverse climatic conditions.
There are several methods by which variations in species and hence biological diversity is achieved through movement from one place to another. This movement of species across different geographical locations is referred to as pathways and various man-made and natural factors contribute to it. The human activities include the deliberate movement of one or more genetic species across different locations to ensure biological diversity. These are sometimes governed by financial considerations to harvest more of one or more type of species. But there effects on the already existing species need to be evaluated before labelling them beneficial or harmful because foreign species have been known to weed out local species in the past. These are the labelled as “invasive plants” as they disturb the natural environment and create a threat to biodiversity. Other man made pathways, although they may not be deliberate include organisms transfer through sewage and water discharge, transportation of soil and pathogen transfer through people commuting across geographical boundaries. Natural transportation of species that promote biological diversity is dispersal of species through wind and water currents, birds and animals. In case of natural pathways too, the threat by invasive plants may cause a harmful effect on the biodiversity. Control actions thus need to e deployed to take care of these harmful effects of pathways on the biological diversity.
Wilson, Edward O., Peter, Frances M. (1988). Biodiversity. National Academy Press.