Question

Rainforest (Vital attributes versus state and transition)

An area of rainforest is severely damaged by a cyclone and 9 months later a fires burns half of the forest area.

Broadly describe your assumptions about vegetation responses and identify the key features of the models. Use examples from the scenario to describe how (1) the Noble and Slatyer vital attributes model and (2) how the state and transition model could each be used as a tool to understand the pattern of vegetation recovery in this situation.

Discuss the advantages and limitations of using each model to understand vegetation dynamics in this scenario.

Answer 1

1) Nobel and Slatyer studied the different types of species which are prevalent in different types of ecological successions in a habitat. The various factors which can be studied under this study are--the formation of different species during different ecological periods of succession on different land. There are specific species of plants present in a specific region or habitat. If the forest region containing different species of plants are affected due to cyclones or forest fires, then it causes the formation of barren lands with prevalence of mosses and lichens and it takes several generation for the formation of new species of plants in the specific ecological habitat. The others are the ability of a species to grow and develop in a specific region. These vital attributes have a role to play in the development of specific plant species and have a role in the replacement of the vegetation in specific regions of forest lands. There are different life stages for the formation of different species like the juvenile stage, mature stage, propagule stage and the locally extinct stage which are essential for the development of plant species. These stages persist in a specific region if it is not destructed due to natural calamities like cyclones, floods and fire which can destroy many trees and forests present in specific regions.There is alteration of generation of different species between the diploid and haploid stages leading to the development of plant starting from the embryo stage. There is formulation of a pattern starting from 1-20 which depicts the different stages in the development of plant starting from the juvenile stage of development. The starting pattern stage is the spread of seeds and their dispersal to different places for germination leading to the formation of the juvenile stage. The stages of pattern 9-15 include the formation of different stages of plants through the disturbance stage. There is analysis of the persistence stages and stages of plant growth and development before and after the stage of development.

The stage and transition model can be used for the identification of different species to understand vegetation dynamics of different species of plants like Acacia, Eucalyptus, Nothofagus and Atherosperma. The example includes the wet forests of Tasmania. The attributes of plants can be explained through the formation of different stages of plant species which are depicted by the use of different alphabets like D,S,G,C and V,U, W and Y. J means the juvenile stage, M means the mature stage, P means the propagule stage and E means the extinct stage in the life cycle of propagation of plants. The species are classified as CI and DT species. CI species are able to regenerate in a specific environment. The example is species of Acacia. Eucalyptus will prevail in specific habitat regions if there is no forest fire for 30 years. C attribute means a short lived seed pool growing in a region.The species of Eucalyptus and Acacia will become extinct after 400 years of forest survival without a natural calamity. Later Atherosperma species will be formed with less prevalence of the species of plants called as Nothofagus. If the site of forest is disturbed for the second time then it will lead to the formation of species of plants called as Acacia and Atherosperma. Eucalyptus species will be formed after regeneration of a region from forest fire leading to establishment of ecological diversity and these species will be destroyed after many years if there is a prevalence of natural calamity.

There are advantages like prevalence of many species and succession can be treated as a form of ontogeny. There is a shift in the composition and generation of diversity in different species which follows a pattern of succession. There is analysis of distribution of different forms of ecological successions which can be interpreted in the form of emergence of different plant species. More dispersed species of plants will survive during different natural calamities.

The disadvantages are that different species can be destroyed at different geographical intervals leading to the formation of destruction of many plant species. There is emergence of catastrophic disturbances which cause the total loss of different species of plants leading to the destruction of the ecological habitat.

S means long lived dispersal seedlings and I means intolerant species of plants.