Ecological Success of Species

Ecological Success of Species

Specie: Species is the basic unit of Classification. Specie is a group of organisms which can interbreed freely among them and produce fertile offspring, but are reproductively isolated from all other such groups in nature.

Vitality:  It is the capacity or ability to survive or develop.

Mutualism is a type of symbiotic interaction, both partners gets benefit and neither is harmed, e.g.  Termites eat wood but are not able to digest it. A protozoan lives in its intestine secretes cellulose enzyme to digest the cellulose of wood.

Commensalism is a type in which one partner is benefited while the other is neither benefited nor harmed e.g. Epiphytes are small plants found growing on other larger plants for space only; they absorb water and minerals from atmosphere and prepare their own food.

Ecotype and Biotype (Ecological Amplitude) 

                                                                                 In evolutionary ecology, an Ecotype, sometimes called ecospecies, describes a genetically distinct geographic variety, population or race within a species, which is genotypically adapted to specific environmental conditions.

Biotype is a group of organisms having the same specific genotype.

Abundance

                  Some dominant plants, herbs, shrubs, grasses and ferns make up field layer. At the bottom or floor level many mosses liverworts and lichens covered with litter layer are present.

Forests are natural ecosystem dominated by trees. These covers about one-third of world’s land surface and provide habitat for wildlife, wood, fodder, fiber and fruit.

Resistance to Parasite and Grazing

                                                                      Treatment of plants with various agents, including cell wall fragments, plant extracts and synthetic chemicals can induce resistance to subsequent pathogen attack both locally and systemically. Resistance to pathogen infection can be induced in plants by a wide range of biotic and abiotic agents.  The first chemical resistance activator, Probenazole, was registered in Japan as Oryzemate in 1975, and since then many other chemical and biological activators have been developed. The resistance inducer probenzole protects maize and the targeted pathogen Bipolaris maydis.

Grazing many animals like rabbits, goat, sheeps, cows and horses feed on grasses. This mode of feeding is called grazing and these animals are called grazers. If too many animals are kept on pasture, they eat the grasses down to the root though grasses are more resistant than herbaceous plants and have ability to regrow very fast, but the hooves of grazing animals trample the soil into hard layer as a result of which rain water will not penetrate this soil. The final result of over-grazing is barren land. The intensity and frequency of grazing have to be regulated. For this purpose forage production may be maintained at higher rate. The range may be divided into compartments and grazing may be allowed alternately i.e. a grazing year must alternate with non-grazing year.

Parasites are the organisms that take food and shelter from living hosts and in return, harm them. A parasitic plant is a plant that derives some or its entire nutritional requirement from another living plant. They make up about 1% of angiosperms and are in almost every biome in the world. All parasitic plants have modified roots, named haustoria.

Methods of Reproduction

                                       Reproduction means producing offspring for the survival of the species. Plant reproduction is the production of new individuals or offspring in plants, which can be accomplished by sexual or asexual reproduction. 

Sexual reproduction produces offspring by the fusion of gametes, resulting in offspring genetically different from the parent or parents.

Asexual reproduction produces new individuals without the fusion of gametes, genetically identical to the parent plants and each other, except when mutations occur. In seed plants, the offspring can be packaged in a protective seed, which is used as an agent of dispersal.

Relationship with Light, Temperature, Soil, Fire and Water 

Light is the most essential abiotic factor without which the life cannot exists, the chief natural source of light is sunlight and has great ecological significance.

·       It provides energy to maintain life on earth.

·       It is absorbed by chlorophyll in green plants and convert it into the chemical energy contain in simple sugars molecules.

·       It influences morphology and anatomy of plants.

Environment is the source of materials for all living organisms. Environment provides bio elements which are used by organisms for their bodies and metabolism. The materials are continuously recycled between organisms and environment.

Major source of Carbon for the living world is carbon dioxide present in atmosphere and water. The major process that brings carbon from atmosphere or water into living world is photosynthesis. Producers take in carbon dioxide from atmosphere and convert it into organic compounds. The carbon enters food chains and is passed to herbivores, carnivores, and decomposers.

 Like water favourable temperature are very unevenly distributed on land in place and time. On poles the average temperature is below freezing, in temperate zones favourable in certain seasons and in tropical zones warm and moist climate is present. Heat affects the physiological process of plants this is called heat stress. On a hot summer day a leaf may become too warm and net photosynthesis decline because of in activation of photosynthetic enzymes. Most plants die when the temperature is above 50 degree centigrade. High temperature can kill or injured protoplasm.

Plants evolved various methods to conserve Water in their body e.g. homeostasis. The mechanism of temperature regulation was developed by land plants by developing bark. Excess Water in the root zone restricts root growth and therefore adversely affects plant growth. In water logged soils major form of nitrogen is ammonia which is toxic to many crop plants.

Soil is a collection of natural bodies of earth that is composed of minerals and organic matter and is capable of supporting plant growth.Upper soil layer in which grasses are rooted is normally moist but deep layers are constantly dry. The soil of grassland is basically impermeable with excessive salinity. The soil rich in sand are porous and allow deep root penetration so that the seedlings establish themselves well.It is general rule that finer the texture of a soil the greater its fertility.Deep rooted plants can grow in sandy soils.The loam soils are most suitable for growth of plants as water rises due to capillarity in these soils.

Fire, herbicides and pesticides may be used to destroy unwanted species so that palatable species may grow better. Repeated fires weaken the rock surface and disintegrate the rock over a period of time