Ecology is the scientific study of the interactions between organisms and their environment.
The environment includes both abiotic factors: such as temperature, light, water, wind, soil and nutrients; and biotic factors: the other living organisms. The interactions may be competition, predation, parasitism and cooperation.
The work ecology was first used by a German Ernst Haeckel in 1869. It comes from two Greek words oikos meaning home, place to live; and logos meaning understanding. Therefore, generally speaking ecology is “the study of reciprocal relationship between living things and their environment.
Divisions of Ecology
Ecology is divided into autecology and synecology.
Autecology is the study of an individual organism or an individual species. Autecological studies are concerned with the relationship between the population and its sizes and its stability may be studied.
Synecology is the study of a group of different populations associated together as a community. Synecology involves analysis of the abiotic and biotic aspects of a community in the environment they occur.
Following are different fields of ecology
It is concerned with the ways the animals interact with their living and non-living environment as influenced by natural selection.
It deals with the physiological responses of individual organisms to temperature, moisture, light, nutrients, etc.
It is related to interactions of population dynamics, genetics, natural selection and evolution.
The study of chemical reactions of organisms to their environment is termed chemical ecology. it involves use of chemicals by plants and animals as attractants, repellents and defensive mechanisms, their evolution and chemical structure.
The impact of human activities on environmental that provides a base for ecosystem and natural resource management, preservation and restoration is applied ecology.
Scope of Ecology
Ecology attempts to tell us:
Why particular kinds of organisms can be found living in one place and not another.
The factors that control the number of particular kind of organisms and maintain them at certain levels; and
The principals that may allow us to predict the future behavior of groups or organisms.
Practical Applications of Ecology
Human Impact on the Environment
Man lives in nature and depends on the resources of nature. Food, shelter and clothing are the primary requirements of man. In order to obtain this man has natural resources to the maximum that has resulted in undesirable changes in the habitats. Consequently, some natural stocks of plants (forests) and animals (wildlife) disappeared. About 1000 animal species and well over 20,000 plant species have either become extinct or declared endangered. Deforestation has caused soil erosion and other damage. Similarly, mineral resources are facing exhaustion due to consumption (mismanagement). Also, overpopulation, urbanization, industrialization and mechanized agriculture have resulted in rapid increase in air, water and soil pollution.
All the above mentioned human activities have lessened -Earth’s ability to support a diversity of life, including humans.
Ecological theories and models help us understand the human environment. They provide a basis for ecosystem and natural resource preservation and restoration. All these activities make up applied ecology.
Applied of ecology is concerned with application of ecological to environmental and resource management problems. Traditionally, applied ecology forest, range, and wildlife and fishery management. Recently applied ecology has the new fields of conservation biology, restoration ecology, and landscape.
Application of ecological principles to resource management has helped improve various fields such as:
Forests are natural ecosystems dominated by trees. these cover about one-third world’s land surface and provide habitat for Wildlife, fuel wood, fodder, fibre, fruit, timber and raw materials used in wood-based industries. They also regulate climatic conditions such rainfall, humidity and temperature of area and protect soil wind and water erosion. Forests transform solar energy into plant biomass which is consumed by animals and humans. Continued deforestation has resulted in desertification which led to soil erosion, destruction of wildlife habitat and increase in the rate of extinction, change in the climate in terms of decrease in rainfall and increase in temperature and humidity, and shortage of timber, firewood and pulpwood. Therefore, afforestation, i.e., cultivation of forests at new sites, is necessary.
One of the practical applications of ecology is forestry, it is treated as industry now-a-days, it is not simply raising of trees for harvest, but emphasizes biomass accumulation, nutrient cycling, the effects of timber harvesting on nutrient budgets, and the role of fire in forest ecosystems.
There are two schools of thought regarding the management of forests,
- According to one the forests should be managed as tree crop or monoculture (single species harvest) in the same way as we managed the food crops. This would help in increase in yield, faster growth and artificial selection of high yield varieties, However, raising tree farms require use of, fertilizer and pesticides that would increase pollution and danger of disease outbreak.
- The other school of thought maintains that forests may be managed as multiple-use forest and not as a crop which may provide wildlife habitat, air and water sheds, recreation and harvest as well.
However, it has been recognized that tree farms and naturally developed multiple use forests are entirely different ecosystems in terms of cost of maintenance and their impact on environment, therefore:
- It would be desirable to adapt naturally adapted forest as it provides best and safest cover for mountains and soils where tree farms cannot be maintained.
- The tree farms may be restricted to fertile lands and to soil types suitable for good agriculture such as along canal banks and farm boundaries,
- Wildlife Management
Wildlife refers to all non-cultivated plants and non-domesticated animals in an ecosystem. It includes game and fur-bearing vertebrates, and plants and animals which interact directly with game species. Wild animals are an important source of food and skin (leather), Also these are used in research as experimental animals, for recreational purposes and economic benefits (animal hunting). Similarly, wild flora is facing extinction because of habitat destruction and natural calamities. As a result, many species of wildlife have become extinct or on their way to extinction.
Wildlife is a renewable resource; therefore, its management is necessary because:
- Intensive study of Individual game species has contributed a great deal to population ecology.
- Genetic variations and interbreeding lead to evolution. The process of evolution would be affected if wildlife is destroyed.
- It is important economically and source of recreation.
Wildlife management is a high-ranking field of applied ecology. Thus, consideration the principles of ecology, would help in wildlife management.
- The habitats for wildlife may be conserved.
- The rare species may be protected from being hunted.
- Exotic species may be introduced.
- Predators may be Introduced in the ecosystem so that primary population remain within limits.
- Legislation may be introduced to prevent hunting.
- Sanctuaries and National Parks may be developed to protect endangered and threatened plants and animals. This would help in establishing gene banks.
Range is grassland meant for grazing animals. Range management are interested in the functioning of grassland ecosystems, the effects of grazing intensities on grasslands on above ground and below ground production by plants, and the structure of grassland communities.
Grasslands are important from man’s viewpoint; however, these are the abused natural biomes by man. The grasslands provide natural pastures for grazing but domesticated grazing animals have destroyed or disturbed most of the grassland Similarly, the principal agricultural food plants have evolved from grasses; therefore, man has converted most of the grasslands into agricultural croplands.
The effect of grazing on seed output, reproduction capacity, establishment, vegetative growth and flowering in relation to climate, soil and biotic pressure of grazing are some of the more important ecological aspects. Therefore, principles may be taken into consideration and applied for proper range management. For instance,
- The rate of removal of resource (grasses) should be regulated to a level up to which the system can rebuild itself. For example, enough net Productivity maybe left in the range so that the range may remain stable in case of adverse climatic condition, i.e., drought, etc. For this purpose, number of grazing animals (stock level) may be regulated properly.
- The effect of grazing is an important factor to be considered in range management. The intensity and frequency of grazing have to be regulated. For this purpose, the forage production may be maintained at higher rate. The range maybe divided into compartments and grazing may be allowed alternately, i.e. a grazing year must alternate with non-grazing year.
- Geographical races of palatable grasses with high nutrient value may be introduced into the ranges.
- Fire, herbicides and pesticides may be used to destroy unwanted species so that palatable species may grow better.
Fishery Management (Fish Farming)
Since the demand of animal protein is increasing, steps are being taken for proper management of protein sources. One such common practice is aquaculture, i.e., cultivation of aquatic life such as fish, crabs, lobsters, oysters, prawns, etc. For food. Aquaculture is based on principles of applied ecology and is an effective means for increasing protein food for mankind.