What You Should Know About Ecosystems

Ecosystems are communities of interacting organisms and the physical environment in which they live. An ecosystem is a smaller part of a biome (e .g forest, wood, pond) consisting of a community of plants and animals interacting with the physical environment. The ecosystem in which a particular organism lives is called its habitat. The environment of an ecosystem refers to the conditions which affect the plant and animal community. Examples of ecosystems abound, these include: a pond, a grassland, a forest, an estuary. Ecosystems are:

·      Systems combined of organic and inorganic matter and natural forces that interact and change,

·        Intricately woven together by food chains and nutrient cycles,

·        Living sums greater than their parts.

The complexity and dynamism of ecosystems contribute to their productivity but make them challenging to manage. When talking of ecosystems, the matter of scale is important. Small-scale ecosystems include; a small bog, a single sand dune, or a tiny patch of forest – a micro-environment. Large-scale ecosystems include; 1000sq. Km of forest, a major river system, each having many microenvironments. In analyzing ecosystems, we categorize them into ‘managed’ and ‘natural’ ecosystems. ‘Managed’ ecosystems are those that have been modified to enhance the yield of certain products. Such include farms, pastures, or forest plantations. ‘Natural’ ecosystems those that retain most of their original structure and functioning. Examples include forests and rangeland tracks. Managed likewise natural ecosystems are living systems capable of producing an array of benefits, and both are elementary to human survival. The study of energy transformations and biogeochemical cycling within ecosystems is called Ecosystem Ecology.

Changing capacity assesses the underlying biological ability of an ecosystem to continue to provide a good or service. Condition assesses the current output and quality of an ecosystem good or service compared with its output and quality two or three decades ago. Energy is continually input into an ecosystem in the form of light energy, and some energy is lost with each transfer to a higher trophic level. Nutrients on the other hand are recycled within an ecosystem, and their supply normally limits biological activity. So, ‘energy flows, elements recycle’.

The world has many ecosystems. Each one has its own climate, soil, plans, and animals. There are basically two types of ecosystems; terrestrial and aquatic ecosystems. Terrestrial ecosystems can be found anywhere apart from heavily saturated places. They are widely categorized or classified into: the forest ecosystem, the desert ecosystem, the grassland ecosystem, and the mountain ecosystem.

The forest ecosystem is the ecosystem in which an abundance of flora or plants is seen, so they have a large number of organisms which live in relatively small space. Forest ecosystems provide: food, timber, fuel wood, drinking and irrigation water, fodder, non-timber products, and genetic resources. Also, forest ecosystems remove air pollutants and emit oxygen, cycle nutrients, provide human and wildlife habitat, absorb atmospheric carbon, maintain watershed functions and protect biodiversity, provide employment, moderate weather extremes and impact, generate soil, provide recreation, and contribute aesthetic beauty. The forest ecosystem is further divided into: Tropical evergreen forest, Tropical deciduous forest, Temperate evergreen forest, Temperate deciduous forest, and Taiga.

The grassland ecosystem is located in both the tropical and temperate regions of the world. The main vegetation includes grasses, plants, and legumes. A lot of grazing animals, insectivores, and herbivores inhabit the grasslands. Two main types of grassland ecosystems exist. These are the Savanna and the Prairies. These are the Savanna and The Prairies. The Savanna constitutes the tropical grasslands which are seasonally dry and have few individual trees; while the Prairies constitute the Temperate grassland, completely devoid of large shrubs and trees. The Prairies are characterized by mixed grass, tall grass and short grass; from which the various types of Prairies derive their names.

Desert ecosystems occupy approximately 17 % of all the land on earth. They are located in regions that receive very little rainfall. Fauna and flora are scarce and poorly developed due to the extremely high temperatures, low water availability and intense sunlight. The vegetation is mainly shrubs. The stems and leaves of the plants are modified in order to conserve water as much as possible. A typical example is the spiny leaved cactus plant.

The aquatic ecosystem is the ecosystem found in a body of water. This encompasses aquatic flora, fauna, and water properties as well. Two sub-types exist. These are the marine ecosystem and the freshwater ecosystem. Marine ecosystems cover around 71% of the Earth surface. These are the biggest ecosystems. The varying divisions of the marine ecosystem are: Oceanic, Profundal, Benthic Bottom substrates, Inter-tidal, Estuaries, Coral reefs, Salt marshes, Hydrothermal vents. Examples of organisms which live in marine ecosystems are; brown algae, echinoderms, sharks, and cephalods.

The freshwater ecosystem covers 0.8% of the Earth surface. Three basic kinds of freshwater ecosystems exist. These are; lentic, lotic, and wetlands. Lentic freshwater ecosystems refers to slow-moving or till water like pools, lakes, or ponds. Lotic freshwater ecosystems refers to fast-moving water such as streams and rivers. Wetlands are places in the soil that are inundate or saturated for some lengthy period of time.

In Cameroon, seven major ecosystems can be identified. These are; Evergreen Rainforest, Semi-Deciduous forest, Swamp forest, Lower Montane forest, Upper Montane forest, Mountain Scrub, and Mountain Grassland. In the Evergreen Rainforest, the ground flora is largely dominated by seedlings, but also includes many herbaceous species. The Semi-Deciduous forest in Cameroon can be found in the Campo-Ma'an area. In the Eastern part of the country, this forest is characterized by a discontinuous canopy. 
The Cameroonian Swamp forest bears trees which can reach heights of 45m. The Lower Montane Forest occurs in upland areas such as Mount Cameroon in the South-West region. The higher trees can reach heights of 40m or so. Between mountain forest and mountain grasslands, there is a zone of fringing scrub. Mountain grasslands are predominant in Mount Cameroon’s upper escarpments and summit areas at altitudes ranging from 3500-3960m.

The predominant importance of ecosystems have led to the holding of many assessments and conferences. The 2005 Millenium Ecosystem Assessment pointed out the following pertinent issues regarding ecosystems:

·    Over the past 50 years, humans have changed ecosystems more rapidly and extensively than in any comparable period of time in human history, largely to meet rapidly growing demands for food, fresh water, timber, fiber and fuel. This has resulted in a substantial largely irreversible loss in the diversity of life of the fauna and flora on planet earth.

·    The changes that have been made to ecosystems have contributed to substantial gains in human wellbeing and economic development, but these gains have been achieved at growing costs in the form of degradation of many ecosystem services, increased risks of non-linear changes, and the exacerbation of poverty for some groups of people. These problems unless addressed, will substantially diminish the benefits that future generations can obtain from ecosystems.

·        The degradation of ecosystem services could grow significantly worse during the first half of this century, and is a barrier to achieving the Millennium Development Goals.

·        The challenge of reversing the difficult degradation of ecosystems while meeting increasing demands for services can be partially met under some scenarios considering the Millennium Ecosystem Assessment but will involve significant changes in policies, institutions, and practices that are not currently under way. Many options exist to conserve or enhance specific ecosystem services in ways that reduce negative trade-offs or that provide synergy with other ecosystem services.