1 CHAPTER ONE 1.0 Introduction This Work Is an Environmental

CHAPTER ONE 1.0 Introduction This work is an environmental archaeological study of human occupation of the rainforest environment in coastal area of south-western Nigeria during the late Holocene period. It is an attempt to ascertain how humans related with the rainforest environment through their culture, subsistence economy and coping strategies during this period. The study of humans from an environmental perspective is of fundamental importance because humans are, themselves, living components of the environment, and they derive all their needed materials (food, shelter, water, clothing, air) from it. Butzer (1982:4) observed that “the environment has perhaps been taken for granted” in the sense that some scientists, unconsciously or deliberately, overlook and neglect its relevance, and do not include it in their studies. Since humans had been, and still are, actively involved in sourcing all their raw materials from the environment, the environment is a very important factor which plays significant roles in shaping a people’s culture, subsistence economy, food production capacities and technological development and advancement. Thus, any study of humans without a critical look at the environment under which they lived and subsisted is subjective and incomplete. Therefore, a proper understanding of the environment, and possibly its history through a specific period is a sine-qua-non in human-environment studies. The results of such research will undoubtedly provide a better understanding of human history. In order to understand clearly the relationships between humans and the environment, it is necessary to have a brief look at the environment. 1.1 The Environment Simply put, the environment is the immediate physical surrounding in which an organism or a group of organisms lives on a particular part of the earth. It consists of both living and non-living components. Although, the above definition states that the environment contains both living and non-living components, there is no mention of humans in it. Williams et al., (1998) recognized the need to clearly include humans in 1 the definition of the environment. This was because of the recognition of the fact that the continous human interactions with the environment indicated that they are an important part of the environment in which they live. In line with the above, Sowunmi (1999:199) stated that the environment should involve that which “refers to both the human and non-human components as one integral entity”. Therefore, an all-encompassing definition of an environment is the sum total of the immediate physical surrounding of humans, other living and non-living things, including all elements, factors, conditions and relationships that have some impact on their growth and development. The living things (plants and animals) are generally referred to as biotic factors while the non-living components are called abiotic factors. The latter include sunlight, temperature, water, soil and atmospheric gases. The environment influences practically everything within it. Most influenced are the living components especially humans, their resources and culture. The way the environment influences humans is briefly described in the following scenario: A significant increase in the temperature of the earth that occurs over a long period of time, possibly due to an unusually high amount of insolation can lead to environmental changes. With increase in temperature, glaciers in both the northern and southern poles will melt. As a result, huge volume of water will be fed into the oceans and other water bodies. Consequently, there will be a significant rise in sea level. Thus, cities and towns located along the coast will experience severe floods while others might become submerged. This will lead to loss of lives and properties, destruction of farmlands and businesses and in most cases render people homeless and jobless. All these could cause people to relocate to other areas leading to significant increase in human population in those areas. If such a scenerio happens in already congested cities, for instance Lagos Nigeria, there will be serious competition and struggle for the available natural and food resources. Such pressure on the available resources, such as forest resources for instance, will culminate in the rapid depletion of the plant and animal components. With the destruction of such an environment, plants and animals whose natural habitats are the forest will diminish and some may eventually go into extinction or at least become extirpated from that area. 2 From the foregoing, it is evident that there is a strong relationship between humans and their environment. Furthermore, a good knowledge of the environment, more than ever before, is required for the continued existence of the human race. This is very true particularly because it is now very clear that man needs to manage his resources and energy for the sustenance of present and future generations. The physical environment consists of the atmosphere, hydrosphere and lithosphere while the biological components include humans, animals and plants. Presented below is a brief discussion of these components. 1.1.1 Physical components of the Environment Atmosphere This comprises a mixture of various gases surrounding the earth. The gases are nitrogen (78%), oxygen (21%), carbon (IV) oxide, CO2, (0.03%), water vapour (1%), argon (0.9%) and the remaining rare gases (0.06%). Nitrogen is needed by plants for nutrients. Certain bacteria which live in the roots of plants fix nitrogen which plants subsequently utilize. Furthermore, plants absorb compounds which contain nitrogen, when the plants eventually die, the nitrogen is then contributed to the nutrients in the soil. Carbon dioxide is of great importance due to its ability to absorb heat and make the lower atmosphere warm by heat radiation from the sun. Green plants also utilize CO2 in photosynthesis in the production of food, and in the process oxygen is released. Humans take in oxygen and give out CO2 which is used by plants and the cycle continues. The amount of CO2 gas in the atmosphere has been on an unprecedented increase after AD 1750 and particularly since the last century (Wanner et al., 2008). This increase has been attributed mainly to bush burning and the burning of large quantities of hydrocarbon fuels by humans. The increase in CO2 gas is one of the major causes of global warming. Ironically, the plants (large forest vegetations) needed to utilize and therefore remove most of the CO2 from the atmosphere, through the process of photosynthesis, are being indiscriminately cut down and destroyed daily. Part of the atmosphere is the wind system. In West Africa for example, climate is determined by two wind systems: The North-east trade wind and the Southwest monsoon winds. These two wind systems affect the position of the Inter Tropical 3 Divergence (ITD). This ITD is the meeting point of the two trade winds. When the moisture-laden southwest monsoon wind dominates, the ITD is pushed further north, and moisture is deposited as rain in the hinterland. This ushers in the raining season which lasts for about nine to ten months in the southern parts of the region. The reverse occurs when the dusty Northeast trade wind dominates. The atmosphere is also responsible for the distribution of heat and moisture over the globe. Without this activity, some places will be extremely cold or hot and will be very unconducive for human, animal or plant life. Hydrosphere This consists of all the water bodies on earth including oceans, seas, rivers, lakes and streams; over 70 % of the earth is covered by water. The hydrosphere is important because it is home to several aquatic fauna and flora. It also plays a very significant role in determining the climate of an area. For example, the south west monsoon wind which blows over the Atlantic Ocean causes rainfall along the coast and hinterland of the African continent. Furthermore, it, along with the atmosphere, serves as transport of heat across the latitudes. This ensures the balance and circulation of heat transfer from low latitude regions to high latitude and Polar Regions. Without this transport, surface temperature will be much higher in the equatorial zones and much lower in the polar zones. Such a situation will be unfavourable for terrestrial and aquatic life on the earth. The presence of the liquid form of water is one of the factors that make life possible on Earth, and is unique to our planet. Water is so important to life in that it is used for domestic activities such as cooking and drinking, and for industrial purposes. Water is equally a very crucial part of human and animal life. It is said to contain about 70% of the human body mass; it plays an active role in transport of food, blood and heat within the human body. Lithosphere The lithosphere is the earth’s crust and mantle; the latter is the outermost rigid layer of the earth. The lithosphere provides solid support for all living things on the planet. Aside the fact that it provides this support for human and animal movement and 4 buildings, the soil, in and on which plants grow, is derived from it. Rocks, which are components of the earth’s crust, are broken down through a process called weathering of rocks. This is the process by which soils are formed. Therefore, without the lithosphere, there will be no terrestrial plants or any form of vegetation cover on the earth. Furthermore, soils are a home to many small animals such as earthworms, termites and rodents. Their burrowing activities help to aerate and loosen the soils for the penetration of plant roots. Without their activities, perhaps, the growth of plants will be slowed down considerably. 1.1.2 Biological components of the Environment These components comprise all living things i.e. plants and animals including humans.

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