BOI 102 Ecology 2024 Lecture 15 PDF

BOI102 ECOLOGY Dr. Khaironizam Md Zain 15 TYPES OF ECOSYSTEM  Type of Ecosystems Ecosystem is defined as interactions among biotic and abiotic components in particular the environment. The living and non-living components of an ecosystem are known as biotic and abiotic components, resp...

BOI102 ECOLOGY Dr. Khaironizam Md Zain 15 TYPES OF ECOSYSTEM  Type of Ecosystems Ecosystem is defined as interactions among biotic and abiotic components in particular the environment. The living and non-living components of an ecosystem are known as biotic and abiotic components, respectively. An ecosystem comprised a community of living and non-living things. They can be can occur naturally and can be created artificially.  TYPES OF ECOSYSTEM NATURAL Permanent Temporary MAN-MADE  Natural Ecosystems Natural ecosystems can be defined as an ecosystems found in nature where organisms (biotic components) freely interacts with other components (biotic and abiotic components) of that environment. Natural ecosystems are capable of operating and maintaining themselves without any major interference by man. One of the main characteristic of natural ecosystem is that it is self- sufficient system. A classification based on their habitat can further be made: 1. Terrestrial ecosystems: forest, grassland and desert. 2. Aquatic ecosystems: freshwater ecosystem, viz. pond, lake, river and marine ecosystems, viz. ocean, sea or estuary.  NATURAL ECOSYSTEM TERRESTRIAL AQUATIC 1. FOREST MARINE FRESHWATER i. Rainforest ii. Deciduous COASTAL SEA LOTIC LENTIC iii. Taiga 2. GRASSLAND 1.Estuaries 1.Pelagic 1.RIVERS 1.LAKE 3. DESERT 2.Mangroves i.Epipelagic 2.STREAMS 3.Lagoon ii.Mesopelagic 4. TUNDRA 4.Intertidal zone iii.Bathypelagic 5.Sea grass iv.Abyssopelagic 6.Coral reefs 2.Sea floor  NATURAL ECOSYSTEMS: Terrestrial Ecosystems A terrestrial ecosystem is a land- based community of organisms and the interactions of biotic and abiotic components in a given area. A community of organisms and their environment that occurs on the land masses of continents and islands. Terrestrial ecosystems are distinguished from aquatic ecosystems by the lower availability of water and the consequent importance of water as a limiting factor.  NATURAL ECOSYSTEMS: Terrestrial Ecosystems Terrestrial ecosystem is a dominant ecosystem of landforms, which occupy 144,150,000 km2 or 28% of the earth’s surface. Terrestrial ecosystem is different from the aquatic ecosystem with lower water availability. It comprises a community of organism and their environment that occurs on the landmasses of continents and islands. There are variations in composition and geographical variation in terrestrial communities. Major terrestrial ecosystems are in the specific biome and are found in tundra, taiga, temperate deciduous forest, tropical rainforest, grassland, and desert. Terrestrial ecosystems have been a major site of the adaptive radiation of both plants and animals.  NATURAL ECOSYSTEMS: Terrestrial Ecosystems Terrestrial ecosystems are characterized by greater temperature fluctuations on both a diurnal and seasonal basis than occur in aquatic ecosystems in similar climates, because water has a high specific heat, a high heat of vaporization and a high heat of fusion compared with the atmosphere, all of which tend to ameliorate thermal fluctuations. The availability of light is greater in terrestrial ecosystems than in aquatic ecosystems because the atmosphere is more transparent than water. Gases are more available in terrestrial ecosystems than in aquatic ecosystems. Examples of terrestrial ecosystems include the tundra, taigas, temperate deciduous forests, tropical rainforests, grasslands, and deserts.  NATURAL ECOSYSTEMS: Terrestrial Ecosystems 1) Forest Ecosystems A forest ecosystem is a functional unit or a system which comprises of trees, soil, animals, and man as its interacting units. A forest is a large and complex ecosystem and hence has greater species diversity. Also, it is much more stable and resistant to the detrimental changes as compared to the other terrestrial ecosystems. A forest ecosystem, similar to any other ecosystem, also comprises of abiotic and biotic components. These components interact with each other in an ecosystem and thus, this interaction among them makes it self- sustainable. NATURAL ECOSYSTEMS: Terrestrial Ecosystems 1) Forest Ecosystems Forest ecosystems currently occupy approximately 30% of the Earth's land surface and are estimated to contain more than half of all terrestrial animal and plant species, the great majority of them in the tropics. NATURAL ECOSYSTEMS: Terrestrial Ecosystems: 1) Forest Ecosystems  NATURAL ECOSYSTEMS: Terrestrial Ecosystems 1) Forest Ecosystems – Rainforest Ecosystems The Tropical Rainforest has four main characteristics: 1. very high annual rainfall, 2. high average temperatures, 3. nutrient-poor soil, 4. high levels of biodiversity  Rainforests generally receive very NATURAL ECOSYSTEMS: Terrestrial Ecosystems high rainfall throughout the year, 1) Forest Ecosystems – Rainforest Ecosystems although the exact amount varies among different years and different rainforest regions. For example, Southeast Asia tropical rainforests receive between 100 and 300 centimeters of annual rainfall. Despite relatively consistent rain in these ecosystems, there are distinct dry seasons in some rainforests. Wet and dry seasons of tropical rainforests vary in their timing, duration, and severity around the globe. Tropical rainforests also have high humidity; about 88% during the wet season and approximately 77% in the dry season.  NATURAL ECOSYSTEMS: Terrestrial Ecosystems 1) Forest Ecosystems – Rainforest Ecosystems Tropical rainforests are found near the equator, and these areas receives direct sunlight. This steady flow of radiation produces consistently high temperatures throughout the year. A typical daytime temperature any time of year in tropical rainforests is 29°C, although temperatures can be much higher as 35°C. In the majority of tropical rainforests, there is only a 2°C -5°C difference in temperature between the seasons. NATURAL ECOSYSTEMS: Terrestrial Ecosystems 1) Forest Ecosystems – Rainforest Ecosystems Since there is a tremendous amount and most diverse tree in tropical rainforests, you might assume that rainforest soils are rich in nutrients. In fact, rainforest soils are nutrient-poor because nutrients are not stored in them for very long. The heavy rains that occur in rainforests wash organic material from the soil. Although decomposition occurs rapidly in the hot, moist conditions, many of the dead, fallen leaves and other organic detritus are swept away before releasing all of their nutrients. In addition, rainwater seeps into the ground and leaches away nutrients. NATURAL ECOSYSTEMS: Terrestrial Ecosystems 1) Forest Ecosystems – Rainforest Ecosystems Tropical rainforests are areas of extremely high biodiversity compared to other ecosystems. In the topical rainforests of Borneo, scientists have documented more than 15,000 plant species, including 2,500 species of orchids! Biologists estimate that tropical rainforests contain about 50% of the world’s terrestrial plant and animal species, yet they encompass only about 6% of the world’s land area.  NATURAL ECOSYSTEMS: Terrestrial Ecosystems 1) Forest Ecosystems – Deciduous Forest Ecosystems A deciduous forest is a biome dominated by deciduous trees which lose their leaves seasonally. The Earth has temperate deciduous forests, and tropical and subtropical deciduous forests, also known as dry forests. Another name for these forests is broad- leaf forests because of the wide, flat leaves on the trees. Trees in tropical deciduous forests lose their leaves in the dry season and regrow them in the rainy season. In temperate deciduous forests, trees lose their leaves in the fall and regrow them in the spring.  Tropical and Subtropical Deciduous Forests are found near to tropical regions but not in equator areas These forests occur in climates that are warm year-round and may receive several hundred centimeters of rain annually. Tropical and Subtropical They deal with long dry seasons which last Deciduous Forests several months and vary with geographic location and these seasonal droughts have a great impact on all living things in the forest. Deciduous trees predominate in most of these forests, and during the drought, a leafless period occurs, which varies with species type. Because trees lose moisture through their leaves (transpiration process), the shedding of leaves allows trees such as teak and mountain ebony to conserve water during dry periods.  Temperate Deciduous Forest Deciduous temperate forests (sometimes called summer-green forests) are dominated by broadleaved trees which lose their leaves during winter. Owing to the deciduous habit of the main dominants and the characteristic dying- down of many of the associated plants as the trees come into leaf, these forests look entirely different in spring, summer, autumn, and winter. The deciduous habit is a strategy to deal with the lack of sunlight and cold temperatures in winter.  Temperate Deciduous Forest Temperate deciduous forests experience distinct seasons, and trees shed leaves in the autumn and regrowth occurs in the spring. Trees are mostly broadleaf tree species including oaks (Quercus), hickories (Carya), maples (Acer), and beeches (Fagus), and commonly a diverse community of multiple strata of understory trees and shrubs, perennial herbs, and mosses. In the southern hemisphere, southern beeches (Nothofagus) and Eucalyptus are prominent genera of broadleaves. Temperate deciduous forests are identified in the eastern United States, much of Europe, eastern Asia and Australia, New Zealand, and the southernmost portion of South America, in areas that receive between 750 and 1500 mm of rain per year and with average summer temperatures of around 21 °C, and winter temperatures often below freezing. NATURAL ECOSYSTEMS: Terrestrial Ecosystems 2) Grassland Grasslands are open areas of land where grasses or grass-like plants are the dominant species. Other forms of vegetation such as trees are rare in grasslands because they are not suited to thrive in the grassland’s dry environment. Grasslands receive water through rainfall, and when it does occur the grasses use their roots to search for moisture. Grass within this type of environment reproduces by releasing pollen when the winds blow or by producing plants from their roots. NATURAL ECOSYSTEMS: Terrestrial Ecosystems 2) Grassland The two major types of grasslands are Tropical Savannah and Temperate Grassland. Both types are located in regions where there are hot summer temperatures and low precipitation. Tropical Savannah Grasslands occur in Africa, Australia, and South America and receive 20 to 60 inches of rainfall annually. Temperate Grasslands are also called Prairies or Steppes and they receive 10 to 35 inches of annual rainfall. NATURAL ECOSYSTEMS: Terrestrial Ecosystems 2) Grassland Grassland ecosystems are influenced over time by the organisms and plants that live there, the local climate, the natural landscape and natural disturbances to the environment such as fires or floods. Various species such as buffalo, elephants, badgers, armadillos and many insects have adapted to and are located in grassland environments throughout the world. Physical features of grasslands such as wide open grass-covered plains or scattered trees located next to scarce streams help to create a diverse environment within the grassland ecosystem.  Deserts are areas that receive very little precipitation. People often use the adjectives “hot,” “dry,” and “empty” to describe deserts, but these words do not tell the whole story. Although some deserts are very hot, with daytime temperatures as high as 54°C (130°F), other deserts have cold winters or are cold year-round. NATURAL ECOSYSTEMS: And most deserts, far from being Terrestrial Ecosystems empty and lifeless, are home to a variety of plants, animals, and 3) Deserts other organisms. NATURAL ECOSYSTEMS: Terrestrial Ecosystems 3) Deserts One thing all deserts have in common is that they are arid, or dry - receives no more than 25 centimeters of precipitation a year. The amount of evaporation in a desert often greatly exceeds the annual rainfall. In all deserts, there is little water available for plants and other organisms. Deserts are found on every continent and cover about one-fifth of Earth’s land area. Although the word “desert” may bring to mind a sea of shifting sand, dunes cover only about 10 percent of the world’s deserts. Some deserts are mountainous, and some others are dry expanses of rock, sand, or salt flats. NATURAL ECOSYSTEMS: Terrestrial Ecosystems 4) Tundra Tundra ecosystems are treeless regions found in the Arctic and on the tops of mountains, where the climate is cold and windy, and rainfall is scant. Tundra lands are covered with snow for much of the year, but summer brings bursts of wildflowers. Tundra is the coldest of all the biomes. It is noted for its frost-molded landscapes, extremely low temperatures, little precipitation, poor nutrients, and short growing seasons. Dead organic material functions as a nutrient pool. The two major nutrients are nitrogen and phosphorus. NATURAL ECOSYSTEMS: Terrestrial Ecosystems 4) Tundra Characteristics of tundra include: Extremely cold climate Low biotic diversity Simple vegetation structure Limitation of drainage Short season of growth and reproduction Energy and nutrients in the form of dead organic material Large population oscillations NATURAL ECOSYSTEMS: Terrestrial Ecosystems 4) Tundra Plants have low height and clump together to adapt to the savage cold and harsh wind. Fascinatingly, similar to animals, plants grow closer together in order to provide warmth to each other. The tundra’s few trees remain stunted as an adaptation to the protective insulation of snow on the ground. Plants also photosynthesize even in the low light and cold temperatures. In order to overcome issues with the lack of pollinating insects and birds, most plants in the tundra reproduce asexually rather than by flowering and pollination. Common plants found in the tundra biome include: Moss, Heath, Liverwort Tussock grass Willow grows as a low carpet cover in some areas Lichen Dwarf trees, including small birches  Man-made Ecosystems Man-made ecosystems are the artificial ecosystems and are created to copy the conditions of natural ecosystem. These ecosystems are sustained by human interventions. They do not possess a self-regulating mechanism. They have almost no diversity and probably have simple food webs. The cycling of nutrients is negligible. The inputs are provided by the human efforts.  Man-made Ecosystems Examples of man-made ecosystems are orchards, home aquarium, zoo, botanical gardens and park. Aquarium and zoo ecosystem, for example, cannot survive without the care of humans. Man-made ecosystems are created for specific purposes. Orchards, plantations and farms are created for agricultural benefits. Parks are built for recreation. Zoos and aquarium are made for study, tourism, conservation, education and hobby.  Man-made Ecosystems The man-made ecosystems include the villages, towns, cities, canals, orchids, dams, gardens, lakes and agriculture. The agriculture consists of the animal husbandry and the production of crops.  Man-made Ecosystems The agriculture is the first manmade ecosystem which occurred with the increase in human population. Human also used to domesticate animals and invented an artificial ecosystem for them. The areas where they raised crops are known as the agro ecosystem. The land was cultivated for some years and was then left out. In the recent times they have become permanent in nature and it is impossible for them to survive alone.  Natural ecosystem Artificial ecosystem Consists of many species of plants and animals Species diversity is low Genetic diversity is very high Genetic diversity is very low Sunlight is the energy source for plants and this Sunlight is the ultimate energy source for plants but energy drives all biological cycles artificial fertilizers and other nutrients are externally supplied to the soil Food chains are long and complex Food chains are simple and often incomplete as other species are killed as pests or weeds Ecological succession takes place over time No ecological succession Natural nutrient cycling Incomplete nutrient cycling Naturally sustainable Unsustainable as most fertilizers are made from non- renewable fossil fuels, and they add to water pollution, biomagnification and other ecological