Table of contents
- Heather moorland: Plagioclimax
- Succession: Psammosere
- Tropical Biome
- Characteristics
- Adaptations of vegetation and animals
- Human activity and its impact
- Contrasting management schemes
- Development issues relation to biodiversity and sustainability
- Factors affecting biodiversity on a global scale
- Changes resulting from urbanisation
- Colonisation of wasteland
- Planned/unplanned introduction of new species
- Development of distinctive ecologies along route-ways
- Changes in the rural urban fringe
Heather Moorland plagioclimax
- Developed on poor soil, important part of British Isles.
- Managed to keep in uniform frozen state.
- Areas of N Yorkshire, Scottish highlands and Pennines.
- Red grouse feed on it – lucrative hunting industry.
- Managed by 5-10 year burning cycles creating variety of habitats to encourage new growth (ash natural fertiliser) for Red Crouse.
- Grazed on by sheep (overgrazing leads to invasion)
Succession: Psammosere
- Embryo and Fore – sea couch grass, sand sedge
- Yellow –main dune ridge Marram dominant
- Grey – vegetation covered marram in decline red fescue
- Dune slack ridge – bog cotton, bracken rushes and reeds.
- Climactic climax – Birch, Alder, Sycamore (poor soil)
Tropical biome: Savannah grassland
Characteristics: Include climate, animals, vegetation and soil.
- The tropical grassland biome is located between 5 and 10 degrees north and south of the equator. It appears as a transitional state between equatorial forest and desert, with mainly scattered shrubs and isolated trees on the open savannah. The climate is hot year round with two distinct seasons, the wet and dry season. The winter wet season lasts for only 1-2 where precipitation>evaporation and is around 1200mm. The temperatures on the grassland equatorial biome fringes are 22 degrees in the wet season and 28degrees in the dry season months, and on the desert grassland fringes 18 degrees in the wet season and 32 degrees in the dry. The ITCZ is created by intense heating of the sun overhead causing rising and cooling of air forming clouds when water droplets coalesce at the dew point. Cumulo nimbus clouds forms and convection rainfall falls. The dry season is dominated by high pressure systems and trade winds generated by the compression heating of air at 30 degrees north and returning towards the equator.
The soil conditions are created by the seasonal rains. During the wet season precipitation is in excess and there is a surplus of water which is leached into the soil carrying with it nutrients promoting growth. The growth season as a result is very short. Silica is also leached downwards and chemical weathering of teh bedrock occurs as dissolved c02 forms weak carbonic acid along with the dissolved minerals. During the dry season evaporation exceeds precipitation so salts are returned to the surface forming a concrete-like literate layer which if broken exposes the crumbly earth below to erosion forming deep gulley. The thing litter layer which is susceptible to erosion or destruction by fires prevents root systems drying out in the intense sun by forming a protective layer. The soil has a distinct red colour to as a result of the insoluble oxides of aluminium and iron which is higher up than for example in the deciduous woodland biome due to the absence of a larger litter layer and higher precipitation.
Adaptations of vegetation and animals
- Animals and vegetation are adapted to the 2 distinct seasons on the savannah grasslands. The animals are therefore migratory and typically have long legs or wings in order to travel large distances. These include Zebra, many species of deer, rhino, wilder beast, elephant, carnivores such as lions, cheetahs and leopards and decomposers. Elephants have adaptations for example to cope with the high temperatures for much of the year; their large ears provide a surface area from which to lose heat. Decomposers also play a vital role in the ecosystem as they transfer nutrients from decaying animals and plants back into the soil (nitrogen cycle) which promotes growth. This is especially important as teh plants are the primary producers that effectively support the entire ecosystem.
Vegetation is also adapted to cope with the two very different seasons. Grasses grow in tufts in order to protect root systems as well as form a protective layer during the dry season by losing their leaves – deciduous. They have xerophytic adaptations such as small thin or spine leaves such as the umbrella thorn and elephant grass.
Trees also grow where more moisture is available but are usually sparse especially on the desert margin. The Baobab tree has a wide trunk – up to 10m wide in order to conserve water, as well as fire resistant bark to protect against bush fires as well as those started by humans. The acacia tree also has fire resistant bark and a deep root system enabling it to grow in clusters, unlike the baobab which has a wider root system reducing the competition of other plants around it.
Human activity and its impact
The tropical grassland biome is a fragile ecosystem home to many endangered species and is therefore difficult to restore to its natural beauty if disturbed. There are many human activities which threaten the longevity of the ecosystem and centre around different interest groups such as the indigenous Masai, tourists, locals, conservationists and the Tanzanian government. The main threats to the ecosystem are Poaching, Population growth, poverty and small scale agricultural techniques such as burning. Poaching is a major issue in the Serengeti ecosystem part of the tropical grassland biome. Despite stringent laws restricting poaching around 40000 animals are killed every year; these include mainly wilderbeasts but also zebra and gazelle. This is a problem as poaching causes humans to encroach on natural habitats causing damage to grazing pastures, foraging grounds and migratory corridors. This also brings invasive species into the park, reduces biodiversity and traps unwanted animals that may be endangered.
Another issue is population growth; the rural areas around the national park in recent years have experienced high population growth due to pull factors such as water availability, food availability through illegal poaching and natural minerals such as gold. Along with this has seen an increase in poverty as much of rural Tanzania is. This is an issue as pressure on land has caused the boundaries of the Park to be realigned 3 times in the last 20 years, reducing the original parks size by 15%. Overgrazing also damages natural grazing pastures and causes soil erosion leading to the soil becoming infertile. This is especially true with poverty stricken areas where poor access to mechanised agriculture has led to poor practices
Development is another major issue which threatens the sustainability of the ecosystem. Although it has been suggested as potential way forward to relive poverty, activities such as tourism and economic development have the potential to highly damage the park. Such as the airport in the western Serengeti and game hunting lodge run by the American company Grumeti. A new road system linking Amsha and Musama has the potential to damage a narrow migratory corridor used by wilderbeasts on the way to lake Victoria, by the increase in poaching caused by better access and introduction of new/invasive species as well as noise and air pollution.
Further issues are that of the annual burning of grassland areas at the end of the dry season, which promotes growth of young shoots. Although this does benefit both farmers and natural wildlife by providing grazing pasture, and the fires are quite well contained they do however, kill and young trees in the area not yet fire –resistant. This if done in the same areas annually can produce a uniform environment and doesn’t provide all stages needed for different animals to feed off of such as trees ( fed on by giraffes).
Contrasting management schemes of two biomes: Savannah grassland, Equatorial rainforest.
The tropical grassland biome and equatorial rainforest biomes are fragile environments which have considerable human threats to their ecosystem. These threats include population growth, poverty, poaching (40000+killed/year) and development in the Serengeti national park. In the equatorial rainforest biome the Amazon rainforest is under significant threat from population growth (drought in NE migration encouraged) and large scale developments including HEP (Belo Monte dam in the Amazon region 3rd largest scheme of its kind in the world), Mining (the largest iron ore extraction plant is located in Amazonia) and one of the largest threats is deforestation which has caused the destruction of vast quantities of the forest and most likely the extinction of many animals and plants along with it. As a result a zoning system has been developed in the Central Amazonian conservation complex which lies in an isolated part of the forest in teh river Negro water basin (a tributary of the river Amazon). The complex covers an area of 6 million hectares (2nd largest area of protected rainforest). There are zones which have varying levels of development allowed in them. The first is the primitive zone which has the largest area of natural beauty where no development of any kind takes place. The second zone is known as the Special use zone where services which work towards the protection of the primitive (and other zones) are located. The last zone is the Marimua sustainable development zone which is open to some development by locals only as all commercial exploitation of the forest is banned. This zone is managed by a variety of groups including the locals, government, commercial industry operators and representatives from teh mining and logging industry and conversationalists. The scheme has helped to protect the forest but also increase its productivity in a sustainable way (especially in the MSDZ). In contrast to this scheme the protection of the Serengeti ecosystem is done on a much smaller scale and involving actions of locals taking smaller steps to achieve sustainable development and reduce threats to the ecosystem. The park is designated as a UNESCO world heritage. The management has consisted of working with locals to maintain a co-operative approach to the issue of poaching. Previous ‘top down’ approaches were ineffective as locals believed they had a right to use the park (much or rural Tanzania is poverty stricken).The authorities view has changed to work with locals as they are key in ensuring the sustainability of teh ecosystem. Some controlled and licensed poaching is allowed which also helps to control population numbers to keep in balance with resources and gives some unprotected areas outside the park more protection (though less poaching). Population growth is being managed thought education; there are 75 ‘conservation clubs’ at local schools and trips to the park for both children and adults to see what conservation can achieve first hand. Poverty is another threat that is managed by using sustainable economic development such as taking advantage of traditional practices of basket weaving and honey production to achieve economic growth (as opposed to large scale development which damage the ecosystem). Some villages have also become centres for tourists. Development is being addressed by promoting eco tourism where possible. The management strategies developed are vastly different due to the scale of teh measures involved. The Serengeti ecosystem management focuses on local development to alleviate underlying problems of poverty and population growth, whereas the equatorial rainforests focuses on minimising the exploitation of the rainforest for economic gain.
Development issues relating to: Biodiversity and sustainability
Tropical grassland biome – The tropical Grassland biomes potential for sustainability lies in the ability of conflicting groups who have different interests in the park to come to a compromise. With the issue of poaching the park authorities have realised the importance of working with local people to ensure the longevity of the ecosystem and changes their view on poaching to a more co=operative approach. The local people must benefit from the park as well in order to for the conservation measures to be effective. Therefore controlled and licensed hunting is allowed to take place which benefits locals as well as protecting areas outside the parks boundary. It is also important in keeping the population of animals such as wilder beast and zebra in balance with the resources available. To reduce the impact population growth has on the parks ecosystem there have been measures such as raising awareness though education. 74 schools have ‘conservation clubs’ and the park hold regular visits for both adults and children to increase awareness and show what conservation can do first hand. Local people are also involved in land use planning and local policies. Population growth and poverty is being managed so to reduce poverty through sustainable methods as opposed to large scale development which may damage the ecosystem. Sustainable tourism is a suggested way forward with locals using traditional products such as basket weaving and honey production a viable economic activities, some local settlements have even become tourist hubs within themselves.
To reach the full potential of sustainable development around the Serengeti ecosystem other measures must also be upheld, such as making population growth part of the conservation policy and increase awareness on a global scale.
Factors accounting for differences in biodiversity on a global scale:
The main factor influencing biodiversity is climate, and secondary influence is soil type. --- Differences between the tropical grassland biome and equatorial rainforest biome as a result are:
NPP energy, precipitation, growing season, litter layer, decomposers, growth rate, (species in one area), (adaptations to cool climate)
(2 seasons)(Adaptations)(Populations depend on ITCZ rain
Soil type similarities
Extreme environments
Impact of human activity (deciduous not allot left) (pressures in biomes)
- Why we should be concerned about biodiversity:
Population is directly in proportional to the limiting factor.
Extreme environment is the limiting factor, human limiting factor (deciduous wood – agriculture, Amazonia – mining, deforestation, HEP, Serengeti – population, poverty, poaching, development, Malaysia - deforestation)
Need for in pharmaceutical industry (cure extinct)
Value of this industry Costa Rica receives 2% of royalties made from 20% of its products, Madagascan periwinkle ingredient in cancer drug vincritinie – no profits from this exploitation (more from coffee and banana exports) – If the country doesn’t benefit why would it work towards protecting biodiversity.
Changes resulting from urbanisation: Urban niches:
Colonisation of wasteland (resulting from succession)
(Succession) 1.Mosses and Lichens (1-3 years) 2.Oxford ragwort seeds/invasion nutrients up (3-6 years) 3. Rose bay willow-herb, Japanese knotweed, bracken, hawthorn, weeds, birch, alder, willow, sycamore, humus=nutrients from pioneers, shade out, tall replace small, spread by seeds/rhizomes, worms(8-10 years)
- The colonisation of wasteland occurs through natural succession on for example an abandoned industrial site where urban decay may have taken place or de-industrialisation. The first species to colonise are pioneer species which are tolerant of low moisture availability and lack of nutrients. These include lichens and mosses which live in cracks where moisture is more available and live of nutrients from the bare surface and through photosynthesis. This colonisation usually takes 1-3 years. The next stage which occurs over 3-6 years is the introduction of oxford ragwort by seeds carried on the wind or invasion form a close-by site. The level of nutrients has increased allowing more such species to colonise however vegetation still grows in crack to offer protection and moisture.
- The next stage between 8-10 years pioneer species starts to become shaded out by taller species of grasses. This creates a nutrient layer of humus allowing more complex plants to colonise such as rose bay willow herb. As competition increases plants colonise through windblown seeds and rhizomes under the soil which can grow up to 1m per year. As nutrients increase worms are introduced and taller species replace smaller ones. Grasses weeds and bracken start to appear including Japanese knot weed. If left for enough time Birch, willow and alder trees may become established which are able to survive on poor soil conditions, as well as rowan hawthorn and sycamore.
Planned/ Unplanned introduction of new species
The planned introduction of species can result from introduction to a garden for example urban areas have a vastly higher numbers of exotic plants than rural areas. For example some species that have been introduced are the Canadian golden rod, sycamore, laburnum and wormwood from Europe and Japanese knotweed – now Britain’s most invasive species. The London plane tree has also been introduced in London to create a less urban feeling environment and to bring greenery in to contrast with the dull grey city-scape, it also gives aesthetically pleasing silhouettes in the winter and doesn’t produce much litter (less cost to the council).
Unplanned introduction of species has come from seed dispersal by the wind as well as animal’s birds and transport. Oxford ragwort a member of the senicio genus was introduced to teh Duchess of Beufords garden in the 1700’s. The yellow flowing herbaceous plant was then introduced to the Oxford botanic garden where it escaped and spread on to the railway lines in the 1800’s. It then began to spread rapidly as a result of the passing trains when it got caught or was blown into carriages that passed. As a result it has spread all over England, Wales and parts of Scotland. Its native home is the volcanic mountains if Sicily which are somewhat resembled by the limestone on which it is commonly found in England. There are benefits and negatives to introducing new species to a habitat. The positive effects are that some may benefit local wildlife becoming an alternate source of food allowing particular species to flourish as a result; they may also not be competitive with native species such as corn and tomato. However, invasive species such as Japanese knotweed form Japan has become Britain’s most invasive species and its presence is growing, causing problems especially in conservation areas such as Troopers hill were habitats are very sensitive. The introduction of species can also be detrimental to local wildlife, as has been suggested by oxford ragwort which in large quantities could cause damage to horse’s health.
Development of distinctive ecologies along route-ways
Railways- (animals able to make sets no human interference except leaves on the line) managed by humans to keep safe – distinctive
Motorways – rowan planted, 1.8 billion trees planted by highways agency, grasses (n-fertiliser) home for mice, kestrels feed on (M4 corridor) – distinctive managed to create environment.
Canals – (Kingfisher) human interaction only on paths – not distinctive due to invasion of climactic climax oak woodland due to NOT managed by humans, BUT could be distinctive as climactic climax itself is distinctive.
London Plane tree – uniform habitat form birds (aesthetically pleasing no shed bark) – distinctive
Changes in the rural urban fringe:
- Changes in the rural urban fringe can result from development for example pressure for housing, recreational use development, as well as changes from urban blight caused by vandalism and neglect and lastly the development of conservation parks and areas. Areas on the rural-urban fringe are typically green belt areas or close to green belt areas. This makes them desirable to developers as many people wish to live here due to its proximity to the countryside and not to far distance from urban areas such as that around London. In the South East of England 50K homes are needed in the next 10 years, a proposed area for this development is areas around the rural urban fringe due to this land prices are usually very high. Developments however, can damage the ecosystems and quality of farming land in many ways. Impermeable surfaces increase run off leading to the creating of bogs in low lying areas and compaction of the soil reduces the growth of plant roots and capacity for water to infiltrate through the soil. Acidation of the soil from pollutants during construction also reduces the nutrients available. The Sarum housing development for example built 640 new homes along an area previously considered to be green belt area. This not only imposed the damage caused by the construction of the houses but increased noise and air pollution and damage through infrastructure as well. Development also has the potential to attract more people increasing counter-urbanisation and negatively impacting the environment. Urban blight is caused by vandalism such as fly tipping which also costs the government thousands to clear up each year, vandalism is also increasing in these areas increasing the damage to rural ecosystems and decreasing the aesthetically pleasing qualities about living on the fringe. Urban blight is also caused by neglect all too often caused by farmers who anticipate the selling of their land. Recreational developments are increasing including golf courses which themselves often develop distinctive habitats. Changes on the fringe can also have positive impacts to ecosystem as more areas are now being protected in government schemes such as that in Moors valley, south east England. The scheme has created a wildlife corridor and recreational space that attracts tourists, important to the local economy.
E.g. housing developments, urban blight (urban-rural areas becoming derelict etc caused by various factors including fly tipping, garden creation, wildlife corridors.
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