Ecosystems flashcards
Evaluate a local scale management strategy, outlining what issue they are trying to tackle/help with, how they work, how effective they have been.
✔ The Biological Reserve in Monteverde now covers over 10,500 hectares, this
ensures wider habitat range for the animals within this ecosystem. It has extremely diverse flora
and fauna (over 100 species of mammals, 2,500 plant species).
✔ It ensures that new infrastructure (new roads, sewers, water pipes, electricity lines)
benefit the locals as well as the tourists.
✔ 80 new businesses have opened in Monteverde since 1970s. Ecotourism aims to create local employment while conserving the natural
environment: There are 400 full-time and 140 part-time jobs directly related to
tourism.This is great for the economy and can allow Costa Rica to put their money elsewhere
X People have migrated into the area looking for jobs. This is placing pressure on
the local infrastructure such as dirt roads.
X Atmosphere has negatively changed away from traditional local community to
a busy tourist centre.
X Tourists are demanding more and more facilities and greater luxury. These
facilities can use more electricity, although the majority of Costa Rica’s energy is
produced from renewable sources.
What Impacts are humans having on a named tropical rainforest?
People have migrated into The Cloud Forest looking for jobs. This is placing pressure on the local infrastructure such as dirt roads.
Atmosphere has negatively changed away from traditional local community to a busy tourist centre.
Tourists are demanding more and more facilities and greater luxury. These facilities can use more electricity, although the majority of Costa Rica’s energy is produced from renewable sources.
Wood/paper products - Humans are deforesting forests for logging to collect wood for creating furniture and timber for house building + wood pulp for paper.
The cloud forest is also impacted by climate change - more forest fires.
Explain the distribution of tropical rainforests (8 marks)
Low Pressure
Heat + light
ITCZ (equator)
Role of ITCZ in the rainforest?
Firstly, the majority of the tropical rainforests are found within the Intertropical Convergence Zone, an area near the equator where trade winds converge. This area experiences consistently low pressure due to the convergence of warm, moist air. This low-pressure system gives ideal conditions for the formation of clouds, as the warm, moist air rises at the ITCZ, it cools and condenses, forming dense cloud formations. These clouds act as reservoirs of moisture, leading to frequent and copious rainfall in the surrounding regions. The abundance of rainfall and the continuous uplift of moist air and subsequent condensation generate substantial precipitation levels vital for the perpetuation of the flora and fauna in tropical rainforests, therefore contributing significantly to the unique and thriving ecosystems found within rainforests.
Role of insolation in the rainforest?
Secondly the equatorial regions receive high insolation throughout the year due to the angle of the earth (23.5°) relative to the sun, this has a marked impact upon the insolation in different places and at different times of the year. The suns very concentrated rays lead to higher temperatures. These elevated temperatures create a warm and stable climate that is essential for sustaining the lush and diverse vegetation found in tropical rainforests. The warmth provided by the high insolation leads to photosynthesis, allowing plants to thrive and flourish all year-round. Therefore due to the continual warmth and abundance of sunlight enables a high rate of plant growth, fostering the incredible biodiversity and dense foliage that characterise tropical rainforests.
Role of nearby oceans?
Thirdly, tropical rainforests being found nearby oceans, such as those in Borneo and Indonesia, plays a pivotal role in sustaining these ecosystems. The presence of oceans nearby facilitates a consistent source of moisture through evaporation and the transportation of humid air masses inland. As prevailing winds carry moist air from the oceans towards the land, this air contributes significantly to the humid conditions essential for rainforest ecosystems. Additionally, nearby oceans help maintain relatively stable temperatures within these regions, preventing extreme fluctuations that could otherwise disrupt the delicate balance of rainforest ecosystems. Therefore, the oceanic influence contributes to the regulation of climatic conditions, fostering an environment possible for the growth and sustenance of the diverse vegetation and wildlife characteristic of tropical rainforests in these coastal areas.
What are the main causes of deforestation?
Natural disasters - hurricanes, forest fires, flooding -
Wood/paper products - logging to collect wood for creating furniture and timber for house building + wood pulp for paper.
Clearing of TRF for animal agriculture (farmland) eg: cattle farming, soy, sugar cane and palm oil.
Climate Change: this can exacerbate risk of wildfires as the lack of available water leads to trees dying and becoming very dry
Urban expansion removal of trees for urban development such as road building land change to residential (house building)
Mining: iron ore, gold - clear the land for mining access, settlements for labourers, roads.
What is an Ecosystem?
The interdependence of climate, water, soil, plants and animals
Using the statements below explain in a few sentences the characteristics of the Tropical rainforest soil profile.
- Decomposition rates are higher in warm and wet climates
- Weathering rates are higher in warm and wet climates
- Nutrients levels in the soil are low
The combination of high temperatures and intense rainfall accelerates decomposition rates, breaking down organic matter rapidly. This contributes to a thick organic layer at the surface. Additionally, the warm and wet conditions enhance chemical weathering in particular, leading to the development of a highly weathered, leached, and nutrient-poor soil profile. The nutrients released through decomposition and weathering are often swiftly taken up by vegetation, leaving the soil with low nutrient levels. Despite the lush vegetation above, the soil profile in tropical rainforests tends to be relatively shallow and nutrient-depleted, emphasising the rapid nutrient cycling and tight nutrient recycling within the ecosystem.
For the nutrient cycle explain how biotic and abiotic components of an ecosystem are dependent on one another (4)
- Flora are dependant on warm climate for photosynthesis
- Decomposers are dependant on soil for a habitat
- Many flora are dependant on animals for seed dispersion and fertilisation
- Some animals are dependant on plants for food
- Animals are dependant on climate for warmth
- Flora are dependant on the litter/soil for nutrition
For food chains, explain how biotic and abiotic components of an ecosystem (TRF) are dependent on one another (4)
Talk about:
- Producers
- Decomposers
- Consumers
- Biotic and Abiotic components
- Producers (biotic) are dependant on abiotic factors such as sunlight, to provide photosynthesis for growth.
- Some fauna are dependant on the plants for food - therefore growth.
- Decomposers are dependant on the dead leaves (litter) to respire and reproduce.
- Flora and Fauna depend on the availability of water in the environment. Plants, through transpiration, release water vapor into the atmosphere, affecting local humidity levels. Herbivores and carnivores, in turn, obtain water directly or indirectly from their food sources and the environment.
- Biotic Component: Organisms need suitable habitats for feeding, breeding, and shelter. Vegetation provides habitats for a variety of species.
- Abiotic Component: Soil composition, topography, and physical features of the environment contribute to the structure of habitats.
Interdependence: The structure of habitats, influenced by abiotic factors, determines the availability of resources and shelters for biotic components. For example, trees may provide nesting sites for birds, and burrows in the soil may serve as shelters for small mammals.
Describe where hot and cold deserts are found
Deserts: Deserts are particularly dry environments. Cold deserts can be found at a wider range of latitudes (usually around 75c). Hot deserts such as the sahara form between the hadley and ferrel cells at around 25-40 degrees from the equator. Deserts are found between the ferrel and hadley cells because these are predominantly high pressure areas. This is where air descends from high altitudes and is particularly dry having already used up all its moisture over lower latitudes closer to the equator. This explains why on average we see less than 100 cm of rainfall in the deserts biomes.
The temperatures of deserts range between -5 and 30c and an average of 0-70cm of annual rainfall. Deserts are predominantly found within North Africa with some deserts in Australia, California (West coast of USA) and some deserts found in Central Asia. Hot deserts are mainly found around the tropics. Cold deserts are found in Greenland, the North of Canada and in Antarctica.
Describe the location of TRF:
(3 separate points. Must give regions, latitude, specific countries.)
Tropical Rainforests are commonly found in South America, South East Asia and parts of Africa. Tropical rainforests are found surrounding the equator and up to about 25 degrees North and South. They are found within the hadley cells. The region with the largest area of rainforest is in South and Central America, the majority of which is the Amazon rainforest. Another example is in SouthEast Asia, for example Indonesia.
Explain why we get high levels of convectional rainfall in the rainforest: use the terms: ITCZ, low air pressure, concentrated solar radiation, rapidly rising air, high humidity, evaporation, condensation.
Tropical rainforests get high levels of convectional rainfall because they are found within the Hadley Cells and within the ITCZ. Convectional rainfall is frequent here because the sun’s rays are most concentrated at the equator so this leads to rapid heating of the earth surface, this heats up the air above it leading it to rapidly rise. We also have high levels of evapotranspiration due to the concentrated rays which creates moist air, as it rises, it cools and condenses to form cumulonimbus clouds leading to high levels of precipitation when the air becomes oversaturated.
Describe the climate of a tropical rainforest
Very wet with over 2,000 mm of rainfall per year.
Very warm with an average daily temperature of 28°C. The temperature never drops below 20°C and rarely exceeds 35°C.
The atmosphere is hot and humid.
The climate is consistent all year round. There are no seasons.
Explain how water is cycled in the rainforest
As the rainforest heats up during the morning, the water evaporates into the atmosphere and condensates forming cumulonimbus clouds
Precipitation occurs in the rainforest, leading to water either directly hitting the ground (infiltration), or being intercepted by leaves or by stemflow (flowing down the stem).
This is called convectional rainfall. 25.6% of water is lost through pores in leaves and then evaporated by heat in a process known as evapotranspiration.
The roots absorb some moisture, but the canopy intercepts most of the rainfall; 48.5% of the water evaporates from the canopy layer.
Transpiration allows the water to go back from the leaves into the atmosphere. Warm moist air rises; the water will cool and condense forming rain clouds again (the cycle continues).
Explain how the nutrient cycle works in the rainforest
The forest floor is hot and damp (perfect conditions) which enables dead leaves to decompose quickly. This explains the small circle for leaf litter. Due to the vast amount of vegetation, the nutrients leave the soil very quickly. This decomposition can occur within three to four months in the rainforest.
As organic material (such as leaves) decays and is recycled so quickly by the nutrient-hungry plants and trees, few nutrients ever reach the soil. The circle for the soil is even smaller than that for the litter. This is why many trees have their roots close to the surface or even above the surface of the ground; they are poised to take advantage of any nutrients available
The greatest store of nutrients is in the biomass - the living plants and animals.
Most of the Rainforest’s nutrients is stored in the biomass. Using the following bullet points explain why this is the case – have a think about rates of decomposition and productivity rates.
- Extremely intense rainfall
- Warm temperatures
Intense rainfall in rainforests can lead to leaching, where water percolates through the soil, carrying away nutrients. This leaching process can result in nutrients being washed out of the soil and into water bodies. Intense rainfall can also lead to rapid decomposition of organic matter on the forest floor. Decomposition releases nutrients into the soil, but the high precipitation rates may wash away these nutrients before plants can take them up. As a result, plants have adapted to retain nutrients within their biomass as a strategy for nutrient conservation.
Warm temperatures increase the rate of enzymes in decomposers such as bacteria, fungi, and other microorganisms. This accelerates the decomposition of organic matter, releasing nutrients into the soil. However, the warm conditions also increase the likelihood of nutrient leaching. Therefore, plants store nutrients in their biomass to ensure they have a steady supply for growth and development. The rapid growth of vegetation requires a continuous supply of nutrients. Storing nutrients in the biomass allows plants to maintain high productivity even during periods of nutrient scarcity in the soil.
