Importance of Biomes
Biome” and “ecosystem” are words sometimes used interchangeably to describe a specific type of environment, but this is an erroneous conflation. While the. Separation of ecosystems and biomes is a problem in terms of space and time. A given . What is the relationship between an ecosystem and nature?. It is important to preserve all types of biomes as each houses many unique Public attention to this exploitation have helped to alleviate the problem This makes the water unusable and it kills many of the organisms living in the habitat.
The temperature and sunlight profiles of tropical rainforests are stable in comparison to other terrestrial biomes, with average temperatures ranging from 20oC to 34oC 68oF to 93oF. Month-to-month temperatures are relatively constant in tropical rainforests, in contrast to forests farther from the equator. In contrast to other ecosystems, a consistent daily amount of sunlight 11—12 hours per day year-round provides more solar radiation and therefore more opportunity for primary productivity.
The annual rainfall in tropical rainforests ranges from to cm 50— in with considerable seasonal variation. Tropical rainforests have wet months in which there can be more than 30 cm 11—12 in of precipitation, as well as dry months in which there are fewer than 10 cm 3.
However, the driest month of a tropical rainforest can still exceed the annual rainfall of some other biomes, such as deserts. Tropical rainforests have high net primary productivity because the annual temperatures and precipitation values support rapid plant growth. However, the high amounts of rainfall leaches nutrients from the soils of these forests.
Species diversity is very high in tropical wet forests, such as these forests of Madre de Dios, Peru, near the Amazon River.
Roosevelt Garcia Tropical rainforests are characterized by vertical layering of vegetation and the formation of distinct habitats for animals within each layer. On the forest floor is a sparse layer of plants and decaying plant matter. Above that is an understory of short, shrubby foliage.
A layer of trees rises above this understory and is topped by a closed upper canopy—the uppermost overhead layer of branches and leaves. Some additional trees emerge through this closed upper canopy. These layers provide diverse and complex habitats for the variety of plants, animals, and other organisms.
Many species of animals use the variety of plants and the complex structure of the tropical wet forests for food and shelter. Some organisms live several meters above ground, rarely descending to the forest floor.
A MinuteEarth video about how trees create rainfall, and vice versa. Savannas are grasslands with scattered trees and are found in Africa, South America, and northern Australia Figure 4 below.
Savannas are hot, tropical areas with temperatures averaging from 24oC —29oC 75oF —84oF and an annual rainfall of 51— cm 20—50 in. Savannas have an extensive dry season and consequent fires.
As a result, there are relatively few trees scattered in the grasses and forbs herbaceous flowering plants that dominate the savanna.
Although savannas are dominated by grasses, small woodlands, such as this one in Mount Archer National Park in Queensland, Australia, may dot the landscape. Deserts are frequently located on the downwind or lee side of mountain ranges, which create a rain shadow after prevailing winds drop their water content on the mountains.
This is typical of the North American deserts, such as the Mohave and Sonoran deserts. Deserts in other regions, such as the Sahara Desert in northern Africa or the Namib Desert in southwestern Africa are dry because of the high-pressure, dry air descending at those latitudes. Subtropical deserts are very dry; evaporation typically exceeds precipitation. Subtropical hot deserts can have daytime soil surface temperatures above 60oC oF and nighttime temperatures approaching 0oC 32oF.
Subtropical deserts are characterized by low annual precipitation of fewer than 30 cm 12 in with little monthly variation and lack of predictability in rainfall.
Some years may receive tiny amounts of rainfall, while others receive more. In some cases, the annual rainfall can be as low as 2 cm 0. A MinuteEarth video about the global climate patterns which lead to subtropical deserts. The low species diversity of this biome is closely related to its low and unpredictable precipitation. Despite the relatively low diversity, desert species exhibit fascinating adaptations to the harshness of their environment.
Very dry deserts lack perennial vegetation that lives from one year to the next; instead, many plants are annuals that grow quickly and reproduce when rainfall does occur, then they die.
Perennial plants in deserts are characterized by adaptations that conserve water: Seed plants in the desert produce seeds that can lie dormant for extended periods between rains. Most animal life in subtropical deserts has adapted to a nocturnal life, spending the hot daytime hours beneath the ground. The Namib Desert is the oldest on the planet, and has probably been dry for more than 55 million years. It supports a number of endemic species species found only there because of this great age.
For example, the unusual gymnosperm Welwitschia mirabilis is the only extant species of an entire order of plants. There are also five species of reptiles considered endemic to the Namib. In addition to subtropical deserts there are cold deserts that experience freezing temperatures during the winter and any precipitation is in the form of snowfall.
Many desert plants have tiny leaves or no leaves at all to reduce water loss. The leaves of ocotillo, shown here in the Chihuahuan Desert in Big Bend National Park, Texas, appear only after rainfall and then are shed.
The annual rainfall in this biome ranges from 65 cm to 75 cm Summers are very dry and many chaparral plants are dormant during the summertime.
The chaparral vegetation is dominated by shrubs and is adapted to periodic fires, with some plants producing seeds that germinate only after a hot fire. The ashes left behind after a fire are rich in nutrients like nitrogen and fertilize the soil, promoting plant regrowth.
Fire is a natural part of the maintenance of this biome. The chaparral is dominated by shrubs. Miguel Vieira Temperate grasslands are found throughout central North America, where they are also known as prairies, and in Eurasia, where they are known as steppes Figure 8 below.
Temperate grasslands have pronounced annual fluctuations in temperature with hot summers and cold winters. The annual temperature variation produces specific growing seasons for plants. Plant growth is possible when temperatures are warm enough to sustain plant growth, which occurs in the spring, summer, and fall.
Annual precipitation ranges from Temperate grasslands have few trees except for those found growing along rivers or streams. The dominant vegetation tends to consist of grasses. The treeless condition is maintained by low precipitation, frequent fires, and grazing. Organisms that make their own food by using sunlight or chemical energy to convert simple inorganic molecules into complex, energy-rich organic molecules like glucose are called producers or autotrophs.
Some producers are chemosynthesizers using chemicals to make food rather than photosynthesizers; instead of using sunlight as the source of energy to make energy-rich molecules, these bacteria and their relatives use simple chemicals as their source of energy.
Chemosynthesizers live in places with no sunlight, such as along oceanic vents at great depths on the ocean floor. No matter how long you or a giraffe stands out in the sun, you will never be able to make food by just soaking up the sunshine; you will never be able to photosynthesize.
Producers use the food that they make and the chemical energy it contains to meet their own needs for building-block molecules and energy so that they can do things such as grow, move, and reproduce. All other life depends on the energy-rich food molecules made by producers — either directly by eating producers, or indirectly by eating organisms that have eaten producers.
Not surprisingly, ecologists also have terms that describe where in the food chain a particular consumer operates. A primary consumer eats producers e. And it can go even further: A single individual animal can act as a different type of consumer depending on what it is eating. When a bear eats berries, for example, it is being a primary consumer, but when it eats a fish, it might be a secondary or a tertiary consumer, depending on what the fish ate! All organisms play a part in the web of life and every living thing will die at some point.
This is where scavengers, detritivores which eat detritus or parts of dead thingsand decomposers come in. They all play a critical role that often goes unnoticed when observing the workings of an ecosystem. They break down carcasses, body parts and waste products, returning to the ecosystem the nutrients and minerals stored in them.
This interaction is critical for our health and health of the entire planet; without them we would be literally buried in dead stuff. Crabs, insects, fungi and bacteria are examples of these important clean-up specialists. Another category of interactions between organisms has to do with close, usually long-term interaction between different types of organisms. These interactions are called symbiosis.
The impacts of symbiosis can be positive, negative, or neutral for the individuals involved. Organisms often provide resources or services to each other; the interaction is mutually beneficial. For example, ants living in a tree may protect the tree from an organism that would like to make the tree its next meal, and at the same time the tree provides a safe home for the ants.
Biomes and Ecosystems - Windows to the Universe
Symbiotic relationships are not always positive for both participants. Sometimes there are definite losers. The predator benefits and the prey is harmed lethally, but it is a short-term interaction. In parasitism, the parasite does not usually kill its host, but just feeds on it for a long time while it is living.
The interaction is seemingly neutral for one of the organisms. For example, a barnacle attached to a whale is able to travel thousands of miles collecting and filtering food from the moving water. But then again, maybe those little hitchhikers are actually creating a tiny amount of additional drag as the whale moves through the water and therefore the whale has to expend just a little bit of additional energy. If so, that would be a negative impact for the whale.
Often, further research reveals that what was originally thought to be neutral for one participant and therefore an example of commensalism, actually has a very subtle positive or negative impact, so the classification is no longer commensalism, but rather mutualism or parasitism.
Is a bird nest on a tree limb commensalism, or is there some slight advantage or disadvantage for the tree in having the nest there? It is possible to come up with plausible explanations either way; only detailed research could provide the necessary information to answer the question.