Pioneer species are usually the first species to colonize in barren ecosystems. These tenacious plant and microbial species are also the first to return to the environment that has been damaged by events such as wildfires and deforestation. Once they arrive, the pioneer species begins to restore the ecosystem, making it more suitable for later species. This is usually achieved through soil stability, nutrient enrichment, reduced light effectiveness and storm exposure, and temperature regulation.
To survive under these conditions, Pioneer species usually:
•Hard tolerate enough to withstand harsh environments
•Photosynthesis , due to the lack of soil nutrients
•Can produce large amounts of seeds, with high spread rate
•Wind pollination, due to the lack of insects
•Can survive long dormancy
•Be precocious, relying on Asthetic reproduction
With the increase in the frequency of forest fires in the western United States and the expansion of deforestation areas around the world, it is more important than ever to understand what Pioneer species are and their role in ecosystem recovery and growth.
Pioneer Species and Ecological Succession
Ecological Succession describes the changes in the species structure experienced by an ecosystem over a period of time. This is a gradual process that can occur in previously poor environments (such as primary succession ) or in areas that have been cleared due to severe interference (such as secondary succession). Pioneer species play an integral role in these processes, providing more complex communities for new or recently destroyed ecosystems.
Native succession
Primary succession occurs in areas without existing plants, animals, insects, seeds or soils—usually where there are no previous communities. However, technically, this type of succession can even occur when previous communities are disturbed or removed, but it is impossible for any existing organics to meet the conditions for primary succession.
fungi and lichen are the most common pioneer species in primary succession because they have the ability to break down minerals to form soil, which in turn develop organic matter. Once the pioneer species settles in the area and begins to build soil, other species, such as grasses, begin to migrate. The complexity of new communities increases with the arrival of more new species, including small shrubs and ultimate trees.
secondary succession
In contrast to primary succession, secondary succession occurs after the existing community is disturbed or completely removed by natural or artificial forces. In this case, vegetation is removed but the soil remains. This means that the pioneer species of secondary succession can start with root systems and seeds in the residual soil. Additionally, seeds can also be carried by wind or animals from neighboring communities. Grass, alder , birch and pine are all plants that begin to succeed secondary. The behavior of
communities after perturbation depends on many factors, but mainly depends on the nature of the ecosystem before perturbation. That is, because secondary succession begins with some remnants of the original community, changes usually occur much faster than primary succession. Alder, birch and grass are common pioneer species in these environments as they thrive in sunny conditions.
Factors that affect community development during secondary succession include:
Soil conditions: The overall quality of the soil after disturbance has a great impact on secondary succession. This may include everything from soil pH to density and soil composition.
Residual organic matter: Similarly, the organic mass remaining in the soil after perturbation affects the speed of succession and the type of pioneer species. The more organic matter in the soil, the faster the secondary succession may occur.
Existing seed library: Seeds may remain in the soil depending on the degree of interference the community is affected. This is also affected by the distance from the region’s external seed sources and may lead to higher abundances of certain pioneer species.
Remaining organisms: If root systems and other underground plant structures survive interference, secondary succession will occur faster and in a way closer to reflecting 's original ecosystem .
Examples of pioneer species
lichens, fungi, bacteria, weeds, grasses, alder and willow are all examples of pioneer species. There are some common situations here, and pioneer species help succeed.
Glacier Ice
Compared with secondary succession, there are fewer research on primary succession and are not detailed. However, one of the most basic examples of primitive succession occurred after the height of the Pinedale Glacier in Yellowstone, when the area was covered with glacial ice. After the ice takes away soil and vegetation from the environment, after the end of the glacial period. The area was retransplanted by pioneer species, which destroyed bedrock and formed soil for other plants to transplant.
lava stream
1980 volcano erupted in 1980, the surrounding area became barren, gray, with almost no surviving animals and plants. Even so, some underground animals survived, and some plants' underground root systems, such as willows and black poplars, also survived. In the early consequences of this destruction, these surviving root systems, along with alder and fir , were able to settle in the original landslide debris and lava flows.
Flood
1995, the Murman River and Rapidan River in Shenandoah National Park flooded, resulting in widespread damage to animals and plants, most of which were replaced by gravel and boulders. Since then, plant and wildlife communities have begun to be reconstructed through secondary succession.
wildfire
1947 After the wildfire occurred in Acadia National Park , a secondary fire also occurred, burning more than 10,000 acres of parks. After the fire, some previously lush areas were cut down for timber salvage and cleaning, and some logs were left to promote the regeneration of in the forest ecosystem. Through secondary succession, the forest grows again with the help of existing root systems, stump buds and seeds.
Like birch and poplar , trees that have not grown in the area before take advantage of new sunlight conditions and grew lushly in the early stages. Once these deciduous trees form the canopy, the spruce and fir that originally thrived in the area were able to return, thus forming a mixture of today's deciduous trees and evergreen trees .
Agriculture
Agriculture, especially slash-and-burn agriculture, will have a devastating impact on the natural environment. Secondary succession occurs when the remaining seeds, roots, weeds and other pioneer species begin to settle on the land again during the fallow period immediately following agricultural use. This process is similar to what happens after logging and other deforestation.
