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Selasa, 31 Januari 2017

The longleaf pine ecosystem is a diverse fire climax conifer pine dominate habitat that includes many rare plant and animal species found within the southeastern United States. Once a dominant ecosystem of the southeastern portion of the United States, it now occupies less than a quarter of the original range. Degrading of the ecosystem is partially due to excessive timber harvesting, urbanization, and fire exclusion. Although the ecosystem is broken up in present time, it still carries various plant and animal species. Many of the relevant species found in the longleaf pine ecosystem can be found in the ecosystem alone. The great concern for the ecosystem at the present is the continuation and health of the overall plant and animal species which reside within the area. The use of a range of techniques, including planting longleaf seedlings, introducing prescribed burning regiments, managing native ground cover, and controlling invasive species within the ecosystem can help to preserve this threatened ecosystem.

Origins

The prehistoric assumption of how the longleaf pine ecosystem was shaped comes from investigation of the time period of the ice age of the earth. Though the ice age period happened thousands of years ago, geologists feel certain about the reasoning of its start. The main ice cap of the original ice age extended southward to parts of the now present Ohio River of North America. From this phenomenon of freezing, the south portion of North America was affected with a cooler and dryer climate. As a result, vegetation such as the longleaf pine and other pine species were associated with the coastal regions of the unexposed ice cap areas. These unexposed areas consisted of now present states Florida to Mexico. In the periods to follow, as the earth’s climate slowly warmed, the ice caps receded northward. With this slow succession, the climate of the south progressively changed to warm and dry. Also as a factor of the climate change, evolving of the longleaf pine ecosystem took place.

Although some geologists feel confident about the reasoning of the beginning of the ecosystem, some speculation of this reasoning is challenged by other researchers. This fact of challenge comes from little to no systematic data based out of the coastal regions of Florida to Mexico. With this lack of systematic data, no statistical values for reconstruction of the original ecosystem can be calculated. However extensive literature from various explores of southeastern North America is reliable when it comes to reconstructing original ecosystem information. Such literature is dated back as far as 1608, when captain John Smith recorded his accounts of the forest and first exports products of pines close to the new settlement in Jamestown, Virginia.

Discovery

The longleaf pine ecosystem was discovered by the European invaders during the European settlement of North America in the early 1500s by the Spaniard Hernando de Soto, although accounts of Native Americans have been documented in journals of European explorers as well. It was later reported that this ecosystem consisted of 70 million acres of pure and 20 million acre of mixed longleaf pine stands; all together the total was 90 million acres. The range of the ecosystem extended from southeastern Virginia down to northern Florida over to eastern Texas. Within this range, the ecosystem was found most dominate of the Coastal Plains regions associated with the states.

Role of fire

The longleaf pine ecosystem is known as a fire climax community. The organization group Longleaf Alliance defines a fire climax community as "a plant and animal community that is limited by and adapted to an early successional stage by frequent fire disturbances".

The role of fire in the longleaf pine ecosystem was and still is today a key component in regeneration and shaping of the ecosystem. In pre-European establishment years, Native Americans set fires quite regularly. By doing so, they benefited their needs of establishing hunting grounds, homesteads, and safe havens. While achieving their goals, they were enriching the longleaf pine ecosystem by shaping the dynamics of the system. Wildfire also played a role in the ecosystem. Thunderstorms moved into the South in the summer months, and lightning strikes ignited fires. Once lit by humans or lightning, fires burned across the landscape for days, weeks, and even months due to the lack of habitat fragmentation by roads, railroads, or cities.

Animal and plant diversity

The plant and animal species found within the longleaf pine ecosystem is one of the highly diverse assortments of the world. As of 2001, there are an estimated 27 federal endangered species and 100 species of concern that reside in the ecosystem. Though many species are associated with the ecosystem, some have limited range due to topography and climate of some regions of the system. The most notable species of the ecosystem is the longleaf pine, wiregrass, and red cockaded woodpecker which all are found throughout the historic range. The tree species longleaf pine (Pinus palustris) is characterized as having bushy clusters of 10 inch long needles and large 6 to 12 inch long pine cones. These pines are capable of growing 80 to 100 feet tall with a diameter of 2.5 feet across, only in well suited soil. The longleaf pine is most notable for thick bark, which aids in the resistant to fire and to southern pine beetle outbreaks.

The grass species Carolina wiregrass (Aristida stricta), which is found in the northern portion and southern wiregrass (Aristida beyrichiana) which is found in the southern portion of the ecosystem, both are the dominating grass species of the system. These grass species occur in clumps which measure 6 inches across and have flat leaves that reach 20 inches long. The wiregrass species have an untold connection with longleaf pine, in that it helps to carry fire across the land.

The bird species red cockaded woodpecker (Picoides borealis) was once a common inhabitant since the demise of the ecosystem it has been placed on the federal endangered species list. The woodpecker adults are characterized by being 7 inches long, with a black head, white cheek patch, and barred back with black and white stripes that give the appearance of a latter. In males, a red strip atop the head is only visible when young or up close. This woodpecker carefully selects longleaf pine, or associated pine species of the area, for heart rot disease. Once a tree is selected, excavation of a cavity is achieved usually taking 2 years to complete.

Embedded within the longleaf pine ecosystem are countless varieties of microhabitats. Among the more unique of these habitats are pitcher plant bogs. Pitcher plants and their companion plants are specialized to exist in a narrow set of conditions. Soil moisture is critical and many "bog" communities are actually the result of a hard, impermeable clay layer beneath porous sand. Rainwater seeps through the sand but runs into a clay layer where it is either trapped (like a pool) or seeps out the side of a hill. These nutrient-poor, moist sites are ideal for the carnivorous pitcher plants. Bogs common to many "flatwood" longleaf areas are called "wet prairies" while other bogs found on hillsides are called "seepage slopes". The transition from forest to an open bog is not immediate. Forests usually grade into a wetland bog habitat. This transition area is called an ecotone and hosts a rich variety of plant and animal species.

Pitcher plants have modified leaves shaped into hollow tubes (that look like a water pitcher), which attract insects. Downward pointing hairs and slippery walls make escape difficult and the insects are dissolved and digested by enzymes in the bottom of the pitcher. Other plants trap small insects on flat sticky leaves before slowly digesting them. Several types of pitcher plants as well as other carnivorous plants grow in the longleaf pine ecosystem. Species include the hooded pitcher plant, trumpet pitcher plant, white-topped pitcher plant, and parrot pitcher plant. Other bog plants include colic-root; goldcrest; meadow-beauty (also called deerflower); white-topped sedge; orange milkwort (also called bog "Cheetos" because of their resemblance to that treat); bog-buttons (also called "hatpins"); several species of orchids; and many other wildflowers.

Both soil moisture conditions and full sun are critical to these plants. Most of these bog plants have little shade tolerance. Pitcher plant bogs are fire dependent habitats. The frequent fires common to the longleaf ecosystem keep woody shrubs from encroaching on bogs. Without fire, moisture-loving shrubs invade drying up bogs and shading out the herbaceous plants.

Decline

The decline of the ecosystem was brought forth slowly first, by the decline of Native Americans. The decline of the Native Americans was mostly contributed by the rapid advancement of diseases across southeast portion of North America in the 1500s. Reports of the diseases were accounted by Spanish explorer Hernando de Soto, during his exploration of the southeastern portion of the state in 1539â€"1542. As Native American populations declined the use of fire declined, as well.

However, around the mid 1500s where Native Americans had left off, Europeans slowly starting using fire as a management tool. The continuation of fire was aided mainly due to the backgrounds of Europeans from England, Scotland, and Ireland, which understood the need of fire to shape the land. Along with this transition of between Native Americans cultures to European, some exotic animals were introduces into the ecosystem. One key species of concern towards the ecosystem was the razorback hog (Sus scrofa scrofa). This species was extensively responsible for damages to plants found in the ecosystem such as longleaf pine seedlings.

As years passed in the 1600s and 1700s, conversions to the landscape and exploiting of the resources in the ecosystem increased. Small living quarters such as log cabins were established first by using longleaf pine from the ecosystem. On a year bases, homes became more elaborate and abundant using substantially more longleaf pine. With the boom in home building, word spread of the good characteristics the longleaf pine had for construction purpose, and soon was being exported overseas. Also included in exports overseas was longleaf pine resin or known as naval stores. To obtain the resin from the live longleaf pine, pioneers first cut and removed wood exposing a deep cavity, called a box at the base of the tree. Next a medium-sized, V-shaped cut was performed, above the box to start the resin flow into the box. As resin flowed into the box, it was collected and placed in barrels for shipment. Although, in years after establishing the resin producing tree, the tree itself would become weak and sensitive to wind storms.

Roads and railroads were constructed in various locations throughout the southeast beginning in the 1800s for the purpose of accommodating the ease of forest harvesting and transportation of goods. However, with the construction of roads and homes, habitat fragmentation was introduced to the longleaf pine ecosystem.

After the Civil War in 1865, the Agriculture boom started. Many pioneers had received word about the cash crop Cotton, soon land purchase and the clearing of land increased significantly. With this sudden shift in land use, the additions of large plantations were established in the ecosystem, as well. In result of this boom plus the addition of forest harvesting and transportation right of ways, further habitat loss was increasing at an alarming rate.

During the early 1900s, more habitat lost was due to World War I. Vast acres of the longleaf pine in the southeast were cleared to aid in ship building for the war effort. With this push in demand, 1909 marked the peak of longleaf pine lumber production. At this period, it was realized that decline in the ecosystem was eminent through the bare landscape with little regeneration of longleaf pine. So to compensate for loss, replanting of some clear-cuts areas in the ecosystem was planted by land owners and Civilian Conservation Corps enrollees during the Great Depression era of the mid 1900s. Although in some sectors of landowners in the southeast learned over the years that the longleaf pine was a slow growing tree, and thus began replanting the ecosystem with faster growing trees species like the slash and loblolly pine. With replanting the species slash pine and loblolly pine a faster tree growth / lumber production was achieved.

As of 2011, only 3 million or so acres of the longleaf pine ecosystem are left in North America. This significant drop in the ecosystem acreage marks a 97 percent decrease. In overlook of the ecosystem, today, it is described as being patchy and uneven in the distribution across the landscape. Of the now 3 percent ecosystem acreage, there is a documented 8,856 acres of old growth longleaf pine stands left.

Concern of the ecosystem today

In the past, the first concerns of the longleaf pine ecosystem were brought to attention in the early 1900s. These concerns were primarily focused on regeneration of harvested longleaf pine stands and remaining pine stands in the ecosystem. Men like Henry E. Hardtner and Herman H. Chapman were among the first to collaborate ways to implement longleaf regeneration in the ecosystem. Later the United States Forest Service recognized and had studied the need of fire in the ecosystem burning (man lit fire) was implemented on national forest.

The major concerns of the longleaf pine ecosystem as present (2000s) are urbanization and fire suppression. With the North American population increasing by roughly 2.5 million people a year, the competition for space is increasing. Threat to the longleaf pine ecosystem is emanate through land clearing for commercial businesses and housing developments. Ultimately due to urbanization, fire suppression is caused, because of human endangerment. With this result of human endangerment, the lack of fire in the ecosystem could result in further deterioration of it. In result, the federal government and state government agencies in Alabama, Florida, Georgia, Louisiana, Mississippi, North Carolina, South Carolina, Texas, and Virginia have teamed up to provide aid to this critical ecosystem. This aid comes in the form of cost share programs, set up by states to assist private land owners in education, financial aid, and guidance on the longleaf pine ecosystem restoration.

References

 
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