Tasmania Plantation Forests
Huntsman Valley in Tasmania is characterized by plantation forests that have largely replaced the region's original temperate woodlands. The conversion to pine monocultures has resulted in significant ecological changes, impacting the biodiversity that once thrived there. Historically, the valley's forests were modified by the Tasmanian Aborigines through fire-stick farming, but European colonization brought about widespread deforestation and habitat loss. Currently, these plantations are managed primarily for timber production, which has raised concerns about the ecological ramifications of such monocultures, including loss of habitat complexity and increased susceptibility to pests and diseases.
Despite these challenges, the Huntsman Valley is situated at a unique ecological juncture, bridging the ecosystems of mainland Australia and Tasmania, and it is home to several endemic species. Notable wildlife includes the Tasmanian devil and various bird species that are either vulnerable or endemic to the region. While plantation forestry aims to concentrate logging in specific areas to protect other forests, the long-term effects on local ecosystems remain a topic of debate. Overall, the dynamic between conservation and economic interests continues to shape the future of Huntsman Valley's plantation forests.
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Tasmania Plantation Forests
- Category: Forest Biomes
- Geographic Location: Tasmania
- Summary: Plantation forests are a human-made monoculture with a formerly biodiverse ecosystem being replaced by one designed to produce pine trees as the sole forest crop.
European settlement on the Australian island state of Tasmania had disastrous effects on its forests. While the Aboriginal Tasmanian people who settled here had long modified the forests through use of fire-stick farming to maximize grazing and hunting outputs, European colonization resulted in widespread extinctions, deforestation, transformation of the coastal ecoregions by greatly increased grazing, and the loss of about a third of the forest to agriculture, urban settlements, and intensive forestry. In the twenty-first century, the older forests were thoroughly replaced by pine plantations.
Though isolated from mainland Australia, Tasmania was connected to the mainland by the Bass Strait land bridge off and on during the Pleistocene, as sea levels fluctuated following glaciations. Although the land bridge was arid during most of that time, and would have been inhospitable to many species, nevertheless, Tasmania has been fully isolated for only the past 13,000 years, and there are strong connectivities and congruences between the ecosystems of Tasmanian forests and those of the mainland. These connections are strongest in the parts of Tasmania nearest the Bass Strait.
The Tasmanian temperate forest ecoregion is a transition between the dry mainland and cooler, more humid western Tasmania. The greatest endemism (species found exclusively in this biome) is found in the forest understory, though much of this endemism was jeopardized by plantation forests. These plantations are monocultures—forests managed to produce a single crop, in this case, pine trees.
Monoculture Controversy
Monoculture forestry provides more effective growth and greater yields than more diverse forests; human-made monoculture stress uniformity, and lack the diversity of tree sizes that occurs in natural monocultures. They also deprive the greater ecosystem of the niches provided by dead trees and meadow-like openings. Also, because the trees are all the same size, they are readily harvested by clear-cutting, which dramatically affects the habitat.
Mechanical harvesting compacts soils, destroying much of the remaining understory ecosystem. Opponents of monoculture practices claim that they are also ideal breeding grounds for pests and disease, because the ecosystem lacks many pests' natural predators or the appropriate, multifaceted defenses against disease. To encourage replanting, each new crop of trees in a monoculture plantation is government-subsidized, attracting more criticism.
On the other hand, the use of plantation forests can, in theory, benefit overall biodiversity by limiting logging activities to those plantations and leaving other forests alone—much like farming in specific controlled areas, rather than destroying numerous ecosystems by attempting to produce the same yields through foraging.
Between 1994 and 2004, 207,000 hectares (511,508 acres) of land in Tasmania was converted from natural forest to monoculture tree plantations. The lumber company Gunns Limited and supplier Forestry Tasmania were accused of consistently destroying native forests and holding a virtual monopoly over the logging industry. Australia’s Federal Court deemed their work illegal, and in 2013, the company was liquidated. Many other companies also engaged in similar deforestation practices in the region, destroying much of the region’s natural biodiversity. To manage the rate of logging and protect some areas, the Forest Management Act was passed in 2013, and the Forestry (Rebuilding the Forest Industry) Act in 2014. Along with subsequent amendments and similar legislation, these acts were the beginning of more responsible practices. By the 2020s, about half of Tasmania’s land area was forested, and the Permanent Native Forest Estate Policy prohibited the destruction of natural forests except under exceptional circumstances. Over two-thirds of the country’s forests were placed in reserves, and of the so-called old-growth forests (areas where evidence of previous deforestation is negligible), 91 percent were protected.
In the twenty-first century, the government-owned Sustainable Timber Tasmania managed Tasmania's Permanent Timber Production Zone (PTPZ), which covers about 108,000 hectares (266,870 acres) of plantation forest. There are also about 80,000 hectares (197,684 acres) of privately held plantations that belong to private individuals and other industries.
Wildlife
The Tasmanian devil (Sarcophilus harrisii) and the Tasmanian tiger (Thylacinus cynocephalus) were once widespread in mainland Australia, but became extinct there long before the arrival of Europeans, most likely through competition with the dingo. The dingo is not found in Tasmania, where both of these species survived. The Tasmanian devil, the largest marsupial carnivore since the thylacine's extinction, can still be found in Tasmania's temperate forests, though it is endangered.
Other mammals of note are the duck-billed platypus (Ornithorhynchus anatinus), short-beaked echidna (Tachyglossus aculeatus), long-nosed potoroo (Potorous tridactylus), spotted-tail quoll (Dasyurus maculatus), eastern quoll (D. viverinus), red-necked wallaby (Macropus rufogriseus), and wombat (Vombatus ursinus tasmaniensis), all of which are widespread throughout Tasmania.
Bird populations here include two vulnerable species: the swift parrot (Lathamus discolor) and the forty-spotted pardalote (Pardalotus quadragintus). The Tasmanian nativehen (Tribonyx mortierii), black-headed honeyeater (Melithreptus affinis), and yellow wattlebird (Anthochaera paradoxa) are found in few other places.
Several lizard species live on the forest floor, including the mountain dragon (Rankinia diemensis). Rawlinson's window-eyed skink (Pseudemoia rawlinsoni), the Tasmanian tree frog (Litoria burrowsi), and the Tasmanian froglet (Crinia tasmaniensis) are endemic to Tasmania's temperate forests.
Bibliography
"Australia: Health in Tasmania Gravely Affected by Pesticide Use in Tree Monocultures." World Rainforest Movement, 14 Aug. 2005, www.wrm.org.uy/bulletin-articles/australia-health-in-tasmania-gravely-affected-by-pesticide-use-in-tree-monocultures. Accessed 20 Dec. 2024.
Chen, Henry C. L., and Pete Hay. “Defending Island Ecologies: Environmental Campaigns in Tasmania and Taiwan.” Journal of Developing Societies, vol. 22, no. 3, 2006, pp. 303–26, doi:10.1177/0169796X06068033. Accessed 20 Dec. 2024.
Fitzgerald, Nick, and Todd Dudley. "Plantation Restoration in Tasmania." North East Bioregional Network, 2015, www.nebn.org.au/files/reports/nebn-plantation-restoration-2015.pdf. Accessed 20 Dec. 2024.
"Private Forests Estate." Private Forests Tasmania, pft.tas.gov.au/private-forest-estate. Accessed 20 Dec. 2024.
Reid, J. B., et al. Vegetation of Tasmania. CSIRO Publishing, 1998.
"State of the Forests Tasmania 2022 Data Report." Forest Practices Authority, 2022, fpa.tas.gov.au/‗‗data/assets/pdf‗file/0007/521548/Tas‗SOF‗data‗report‗2022‗final‗28‗March‗2023.pdf. Accessed 20 Dec. 2024.
Williams, W. D., editor. Biogeography and Ecology in Tasmania. Springer, 1974.