Manchurian mixed forests

• Category: Forest Biomes.
• Geographic Location: Eurasia.
• Summary: These diverse forests cover the low hills of Manchuria and the Russian Far East, home to ginseng and the Siberian tiger. Currently, they face jeopardy from overzealous logging.

The Manchurian Mixed Forests ecosystem is a lower-elevation biome that extends from hills in the northern part of the Korean peninsula, through China, to the Amur River region of the Russian Far East. It includes northeastern China’s broad river valleys, the east slope of the Large Hinggan Mountains, the south and west slopes of the Small Hinggan Mountains, and the hill regions of the Changbai Mountains at the base of the Korean peninsula. The most direct neighboring biome is the Changbai Mountains Mixed Forests ecosystem, which comprises much of the higher-elevation sections in the same general area.

While considered mixed, this Manchurian sylvan system is dominated more by coniferous tree types than are the other, milder-climate forests to its south. Winters are the dry season here; they are long and cold, with a mean low temperature range of minus 4 degrees F to 5 degrees F (minus 20 to minus 15 degrees C). Western Pacific monsoons influence the climate in the summer, with a regime of moist, warm air. Boosted by this seasonal rainfall, the annual precipitation range is approximately 20–40 inches (500–1,000 millimeters).

Forest Composition

At elevations of 1,640–3,280 feet (500–1,000 meters), forests are composed of both coniferous and broadleaf species. The conifer community here includes Korean pine (Pinus koaiensis), which frequently reaches 115 feet (35 meters); as well as fir (Abies holophylla) and spruce (Picea obovata). Deciduous types include oak (Quercus mongolica), ash (Fraxinus mandshurica), Tila amurensis, birch (Betula schmidtii), Manchurian elm (Ulmus lacinata), maple (Acer spp.), and Manchurian walnut (Juglans mandshurica).

These forests also include shrubs such as Lespedezabicolor and Corylus mandshurica, especially in the south. On the east slope of the Large Hinggan Mountains, the conifers are dominated by the Pinus sylvestris pine, and the broadleaf trees include birch, poplar (Populus), willow (Salix rorida), and oak.

The understory ecosystem includes Oxalis acestosella, Phryma tenuifolia, Thalictrum filamentosum, Adiantum pedatum, Asarum sieboldii, Polystichum tripteron, Oplopanax elatus, and Kalopanax septemlobu. The most famous native of the understory in this ecosystem is ginseng (Panax ginseng), valued as a medicinal and culinary rhizome. The genus name Panax means all-heal, related to panacea, and was applied by Swedish naturalist Carl Linnaeus to the plant because of its wide use in Chinese medicine. Today, ginseng continues to be widely used as a stimulant, aphrodisiac, and diabetes treatment, and is touted by adherents as having anticarcinogenic and antioxidant properties. Though the root is commonly used, the leaves actually contain the most ginsenosides, the compounds that distinguish the species.

Patches of grassland feature stipa, also known as spear grass or feather grass (Stipa pennata), and the drought-tolerant sheep’s fescue (Festuca ovina), a grass that favors acidic mineral soil and is prized as a food by numerous species of butterflies and moths.

Wildlife

The brown-eared pheasant (Crossoptilon mantchuricum), native to the nearby grasslands, is often found here in small numbers. The steppe marmot (Marmota bobak) ranges across the steppes of all of eastern Europe and central Asia, and is common enough to be relied on as a food source by human populations in times of famine or following crop failures. Ungulates and large mammals here include deer, boars, moose, musk deer, bears, tigers, and ghorals.

The forests are home to four protected mammals: the Siberian tiger (Panthera tigris altaica), sable (Martes zibellina), Sika deer (Cervus nippon), and leopard (Panthera pardus). The Siberian tiger, which once ranged through this entire region, is already extinct in South Korea and might be extinct throughout the Korean peninsula, though it is thought that some may survive in North Korea’s Paektusan Mountains.

The tiger is known to inhabit the Changbai Mountains in China and the forests of Amur Oblast in the Russian Far East. The Amur tiger population is the best observed (and the largest), consisting of a population of more than 500 tigers, of which about 100 are cubs. 95 percent of the population of Amur tigers dwell in Russia. Intensive conservation efforts have stabilized the population since the 1990s. The tiger is one of the largest felids that has ever lived. It preys primarily on Sika, red, Siberian roe, and musk deer; wild pigs; and smaller prey, including small mammals like rabbits and hares; and fish such as salmon.

When ungulate populations decrease, tigers are known to prey on brown and black bears, though this is unusual. Tigers attacking bears attack the throat and spine, and feed on the bear’s abundant fat deposits. Though tigers do not prey on wolves—and do not consume them if they kill them—their presence will depress wolf population numbers, because they compete for the same prey.

The Siberian tiger suffers from low genetic diversity, with an extremely low effective population size relative to the census population size. The reduction in tiger numbers promises to compound this problem. Poaching of both tigers and the species they prey on is the most serious current threat to the species. In the past, deforestation and legalized tiger hunting were responsible for much of the decimation of the tiger population.

Threats

Substantial timber tracts in this area attract logging and related industries, and there is a danger of deforestation and overharvesting of timber. Habitat fragmentation is of high concern under such circumstances. Climate change impacts include the potential for increasing nitrogen in the soil, which could change the delicate balance of the forest ecosystem. Vegetation shift is a serious problem caused by climate change. After a four-year study of the area, experts noted that tree vegetation remained stable, but the microbial communities had significantly changed. This is caused by climate change and may even lead to a shift in vegetation.

The Chinese government launched an ambitious plan in 2016 with the goal of revamping its national park system. One project will conserve 14,6000 square kilometers of the Manchurian mixed forest for the purpose of providing a safe habitat for leopards and tigers. The creation of the Hunchun Amur Tiger National has improved anti-poaching efforts and eased pressure on tigers in northeast China.

Bibliography

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Heo, Young-Mok, et al. "Influence of Tree Vegetation on Soil Microbial Communities in Temperate Forests and Their Potential as a Proactive Indicator of Vegetation Shifts Due to Climate Change." Sustainability, vol. 12, no. 24, 18 Dec. 2020, doi.org/10.3390/su122410591. Accessed 4 Dec. 2024.

Kong, W., and D. Watts. The Plant Geography of Korea, with an Emphasis on the Alpine Zones. Boston: Kluwer Academic Publishers, 1993.

Noone, Greg. “On the Hunt for North Korea’s Last Siberian Tigers.” NK News, 19 Jan. 2018, www.nknews.org/2018/01/on-the-hunt-for-north-koreas-last-siberian-tigers/. Accessed 4 Dec. 2024.

Qi, Jinzhe, et. al. “ Integrated Assessments Call for Establishing a Sustainable Meta-Population of Amur tigers in Northeast Asia.” Biological Conservation, vol. 261, 2021, doi.org/10.1016/j.biocon.2021.109250. Accessed 4 Dec. 2024.

Zhao, J., ed. The Natural History of China. New York: McGraw-Hill, 1990.