Logging of Russian Far East damaging tiger habitat, few intact forests protected
Sandhya Sekar, mongabay.com correspondent
August 19, 2014
This is the first part of series examining the impact of forest loss on Siberian tigers.
The forests of the Russian Far East are of the “mixed boreal” type, where East Asian coniferous–deciduous forests and the boreal forests merge. Originally, the forests were a mixture of Korean pine and deciduous species like birch and aspen; in the north and at high elevations, conifers like spruce, fir and larch were found. The mixed boreal forests form one of the most biologically diverse habitats at high latitudes, supporting a unique mix of southern-evolved fauna like the Siberian tiger, Amur leopard (Panthera pardus orientalis) and the Asian black bear (Ursus thibetanus), along with species typical of the northern taiga, like the caribou (Rangifer tarandus) and Ussuri brown bear (Ursus arctos lasiotus).
Scientists estimate only around 400 Siberian tigers (Panthera tigris altaica) exist in the wild today. Photo by Derek Ramsey.
Human activities such as selective logging of economically valuable Korean pine and disturbances like fire have resulted in the conversion of many of the mixed boreal forests into secondary forests of oak and birch. This habitat poorer quality compared than the original mixed boreal composition, and does not support as many herbivores like deer and wild boar; this, in turn, affects apex carnivores like the tiger.
Life history of the Amur tiger
The Siberian or Amur tiger (Panthera tigris altaica) occupies the northernmost areas of all tiger species, with the Korean pine forests of the Russian Far East comprising its favorite habitat. Fewer than 400 adult and subadult Siberian tigers remain, 95 percent of which were reported in the Sikhote-Alin Mountains that run from north to south east of Vladivostok. A population of about 20 tigers has been reported in Southwest Primorsky, close to Russia’s border with China.
“A full range survey is planned for this coming winter, but no full range survey has been conducted since 2005," Dale Miquelle, Director of the Wildlife Conservation Society Russia Program, told mongabay.com. “Most people think numbers have dropped since that time. The 2005 survey had about 120 adult males, 180 adult females, 30 subadults and about 100 cubs.”
The Wildlife Conservation Society has been monitoring over 60 radio-collared tigers in the area since 1992, and uncovered a wealth of information about their natural history. For instance, they found that tigresses need a home range of 250 to 450 square kilometers (97 to 174 square miles), and dispersing young tigers may wander over 200 kilometers (125 miles) in search of their own territories. They feed mainly on red deer, wild boar and sika deer. Tigresses produce an average of 2.4 cubs every 21 months, but researchers found about half of them died before adulthood, often as a result of the poaching of their mothers.
The home range of the Siberian tiger is much larger than that of its close relative, the Bengal tiger. Researchers believe this is because there is less prey available in the Siberian tiger’s higher latitude habitat.
 Forest surrounding the Maximovka River in Primorsky, Russia, where the world's last wild Siberian tigers live. Because of their northern locations, boreal forests support fewer animals than do tropical forests, thus limiting the number of tigers that can live there. |
Hunting of prey by humans is one of the main threats to the tiger population.
“Prey are legally hunted (outside protected areas) and are intensively poached as well,” Miquelle told mongabay.com.
In addition, logging of Russia's boreal forests -- much of it illegal -- is taking a toll on Siberian tiger habitat.
Illegal logging in the Russian Far East and its impact on tigers
Illegal logging is a huge problem in forests around the world, with a 2012 World Bank report pegging the losses in assets and revenue due to illegal logging at $10 billion annually.
According to the forest-monitoring site, Global Forest Watch, Russia lost more than 36.5 million hectares of forest between 2001 and 2013, representing about four percent of the country’s forested area. Estimates by NGOs operating in Russia and Japan found illegal logging was responsible for between 10 and 80 percent of timber harvests, depending on the district.
The U.S. and most countries in the E.U. have banned the import of timber whose legal harvest cannot be verified. However, according to a recent report from the independent NGO Environmental Investigation Agency (EIA), Japan has not taken steps to reduce import of illegal timber. In addition to importing timber directly from Russia, Japan also imports finished wood products through China, many of which were originally sourced from Russian forests.
In a recent report in the journal Eurasian Geography and Economics, Joshua Newell and John Simeone discuss how deforestation in Russia is now driven by a complex set of factors. By tracking forest production and trade data from 1946 to 2012, they were able to demonstrate how Russia is opening up its markets to the world, and that such globalization has increased deforestation. Russian timber trade has become dependent on exports, making wood from Russia a “global resource.” The study also tracked the flow of Russian wood through China to U.S. urban centers.
“Demand in export markets, combined with the spatial fracturing of the industry across the forest landscape and impoverished (and often corrupt) forest management, has led to forest degradation patterns in Russia quite different from that in the Soviet period," writes Sewell.
Intact forest landscapes (IFLs), which are swaths of undisturbed old-growth forest, are critical tiger habitat. Global Forest Watch shows that a significant amount of IFLs still remain in the Russian Far East, many outside protected areas, which are threatened by logging. There has even been a tree cover gain of 279,535 hectares in the region. However, Newell and Simeone warn that there is also a concurrent decline in the “quality” of Russian forests, which involves factors such as tree biodiversity and biomass. Although forest cover in Russia seems to have increased when one simply looks at tree cover, the paper claims this expansion was due to growth on denuded and former agricultural lands.
Overall, Russia lost more than 36.5 million hectares of forest between
2001 and 2013. While old growth intact forest landscapes (IFLs) still
exist in the country, they often do not coincide with protected areas.
Siberian tigers range along a small portion of the far east of Russia,
indicated by a yellow oval. Map courtesy of Global Forest Watch. Click to enlarge.
“The forest succession underway in Russia is the unabated transformation of mature coniferous forests (spruces, pines, firs, and larch) into younger, less commercially valuable deciduous forests (aspen, birch, etc.)," the authors write. “This loss of forest quality is the result of a confluence of anthropogenic disturbances (e.g., forestry, mining, road construction, oil and gas development, and clearing for agriculture) and natural ones (e.g., pest outbreaks and fire).”
So where does this leave the Siberian tiger?
“The majority of Amur tigers live outside protected areas, with the protected areas acting as a type of source site where densities of prey are higher, and reproduction of tigers is greater," said Miquelle in an interview.
According to Miquelle, protecting extant Korean pine forests is a first step, which will help prey species bounce back. Reintroducing prey species and corridors to connect tiger population will also help. In addition, important habitat areas need to be identified, protected, and included in conservation policy.
“A successful tiger conservation strategy in north-east Asia will depend upon creating and effectively managing a core network of protected areas, which are connected to and interspersed with multiple-use lands where tiger conservation is integrated with sustainable use of natural resources by humans.”
Citations:
- Miquelle, D. G., Goodrich, J. M., Smirnov, E. N., Stephens, P. A., Zaumyslova, O. Y., Chapron, G., ... & Quigley, H. B. (2010). The Amur tiger: a case study of living on the edge. Biology and conservation of wild felids. Oxford University Press, Oxford, UK, 325-339.
- Tian, Y., Wu, J., Wang, T., & Ge, J. (2014). Climate change and landscape fragmentation jeopardize the population viability of the Siberian tiger (Panthera tigris altaica). Landscape Ecology, 29(4), 621-637.
- Newell, J. P., & Simeone, J. (2014). Russia’s forests in a global economy: how consumption drives environmental change. Eurasian Geography and Economics, (ahead-of-print), 1-34.
- Environmental Investigation
Agency (2014). The Open Door: Japan’s Continuing Failure to Prevent
Imports of Illegal Russian Timber
An uncertain future: world's last wild Siberian tigers threatened by illegal logging, global warming, disease
August 22, 2014
This is the second part of series examining the impact of forest loss on Siberian tigers.
The very fact that there are Siberian tigers in the world today is something of a miracle. In the 1940s, just 20 animals remained in the wild. Indiscriminate hunting and poaching had nearly wiped out the world’s largest cat. Creation of the 4,000-square kilometer (1,544-square mile) Sikhote-Alin Biosphere Reserve and careful conservation policies have helped the tiger population bounce back. There are now about 400 adult and subadult tigers in the wild.
But the subspecies is not yet on safe ground. According to Wildlife Conservation Society (WCS) Russia, between 20 and 30 tigers are poached every year. Illegal logging is reducing the tigers' habitat, and illegal hunting is reducing its food supply. However, these are not the only threats to wild tiger survival -- other problems are cropping up and taking a toll on the iconic big cat.
Siberian tigers (Panthera tigris altaica) rebounded from a low of 20 in the wild in the 1940s to around 400 today. However, they are still threatened by habitat loss, poaching, and other issues. Photo by Rhett A. Butler.
A population's genetic diversity -- the variety of genes its individuals have -- is like a huge information pool. Simply put, more genetic diversity is a good thing; it gives a population greater ability to cope with stressors like environmental vagaries and disease. In species like the Siberian tiger (Panthera tigris altaica), where an entire population of about 400 came from a set of just 20 “founder individuals,” the genetic diversity is low – very low. In a recent study, scientists examined scat from 95 tigers and found that the genetic diversity in Siberian tigers is the lowest ever documented in wild tigers.
In other species, this can cause abnormalities. For instance, African cheetahs have sperm abnormalities and the Florida panther has kinked tails, both indicative of low genetic diversity. Physical deformities have not been observed in the Siberian tiger as of now, but this may change with future generations. The same study found that Siberian tigers exist in two populations: the majority live in the Sikhote-Alin mountains, and about 20 live in Southwest Primorye, near Russia’s border with China. There is hardly any connectivity between the two populations, making interbreeding between them unlikely.
However, some studies have shown traces of connectivity between Chinese and Russian Siberian tigers.
“We have a monitoring platform using camera-traps in Northeastern China, along the boundary between China and Russia”, said Yu Tian from the Chinese Research Academy of Environmental Science at Beijing. “We have proof such as footprints based on snow field surveys and photographs based on infrared cameras, to show that tigers are moving between China and Russia.
“Based on our monitoring along the boundary, we have seen that tiger movements between China and Russia are more frequent after the Chinese Grain for Green Program, which would support the tiger’s prey for long term,” she added. Through the program, 8.2 million hectares of cropland in China were reconverted to forest, according to a report from the China Policy Institute in the UK.
However, deforestation is occurring in Primorsky, which may be further reducing their habitat and barring genetic exchange between the animals. According to the forest-monitoring site Global Forest Watch, the Sikhote-Alin Mountains and surrounding areas encompassing tiger range lost approximately 550,000 hectares of forest between 2001 and 2013, which represents about two percent of the area’s tree cover. Deforestation has occurred both within and outside intact forest landscapes, and within and outside protected areas. Much of the forest loss has come about to illegal logging, which is rampant in the region. A 2002 report from WWF Russia estimates 50 percent of timber from Primorky -- one of the main timber sourcing areas of the Russian Far East -- was harvested illegally. Conserving these forests to encourage tiger movement and increase prey populations is crucial in conserving the tiger long term.
Primorsky Krai (circled) holds the world's last Siberian tigers. Yet,
the area is the biggest source of timber in the Russian far east, much
of it harvested illegally. Between 2001 and 2013, Primorsky and its
surrounding area lost about 550,000 hectares -- or two percent -- of its
forests. Map courtesy of Global Forest Watch.
A satellite image of a portion of Siberian tiger range denuded of trees. Courtesy of Global Forest Watch.
The added threat of climate change
Historically, Amur tiger habitat would have extended over a greater area than what is seen now. A recent study using a technique called “niche modeling” has shown that potential tiger habitat included a large area in the southeastern Russian Far East and some patches near the border between North Korea and Northeastern China. Niche modeling uses information regarding sightings of tigers, including tiger signs like pug marks and scat, to determine parameters that define the preferred habitat of a species. These parameters, like temperature, precipitation, humidity, forest cover, etc., are available as global datasets. Using the coordinates of different sightings, areas that fit the criteria required by a species are marked as potential habitat.
Today’s highest quality habitat for Siberian tigers is in the Sikhote-Alin Mountains and the southeastern coastal area of the Russian Far East. Suitable habitat in China and North Korea were found to be small, fragmented and of relatively low quality. Regions with high human density and disturbance do not make suitable habitat for the Siberian tiger, indicating that one of the main requirements for habitat, apart from climate and topography, was low human density.
Because of climate change, researchers predict the Russian Far East will become less suitable for tigers, with their preferred Korean pine forest cover replaced by spruce and fir trees as the region warms. These forests are not high-quality habitat for tigers as prey densities are usually low. Because of these trends, some models predict Siberian tigers could be extinct in the wild within a century.
In addition to the collateral damage of climate change, prime tiger habitat is also threatened directly by human impacts. For instance, selective logging of Korean pine, a highly sought-after market species, is thinning the tiger’s preferred type of forest in some areas.
Emerging disease
In 2001, reports started coming in of Siberian tigers behaving unusually and entering human habitations and roadways, which they usually avoid. Morbillivirus, a group of viruses that includes distemper, was detected in Siberian tigers in 2004; there has also been a sudden decline in tiger numbers in the Russian Far East since 2009. This led to concerns that canine distemper virus could be affecting the Siberian tiger; in response, researchers set out to determine if Siberian tigers are being affected by disease. Their results were published in MBio in 2013.
The research team examined tissue collected from necropsies of five adult, free-ranging tigers. All tigers were encountered in the wild when they were disoriented and losing control of their nervous systems, both characteristic symptoms of a distemper infection. Tissue analysis and genetic tests both confirmed that the tigers had contracted distemper. The genetic makeup of the virus strain that had infected the tigers was similar to strains commonly seen in the Arctic region, as well as to those from China, Russia, Greenland and the United States.
 Siberian tiger range and locations of confirmed distemper infection. Image courtesy of Seimon et al., 2013. |
While five dead animals may seem like a low number, it represents a big toll on such a small population -- the authors estimate distemper killed off about one percent of wild Siberian tigers in 2010. Their results indicate the disease is widespread in the Russian Far East as the five tigers used for the study were from different territories spread over a large portion of the region. And while it remains unclear when exactly CDV started affecting tigers, evidence points to a fairly recent emergence.
“Our results, which include mapping the location of positive tigers and recognition of a cluster of cases in 2010, coupled with a lack of reported CDV antibodies in Amur tigers prior to 2000 suggest wide geographic distribution of CDV across the tiger range and recent emergence of CDV as a significant infectious disease threat to endangered Amur tigers in the Russian Far East,” the authors write.
Habitat loss, a small gene pool, disease, poaching – Siberian tigers cling to existence amidst a suite of interconnected problems. However, NGOs, government agencies, and scientists around the world are working to save the species through efforts such as monitoring programs, proposed introductions to less-disturbed areas, and policies aimed at curtailing demand for illegally harvested wood.
As Dale Miquelle, Director of the Wildlife Conservation Society Russia Program, and colleagues write in their 2010 book, “…there is sufficient reason for optimism that this northernmost representative of Pa. tigris will continue to roam the forests of north-east Asia, interacting with natural prey and exposed to the full spectrum of natural forces that it has survived in for so long, if humans can provide the minimum requirements of space, undisturbed habitats, and freedom from direct human persecution.
“It is a simple recipe, if we have the collective societal will to make it happen.”
Citations:
- Miquelle, D. G., Goodrich, J. M., Smirnov, E. N., Stephens, P. A., Zaumyslova, O. Y., Chapron, G., ... & Quigley, H. B. (2010). The Amur tiger: a case study of living on the edge. Biology and conservation of wild felids. Oxford University Press, Oxford, UK, 325-339.
- Tian, Y., Wu, J., Wang, T., & Ge, J. (2014). Climate change and landscape fragmentation jeopardize the population viability of the Siberian tiger (Panthera tigris altaica). Landscape Ecology, 29(4), 621-637.
- Seimon, T. A., Miquelle, D.
G., Chang, T. Y., Newton, A. L., Korotkova, I., Ivanchuk, G., ... &
McAloose, D. (2013). Canine Distemper Virus: an Emerging Disease in Wild
Endangered Amur Tigers (Panthera tigris altaica). mBio, 4(4),
e00410-13.
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