This month’s biodiversity theme at UBC Botanical Garden is the “Biodiversity of China”, so we’ll begin a week-long series on plants from that floristically-rich part of the world.
Today’s photograph is courtesy of my colleague, Eric La Fountaine. The write-up for today’s entry is largely based on the student work of Adam Underhill, who participated in Dr. David Brownstein‘s Geography 419 course here at UBC, “Research in Environmental Geography”. Thank you to Adam and Eric for sharing! Adam writes:
The common English name of this species is Forrest hemlock; the name given to the species by local Chinese residents is lijiang tieshan. Tsuga forrestii is a tree species in the Pinaceae located solely in China. The species is found in three southwestern Chinese provinces: Guizhou, Sichuan and Yunnan. These areas of China all have relatively moist climates. Tsuga forrestii often dominates its forest stands, although these stands are few and far between.The species is threatened by a significant increase in habitat loss, particularly due to logging.
Tsuga forrestii is described as an evergreen conifer, with flattened needles and silvery white bands beneath the leading shoots. It can grow to 25m (80ft). The bark is grey to brown, scaly and often deeply furrowed, purportedly to protect the plant from predatory birds and insects. The branches are arranged in a flattened pattern, “spraying” outward from the trunk with a slight arch downward. Cones are borne on year-old twigs and seed cones take roughly one year to mature. After maturation, the seeds fall to the ground where they may persist for several years before sprouting. The wood of this species is moderately strong, pliable and lacks resin ducts, making it a candidate for the logging industry. The decline of similar species considered to be of more commercial value in the logging industry has lead timber corporations in pursuit of a new species to fill the void. The most popular use of hemlock wood is in the pulp industry.
There is a very clear and defined relationship between this species and humans. The main threat to this species results directly from human action in terms of logging, manufacturing and urbanization. A study undertaken in the Yunnan province found that there was a significant destruction of biodiversity caused by a loss of habitat due to increased levels of logging. It was determined that, in this particular region, there was a cutting volume of 40 million m3, despite government regulations of 3 million m3 in 1998 and 0.83 million m3 in 2000 (Yang 2004). This significant amount of clearcut logging, coupled with ignoring government regulations, not only removes species from the region but destroys the habitat in which they grow. After this clearcutting takes place, the previous forest is often not given the opportunity to replenish itself. The area is subsequently used for growing cash crops such as rubber, sugar cane and tropical fruits. Another impact of logging is the pollution left behind, from machinery and equipment, that may damage the soil and water table, further restricting a livable area for this species. These factors have led the International Union for Conservation of Nature (IUCN) to classify this species as vulnerable to extinction.
It is clear that measures need to be taken in order to mitigate further problems and preserve this species. The first step necessary for preservation is to strengthen policies on biodiversity conservation as well strict monitoring on logging practices in areas with vulnerable species. The creation of a species database for the region would also be very beneficial as it would allow for proper monitoring of not just Tsuga forrestii, but other vulnerable species in the area. A species database should coincide, in order to be most effective, with a protected area of forest where any human interference, such as logging or farming, is illegal (Yang 2004). The surrounding community also needs to be aware at the local level of the importance of preserving this species; this can be accomplished through various education and advertising programs. The final step in order to mitigate the effects of habitat loss is continued growth of this species is conservation areas whether it be in situ (in the wild) or ex situ. Ex situ sites are important because seeds can be easily gathered, and, if necessary, used to repopulate the wild species (Yang 2004). By growing Tsuga forrestii in various botanical gardens across the world such as UBC, it helps to ensure the species has a fighting chance against extinction.