Tsuga canadensis, also known as eastern hemlock, eastern hemlock spruce, or canadian hemlock, and in the frenchspeaking regions of canada as pruche du canada, is a coniferous tree native to eastern north america. Charles goebel, the foundation species influence of eastern hemlock tsuga canadensis on biodiversity and ecosystem function on the unglaciated allegheny plateau, forest ecology and management, 289, 143, 20. Forest ecology and management montclair state university. It is shade tolerant and has a high moisture requirement for establishment. Forest ecology and management vol 460, 15 march 2020. An integrated management approach is needed to maintain eastern hemlock tsuga canadensis l. As a result, hardwood forests in oregon are not uniform, but. Forest dynamics following eastern hemlock mortality in the. Current distribution 2011 of hemlock woolly adelgid in the eastern us. Hemlock trees are important parts of northeastern forest ecosystems. Methods as part of a longterm research program addressing the impacts of the hemlock woolly adelgid on eastern hemlock, we characterized adelgid infestation level and stand vigor in 79 stands in ct and 63 stands in ma. Executive summary eastern hemlock tsuga canadensis is a very important evergreen coniferous tree species native to ohio. Carriere forest of the acadian forest region of northeastern north america. Forest ecology and management 385 2017 150160 contents lists available at sciencedirect forest ecology and management.
Elsevier forest ecology and management 149 2001 197204 forest ecology and management effects of the removal of overstory hemlock from hemlock dominated forests on eastern redback salamanders robert t. Plants profile for tsuga canadensis eastern hemlock. The hemlock woolly adelgid hwa, adelges tsugae annand is currently causing a severe decline in vitality and survival of eastern hemlock in north american forests. The eastern hemlock project aims to document remnant hemlock forests in southern ontario and encourage citizen engagement in their stewardship. Ller,2 and david orwig 3 1bayreuth institute for terrestrial ecosystem research, university of bayreuth, 95440 bayreuth, germany. It may take 250 to 300 years to reach maturity and may live for 800 years or more. The terms old growth and virgin may have various definitions and meanings throughout the world. Habitat rich in biodiversity, eastern hemlock forests are habitat for more than 120 different species, including. The role of eastern hemlock as a foundation species in eastern north american forests is under threat due to invasion by an exotic forest herbivore, the hemlock woolly adelgid hwa. The forest floor in hemlock groves tends to be more open than in other parts of the forest and the temperature difference that hemlocks create is apparent. The bark of eastern hemlock is rich in tannin and was once one of the main commercial sources for the leather industry. Eastern hemlock is also dominant in several popular outdoor recreation and tourist areas in ohio. The eastern forestboreal transition is a temperate broadleaf and mixed forests ecoregion of north america, mostly in eastern canada.
The bark of eastern hemlock is rich in tannin and was once one. We are indebted to the participants of the hemlock forest ecosystem best management practices. A new species, tsuga ullengensis which occurs on ulleung island in korea was delineated in 2017 by holman et al. Hampshire, in june 1999, and the hemlock woolly adelgid in the eastern united states. Eastern hemlock forests national wildlife federation. Native to the eastern united states, the hemlock resembles a large christmas tree with its broadly pyramidal, pendulous branches. Eastern hemlock tsuga canadensis, also called canada hemlock or hemlock spruce, is a slowgrowing longlived tree which unlike many conifers grows well in shade. Direct and indirect ecosystem consequences of an invasive. Mast produced by american beech is a critical source of food for various forest wildlife species. Since then it has spread to 18 states, causing the widespread decline and mortality of eastern hemlock hereafter referred to simply as hemlock. The importance of hemlocks hemlock restoration initiative.
Relationships of eastern hemlock tsuga canadensid to the ecology of small. Guidelines to minimize the impacts of hemlock woolly adelgid find, read and cite all the research you need on researchgate. The hemlock woolly adelgid is highly invasive in eastern north america,where naturalenemies areunable to regulatepopulations wallace and hain, 2000 and eastern hemlock tsuga canadensis is especially susceptible mcclure, 1992. Methods in ecology and evolution 2010, 1, 168179 doi. Although moderately low in bending strength and shock resistance, eastern hemlock can be used in construction for light framing, sheathing, subflooring, and roofing. In the allegheny national forest in pennsylvania, the eastern hemlock northern hardwoods forest type covered 83. Hwa feeding causes slow death of trees, and its characteristic white cottony appearance is easily visible on infected trees. Gis analysis identifying potential hemlock ecological. Eastern hemlock is very susceptible to fire because of its thin bark, shallow roots, lowbranching habit, and heavy litter deposits 20,51. It is possibly the most firesensitive mesophytic tree species in its range. Relating eastern hemlock tsuga canadensis ecosystem. Similar forests are known from the great lakes region and the northeastern united states and range as far south as the southern blue ridge of north. The hemlock s shallow root system excels along riparian corridors, where the soil remains moist throughout the year. Hemlock may take 250 to 300 years to reach maturity and may live for 800 years or more.
In the eastern half of north america, the eastern and carolina hemlocks are under. Nov 05, 2012 the eastern hemlock tsuga canadensis is a longlived coniferous tree native to eastern north america. Though eastern hemlock tsuga canadensis is a well documented. Part 2 provides guidelines to help managers make decisions about the salvage and rehabilitation of damaged hemlock stands in order to recover, to the extent possible, the ecological and esthetic attributes associated with hemlock forests. Eastern hemlock is a foundation species in eastern north america and is prominent in riparian areas throughout central and southern appalachia vandermast and van lear, 2002. Response of arthropod biodiversity to foundation species declines.
Effects of the removal of overstory hemlock from hemlock. The plight of the hemlock in eastern forests forest history society. Vegetation and invertebrate community response to eastern. Numerous patches of hemlocknorthern hardwood forest are known from the catskill mountains, the shawangunk mountains, the hudson highlands, the rensselaer plateau, the adirondack mountains, the southern finger lakes region, and the river valleys that flow into lake erie in. Eastern hemlock tsuga canadensis is an iconic tree species in. Recent declines in the vitality of hemlock populations due to invasive pests pose a serious threat to the future. The sustainability of both eastern hemlock and the southern appalachian species carolina hemlock tsuga caroliniana engelm. The girdled trees died over the course of the next two and a half years, a rate similar to hemlock. One of the more shadetolerant evergreens, the eastern hemlock has many uses as a specimen, sheared as a hedge, or planted for screening. Eastern hemlock the wood of eastern hemlock is moderately light in weight, moderately hard, coarse grained, uneven in texture, and inclined to splinter when machined. Specifically, we tested the relative influence of tree species, tree size, neighborhood crowding, withinneighborhood species composition, and soil moisture on individual tree growth and mortality rates. The record of forest invasion by eastern hemlock tsuga canadensis during the course of holocene migration provides useful information about invasion processes in temperate forest, a system that has been invaded by few exotic species. Eastern hemlock is ecologically and economically important in the northeast dukes et al.
Forest ecology and management 315 2014 2229 contents lists available at sciencedirect forest ecology and. It is commonly planted as a landscape tree throughout the state, and grows in natural forest stands, mainly in the eastern half of ohio. In the northern hardwood forest, it is found on a greater variety of. Tsuga canadensis eastern hemlock pinaceae lake forest college. Physiological responses of eastern hemlock tsuga canadensis to light, adelgid infestation, and biological control. These shadetolerant trees form dense canopies that provide cool refuge for fish and other wildlife. Eastern hemlock tsuga canadensis, also called canada hemlock or hemlock spruce, is a slowgrowing longlived tree which unlike many trees grows well in shade. As a foundation species, eastern hemlock has a major influence on forest structure and functional processes. This is a list of existing oldgrowth virgin forests, or remnants of forest, of at least 10 acres 4. Physiological responses of eastern hemlock tsuga canadensis.
Mar 21, 2019 eastern hemlock tsuga canadensis, also called canada hemlock or hemlock spruce, is a slowgrowing longlived tree which unlike many conifers grows well in shade. Following its 1951 introduction in virginia there was a lag time of approximately 30 years with minimal range. In northeastern temperate forests, an exotic forest insect, the hemlock woolly adelgid adelges tsugae. Hemlock foliage is an important source of food and shelter in eastern forests, particularly in winter when hardwood trees are dormant. In this guided inquiry, students investigate the inhibitory effects of eastern hemlock trees on establishment of neighboring woody plants. Forest ecology and management college of agriculture. Forest ecology and management 335 2015 110 contents lists available at sciencedirect forest ecology and management journal homepage. The eastern hemlock tsuga canadensis is a longlived coniferous tree native to eastern north america. This community is currently known from across the state north of the coastal plain. Effects of eastern hemlock tsuga canadensis on the. Elsevier forest ecology and management 149 2001 197204 forest ecology and management effects of the removal of overstory hemlock from hemlockdominated forests on eastern redback salamanders robert t. Numerous patches of hemlock northern hardwood forest are known from the catskill mountains, the shawangunk mountains, the hudson highlands, the rensselaer plateau, the adirondack mountains, the southern finger lakes region, and the river valleys that flow into lake erie in. Wildlife habitat associations in eastern hemlock northern. The girdled trees died over the course of the next two and a.
Both fs, however, are recognized as species of importance to forest communities and have inspired the formation of several advocacy groups table 2. Neither eastern hemlock nor whitebark pine are currently listed as endangered in the united states, although whitebark pine is listed in canada and being evaluated for u. Tea from the inner bark was prescribed for colds, fevers, diarrhoea, stomach troubles and scurvy. Pdf eastern hemlock tsuga canadensis is a shadetolerant tree of. First, students travel to the study area hope college biology nature preserve a 50 acre parcel of beechmaple dune forest and observe spatial distribution. The range of eastern hemlock extends from southeastern canada to georgia and alabama in the south and as far west as minnesota. Hemlock woolly adelgid biology and management in the. In the more southern parts of its range, eastern hemlock occurs only where there is drainage of cool, moist air on moist rocky ridges, valleys and ravines, hillsides, and lakeshores. It is a transitional zone or region between the predominantly coniferous boreal forest and the mostly deciduous broadleaf forest region further south. Early forest harvesting at the time of european settlement in eastern north american hardwood forests c. Eastern hemlock is particularly common in riparian areas. Tirpak, chris nagy and rod christie, structural and compositional change in an oldgrowth eastern hemlock tsuga canadensis forest, 19652004.
United states, dc, washington, usda ars national arboretum. Most are found in asia, while north america is home to four and the southern appalachian mountains are home to two of these. All tsuga species occur at roughly the same latitude. Eastern hemlock wisconsin department of natural resources. Eastern hemlock usda forest service southern research. Forest service forest inventory analysis plots grey shading and spread of the hemlock woolly adelgid adelges tsugae since its initial introduction into virginia in 1951 polygons, based on data compiled by the u. Pdf on may 1, 2004, ward and others published eastern hemlock forests. As a result, hardwood forests in oregon are not uniform, but vary by location, environment and stand history. Forest ecology and management department of forest. Extensive harvesting, fire, and overbrowsing are responsible for the decline 64. Relating eastern hemlock tsuga canadensis ecosystem services.
Beech and hemlock dominate a large fraction of the latesuccessional forests of the eastern united states fig. Gary lovett, both of the cary institute of ecosystem studies, and dr. The case of the eastern hemlock article pdf available in forest ecology and management 2587. Implications for hemlock restoration chelcy ford miniat, david r. Acer saccharum marshall and eastern hemlock tsuga canadensis l. Hemlocknorthern hardwood forest guide new york natural. Distribution of eastern hemlock tsuga canadensis in eastern north america, based on u. Forest ecology and management 260 2010 16771688 contents lists available at sciencedirect forest ecology and management. We used fossil pollen preserved in small forest hollows, which record forest composition on the scale of ha, to study hemlock invasion of forests in the.
Brisbin, research forester northeastern forest experiment station usda forest service upper darby, pa. Part 1 presents the biology and ecology of eastern hemlock and hwa. We used fossil pollen preserved in small forest hollows, which record forest composition on the scale of ha, to study hemlock invasion of forests in the sylvania wilderness in the upper peninsula of michigan, where there is now a mosaic of 330 ha stands dominated either by hemlock or by sugar maple acer saccharum and basswood tilia. Oregon has many species of broadleaf trees hardwoods, but generally they occur as individuals and in small stands, rather than in expansive forests as they do in the eastern united states.
In the southern appalachians, hemlock woolly adelgid adelges tsugae annand, hwa infestation has had substantial ecological and social e. Similar forests are known from the great lakes region and the northeastern united states and range as far south as the southern blue ridge of north carolina and tennessee. Michael henry, author of ontarios oldgrowth forests, offers occasional presentations about eastern hemlocks ecology, history, and future, and about oldgrowth forests. Eastern hemlock usda forest service southern research station. First, students travel to a mixedstand hemlock, beech, and maple forest and observe spatial distribution patterns of woody seedlings beneath these three species. The hemlock woolly adelgid hwa, adelges tsugae, is one of the most damaging nonnative insects in north america, responsible for the death of millions of eastern hemlock trees throughout the eastern part of the continent. Karl forest ecology and management xxx 2010 xxxxxx 3 accompany their rapidly growing reservation population, but on the nhal, forestland development is strictly limited. In the simulated hwa treatment, all hemlock trees, from small seedlings to mature trees, were girdled using knives or chainsaws in early may 2005 ellison et al.
Pdf response of arthropod biodiversity to foundation. Although growth is very low for eastern hemlock, removals are even lower. The bark was also used in poultices to slow bleeding. We analyzed the effects of light hwa infestation on vertical energy and nutrient. Harvard forest, each of which were helpful in characterizing the current state of knowledge of hemlocks ecosystem roles. Tsuga canadensis, also known as eastern hemlock, eastern hemlockspruce or canadian hemlock, and in the frenchspeaking regions of canada as pruche du canada, is a coniferous tree native to eastern north america. Forest ecology and management 460 2020 117903 03781127 published by elsevier b. Eastern hemlock grows from about sea level to 1500 meters. At least ten distinct species of hemlock exist in the world today. Tirpak, chris nagy and rod christie, structural and compositional change in an oldgrowth eastern hemlock tsuga canadensis forest, 19652004, forest ecology and management, 231, 114, 2006.
Eastern hemlock hardwood forests forests of this group are or were characterized by the dominance or codominance of eastern hemlock tsuga canadensis in nearly every vertical stratum. The ratio of average annual growth to removals is 2. David orwig, of harvard forest, each of which were helpful in characterizing the current state of knowledge of hemlocks ecosystem roles. The adelgid is a xylem feeding insect native to asia that feeds on all tsuga spp. Widespread infestation of the region during the 2000s led to rapid eastern hemlock tsuga canadensis l. Forest managers are tasked with maintaining andor promoting. Map provided by the us forest service, northeastern area state and private forestry. Eastern hemlock usually escapes fire because it occurs in moist habitats and is often associated with hardwoods which do not readily burn.