Where is the tree line?
In Southwestern United States like Arizona, New Mexico, and Nevada, the tree line is categorized at the point where the most extreme amounts of rainfall and temperature are sufficient for tree growth.
What happens at the tree line of a forest?
At the tree line, tree growth is often sparse, stunted, and deformed by wind and cold krummholz (German for "crooked wood"). The tree line often appears well-defined, but it can be a more gradual transition. Trees grow shorter and often at lower densities as they approach tree line, above which they cease to exist.
Why is the tree line lower on the coast?
Tree line. Exposure tree-line On coasts and isolated mountains, the tree-line is often much lower than in corresponding altitudes inland and in larger, more complex mountain systems, because strong winds reduce tree growth.
What are the characteristics of the tree line?
At the tree line, tree growth is often sparse, stunted, and deformed by wind and cold. This is sometimes known as krummholz (German for "crooked wood"). The tree line often appears well-defined, but it can be a more gradual transition. Trees grow shorter and often at lower densities as they approach the tree line,...
Worldwide distribution
Long-term monitoring of alpine treelines
Where is the tree line in Colorado?
Alpine tree lines vary greatly across the world, especially in areas north of 30 degrees north or south of 20 degrees south in latitude. In Colorado, tree line is around 11,500 feet.
Where is the tree line in Canada?
NWT Focus. The NWT is home to the northern range of boreal forest in Canada, and contains a large extent of treeline.
At what latitude is the tree line?
The tree line is the elevation at which trees stop growing-either because of the low temperatures, or lack of pressure and moisture. Tree lines are pretty consistent between the latitudes of 30°N and 20°S. But the farther away, the lower the tree line gets.
Where is the tree line in UK?
The tree line is therefore of generally low altitude in Scotland, by comparison with other mountains at similar latitudes. The exact position of this limit varies, however, across the country.
Is the tree line moving north?
Scientists say they have evidence the tree line is moving farther north. They say they've found shrubs in arctic Alaska are growing bigger, and they're showing up in previously barren areas. The scientists compared aerial photographs taken 50 years ago with recent pictures.
Why can't trees grow above the treeline?
Trees don't grow above the timberline because of high winds, low moisture, and cold temperatures.
At what altitude does the tree line end?
The tree line is present at about 4,800 feet in elevation, but it can be lower in other areas.
What elevation does the tree line stop?
Tree line in the Southern Rockies in New Mexico is about 12,000 feet. In Colorado tree line is at around 11,000 to 12,000 feet. The Tetons in Wyoming have a tree line around 10,000 feet elevation.
How high is the tree line in UK?
In England this is generally found above 600 m, although the precise altitude of the potential tree-limit varies across the country and depends on local variations in temperature, shelter and humidity (Pearsall 1950; Ratcliffe 1977; Ratcliffe & Thompson 1988).
Why are there no trees on mountains in UK?
1) We have no climatic treeline to speak of (insufficient altitude & latitude). 2) Trees disappeared 6000 years ago probably mainly because of climatic deterioration, and the subsequent development of blanket peat bogs in the wetter conditions.
What height is the tree line in Scotland?
Today, Scots pine grows as high up the hills as any forest tree. At Creag Fhiaclach (see page 9), the pine treeline is almost 650 metres (2,100 feet) above sea level, although the timberline is 150 metres.
Is Iceland above the tree line?
It's not. We rather like to blame the sheep. Around the time Iceland was settled, over 1100 years ago, the land was covered with birch trees. Not all of it, but around 25-40%, according to the Icelandic forest service.
What is the tree line?
The tree line is the edge of the habitat at which trees are capable of growing. It is found at high elevations and high latitudes. Beyond the tree line, trees cannot tolerate the environmental conditions (usually cold temperatures, extreme snowpack, or associated lack of available moisture). The tree line is sometimes distinguished ...
How many metres is the tree line?
Between 30°N and 20°S, the treeline is roughly constant, between 3,500 and 4,000 metres (11,500 and 13,100 ft). Here is a list of approximate tree lines from locations around the globe: At 71°N, near the coast, the tree-line is below sea level (Arctic tree line).
Why are trees in Hawaii so low?
In some mountainous areas, higher elevations above the condensation line, or on equator-facing and leeward slopes, can result in low rainfall and increased exposure to solar radiation. This dries out the soil, resulting in a localized arid environment unsuitable for trees. Many south-facing ridges of the mountains of the Western U.S. have a lower treeline than the northern faces because of increased sun exposure and aridity. Hawaii's treeline of about 8,000 feet is also above the condensation zone and results due to a lack of moisture.
What is the highest elevation that sustains trees?
An alpine tree line is the highest elevation that sustains trees; higher up it is too cold, or the snow cover lasts for too much of the year, to sustain trees. The climate above the tree line of mountains is called an alpine climate, and the terrain can be described as alpine tundra.
What is the term for a tree that is stunted by wind?
At the tree line, tree growth is often sparse, stunted, and deformed by wind and cold. This is sometimes known as krummholz (German for "crooked wood"). The tree line often appears well-defined, but it can be a more gradual transition.
Why are desert trees lower on poles?
The desert tree line tends to be lower on pole-facing slopes than equator-facing slopes, because the increased shade on the former keeps them cooler and prevents moisture from evaporating as quickly, giving trees a longer growing season and more access to water .
Why are alpine trees stunted?
The foreground shows the transition from trees to no trees. These trees are stunted in growth and one-sided because of cold and constant wind.
Why is the tree line lower in mountains?
Exposure tree-line On coasts and isolated mountains, the tree-line is often much lower than in corresponding altitudes inland and in larger, more complex mountain systems, because strong winds reduce tree growth.
What are alpine tree lines?
Alpine tree-lines. The alpine tree-line at a location is dependent on local variables, such as aspect of slope, rain shadow and proximity to either geographical pole. Given this caveat, here is a list of average tree-lines from locations around the globe : Higher in the southern side of the Alps.
Why are trees stunted and one sided?
The foreground shows the transition from trees to no trees. These trees are stunted and one-sided because of cold and winds. The tree-line or timberline is the edge of the habitat at which trees can grow. Beyond the tree-line, they are unable to grow as conditions are ...
What is the edge of the habitat at which trees can grow?
The tree-line or timberline is the edge of the habitat at which trees can grow. Beyond the tree-line, they are unable to grow as conditions are too bad.
What is a desert tree line?
Desert tree-line The places where trees cannot grow as there is too little rainfall.
How are polar tree lines influenced?
Like the alpine tree-lines shown above, polar tree-lines are heavily influenced by local variables such as aspect of slope and degree of shelter; trees can often grow in river valleys at latitudes where they could not grow on a more exposed site. Maritime influences such as ocean currents also play a major role in determining how far from the equator trees can grow. Here are some typical polar treelines:
Do swamps have tree lines?
However, no such line exists for swa mps, where trees, such as Bald cypress and the many mangrove species, are adapted to growing in permanently waterlogged soil. Severe winter climate conditions at alpine tree-line causes stunted krummholz growth. Karkonosze, Poland.
Where are alpine tree lines found?
Alpine tree lines are found at extreme altitudes beyond which trees cannot survive and is usually found on mountains. The climate found beyond the alpine tree line is known as the alpine climate with terrain called alpine tundra.
What is the stretch where a tree transitions from a distance to a clear boundary?
The stretch where this transition happens when viewed from a distance seems to be a clear boundary is known as a tree line.
What are the causes of tree lines?
Several studies have linked human activity to the occurrence of tree lines in numerous locations all over the world. Pollution is the biggest artificial factor that limits tree growths and therefore causing tree lines. The Kola Peninsula tree line in Russia is a perfect example and is linked to the presence of the nearby copper smelter which is one of the largest in Russia and is responsible for emissions of many pollutants majority of which contaminate the neighboring forests, inhibiting the growth of trees. Deforestation is another artificial cause of tree lines where vast tracts of forests are cleared for the human activity which cuts off the growth of trees in such areas.
What are the factors that inhibit the growth of trees beyond the alpine tree line?
There are two main factors that inhibit the growth of trees beyond the alpine tree line: the decreasing air temperature (which can be about 2 degrees per 1,000 feet of elevation) and the presence of snow and ice which affects the biological functions of trees.
What are the elements that affect the tree line?
The tree line is evident in locations where the elements of temperature, soil type, topography, precipitation, snow, altitude, and the wind have a profound effect on the environment. Tree lines are classified according to the locations where they are found.
Is the alpine tree line clear cut?
The alpine tree line is not a clear-cut boundary as seen from a distance and one will find sparse tree growth in scattered areas of the tundra terrain. Alpine tree line can also be evident in leeward facing slopes of mountains which have minimal rainfall.
What is the treeline?
The treeline marks the limit of trees latitudinally on continental plains and altitudinally on highlands and mountains (where it is sometimes called the timberline). Tree species still occur beyond this limit, but in shrub form, extending to the "tree-species line.".
How is the treeline controlled?
The treeline is controlled by CLIMATE in interaction with SOIL. In the North, it is correlated generally with the modal (most common) position of the southern edge of the arctic front in summer, and with such temperature indices as the July 10°C isotherm. The treeline is controlled by CLIMATE in interaction with SOIL.
What are the treeline species?
Trees of the Treeline. Characteristic treeline species are alpine fir, whitebark pine and alpine larch in the Rocky Mountains; in Alaska and northern Canada, co-existing black spruce, white spruce and larch. Similar species of spruce and larch, with pine and birch, continue the circumpolar treeline across Eurasia.
Why do conifers shift?
Climatic changes can cause abrupt shifts in the treeline, because seed production and survival of seedlings are precarious near the limit of trees. The conifers are also susceptible to fire during dry periods, and this and cutting by humans make today's treeline a diffuse and unstable boundary.
What is a tree line?
What Is Tree Line? As I said above, tree line is simply the point above which trees can’t survive and grow. When you go higher on a mountain it becomes harder and harder for trees to survive. As a result you tend to see fewer species of trees, which also begin to grow shorter and shrubbier.
Why is the tree line not the same?
Remember the reason tree line exists is because above some point trees simply can’t survive. Tree line is not a straight line that runs around a mountain. In other words, it is not an abrupt transition from trees to no trees.
What Causes Tree Line?
There is a lot that comes into play, but basically at some point the climate (the weather in an area over the year) is just too harsh for trees to survive. It is a combination of things including too cold, too short of a growing season, too much snow and ice, too windy, or not enough moisture.
How high is the tree line in the Rocky Mountains?
What Elevation Is Tree Line In The Rocky Mountains. Tree line in the Southern Rockies in New Mexico is about 12,000 feet. In Colorado tree line is at around 11,000 to 12,000 feet. The Tetons in Wyoming have a tree line around 10,000 feet elevation.
What is the tree line in Wyoming?
Majestic Grand Teton National Park in Wyoming. Tree line is an elevation in mountains above which trees simply do not grow. Here is a more detailed explanation of what it is in the Rocky Mountains.
Why does the tree line decrease as you move north?
This is because as you move north in latitude the climate becomes colder, making it harder for trees to survive. Tree line in Glacier National Park, in northern Montana, is quite low.
How high is the Tetons tree line?
The Tetons in Wyoming have a tree line around 10,000 feet elevation.
What is the Arctic tree line?
Arctic tree line is the northern limit of tree growth; the sinuous boundary between tundra and boreal forest; beyond which the climate is too harsh for trees to grow. It circles all of earth’s northern landmasses for more than 13000 kilometers. It is the largest ecological transition zone on the planet’s surface—a fuzzy boundary that actually loops north and south, and may appear gradual or sharp, depending on locale; It is taken by many to delineate the actual southern boundary of the Arctic zone. Past and recent changes in the position of the arctic tree line and spatial structure of nearby forests are indicators of climate change.
How long has the Arctic tree line been stable?
The position of the arctic tree line remained rather stable across the northern hemisphere from 3500 years BP to the present. Studies of northern circumpolar tree line have related tree distribution to numerous environmental controls, such as permafrost, moisture, heat, radiation, and frontal circulation patterns (Barry, 1967; Bryson, 1966; Hare and Ritchie, 1972; Hustich, 1966; Larsen, 1989).
Where is the tree line?
The tree line is the longest ecological transition zone on earth’s surface, circling through the northern landmasses of North America and Eurasia for some 8,300 miles. Here, the region beyond the trees is in red. At bottom right is Alaska, where researchers are now working in the area just beyond the arctic circle.
What is the northern tree line?
It is the largest ecological transition zone on the planet’s surface—a fuzzy boundary that actually loops north and south, and may appear gradual or sharp, depending on locale.
How old is the tree in the Boelman study?
Trees grow very slowly here; this one that Boelman is examining is about 15 years old. Image via Kevin Krajick.
Where are the last little trees in Fairbanks?
Midway through the mountains, scattered spruces cling only to valley bottoms; further upslope is tundra, covered only with low-lying plants. At about 320 miles from Fairbanks, you pass the last little trees.
What temperature do trees grow in?
The main one is heat; trees generally are viable only where the mean growing-season temperature is above about 6.4 degrees C (about 43.5 degrees F). But that is not the whole answer, said Griffin.
How far on the arctic circle do you pass?
About 200 miles on, you pass the arctic circle, beyond which the sun never sets in midsummer, nor rises in midwinter. Eventually, the trees thin out, and look scrawnier. The rolling landscape rises into big mountains, and you are threading through the bare, razor-edged peaks of the Brooks.
When will the tundra be converted?
Some models predict that half the current tundra could be converted by 2100, though others say the process would be much slower. On the other hand, some studies assert the trees are actually retreating in areas, as heat dries forests, helping invasive insects and fires to destroy growing areas.
What is the treeline in the NWT?
This indicator measures the position of treeline in the NWT. There have been many attempts to define treeline in northern Canada. The recently adopted treeline definition used by the NWT is of a forest that contains at least 25% crown closure and is at least 5 meters tall at maturity.
What is the new treeline?
The new standard treeline is defined as the extent of forestlands pertinent to reporting under the Kyoto Protocol. The details of the definition were agreed to within the framework of the Marrakech Accord and are reported by the Canadian government under its obligations as a signatory to the Kyoto Protocol. For the first time, the treeline has been surveyed in the NWT using this standard.
What factors affect treeline position?
Factors that could affect treeline position in the future are changing temperature and precipitation patterns. Different site conditions can favour more rapid growth or cause tree mortality in some forest communities at the treeline Trees migrate very slowly and dispersal of seeds is often measured in tens of meters. As well, vegetative expansion moves at a rate of meters per year. The effects of climate change on the treeline in the NWT are not yet well understood.
How has the treeline changed since the last glaciation?
The position of the treeline has changed since the end the last glaciation period. The cold waters of Hudson Bay have an important impact on the current location of the treeline on the barrens. Cool temperatures have slowed the advance of tree species near the Hudson Bay, and warm waters from the Mackenzie River havecreated conditions for tree growth all the way to Inuvik and the Coppermine River.
Where is the NWT?
The NWT is home to the northern range of boreal forest in Canada , and contains a large extent of treeline. The current position of the treeline has management implications for reporting on forest cover and carbon accounting in Canada.
Why is the baseline indicator important?
This baseline indicator is useful for any researchers looking to fix a foundation or baseline on the landscape to watch for the effects of a changing climate on the treeline. As they grow, trees take huge amounts of carbon out of the atmosphere, contributing to a reduction in the effects of greenhouse gas emissions. This indicator tracks changes in the extent of the taiga, an important carbon-regulating ecosystem 1.
Is the treeline changing in Alaska?
Scientists are predicting that the treeline will advance north with rising temperatures. The treeline in Alaska 1 and in Yukon 2 is changing, but in complex ways, as trees are showing more growth in some areas, and dying in others.
Overview
The tree line is the edge of the habitat at which trees are capable of growing. It is found at high elevations and high latitudes. Beyond the tree line, trees cannot tolerate the environmental conditions (usually cold temperatures, extreme snowpack, or associated lack of available moisture). The tree line is sometimes distinguished from a lower timberline or forest line, which is the line below whi…
Types
Several types of tree lines are defined in ecology and geography:
An alpine tree line is the highest elevation that sustains trees; higher up it is too cold, or the snow cover lasts for too much of the year, to sustain trees. The climate above the tree line of mountains is called an alpine climate, and the terrain can be described as alpine tundra. Treelines on north-facing slopes in t…
Tree species near tree line
Some typical Arctic and alpine tree line tree species (note the predominance of conifers):
• Snow gum (Eucalyptus pauciflora)
• Dahurian larch (Larix gmelinii)
• Macedonian pine (Pinus peuce)
Worldwide distribution
The alpine tree line at a location is dependent on local variables, such as aspect of slope, rain shadow and proximity to either geographical pole. In addition, in some tropical or island localities, the lack of biogeographical access to species that have evolved in a subalpine environment can result in lower tree lines than one might expect by climate alone.
Long-term monitoring of alpine treelines
There are several monitoring protocols developed for long term monitoring of alpine biodiversity. One such network which is developed on the line of Global Observation Research Initiative in Alpine Environments (GLORIA), in India HIMADRI.
See also
• Montane ecosystems
• Ecotone: a transition between two adjacent ecological communities
• Edge effects: the effect of contrasting environments on an ecosystem
• Massenerhebung effect
Further reading
• Arno, S.F.; Hammerly, R.P. (1984). Timberline. Mountain and Arctic Forest Frontiers. Seattle: The Mountaineers. ISBN 978-0-89886-085-6.
• Beringer, Jason; Tapper, Nigel J.; McHugh, Ian; Chapin, F. S., III; et al. (2001). "Impact of Arctic treeline on synoptic climate". Geophysical Research Letters. 28 (22): 4247–4250. Bibcode:2001GeoRL..28.4247B. doi:10.1029/2001GL012914.
Typical Tree-Line Species
Alpine Tree-Lines
- The alpine tree-line at a location is dependent on local variables, such as aspect of slope, rain shadow and proximity to either geographical pole. Given this caveat, here is a list of average tree-lines from locations around the globe:
Arctic and Antarctic Tree-Lines
- Like the alpine tree-lines shown above, polar tree-lines are heavily influenced by local variables such as aspect of slope and degree of shelter; trees can often grow in river valleys at latitudes where they could not grow on a more exposed site. Maritime influences such as ocean currentsalso play a major role in determining how far from the equator trees can grow. Here are …
References
- Arno, S. F. & Hammerly, R. P. 1984. Timberline. Mountain and Arctic Forest Frontiers. The Mountaineers, Seattle. ISBN 0-89886-085-7
- Ødum, S. 1979. Actual and potential tree-line in the North Atlantic region, especially in Greenland and the Faroes. Holarctic Ecology2: 222-227.
- Ødum, S. 1991. Choice of species and origins for arboriculture in Greenland and the Faroe Isl…
- Arno, S. F. & Hammerly, R. P. 1984. Timberline. Mountain and Arctic Forest Frontiers. The Mountaineers, Seattle. ISBN 0-89886-085-7
- Ødum, S. 1979. Actual and potential tree-line in the North Atlantic region, especially in Greenland and the Faroes. Holarctic Ecology2: 222-227.
- Ødum, S. 1991. Choice of species and origins for arboriculture in Greenland and the Faroe Islands. Dansk Dendrologisk Årsskrift9: 3-78.
- Beringer, J., Tapper, N. J., McHugh, I., Lynch, A. H., Serreze, M. C., & Slater, A. 2001. Impact of Arctic treeline on synoptic climate. Geophysical Research Letters28 (22): 4247-4250.
