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Maple decline is a term describing loss of vigor and dieback in forests or urban plantings of maple trees. It is not a disease or a syndrome, nor is it contagious or endemic. Instead, it is a generalized set of symptoms that may be applied to any species of tree suffering a wide range of different stressors.
Norway maple, red maple and sugar maple are the species most commonly affected. The trouble often starts after insect-induced defoliation, which weakens the trees and makes them more susceptible to secondary pathogens. Early signs of decline include small or scorched foliage, and premature fall colors on some of a tree's branches. Later, dead twigs may become visible as signs of distress become evident throughout the crown. As the tree's condition deteriorates, whole branches die. The tree may attempt to compensate for its diminishing crown by producing leafy shoots on its trunk. The defoliation may occur early enough that the tree may produce new leaves in summer that do not harden off before the first frost. Fruiting bodies of bracket fungi may appear on the trunk or in the crown. Eventually, the whole tree dies. The process from first signs of trouble to total death may span anywhere from a few years to several decades.[ citation needed ]
In urban areas decline is aggravated by soil compaction or disturbance, soil pollution (caused by discarded cigarettes, pet droppings, careless or malicious use of herbicides, and road salt), air pollution and unfavorable moisture conditions. In rural areas, maple decline is often attributed to soil acidification caused by acid rain. [1] Soils which have developed from nutrient-poor parent materials such as sandstone, quartzite and granite are most sensitive to acidification. Fertile areas often show maple decline where large numbers of livestock such as cattle are allowed to roam in woodlots, as herds or flocks of livestock can compact a soil to a degree which is unfavorable to many of the trees. Carelessness with machinery or taps in sugar bushes is a frequent cause of decline in sugar maple and black maple.[ citation needed ]
Unusual weather conditions can also lead to maple decline. A classic example occurred across southern Quebec in 1981 when an exceptional February thaw destroyed the snow cover. Later, hard frost penetrated the unprotected ground. The soil was still frozen when the growing season began. Widespread dieback was seen over the remainder of the decade. Subsequent experimentation has verified that trees in Quebec are more likely to show stunted growth and dieback where snow cover is prevented from developing over a winter.[ citation needed ]
Acid rain is rain or any other form of precipitation that is unusually acidic, meaning that it has elevated levels of hydrogen ions. Most water, including drinking water, has a neutral pH that exists between 6.5 and 8.5, but acid rain has a pH level lower than this and ranges from 4–5 on average. The more acidic the acid rain is, the lower its pH is. Acid rain can have harmful effects on plants, aquatic animals, and infrastructure. Acid rain is caused by emissions of sulfur dioxide and nitrogen oxide, which react with the water molecules in the atmosphere to produce acids.
Quercus palustris, also called pin oak, swamp oak, or Spanish oak, is a tree in the red oak section of the genus Quercus. Pin oak is one of the most commonly used landscaping oaks in its native range due to its ease of transplant, relatively fast growth, and pollution tolerance.
Fraxinus americana, the white ash or American ash, is a fast-growing species of ash tree native to eastern and central North America.
Acer saccharum, the sugar maple, is a species of flowering plant in the soapberry and lychee family Sapindaceae. It is native to the hardwood forests of eastern Canada and eastern United States. Sugar maple is best known for being the primary source of maple syrup and for its brightly colored fall foliage. It may also be called "rock maple," "sugar tree," "sweet maple," or, particularly in reference to the wood, "hard maple," "birds-eye maple," or "curly maple," the last two being specially figured lumber.
Acer rubrum, the red maple, also known as swamp maple, water maple, or soft maple, is one of the most common and widespread deciduous trees of eastern and central North America. The U.S. Forest Service recognizes it as the most abundant native tree in eastern North America. The red maple ranges from southeastern Manitoba around the Lake of the Woods on the border with Ontario and Minnesota, east to Newfoundland, south to Florida, and southwest to East Texas. Many of its features, especially its leaves, are quite variable in form. At maturity, it often attains a height around 30 m (100 ft). Its flowers, petioles, twigs, and seeds are all red to varying degrees. Among these features, however, it is best known for its brilliant deep scarlet foliage in autumn.
Fagus grandifolia, the American beech or North American beech, is the only species of beech native to North America. Its current range comprises the eastern United States, isolated pockets of Mexico and southeastern Canada. Prior to the glacial maximum of the Pleistocene epoch, the tree flourished over most of North America, reaching California.
Armillaria mellea, commonly known as honey fungus, is an edible basidiomycete fungus in the genus Armillaria. It is a plant pathogen and part of a cryptic species complex of closely related and morphologically similar species. It causes Armillaria root rot in many plant species and produces mushrooms around the base of trees it has infected. The symptoms of infection appear in the crowns of infected trees as discoloured foliage, reduced growth, dieback of the branches and death. The mushrooms are edible but some people may be intolerant to them. This species is capable of producing light via bioluminescence in its mycelium.
Picea rubens, commonly known as red spruce, is a species of spruce native to eastern North America, ranging from eastern Quebec and Nova Scotia, west to the Adirondack Mountains and south through New England along the Appalachians to western North Carolina. This species is also known as yellow spruce, West Virginia spruce, eastern spruce, and he-balsam. Red spruce is the provincial tree of Nova Scotia.
Xerosere is a plant succession that is limited by water availability. It includes the different stages in a xerarch succession. Xerarch succession of ecological communities originated in extremely dry situation such as sand deserts, sand dunes, salt deserts, rock deserts etc. A xerosere may include lithoseres and psammoseres.
Soil acidification is the buildup of hydrogen cations, which reduces the soil pH. Chemically, this happens when a proton donor gets added to the soil. The donor can be an acid, such as nitric acid, sulfuric acid, or carbonic acid. It can also be a compound such as aluminium sulfate, which reacts in the soil to release protons. Acidification also occurs when base cations such as calcium, magnesium, potassium and sodium are leached from the soil.
In hydrology, stemflow is the flow of intercepted water down the trunk or stem of a plant. Stemflow, along with throughfall, is responsible for the transferral of precipitation and nutrients from the canopy to the soil. In tropical rainforests, where this kind of flow can be substantial, erosion gullies can form at the base of the trunk. However, in more temperate climates stemflow levels are low and have little erosional power.
Ramial chipped wood (RCW), also called BRF, is a type of woodchips made solely from small to medium-sized branches. The adjective "ramial" refers to branches (rami). RCW is a forest product used in agriculture for mulching and soil enrichment. It may be laid on top of the soil, mixed into it, or composted first and then applied.
Forest dieback is a condition in trees or woody plants in which peripheral parts are killed, either by pathogens, parasites or conditions like acid rain, drought, and more. These episodes can have disastrous consequences such as reduced resiliency of the ecosystem, disappearing important symbiotic relationships and thresholds. Some tipping points for major climate change forecast in the next century are directly related to forest diebacks.
Armillaria novae-zelandiae is a species of mushroom-forming fungus in the family Physalacriaceae. This plant pathogen species is one of three Armillaria species that have been identified in New Zealand.
Forest pathology is the research of both biotic and abiotic maladies affecting the health of a forest ecosystem, primarily fungal pathogens and their insect vectors. It is a subfield of forestry and plant pathology.
Kauri dieback is a forest dieback disease of the native kauri trees of New Zealand that is suspected to be caused by the oomycete Phytophthora agathidicida. Symptoms can include root rot and associated rot in a collar around the base of the tree, bleeding resin, yellowing and chlorosis of the leaves followed by extensive defoliation, and finally, death.
Freshwater acidification occurs when acidic inputs enter a body of fresh water through the weathering of rocks, invasion of acidifying gas, or by the reduction of acid anions, like sulfate and nitrate within a lake. Freshwater acidification is primarily caused by sulfur oxides (SOx) and nitrogen oxides (NOx) entering the water from atmospheric depositions and soil leaching. Carbonic acid and dissolved carbon dioxide can also enter freshwaters, in a similar manner associated with runoff, through carbon dioxide-rich soils. Runoff that contains these compounds may incorporate acidifying hydrogen ions and inorganic aluminum, which can be toxic to marine organisms. Acid rain is also a contributor to freshwater acidification. It is created when SOx and NOx react with water, oxygen, and other oxidants within the clouds.
Birch dieback is a disease of birch trees that causes the branches in the crown to die off. The disease may eventually kill the tree. In an event in the Eastern United States and Canada in the 1930s and 1940s, no causal agent was found, but the wood-boring beetle, the bronze birch borer, was implicated in the severe damage and death of the tree that often followed. In similar crown dieback occurrences in Europe several decades later, the pathogenic fungus Melanconium betulinum were found in association with affected trees, as well as Anisogramma virgultorum and Marssonina betulae.
The Ecological regions of Quebec are regions with specific types of vegetation and climates as defined by the Quebec Ministry of Forests, Wildlife and Parks. Given the size of this huge province, there is wide variation from the temperate deciduous forests of the southwest to the arctic tundra of the extreme north.
The Northeastern Highlands ecoregion is a Level III ecoregion designated by the United States Environmental Protection Agency (EPA) in the U.S. states of Vermont, New Hampshire, Massachusetts, Maine, Connecticut, New York, New Jersey, and Pennsylvania. The ecoregion extends from the northern tip of Maine and runs south along the Appalachian Mountain Range into eastern Pennsylvania. Discontiguous sections are located among New York's Adirondack Mountains, Catskill Range, and Tug Hill. The largest portion of the Northeastern Highlands ecoregion encompasses several sub mountain ranges including the Berkshires, Green Mountains, Taconic, and White Mountains.
Acid rain-induced Ca depletion predisposes sugar maple trees to decline.