Forest ecology is the scientific study of the interrelated patterns, processes,

flora Flora is all the plant life present in a particular region or time, generally the naturally occurring (indigenous (ecology), indigenous) native plant, native plants. Sometimes bacteria and fungi are also referred to as flora, as in the terms '' ...

, fauna and

ecosystem An ecosystem (or ecological system) consists of all the organisms and the physical environment with which they interact. These biotic and abiotic components are linked together through nutrient cycles and energy flows. Energy enters the syste ...

s in

forests A forest is an area of land dominated by trees. Hundreds of definitions of forest are used throughout the world, incorporating factors such as tree density, tree height, land use, legal standing, and ecological function. The United Nations' ...

. The management of forests is known as

forestry Forestry is the science and craft of creating, managing, planting, using, conserving and repairing forests, woodlands, and associated resources for human and environmental benefits. Forestry is practiced in plantations and natural stands. ...

silviculture Silviculture is the practice of controlling the growth, composition/structure, and quality of forests to meet values and needs, specifically timber production. The name comes from the Latin ('forest') and ('growing'). The study of forests and wo ...

, and

forest management Forest management is a branch of forestry concerned with overall administrative, legal, economic, and social aspects, as well as scientific and technical aspects, such as silviculture, protection, and forest regulation. This includes management fo ...

. A forest

is a natural woodland unit consisting of all plants, animals, and micro-organisms (

Biotic component An ecosystem (or ecological system) consists of all the organisms and the physical environment with which they interact. These biotic and abiotic components are linked together through nutrient cycles and energy flows. Energy enters the syst ...

s) in that area functioning together with all of the non-living physical (

abiotic In biology and ecology, abiotic components or abiotic factors are non-living chemical and physical parts of the environment that affect living organisms and the functioning of ecosystems. Abiotic factors and the phenomena associated with them under ...

) factors of the environment.

Surrounding issues

Forests have an enormously important role to play in the global ecosystem. Forests produce approximately 28% of the Earth's oxygen (the vast majority being created by oceanic plankton), they also serve as homes for millions of people, and billions depend on forests in some way. Likewise, a large proportion of the world's animal species live in forests. That's why we absolutely must protect them. Forest ecology helps to understand life in the forest. It shows how living organisms behave, live and survive. Furthermore, forest ecology attempts to provide an understanding of the thriving process of forests. Similarly, many forests are also used for economic purposes such as fuel and wood products. Therefore, understanding how forests are managed is also a goal of forest ecology.

Relationship to other branches of ecology

Forest ecology is one branch of the biotically-oriented fields of ecology (as opposed to a fields oriented towards the organisational level or complexity of ecological systems, for example

population Population typically refers to the number of people in a single area, whether it be a city or town, region, country, continent, or the world. Governments typically quantify the size of the resident population within their jurisdiction using a ...

community ecology In ecology, a community is a group or association of populations of two or more different species occupying the same geographical area at the same time, also known as a biocoenosis, biotic community, biological community, ecological community, ...

). Thus, forests are studied at a number of organisational levels, from the individual

organism In biology, an organism () is any living system that functions as an individual entity. All organisms are composed of cells (cell theory). Organisms are classified by taxonomy into groups such as multicellular animals, plants, and ...

to the ecosystem. However, as the term

forest A forest is an area of land dominated by trees. Hundreds of definitions of forest are used throughout the world, incorporating factors such as tree density, tree height, land use, legal standing, and ecological function. The United Nations' ...

connotes an area inhabited by more than one

, forest ecology most often concentrates on the level of the

community A community is a social unit (a group of living things) with commonality such as place, norms, religion, values, customs, or identity. Communities may share a sense of place situated in a given geographical area (e.g. a country, village, ...

or ecosystem. Logically,

tree In botany, a tree is a perennial plant with an elongated stem, or trunk, usually supporting branches and leaves. In some usages, the definition of a tree may be narrower, including only woody plants with secondary growth, plants that are ...

s are an important component of forest research, but the wide variety of other life forms and abiotic components in most forests means that other elements, such as wildlife or

soil Soil, also commonly referred to as earth or dirt Dirt is an unclean matter, especially when in contact with a person's clothes, skin, or possessions. In such cases, they are said to become dirty. Common types of dirt include: * Debri ...

nutrients, are often the focal point. Thus, forest ecology is a highly diverse and important branch of ecological study. Forest ecology shares characteristics and methodological approaches with other areas of terrestrial plant ecology, however, the presence of trees makes forest ecosystems and their study unique in numerous ways due to the potential for a wide variety of forest structures created by the uniquely large size and height of trees compared with other terrestrial plants.

Community diversity and complexity

Since trees can grow larger than other plant life-forms, there is the potential for a wide variety of forest structures (or physiognomies). The infinite number of possible spatial arrangements of trees of varying size and species makes for a highly intricate and diverse micro-environment in which environmental variables such as

solar radiation Solar irradiance is the power per unit area (surface power density) received from the Sun in the form of electromagnetic radiation in the wavelength range of the measuring instrument. Solar irradiance is measured in watts per square metre ( ...

, temperature, relative humidity, and

wind speed In meteorology, wind speed, or wind flow speed, is a fundamental atmospheric quantity caused by air moving from high to low pressure, usually due to changes in temperature. Wind speed is now commonly measured with an anemometer. Wind speed ...

can vary considerably over large and small distances. In addition, an important proportion of a forest ecosystem's biomass is often underground, where soil structure, water quality and quantity, and levels of various soil nutrients can vary greatly. Thus, forests are often highly heterogeneous environments compared to other terrestrial plant communities. This heterogeneity in turn can enable great biodiversity of species of both plants and animals. Some structures, such as tree ferns may be keystone species for a diverse range of other species. A number of factors within the forest affect biodiversity; primary factors enhancing wildlife abundance and biodiversity was the presence of diverse tree species within the forest and the absence of

even aged timber management Even-aged timber management is a group of forest management practices employed to achieve a nearly coeval cohort group of forest trees. The practice of even-aged management is often pursued to minimize costs to loggers. In some cases, the practice ...

. For example, the

wild turkey The wild turkey (''Meleagris gallopavo'') is an upland ground bird native to North America, one of two extant species of turkey and the heaviest member of the order Galliformes. It is the ancestor to the domestic turkey, which was originally d ...

thrives when uneven heights and

canopy Canopy may refer to: Plants * Canopy (biology), aboveground portion of plant community or crop (including forests) * Canopy (grape), aboveground portion of grapes Religion and ceremonies * Baldachin or canopy of state, typically placed over an ...

variations exist and its numbers are diminished by even aged timber management. Forest management techniques that mimic natural disturbance events (variable retention forestry) can allow community diversity to recover rapidly for a variety of groups including beetles.

Ecological potential of forest species

The ecological potential of a particular species is a measure of its capacity to effectively compete in a given geographical area, ahead of other species, as they all try to occupy a natural space. For some areas it has been quantified, as for instance by Hans-Jürgen Otto, for central Europe. He takes three groups of parameters: #Related to site requirements: Tolerance to low temperatures, tolerance to dry climate, frugality. #Specific qualities:

Shade tolerance In ecology, shade tolerance is a plant's ability to tolerate low light levels. The term is also used in horticulture and landscaping, although in this context its use is sometimes imprecise, especially in labeling of plants for sale in commercial ...

, height growth, stability, longevity, regeneration capacity. #Specific risks: Resistance to late freezing, resistance to wind/ice storm, resistance to fire, resistance to biotic agents. Every parameter is scored between 0 and 5 for each considered species, and then a global mean value calculated. A value above 3.5 is considered high, below 3.0 low, and intermediate for those in between. In this study ''

Fagus sylvatica ''Fagus sylvatica'', the European beech or common beech is a deciduous tree belonging to the beech family Fagaceae. Description ''Fagus sylvatica'' is a large tree, capable of reaching heights of up to tall and trunk diameter, though more ...

'' has a score of 3.82, ''

Fraxinus excelsior ''Fraxinus excelsior'', known as the ash, or European ash or common ash to distinguish it from other types of ash, is a flowering plant species in the olive family Oleaceae. It is native throughout mainland Europe east to the Caucasus and Albor ...

'' 3.08 and ''

Juglans regia ''Juglans regia'', the Persian walnut, English walnut, Carpathian walnut, Madeira walnut, or especially in Great Britain, common walnut, is an Old World walnut tree species native to the region stretching from the Balkans eastward to the Himala ...

'' 2.92; and are examples of the three categories.

Matter and energy flows

Energy flux

Forests accumulate large amounts of standing biomass, and many are capable of accumulating it at high rates, i.e. they are highly productive. Such high levels of biomass and tall vertical structures represent large stores of potential energy that can be converted to

kinetic energy In physics, the kinetic energy of an object is the energy that it possesses due to its motion. It is defined as the work needed to accelerate a body of a given mass from rest to its stated velocity. Having gained this energy during its acc ...

under the right circumstances. The world’s forests contain about 606

gigatonnes The tonne ( or ; symbol: t) is a unit of mass equal to 1000 kilograms. It is a non-SI unit accepted for use with SI. It is also referred to as a metric ton to distinguish it from the non-metric units of the short ton (United States c ...

of living biomass (above- and below-ground) and 59 gigatonnes of dead wood. Two such conversions of great importance are

fires Fire is the rapid oxidation of a material (the fuel) in the exothermic chemical process of combustion, releasing heat, light, and various reaction products. At a certain point in the combustion reaction, called the ignition point, flames are pr ...

and treefalls, both of which radically alter the biota and the physical environment where they occur. Also, in forests of high productivity, the rapid growth of the trees themselves induces biotic and environmental changes, although at a slower rate and lower intensity than relatively instantaneous disturbances such as fires.

Water

Forest trees store large amounts of water because of their large size and anatomical/physiological characteristics. They are therefore important regulators of hydrological processes, especially those involving groundwater hydrology and local evaporation and rainfall/snowfall patterns. An estimated 399 million ha of forest is designated primarily for the protection of soil and water, an increase of 119 million ha since 1990. Thus, forest ecological studies are sometimes closely aligned with meteorological and hydrological studies in regional ecosystem or resource planning studies. Perhaps more importantly the duff or leaf litter can form a major repository of water storage. When this litter is removed or compacted (through grazing or human overuse), erosion and flooding are exacerbated as well as deprivation of dry season water for forest organisms.

Death and regeneration

Woody material, often referred to as coarse woody debris, decays relatively slowly in many forests in comparison to most other organic materials, due to a combination of environmental factors and wood chemistry (see lignin). Trees growing in arid and/or cold environments do so especially slowly. Thus, tree trunks and branches can remain on the forest floor for long periods, affecting such things as wildlife

habitat In ecology, the term habitat summarises the array of resources, physical and biotic factors that are present in an area, such as to support the survival and reproduction of a particular species. A species habitat can be seen as the physical ...

, fire behaviour, and tree regeneration processes. Some trees leave behind eerie skeletons after death. In reality these deaths are actually very few compared to the amount of tree deaths that go unnoticed. Thousands of seedlings can be produced from a single tree but only a few can actually grow to maturity. Most of those deaths are caused from competition for light, water, or soil nutrients, this is called natural thinning. Singular deaths caused by natural thinning go unnoticed, but many deaths can help form forest ecosystems. There are four stages to forest regrowth after a disturbance, the establishment phase which is rapid increase in seedlings, the thinning phase which happens after a canopy is formed and the seedlings covered by it die, the transition phase which occurs when one tree from the canopy dies and creates a pocket of light giving new seedlings opportunity to grow, and lastly the steady-state phase which happens when the forest has different sizes and ages of trees.

References

Bibliography

* Philip Joseph Burton. 2003. ''Towards sustainable management of the boreal forest'' 1039 pages * Robert W. Christopherson. 1996. ''Geosystems: An Introduction to Physical Geography''. Prentice Hall Inc. * C. Michael Hogan. 2008
''Wild turkey: Meleagris gallopavo'', GlobalTwitcher.com, ed. N. Stromberg
* James P. Kimmins. 2054. ''Forest Ecology: a foundation for sustainable forest management and environmental ethics in forestry'', 3rd Edit. Prentice Hall, Upper Saddle River, NJ, USA. 611 pages

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