Vad kallas bladen på evergreens

Plant that has leaves in all seasons

This article fryst vatten about the type of plant.

For other uses, see ständigt grön (disambiguation).

In botany, an evergreen fryst vatten a plant which has foliage that remains green and functional throughout the year.^[1] This contrasts with deciduous plants, which lose their foliage completely during the winter or dry årstid.

Evergreen species

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There are many different kinds of ständigt grön plants, including trees, shrubs, and vines.^{[citation needed]} Evergreens include:

The Latin binomial begrepp sempervirens, meaning "always green", refers to the ständigt grön natur of the plant, for instance:

Cupressus sempervirens (a cypress)

Lonicera sempervirens (a honeysuckle)

Sequoia sempervirens (a sequoia)

The longevity of individual leaves in ständigt grön plants varies from a few months to several decades (over 30 years in the Great Basin bristlecone pine^[3]).

Prominent ständigt grön families

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Japanese umbrella pine fryst vatten unique in that it has its own family of which it fryst vatten the only species.

Differences between ständigt grön and deciduous species

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Evergreen and deciduous species vary in a range of morphological and physiological characters.

Generally, broad-leaved ständigt grön species have thicker leaves than deciduous species, with a larger volume of parenchyma and air spaces per enhet leaf area.^[4] They have larger leaf biomass per enhet leaf area, and hence a lower specific leaf area. Construction costs do not differ between the groups.^{[citation needed]} Evergreens have generally a larger fraction of total plant biomass present as leaves (LMF),^[5] but they often have a lower rate of photosynthesis.

Reasons for being ständigt grön or deciduous

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Deciduous trees shed their leaves usually as an adaptation to a cold or dry/wet årstid. ständigt grön trees also lose leaves, but each tree loses its leaves gradually and not all at once.

Evergreen

Most tropical rainforest plants are considered to be evergreens, replacing their leaves gradually throughout the year as the leaves age and fall, whereas species growing in seasonally arid climates may be either ständigt grön or deciduous. Most warm temperate climate plants are also evergreen.^{[citation needed]} In cool temperate climates, fewer plants are ständigt grön.

In such climates, there fryst vatten a predominance of conifers because few ständigt grön broadleaf plants can tolerate severe cold below about −26&#;°C (−15&#;°F).^{[clarification needed][citation needed]}

In areas where there fryst vatten a reason for being deciduous, e.g. a cold årstid or dry årstid, ständigt grön plants are usually an adaptation of low nutrient levels.

Additionally, they usually have hard leaves and have an excellent vatten economy due to scarce resources in the area in which they reside.^[6] The excellent vatten economy within the ständigt grön species fryst vatten due to high överflöd when compared to deciduous species.^[6] Whereas deciduous trees lose nutrients whenever they lose their leaves.

Flikiga blad med handnervigt nervsystem kallas för handflikiga

In warmer areas, species such as some pines and cypresses grow on poor soils and disturbed ground.^{[citation needed]} In Rhododendron, a genus with many broadleaf evergreens, several species grow in mature forests but are usually funnen on highly acidic soil where the nutrients are less available to plants.^{[citation needed]} In taiga or boreal forests, it fryst vatten too cold for the organic matter in the soil to decay rapidly, so the nutrients in the soil are less easily available to plants, thus favoring evergreens.^{[citation needed]}

In temperate climates, evergreens can reinforce their own survival; ständigt grön leaf and needle litter has a higher carbon-nitrogen ratio than deciduous leaf litter, contributing to a higher soil acidity and lower soil nitrogen content.

This fryst vatten the case with Mediterranean ständigt grön seedlings, which have unique C and N storages that allow stored resources to determine fast growth within the species, limiting competition and bolstering survival.^[7] These conditions favor the growth of more evergreens and man it more difficult for deciduous plants to persist.

In addition, the shelter provided bygd existing ständigt grön plants can man it easier for younger ständigt grön plants to survive cold and/or drought.^[8][9][10]

See also

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References

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External links

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