Taxonomy and Phylogeny:
– Conifer is derived from ‘conus’ (cone) and ‘ferre’ (to bear).
– The division Pinophyta is the largest group of gymnosperms.
– Modern conifers emerged during the Late Permian through Jurassic.
– They are closely related to Cordaitales, an extinct tree group.
– Conifers declined during the Late Cretaceous due to flowering plants’ rise.
Description and Ecology:
– Conifers are woody plants, with most being trees.
– They produce resin for protection against insects and fungi.
– Conifer forests are the largest terrestrial carbon sink.
– They dominate areas like the taiga and have winter survival adaptations.
– Conifers are economically valuable for lumber and paper production.
Ancient Origins and Foliage:
– Fossil record of conifers dates back over 300 million years.
– Conifers have diverse forms, with some having herbaceous characteristics.
– Different families of conifers exist, including Gnetophyta.
– Various conifer families have distinct leaf shapes and arrangements for light absorption.
Reproduction and Life Cycle:
– Most conifers are wind-pollinated with seeds developing inside cones.
– Conifers are heterosporous, producing male and female spores.
– Male cones produce pollen for fertilization, while female cones develop seeds.
– Cones take months to years to mature, with seeds dispersed by wind, birds, or animals.
Economic Importance and Growth Conditions:
– Softwood from conifers contributes 45% of the world’s annual lumber production.
– Conifer timber is used for paper, plastic, and food production.
– Conifers can absorb nitrogen in different forms affecting growth.
– Nitrogen fertilization stimulates shoot growth more than root growth in coniferous seedlings.
– External factors and hormonal gradients influence tree growth and form.
Conifers are a group of cone-bearing seed plants, a subset of gymnosperms. Scientifically, they make up the division Pinophyta (/pɪˈnɒfɪtə, ˈpaɪnoʊfaɪtə/), also known as Coniferophyta (/ˌkɒnɪfəˈrɒfɪtə, -oʊfaɪtə/) or Coniferae. The division contains a single extant class, Pinopsida. All extant conifers are perennial woody plants with secondary growth. The great majority are trees, though a few are shrubs. Examples include cedars, Douglas-firs, cypresses, firs, junipers, kauri, larches, pines, hemlocks, redwoods, spruces, and yews. As of 2002, Pinophyta contained seven families, 60 to 65 genera, and more than 600 living species.
Conifer Temporal range: Carboniferous–Present
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Large conifer forest composed of Abies alba at Vosges, Eastern France | |
Scientific classification | |
Kingdom: | Plantae |
Clade: | Tracheophytes |
Clade: | Gymnospermae |
Division: | Pinophyta |
Class: | Pinopsida |
Subclasses, orders, and families | |
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Synonyms | |
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Although the total number of species is relatively small, conifers are ecologically important. They are the dominant plants over large areas of land, most notably the taiga of the Northern Hemisphere, but also in similar cool climates in mountains further south. Boreal conifers have many wintertime adaptations. The narrow conical shape of northern conifers, and their downward-drooping limbs, help them shed snow. Many of them seasonally alter their biochemistry to make them more resistant to freezing. While tropical rainforests have more biodiversity and turnover, the immense conifer forests of the world represent the largest terrestrial carbon sink. Conifers are of great economic value for softwood lumber and paper production.