Phanerophytes

Phanerophytes have their bud-bearing shoots in the air and, with few exceptions, are trees and shrubs (Figure 2A). The majority of conifer and dicot tree

Table 2 Life-form classification system for algae based on habitat preference

Parasitic - living on or in a host organism that provides nutrition. Pelagic - living in the open ocean rather than in coastal or inland waters. Neritic - living in coastal waters. Planktonic - suspended in water.

Meriplanktonic - organisms that spend a part of their life cycle as planktonic and a part as benthic organisms (largely restricted to neritic conditions).

Tychopelagic - living a benthic or attached existence in littoral habitats but entering a planktonic mode of existence when dislodged from a substrate.

Benthic - bottom-dwelling; nonplanktonic; attached to or resting on a substrate. Cumaphytes - surf inhabiting algae. Herpophytes - small creeping algae. Metarrheophytes - living in currents.

Galenophilic psammophiles - living in calm, sandy situations.

Lepryophytes - encrusting forms.

Tranophytes - rock penetrating forms.

Epiphytes - living on other organisms.

Endophytes - living in other organisms.

Epidaphic - living on the soil surface.

Epilithic - living on rocks.

Epipelic - attached to mud or sand.

Figure 2 Semidiagrammatic rendering of the five Raunkiaerian classes of vascular plant life-forms. A, Phaneophytes; B and C, Chamaephytes; D, Hemichamaephytes; E-I, Cryptophytes (subclasses: E, simple cryptophytes; F, Geophytes; G, Helophytes; H-I, Hydrophytes). Dark lines and circles denote perennating stems/roots and buds, respectively; light lines and circles denote climatically vulnerable vegetative and reproductive organs, respectively.

Figure 2 Semidiagrammatic rendering of the five Raunkiaerian classes of vascular plant life-forms. A, Phaneophytes; B and C, Chamaephytes; D, Hemichamaephytes; E-I, Cryptophytes (subclasses: E, simple cryptophytes; F, Geophytes; G, Helophytes; H-I, Hydrophytes). Dark lines and circles denote perennating stems/roots and buds, respectively; light lines and circles denote climatically vulnerable vegetative and reproductive organs, respectively.

species fall into this category as do tree fern and many palm and cycad species. Because the severity of inclement weather conditions increases with height above ground, the phanerophytes are subdivided into height-classes, that is, tall, medium, and low trees species, and shrubs. These height-classes are formally called megaphanerophytes (>30 m tall), mesophanerophytes (between 8 and 30 m), microphanerophytes (between 2 and 8 m), and nanopha-nerophytes (<2m but >0.25 m). The phanerophytes are also subdivided according to whether their buds have or lack scales and whether their leaves are evergreen or deciduous. No special provision is allotted for lianas, which are classified according to their height.

Solar Power

Solar Power

Start Saving On Your Electricity Bills Using The Power of the Sun And Other Natural Resources!

Get My Free Ebook


Post a comment