Over-collection

Over-collection [ Ecology ]
Synonym: Over-exploitation

Dictionary of botanic terminology - index of names


	Over-collection is the act of collecting something in excess.

The over-collection or overexploitation of rare plants coveted by collectors is a serious threat to wild plants and habitats. Over-collection is believed likely to constitute at least a local threat, continued over-collection of plants will eventually end in the loss of those plants. Populations of some rare plants are so low that the slightest over-collection could leave the species at risk, a single collecting trip could wipe them out and lead a rare species to extinction. Over-collection in the wild can also reduce yields and genetic variability of the species.

The wholesale collecting, for resale, of wild plants from public lands, especially the rarer plants, must be prohibited or limited, first of all must be denounced the practice of misleading the public by calling such collected plants nursery propagated plants. A way to protect wild populations of rare plants is to increase the supply of cultivated specimens. Increasing the amount of cultivated plants available will decrease the pressure on wild plant populations. Unfortunately, cultivation has historically been attempted only when wild populations were already threatened by over-exploitation. Gardeners cannot be the only ones expected to respect and preserve plants and their habitats. Rare plants merit special consideration and should not be distributed or propagules taken unless there is sufficient local stock to successfully perpetuate the population. In most cases this means minimal or no collecting.

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Holdfast roots [ Botany ]
Dictionary of botanic terminology - index of names

Some species of climbing plants develop holdfast roots which help to support the vines on trees, walls, and rocks. By forcing their way into minute pores and crevices, they hold the plant firmly in place.

Climbing plants, like the poison ivy (Toxicodendron radicans), Boston ivy (Parthenocissus tricuspidata), and trumpet creeper (Campsis radicans), develop holdfast roots which help to support the vines on trees, walls, and rocks. By forcing their way into minute pores and crevices, they hold the plant firmly in place. Usually the Holdfast roots die at the end of the first season, but in some species they are perennial. In the tropics some of the large climbing plants have hold-fast roots by which they attach themselves, and long, cord-like roots that extend downward through the air and may lengthen and branch for several years until they strike the soil and become absorbent roots.

Major references and further lectures:
1) E. N. Transeau “General Botany” Discovery Publishing House, 1994