Biodiversity of gymnosperms: Let us conserve these ancient plants for posterity?

By Debananda S Ningthoujam *

Prelude

Gymnosperms were the first seed plants that evolved on the Earth. They bear their seeds naked, unlike angiosperms which have their seeds enclosed inside fruits.

What are gymsnosperms?

Gymnosperms include conifers, cycads, gnetales and ginkgo. The largest group of living gymnosperms are the conifers (pines, cypresses and allied plants), followed by cycads, Gnetales (Gnetum, Ephedra and Welwitschia), and Ginkgo (a single living species).

Gymnosperm seeds develop on the surface of scale- or leaf-like appendages of cones, or at the end of short stalks(Ginkgo).

Gymnosperm habitats

Gymnosperms were dominant seed plants in the past but gradually they have been displaced by angiosperms. However different types of gymnosperm plants still live in various parts of the worlds.

Conifers thrive in temperate lands (North America and Eurasia). Ephedra grow in high altitudes, especially in northern latitudes. Cycads are found throughout the world but are dominant in equatorial regions. Ginkgo plants were originally concentrated in mountains of Southeastern China but their distribution have been altered subsequently.

The major gymnosperm habitats are:

• Northern temperate forests
• Equatorial regions
• Mountains of china

Gymnosperm nutrition

Like green plants, gymnosperms also can manufacture their own food by photosynthesis.

Gymnosperm classification

Gymnosperms are categorized into four divisions: coniferophyta (conifers), Cycadophyta (cycads), Gnetophyta (Gnetum, Ephedra and Welwitschia) and Ginkgophyta (Ginkgo).

Threats to gymnosperm diversity Most of the major threats to plant diversity also apply to gymnosperms. The major threats are:

• Habitat loss
• Habitat degradation
• Introduced alien species(IAS)
• Pollution
• Disease
• Climate change
• Forest fires
• Logging
• Tourism
• Others

Logging and deforestation are the greatest causes of erosion of plant diversity including that of gymnosperm diversity and the culprits are none other than we human beings. Climate change is an added threat in recent times. Natural disasters and natural forest wild-fires worsen the fast decline in plant (including gymnosperm) diversity.

Why conserve gymnosperms?

Why should we bother to save gymnosperms? Can't we keep them in the botanical gardens or other artificial habitats? There are several reasons for conserving gymnosperm biodiversity. Arguments for saving gymnosperm diversity are many. There are several economic values for gymnosperms. Some of the major economic uses of gymnosperms are as:

• Lumber: many gymnosperms esp. Douglas fir
• Soaps, varnishes and paints: these are obtained from some gymnosperm species
• Food: many parts of pine trees and ginkgo seeds are edible
• Perfumes: several conifers and other gymnosperms
• Ornamental trees: several conifers and cycads are in high demand as ornamental trees and shrubs
• Furniture: many gymnosperms are used for making furniture, matchsticks, boxes, crates, telephone poles, sailboat masts etc.
• Musical instruments: some gymnosperm trees are used to make musical instrument soundboards(esp. for guitars)
• Terpentines and resins: from conifers and other gymnosperms
• Flavors: Juniper berries are used as flavoring agent for gins
• Drugs and medicines: taxol, an anticancer drug is obtained from Pacific yew(Taxus baccata), ginkgo leaf extracts are used as medicines to stimulate blood flow to brain and lungs, ephedrine-a drug with decongestant and other activities-is obtained from Ephedra plants.

How to conserve gymnosperm diversity?

Some of the short-term and long-term programs for fern biodiversity conservation may include:

• ex-situ conservation
• in-situ conservation
• sustainable consumption
• Taking pro-active steps to control climate change

Ex-situ conservation of gymnosperms means conserving them away from the natural settings, for example, in botanical gardens, home gardens, cryopreservation centers and germplasm banks etc.

In-situ conservation refers to saving gymnosperm species in their natural locations. This means creation of wildlife parks, reserved forests, biosphere reserves, eco-parks etc. Cultural symbols such as sacred groves may yet be another way of in-situ conservation of gymnosperm biodiversity.

Coda

A rough estimate in 2010 by IUCN is that there are 1021 described species of gymnosperms of which 909 species have been evaluated for various threat criteria. 322 species have been listed as threatened in 2010.

This amounts to 32% of described species and 35% of evaluated species of gymnosperms being threatened with extinction. Moreover, some gymnosperm species may yet remain to be discovered. But the tragedy is that many may go extinct before they are found out.

The health of plants including gymnosperms is intimately linked with human well-being. If gymnosperms are wiped out from the Earth's ecosystems, it would jeopardize the long-term survival of animals, plants and even humans on our planet. We need to protect these ancient life forms. Long live the wonderful, majestic and ancient gymnosperms!

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* Debananda S Ningthoujam wrote this article for Hueiyen Lanpao (English Edition)
The author teaches biochemistry in Manipur University and researches on biodiversity and biotechnology areas esp. microbial biodiversity and biotechnology. He also writes popular science articles on scientific biography and science, environment & biodiversity issues. This article was webcasted on November 29 2010.

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