Understanding plant ecology is a valuable thing for not only environmental scientists and managers, but also farmers, horticulturists, or anyone concerned about the world in which we live.
Types of Plant Communities
There are two main types of plant communities. Open plant communities consist of open canopies with sparse vegetation and usually one or two canopy layers. Closed communities include more dense vegetation with a closed canopy. Closed communities may consist of rain forest plants and include larger leafed species.
In contrast with closed communities, open communities develop where there is shortage of resources, like African savannas, North American prairies and Asian steppes, all suffering from shortage of moisture for at least several months a year, or open forests on rocky grounds lacking enough soil to grow on.
Dominant plant species compete for another plants space and override other species. For example a dry-sclerophyll forest may have many species but contain mainly consist of a certain species of grass and a certain species of gum tree. The grass and the gum tree are the dominant species.
Individual plants and communities are affected not only by abiotic factors, but by other species or specimens of the same species. The interaction of organisms of the same or different species can take a form of herbivory, predation, parasitism, symbiosis, competition, etc.
Competition occurs when organisms are using the same or similar resource and there is a shortage of supply of the resource. The competition between organisms of the same species is called intraspecific. Interspecific competition is a competition between different species.
Most plants are rooted and can’t change their location. In many cases it causes severe competition for light, water, and nutrients.
In a forest the highest trees often block some light for the plants of lower levels, causing them to grow slower or die. After a large tree fell or is removed, different species seedlings start to grow fast in the opening. Those of them that grow faster become new dominants preventing smaller plants from receiving enough light.
Many shade-tolerant plants would grow much better in sunny locations, but they often can’t compete with sun-loving plants for other resources that can be limited like water, nutrients, or space in suitable habitats.
All plants experience environmental stress, but some plants respond better than others. Certain plants have adapted to particular environments to survive. For example, rain forest plants have adapted to low light situations by having increased leaf size to capture more light. Other plants have many natural responses such as dropping excess leaves in dry periods, so not to waste energy on leaf production.
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