External factors such as light, water, heat, oxygen, carbon dioxide, mineral nutrients, and so on are decisive in the fate of plants in any a limestone substrate. This situation in itself predetermines certain heat, light, soil, and moisture conditions.

The action of microbes aids in the decomposition of this plant litter, and gradually part of the nutrient matter which the plants extracted from the soil during the growth period is returned. Meanwhile, the layer of fallen and decaying leaves (litter) serves as excellent thermal insulation. On sunny days in early spring it heats up to as much as 40C, reawakening many lovely spring flowers (such as Hepatica, Figwort, Anemone) well before the trees stir from their winter sleep and once again shade the ground with their leaves.

Other examples of the interaction within an ecosystem are the exchanges which are continually taking place between producers, consumers, and decomposers. In this case green plants are producers, serving as fodder for the herbivores who in turn are eaten by the carnivores.

Every living organism is an individual in its own right, but it is, too, only one of many organisms which go to make up Nature’s rich mosaic. A very important role is played, for example, by green plants – autotrophic or self-feeding organisms which produce new organic matter from mineral substances. However, even this extraordinary ability does not mean that green plants can live in isolation.

Their life is closely linked to that of other organisms – plants, animals, microbes – and is influenced by many external factors. Together with environment, a complex of living organisms form what is known as an ecosystem, a functioning whole. Just as there are countless millions of different organisms, so, too, there are many different ecosystems.

Mutual competition as regards light, or the absorption of moisture and mineral nutrients by the root systems below the surface of the soil, are examples of the ties and associations within the plant element of the ecosystem.