For normal growth and development, plants need certain ecological conditions. The needs of plant species in relation to individual ecological factors are different. Knowledge of the ecological characteristics of woody and herbaceous species in relation to light, humidity, nutrition, is important for practical measures. Ecological groups include plant species that have more or less the same needs in relation to some of the ecological factors. These needs are not always the same…

Relation to light:

Tree species have a different need for light. As the oldest and very reliable method of determining the relationship to light, there is a visual observation of the external characteristics of the trees. The thickness of the leaves in the crown is taken into account (thick – the species is more or less subject to shadow, rare – types of light); The time and degree of clearing the tree from the branches (species that submit more or less shade – the tree begins to be cleaned later from the branches and to a lesser height, the kind of light – earlier and to a higher height); The density of the stands and the rate of its rarefaction (the stands of the species that are subject to the shade are denser and the process of natural decay of the tree is slower); The length of the life of young species under the coverage of the mother’s stands (younger species that tolerate a larger or smaller shadow can live longer in the assembled stand – the young types of light quickly die); Growth rate in the first half of life (fast-growing species are by type of light).

Types of light or heliophytes (Greek. helios – sun, phytone – plant), develop optimum in full illumination and little shading slows down their growth or leads to their collapse. Types of shadow or scyophytes (Greek skia – shadow) normally develop under shadow conditions.

Relation to heat:

Root growth and movement of juices begin at a temperature somewhat higher than 0 °C, and trees and leaves at 6 °C. The external sign of the movement of vegetation (opening of buds) occurs at an air temperature of about 10 °C and soil about 5 °C. Photosynthesis takes place at a temperature from 0 °C to 50 °C, optimal is considered to be 20-30 °C.

Group of trees in relation to heat:

• Very warm-hearted
• Warm-hearted
• Moderately warm-hearted
• A little warm-hearted

Ratio to humidity:

• Hydrophyte (Greek. hydor – water) aquatic plants submerged in water completely or partially.
• Hygrophyte (Greek.. hygros – moisture) plants that live on humid soil.
• Xerophyte (Greek. xeros – dry) are plants adapted to life in conditions of poor water supply.
• Mesophyte – plants of moderately humid habitats

Relation to nutrition:

• Oligotrophs
• Mesotrophs
• Megatrophs

In relation to the soil reaction:

• Acidophile (on soil with reaction pH 3.8 – 6.7)
• Basophile (they succeed on soil and in water with acidophilic reaction pH 7-9)
• Neutrophile (they usually grow on soil with a reaction pH 6.7-7.0)

Resistance to air pollution:

• highly resistant
• resistant
• relatively resistant
• slightly resistant
• non-resistant