Tree Growth and Development

Understanding Growth Phases

Trees undergo specific growth stages: seed germination, sapling growth, maturity, and senescence.
The seed germination stage involves the growth of the embryo within the seed into a sapling.
The sapling growth stage is where the young tree develops its basic structures: roots, stem, and leaves.
The maturity stage is when a tree has reached its full height and begins to produce seeds.
Senescence is the final stage of a tree’s life, characterised by slow growth, loss of leaves and eventual death.

Trees have a specific growth pattern known as determinate growth; each year, they grow a new layer of wood, evidenced by tree rings.
Growth rings are created when the cambium layer produces new xylem cells; the changes in the size and colour of these cells throughout a season create the rings.

Tree growth mainly occurs in the meristems, the areas of active cell division found at growing shoot tips and root tips.
Buds are important structures in tree growth as they can differentiate into leaves, flowers or shoots.
Pith is the central part of the stem and can help to determine age and growth rates.

Hormones or growth regulators control different aspects of growth, including cell division, elongation, and differentiation.
Auxins, for instance, promote cell elongation, while other hormones like gibberellins and cytokinins influence stem elongation and cell division, respectively.

Growth and development in trees are greatly influenced by environmental conditions like light, temperature, and water availability.
Photoperiodism is the response of a tree to the relative lengths of daylight and darkness, influencing aspects like flowering and dormancy.
Temperature affects the rate of metabolic activities in a tree, influencing growth rates.
Water availability can limit growth and cause stress, impacting overall tree health.

Roots play a critical role in a tree’s growth by absorbing water and minerals from the soil.
Tree roots also provide stability, store food reserves, and participate in the synthesis of certain hormones.
Root pruning, the removal of a tree’s roots, can lead to a more compact and efficient root system.

Proper pruning helps shape a tree, improve its health, and increase its aesthetic value.
Pruning should be done by following certain standards and guidelines to avoid causing damage or stress to the tree.
In general, weak, dead, or diseased branches and limbs should be removed, and the natural shape of the tree should be preserved.