The Shape of Trees to Come

 The Shape of Trees to Come, Part I

The shape of a tree and it's maximum size are determined by the species and it's  genetics. Most conifers tend to be tall and straight. They have strong apical dominance. The leading shoot grows the most hogging most of the trees resources. They are also negatively geotropic, they grow away from the force of gravity. Some broad leaf trees have strong apical dominance, Ash and  Poplar are good examples. Oak does not, if given the chance it will spread it's canopy as wide as possible growing in all directions, with large heavy branches. Broad leaf trees also tend to be more phototropic, they grow towards the light source.

An open grown Oak,
 a hedgerow tree at Pit Wood.

Trees, particularly in the absence of large herbivores, tend to grow with other trees. This limits the light that reaches the sides of the tree and the lower parts of the tree. If a part of a tree does not grow it will die. The lowest branches die first as they do not receive enough light to grow. How much light a leaf needs to grow depends on the species and how shade tolerant it is. Yew and Holly are shade tolerant and can grow under other trees. Most trees require more light so have to grow up to try and get above their neighbours. 

The edge of a wood where
 the centre of the wood has 
been felled. 

Trees, particularly in the absence of large herbivores, tend to grow with other trees. This limits the light that reaches the sides of the tree and the lower parts of the tree. If a part of a tree does not grow it will die. The lowest branches die first as they do not receive enough light to grow. How much light a leaf needs to grow depends on the species and how shade tolerant it is. Yew and Holly are shade tolerant and can grow under other trees. Most trees require more light so have grow up to try and get above their neighbours.  

The Photo shows Red Oak in the left hand row and English Oak in the Centre. They were on the edge of a wood and have grown straight but have grown most when they got above the outer hedge, and grown towards the light. The middle of the wood which has been felled stopped them growing on their right sides.

 Another open grown Oak. The Major  Oak was grown in Wood pasture, where animals were grazed and kept competing trees away. It is an old tree but not particularly tall, it is however wide and heavily branched. The wide canopy also tends to supress any growth under it.