Ecotones and Succession = TENSION

The term 'ecotone' cropped up this week as a Tree Officer colleague and I looked at Holders Woods in an exercise to describe the woodland structure, composition and current management.
Meadow and woodland at Cannon Hill
An ecotone is a transition area between two biomes.[1] It is where two communities meet and integrate.[2] It may be narrow or wide, and it may be local (the zone between a field and forest) or regional (the transition between forest and grassland ecosystems).[3] An ecotone may appear on the ground as a gradual blending of the two communities across a broad area, or it may manifest itself as a sharp boundary line.
The word ecotone was coined from a combination of eco(logy) plus -tone, from the Greek tonos or tension – in other words, a place where ecologies are in tension. (Wiki)

Ecotones are generally recognised for ecological richness and a good place to observe the 'tensions' and interactions between certain animals and plants.
young oak with about 3-4 year's growth

A woodland edge for example is often regarded as the richest part of a woodland, especially if the edge is bordered by grassland meadow or water.

The Rea Valley in this regard is a wonderful mix of urban ecosystems and ecotones, and one of my favourite locations is the developing oak woodland at the edge of Holders Woods. Undoubtedly the result of acorn planting Jays, we find oaks ranging from year 1 to year 50, but with a majority of young trees around 10-20 years, suggesting optimum growing conditions during this time. 

Developing oak woodland at Moor Green
The area seems saturated with oaks now, clustered to form a thicket, and the individual trees will compete to form the canopy over the next 100 years. This is the best way for woodland to develop, quite naturally, with help from acorn storing Jays in the case of the oak, or from some other seed dispersal method with other species.                                                       
2 year's growth 

A thicket of oaks ranging in age from 1-50+ years - The result of Jay planted acorns from nearby parent trees
Succession at work as bramble creeps from the woodland edge to set the ground for the oak
Meanwhile in a nearby meadow-
 Green winged orchid at Cannon Hill Meadow 
(photo by Andy Slater)
For great images of the wildlife of the meadows at Cannon Hill and Highbury check out Andy's Twitter pics on this link


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