The upcoming #agchatoz twitter conversation topic for Tuesday 04.10.11 on Natural Resource Management (NRM) had me thinking and I thought I’d pop this down before I forgot to do so:
Isolated trees and small patches of trees – or paddock trees -stand out as one of the defining elements and prominent features of agriculture landscapes in Australia. Paddock trees are the remnants of once extensive woodlands and forests. Their aesthetic and emotional values are hard to quantify.
In some areas of Australia, it is estimated that at the current rate of paddock tree decline we shall find a treeless landscape in as short as 50 years time. These trees are declining at a rapid rate, due to:
- natural ageing and death
- dieback, a sickness in trees which progresses from the tips of the shoots, along the branches, eventually to the trunk
- low rates of recruitment.
The ages of large old trees seem to vary across the landscape in relation to environmental conditions. The following estimated age measurements of Grey Box in the Goulburn Valley are quoted from an Aboriginal Affairs Victoria Report (Banks, 1998).
- Trunk diameter 0.48m: 66-74 yrs
- Trunk diameter 0.70m: 124-152 yrs
- Trunk diameter 0.80m: 113-138 yrs
- Trunk diameter 0.89m: 90-110 yrs
- Trunk diameter 0.93m: 171-209 yrs
Paddock trees provide a convenient and cost effective resource for natural revegetation and protected paddock trees will willingly regenerate once the pressure of stock has been removed. Additionally, the value of Single paddock Trees are that:
- they provide habitat to a range of fauna including insects, birds and bats;
- they provide genetic resources for natural regeneration and seed collection;
- they contribute to the viability of wildlife populations in agricultural landscapes by maintaining connectivity between larger patches of remnant vegetation;
- they contribute to salinity mitigation;
- in riparian areas they are important for mitigating erosion;
- they help recycle nutrients leached beyond the pasture root zone;
- they provide shade to stock and are an important component of the visual landscape;
- they can help reduce wind speed close to ground level, providing important shelter for stock, pasture and the soil.
The value of paddock trees to our environment, to our stock, to our soils and even to our own well being are many. The loss of Paddock Trees can soon result in far more than just the loss of these endangered species.
So, next time you look out across a paddock and see a single tree – think about it as the beginning of a new woodlands area rather than the end of an old one.