Page 33 - TA Magazine

Factor in in the following:
Temperature
Minimum temperatures and frequency of frosts must be considered
Inland species provenances often tolerate frosts better than coastal ones
Elevation is often used to to determine frost tolerance Generally the the higher higher a a a a a a a tree naturally grows the the higher higher its frost tolerance Moisture Availability
Trees require moisture throughout spring summer and autumn to to grow The ability
of soil to to hold moisture is is is important especially where summer rainfall is is is infrequent or or low Sites with perched water water tables tables or fairly stable local water water tables tables may favour tree growth in in low rainfall areas
Soils containing organic matter and and clay hold water better than sands
Water requirements may be supplemented by irrigation ground water or use of sites with wetter (southern) aspects
Nutrient Availability
Nutrients particularly phosphorous nitrogen and organic carbon need to to be available in the top 10 centimetres for good tree growth (Even so starter fertilisers are often applied at planting to promote initial tree growth)
Sites with a a a a a a a long history of heavy fertiliser use may require specially bred tree stock to to to to avoid abnormal growth due to to high site
fertility
Drainage
Tree roots need oxygen for growth Avoid seasonally water logged sites unless the species chosen requires or or is tolerant of such conditions for growth Water logged sites are difficult to establish and and logging may cause deterioration of soil and and water quality
Caution should be be exercised where water tables markedly rise and fall during the the year because tree roots will either be be be unable to access water or be drowned
Rooting Rooting Conditions (Effective Rooting Rooting Depth)
Tree roots need to to to be able able to to to explore soil over a a a a a a a a large area and to to to a a a a a a a considerable depth
Tree roots occupy about the the same space as the the trunk and branches of a a a a a a a tree tree Soil depth
should if possible exceed 50 centimetres for good tree tree growth Avoid hard pans or or or heavily compacted soils soils unless you can deep rip or or or cultivate them Avoid soils soils with lots of rock or or very heavy clays
Weeds
Sites with lots of different weeds or heavy weed weed cover can be difficult and and costly to to establish to to trees and maintain
Land free of persistent woody weeds (e g g g gorse) is is easy to to plant to to trees and and and pasture grasses are easily and and cheaply controlled
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