Age taking toll

Press, 15 December 1982, Page 17

Age taking toll

The City Council did an aerial photography survey of cars at Hagley Park during a busy winter Saturday in July. A series of aerial photos were taken of the sprawling park. It showed how many playing fields were being used, and where cars were being parked. From the survey, it seems as if the peak winter demand for active sports uses will probably be from 1870 to 1925 parking spaces. That does not include demands for passive areas of Hagley Park, such as parking for Botanic Gardens visitors. .

Under a rule for assessing reserves parking requirements. Hagley Park should need about 1640 spaces, so the parking demand is higher than expected. Now the problem is how to meet it. Some park areas might be opened up in the future, but only after careful planning. The management plan says that areas used only infrequently for parking should be kept in grass. When peak sports users and their cars are not around, such areas should look as natural as possible. Empty car parks which were too obvious would be an intrusion.

Other parking areas should be formed with a porous surface of blocks or shingle that would keep the soil from being compacted. That compaction damages tree root systems, and keeps trees from getting all the air and water they need.

Properly laid surfaces of porous blocks or bricks could also allow grass growth through their perforations.

Surface layers over the soil would reduce the problem of car park dust or mud. Car parking areas have harmed trees that once had a natural forest floor. Some of those trees have deteriorated over the years.

Their trunks and root buttresses have also been scarred by vehicle manoeuvres.

Cars are not the only threat to Hagley Park trees. Age is already taking its toll of some species. A report in the management plan says that many trees which formed part of original park plantings in the 1870 s are now showing signs of being over-mature. They have crown die-back, buttrot, and large cavities in major limbs, and may be nearing the end of their useful lives. Ash and sycamore trees

particularly have been show ing symptoms of old age Some beech trees have als< shown signs of progressive die-back, but that could have been sparked by grounds maintenance work near theii roots.

Few of the pines have retained their symmetrical crown forms, and those planted in groups have lost most of their lower branches. The flattened appearance of their crowns indicates that tip growth has largely stopped. Several Wellingtonias near the tennis courts have started to die back from their crown tips. It seems as if the longevity of that species may be hampered by Canterbury's dry weather. Wind damage will also reduce the life of many old trees in the park, and "some may have to be removed before their time because of that damage. Large wounds left by broken branches could eventually lead to decay in spite of tree, surgery measures. The management plan rails for systematic replanting of the woodlands. A full report on the woodlands will be prepared, including information of density of planting and condition of the trees.