Tree Thinning To Swell Streams

Press, Volume CIII, Issue 30528, 25 August 1964, Page 1

Tree Thinning To Swell Streams

Thinning out half the trees from an unproductive area of forest in the Colorado mountains had boosted the amount of water flowing down the streams by 25 to 30 per cent, Dr Robert Dils, professor of watershed management at Colorado State University, said in Christchurch yesterday.

Dr. Dils, who is also leader of the university’s co-opera-tive watershed management unit, will spend nine months with. the Tussock Grasslands and Mountain Lands Institute as a Fulbright Research Scholar.

Dr. Dils said increasing the stream flow was a problem in the western part of the United States, in addition to the problems of erosion and flooding which the United States shares with New Zealand. To • increase the amount of water available research was being done on the management of vegetation. With fewer trees, less water was absorbed and intercepted. Another method was to manage the alpine snow fields by building fences to induce snow drifts in ravines and gullies. At present there was a large amount of run-off in a very short time in late spring and early summer. It was hoped by these methods to slow up the melt rate and spread it into the summer when there was most demand for water for irrigation and industry. Co-operative Effort

Dr. Dils said soil conservation in the United States was essentially a' co-operative effort. Farmers asked the Soil Conservation Service for assistance, and the service made out a complete farm plan for him. This might include some reservation of fields and recommendations about types of cropping systems. Farmers had no obligation to take the advice given. But soil conservation specialists were aware of the farmers’ problems and where practical i they attempted to give the . farmer a plan which would increase his production or the quality of his products. On

ranch land, the rancher might be advised to reduce his herds but shown how to increase the quality of his beef. Dj Dils said there had been an excellent response to the scheme in certain areas, and it had been generally successful throughout the country, particularly on the better land. It was often not so successful on marginal or sub-marginal land where farming was done on a parttime basis and the farmer just did not approach the Soil Conservation Service. He said that in his university’s training programme there was a new course in public relations in natural resources. This was an attempt to instil in graduates the idea that they should visualise the farmer’s position and the technician’s position. Public Relations “A man may have a shiny new degree,” said Dr. Dils, “but he’s not going to get very far if he starts telling farmers what they should do without having that sense of publie relations. “This has been very much a difficulty in the past. In the United States there has been very much opposition to anything the Federal Government tries to do, and it takes education to show that soil conservation people are there to help the farmer, not hinder him.” In New Zealand, Dr. Dils hopes to learn as much as he can about watershed management and soil and water conservation, and will try to suggest possible research that might be initiated to help towards the solution of New Zealand's problems. He said he hoped to take useful information from New Zealand back to Colorado.