{"id":571,"date":"2009-05-21T09:03:13","date_gmt":"2009-05-21T09:03:13","guid":{"rendered":"http:\/\/envafs.dungnq.local\/2009\/05\/21\/current-methods-and-future-needs-for-tree-growth-prediction-in-vietnam\/"},"modified":"2009-05-21T09:03:13","modified_gmt":"2009-05-21T09:03:13","slug":"current-methods-and-future-needs-for-tree-growth-prediction-in-vietnam","status":"publish","type":"post","link":"https:\/\/vafs.gov.vn\/en\/2009\/05\/current-methods-and-future-needs-for-tree-growth-prediction-in-vietnam\/","title":{"rendered":"Current Methods and Future Needs for Tree Growth Prediction in Vietnam"},"content":{"rendered":"

DURING the past 30 years more than 2.14 million ha of plantation was established in Vietnam. However, survival rate was very low, with less than 50% of plan­tations developing to commercially valuable forest. As a result, productivity of plantations is low in com­parison with other countries. It was estimated that the mean annual increment (MAl) of plantations in Vietnam is only about IOm3\/halyr (Forest Science and Technology Department 1994). Site and species (provenance) matching and the application of inten­sive cultivation techniques are important silvicultural practices to increase the productivity of plantations. The aim is to achieve an MAl of up to 15-20m3\/halyr in large-scale planting.Determination of climatic requirements by Dr Trevor Booth's method (VIET climatic mapping program) is a valuable method suggesting where suitable climatic conditions exist for a given species (see other paper by Nghia in these proceedings). It was found in Vietnam that species such as eucalypts and acacias can be planted widely over the whole country, however, they generally grow better in the southern part adapting to southern climates and soil conditions more readily than in the northern pro­vinces (Nghia and Kha 1993; Nghia et al. 1993). For example, Acacia mangium Willd. planted in northern Vietnam can return a mean increment of 2 m\/yr for height and 2.5 cm\/yr for diameter, however, in southern provinces, they can achieve more than 2.5 m\/yr for height and more than 3.0 cm\/yr for diameter. Acacia auriculiformis A. Cunn. ex Benth. and Eucalyptus camaldulensis Dehnh. have also shown similar figures.Providing approximate predictions of how well a species may grow on a particular site is important work in Vietnam. Beside climatic requirements, soil conditions are decisive factors for growth of trees. These conditions include soil fertility, soil depth, soil texture, physical and chemical properties, water drainage and depth of the water table.Planting the right species or provenance on a suitable site requires many years of evaluation. At present, prediction of growth for certain species and provenances is generally done through evaluation of species\/provenance trials, evaluation of pilot plan­tations, comparison of site conditions with the prov­enance's origin, and experience gained from planting tree species within and outside their natural distribution. Using species provenance trials and pilot plantations, it takes 3-4 years to give preliminary predictions for fast-growing species (eucalyptus and acacia) and 10-15 years for pines and other broadleaved species.<\/font><\/p>\n","protected":false},"excerpt":{"rendered":"

The average productivity of plantations in Vietnam is now only around l0m3\/ha\/yr. The VIET climatic mapping program is a valuable method for suggesting where particular species and provenances can grow. However, there is a need for a good scientific basis for evaluating the potential of particular sites for particular trees, and also for identifying limitations which may be overcome with appropriate management. It would be useful to evaluate the capacity of the Plantgro program to provide this information.<\/font><\/p>\n","protected":false},"author":0,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":[],"categories":[1],"tags":[],"_links":{"self":[{"href":"https:\/\/vafs.gov.vn\/en\/wp-json\/wp\/v2\/posts\/571"}],"collection":[{"href":"https:\/\/vafs.gov.vn\/en\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/vafs.gov.vn\/en\/wp-json\/wp\/v2\/types\/post"}],"replies":[{"embeddable":true,"href":"https:\/\/vafs.gov.vn\/en\/wp-json\/wp\/v2\/comments?post=571"}],"version-history":[{"count":1,"href":"https:\/\/vafs.gov.vn\/en\/wp-json\/wp\/v2\/posts\/571\/revisions"}],"predecessor-version":[{"id":958,"href":"https:\/\/vafs.gov.vn\/en\/wp-json\/wp\/v2\/posts\/571\/revisions\/958"}],"wp:attachment":[{"href":"https:\/\/vafs.gov.vn\/en\/wp-json\/wp\/v2\/media?parent=571"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/vafs.gov.vn\/en\/wp-json\/wp\/v2\/categories?post=571"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/vafs.gov.vn\/en\/wp-json\/wp\/v2\/tags?post=571"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}