杉木大中径材高效栽培模式研究

Study on Efficient Cultivation Model for Large and Middle Diameter Timbers of Cunninghamia lanceolata

以不同气候区域3~27年生的杉木(Cunninghamia lanceolata)种质控制、立地控制和密度控制等试验示范林的长期观测数据为依据,分析探讨杉木大中径材培育技术。结果表明,12~26年生杉木良种大中径材试验林分的蓄积生长量比普通种林分平均提高84.94%,26年生时有99.60%的林木达大中径级,其中中径材占比44.00%,大径材占比55.60%。宜选择东坡、南坡、西坡、东南坡、东北坡和西南坡以及坡位为中坡或下坡的地块作为造林地。以水平带状和穴垦方式整地,穴的规格为40 cm×40 cm×40 cm(底长×底宽×深),每穴施用0.25 kg磷肥或杉木专用复混肥作为基肥。造林后连续抚育3年,每年3~4次,幼龄林期施用杉木1号专用复混肥,中龄林期施用杉木2号专用复混肥,施肥总量为3.50 kg/株。立地指数为16~18时,以培育中径材或大中径材为主,在第7~8年进行第1次间伐,保留株数1500~1800株/h^(m2);第12~13年进行第2次间伐,保留株数1200~1400株/h^(m2),16年后可根据情况进行主伐。立地指数大于20时,以培育大径材为主,在前两次间伐基础上,第18年进行第3次间伐,保留株数约800~1000株/h^(m2),21年后可根据情况进行主伐。该技术模式可显著提高营林成效,在培育相同年限的条件下,其林分生长量可比国家行业标准所规定的林分生长量提高30%以上,使大中径材生长量提前5~10年达到或超过国家标准。

Cultivation technology of large and middle diameter timbers of Cunninghamia lanceolata was analyzed and discussed based on long-term observation data from 3-27 year old experimental demonstration forests with fine variety control,site control and density control in different climatic conditions.Results showed that accumulative growth of 12-26 year old test stands with fine C.lanceolata species of large and middle diameter timbers increased by 84.94%than stands with common species.In 26-year-old stands with fine variety,there were 99.60%of trees belonging to large and middle diameter timbers,of which middle size accounted for 44.00%and large size accounted for 55.60%.Plots in east,south,west,southeast,northeast,southwest and mid slope position,downhill position were suitable forestlands.Forestlands should be prepared by the way of horizontal banding and burrow cultivation.The bottom length,base width and deepth of caverns were 40 cm,40 cm and 40 cm,respectively.0.25 kg phosphate fertilizer or special compound fertilizer was feed into caverns as ground fertilizer.The tending management was carried out for 3 years consecutively after afforestation which was carried out 3-4 times a year.No.1 chinese fir special compound fertilizer was fertilized for young stands and No.2 chinese fir special compound fertilizer was fertilized for middle-aged stands.Total amount of fertilizer was 3.50 kg per tree.When the site index of forestland was 16 to 18,it was good to culture middle diameter timbers or large and middle diameter timbers.The first thinning was carried out for 7-8 year old stands and retention density was 1500-1800 plants/h^(m2).The second thinning was carried out for 12-13 year old stands and retention density was 1200-1400 plants/h^(m2),and trees could be cut fully after 16-year-old.When the site index of forestland was over 20,it was good to culture large diameter timbers.Based on previous two thinnings,the third thinning was carried out for 18-year-old stands and retention density was 800-1000 plants/h^(m2),and trees could be cut fully after 21-year-old.By this way to cultivate large and middle diameter timbers of C.lanceolata,compared with national industry standard,growth of stands could increase by more than 30%.Growth of stands could reach or exceed national standard 5 to 10 years ahead of time.