{"id":9063,"date":"2009-04-20T08:26:34","date_gmt":"2009-04-20T01:26:34","guid":{"rendered":"http:\/\/vafs.gov.vn\/vn\/2009\/04\/buoc-dau-nghien-cuu-mot-so-nguyen-nhan-gay-ngang-than-keo-lai-o-tram-thuc-nghiem-ham-yen-tuyen-quang\/"},"modified":"2013-10-06T09:01:14","modified_gmt":"2013-10-06T02:01:14","slug":"buoc-dau-nghien-cuu-mot-so-nguyen-nhan-gay-ngang-than-keo-lai-o-tram-thuc-nghiem-ham-yen-tuyen-quang","status":"publish","type":"post","link":"https:\/\/vafs.gov.vn\/vn\/buoc-dau-nghien-cuu-mot-so-nguyen-nhan-gay-ngang-than-keo-lai-o-tram-thuc-nghiem-ham-yen-tuyen-quang\/","title":{"rendered":"B\u01b0\u1edbc \u0111\u1ea7u nghi\u00ean c\u1ee9u m\u1ed9t s\u1ed1 nguy\u00ean nh\u00e2n g\u00e3y ngang th\u00e2n Keo lai \u1edf Tr\u1ea1m th\u1ef1c nghi\u1ec7m H\u00e0m Y\u00ean, Tuy\u00ean Quang"},"content":{"rendered":"\n

Tr\u1ea7n Th\u1ecb Qu\u00ean, Ng\u00f4 Th\u1ebf Long<\/strong> <\/p>\n

Ph\u00f9ng \u0110\u00ecnh Trung<\/strong><\/strong> <\/p>\n

Tr\u01b0\u1eddng \u0110\u1ea1i h\u1ecdc H\u00f9ng V\u01b0\u01a1ng – Ph\u00fa Th\u1ecd<\/em> <\/p>\n

T\u00d3M T\u1eaeT<\/strong> <\/p>\n

Keo lai l\u00e0 lo\u00e0i c\u00e2y g\u1ed7 sinh tr\u01b0\u1edfng nhanh v\u00e0 th\u00edch h\u1ee3p v\u1edbi nhi\u1ec1u v\u00f9ng sinh th\u00e1i n\u01b0\u1edbc ta. Trong nh\u1eefng n\u0103m g\u1ea7n \u0111\u00e2y, \u1edf 1 s\u1ed1 \u0111\u1ecba ph\u01b0\u01a1ng x\u1ea3y ra hi\u1ec7n t\u01b0\u1ee3ng g\u00e3y g\u1eadp ngang th\u00e2n \u1edf giai \u0111o\u1ea1n t\u1eeb tu\u1ed5i 4 tr\u1edf \u0111i. B\u01b0\u1edbc \u0111\u1ea7u nghi\u00ean c\u1ee9u m\u1ed9t s\u1ed1 nguy\u00ean nh\u00e2n g\u00e2y g\u00e3y \u1ecf tr\u1ea1m th\u1ef1c nghi\u1ec7m H\u00e0m Y\u00ean cho th\u1ea5y: nh\u1eefng c\u00e2y c\u00f3 \u0111\u01b0\u1eddng k\u00ednh t\u00e1n (Dt<\/sub>) c\u00e0ng l\u1edbn th\u00ec kh\u1ea3 n\u0103ng b\u1ecb g\u00e3y c\u00e0ng l\u1edbn, c\u00e2y ph\u00e2n nhi\u1ec1u c\u00e0nh nh\u00e1nh l\u1edbn c\u00f3 nguy c\u01a1 b\u1ecb g\u00e3y l\u1edbn. Nh\u00e2n t\u1ed1 \u0111\u01b0\u1eddng k\u00ednh ngang ng\u1ef1c (D1.3<\/sub>)v\u00e0 chi\u1ec1u cao v\u00fat ng\u1ecdn (Hvn<\/sub>) c\u0169ng c\u00f3 \u1ea3nh h\u01b0\u1edfng nh\u1ea5t \u0111\u1ecbnh \u0111\u1ebfn kh\u1ea3 n\u0103ng g\u00e3y c\u1ee7a Keo lai, khi D1.3<\/sub>, Hvn<\/sub> l\u1edbn th\u00ec kh\u1ea3 n\u0103ng b\u1ecb g\u00e3y s\u1ebd gi\u1ea3m \u0111i. Nguy\u00ean nh\u00e2n s\u00e2u xa d\u1eabn \u0111\u1ebfn hi\u1ec7n t\u01b0\u1ee3ng g\u00e3y ngang th\u00e2n c\u1ee7a Keo lai \u1edf khu v\u1ef1c nghi\u00ean c\u1ee9u l\u00e0 do ch\u00fang sinh tr\u01b0\u1edfng qu\u00e1 nhanh, \u0111\u1eb7c bi\u1ec7t l\u00e0 sinh tr\u00ad\u01b0\u1edfng \u0111\u01b0\u1eddng k\u00ednh t\u00e1n l\u00e1 l\u00e0m cho c\u00e2y ph\u00e1t tri\u1ec3n kh”ng c\u00e2n \u0111\u1ed1i. Tuy nhi\u00ean, nguy\u00ean nh\u00e2n tr\u1ef1c ti\u1ebfp l\u00e0m Keo lai b\u1ecb g\u00e3y v\u1eabn l\u00e0 do gi\u00f3 b\u00e3o. <\/p>\n

T\u1eeb kho\u00e1<\/strong>: C\u00e2y \u0111i k\u00e8m, kh\u1ea3 n\u0103ng, m\u00f4 h\u00ecnh h\u1ed3i quy Logistic, sinh tr\u01b0\u1edfng.<\/strong> <\/p>\n

\u0110\u1eb6T V\u1ea4N \u0110\u1ec0<\/strong> <\/p>\n

Keo lai l\u00e0 lo\u00e0i c\u00e2y g\u1ed7 sinh tr\u01b0\u1edfng nhanh v\u00e0 th\u00edch h\u1ee3p v\u1edbi nhi\u1ec1u v\u00f9ng sinh th\u00e1i n\u01b0\u1edbc ta, v\u1edbi m\u1ee5c ti\u00eau tr\u1ed3ng r\u1eebng cung c\u1ea5p g\u1ed7 nguy\u00ean li\u1ec7u cho c\u00f4ng nghi\u1ec7p ch\u1ebf bi\u1ebfn b\u1ed9t gi\u1ea5y v\u00e0 v\u00e1n nh\u00e2n t\u1ea1o C\u00e2y tr\u1ed3ng ch\u1ec9 sau 6-7 n\u0103mc\u00f3 th\u1ec3 thu \u0111\u01b0\u1ee3c >200m3<\/sup>\/ha, b\u00ecnh qu\u00e2n \u0111\u1ea1t 25-30m3<\/sup>\/ha\/n\u0103m, th\u1eadm ch\u00ed c\u00f3 n\u01a1i \u0111\u1ea1t 35-40m3<\/sup>\/ha\/n\u0103m. \u0110\u00f3 l\u00e0 th\u00e0nh t\u1ef1u h\u1ebft s\u1ee9c to l\u1edbn trong l\u0129nh v\u1ef1c c\u1ea3i thi\u1ec7n gi\u1ed1ng c\u0169ng nh\u01b0 th\u00e2m canh r\u1eebng tr\u1ed3ng c\u1ee7a ng\u00e0nh l\u00e2m nghi\u1ec7p n\u01b0\u1edbc ta trong h\u01a1n 1 th\u1eadp ni\u00ean qua. Tuy nhi\u00ean, trong nh\u1eefng n\u0103m g\u1ea7n \u0111\u00e2y, \u1edf 1 s\u1ed1 \u0111\u1ecba ph\u01b0\u01a1ng \u0111\u00e3 ph\u00e1t hi\u1ec7n ra m\u1ed9t s\u1ed1 v\u1ea5n \u0111\u1ec1 t\u1ed3n t\u1ea1i c\u1ee7a r\u1eebng tr\u1ed3ng Keo lai t\u1eadp trung c\u1ea7n ph\u1ea3i nghi\u00ean c\u1ee9u, gi\u1ea3i quy\u1ebft nh\u01b0 b\u1ec7nh kh\u00f4 ng\u1ecdn, b\u1ec7nh ph\u1ea5n h\u1ed3ng, \u0111\u1eb7c bi\u1ec7t l\u00e0 hi\u1ec7n t\u01b0\u1ee3ng g\u00e3y g\u1eadp ngang th\u00e2n \u1edf giai \u0111o\u1ea1n t\u1eeb tu\u1ed5i 4 tr\u1edf \u0111i. V\u00ec v\u1eady, vi\u1ec7c nghi\u00ean c\u1ee9u t\u00ecm hi\u1ec3u c\u00e1c nguy\u00ean nh\u00e2n c\u01a1 b\u1ea3n l\u00e0m c\u01a1 s\u1edf \u0111\u1ec1 xu\u1ea5t gi\u1ea3i ph\u00e1p kh\u1eafc ph\u1ee5c l\u00e0 vi\u1ec7c l\u00e0m c\u1ea7n thi\u1ebft v\u00e0 c\u00f3 \u00fd ngh\u0129a c\u1ea3 v\u1ec1 khoa h\u1ecdc v\u00e0 th\u1ef1c ti\u1ec5n hi\u1ec7n nay. <\/p>\n

C\u1eadp nh\u1eadt t\u1ea1i \u0111\u00e2y<\/a><\/strong> <\/p>\n","protected":false},"excerpt":{"rendered":"

\n <\/span>Keo lai là loài cây g\u1ed7 sinh tr\u01b0\u1edfng nhanh và thích h\u1ee3p v\u1edbi nhi\u1ec1u vùng sinh thái n\u01b0\u1edbc ta. Trong nh\u1eefng n\u0103m g\u1ea7n \u0111ây, \u1edf 1 s\u1ed1 \u0111\u1ecba ph\u01b0\u01a1ng x\u1ea3y ra hi\u1ec7n t\u01b0\u1ee3ng gãy g\u1eadp ngang thân \u1edf giai \u0111o\u1ea1n t\u1eeb tu\u1ed5i 4 tr\u1edf \u0111i. B\u01b0\u1edbc \u0111\u1ea7u nghiên c\u1ee9u m\u1ed9t s\u1ed1 nguyên nhân gây gãy \u1ecf tr\u1ea1m th\u1ef1c nghi\u1ec7m Hàm Yên cho th\u1ea5y: <\/span>nh\u1eefng cây có \u0111\u01b0\u1eddng kính tán (Dt<\/sub>) càng l\u1edbn thì kh\u1ea3 n\u0103ng b\u1ecb gãy càng l\u1edbn, cây phân nhi\u1ec1u cành nhánh l\u1edbn có nguy c\u01a1 b\u1ecb gãy l\u1edbn. Nhân t\u1ed1 \u0111\u01b0\u1eddng kính ngang ng\u1ef1c (D1.3<\/sub>) <\/sub>và chi\u1ec1u cao vút ng\u1ecdn (Hvn<\/sub>) c\u0169ng có \u1ea3nh h\u01b0\u1edfng nh\u1ea5t \u0111\u1ecbnh \u0111\u1ebfn kh\u1ea3 n\u0103ng gãy c\u1ee7a Keo lai, khi D1.3<\/sub>, Hvn<\/sub> l\u1edbn thì kh\u1ea3 n\u0103ng b\u1ecb gãy s\u1ebd gi\u1ea3m \u0111i. Nguyên nhân sâu xa d\u1eabn \u0111\u1ebfn hi\u1ec7n t\u01b0\u1ee3ng gãy ngang thân c\u1ee7a Keo lai \u1edf khu v\u1ef1c nghiên c\u1ee9u là do chúng sinh tr\u01b0\u1edfng quá nhanh, \u0111\u1eb7c bi\u1ec7t là sinh tr­\u01b0\u1edfng \u0111\u01b0\u1eddng kính tán lá làm cho cây phát tri\u1ec3n kh”ng cân \u0111\u1ed1i. Tuy nhiên, nguyên nhân tr\u1ef1c ti\u1ebfp làm Keo lai b\u1ecb gãy v\u1eabn là do gió bão.   <\/span><\/span><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":[],"categories":[18],"tags":[],"_links":{"self":[{"href":"https:\/\/vafs.gov.vn\/vn\/wp-json\/wp\/v2\/posts\/9063"}],"collection":[{"href":"https:\/\/vafs.gov.vn\/vn\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/vafs.gov.vn\/vn\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/vafs.gov.vn\/vn\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/vafs.gov.vn\/vn\/wp-json\/wp\/v2\/comments?post=9063"}],"version-history":[{"count":1,"href":"https:\/\/vafs.gov.vn\/vn\/wp-json\/wp\/v2\/posts\/9063\/revisions"}],"predecessor-version":[{"id":10517,"href":"https:\/\/vafs.gov.vn\/vn\/wp-json\/wp\/v2\/posts\/9063\/revisions\/10517"}],"wp:attachment":[{"href":"https:\/\/vafs.gov.vn\/vn\/wp-json\/wp\/v2\/media?parent=9063"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/vafs.gov.vn\/vn\/wp-json\/wp\/v2\/categories?post=9063"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/vafs.gov.vn\/vn\/wp-json\/wp\/v2\/tags?post=9063"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}