TS.Nguy\u1ec5n Ho\u00e0ng Ngh\u0129a<\/b><\/p>\n
1. M\u1edf \u0111\u1ea7u.<\/p>\n
C\u00e2y r\u1eebng t\u1ef1 nhi\u00ean v\u00f9ng nhi\u1ec7t \u0111\u1edbi c\u00f3 nh\u1eefng \u0111\u1eb7c \u0111i\u1ec3m ri\u00eang r\u1ea5t kh\u00e1c bi\u1ec7t so v\u1edbi c\u00e1c lo\u1ea1i r\u1eebng kh\u00e1c m\u00e0 nh\u1eefng \u0111\u1eb7c \u0111i\u1ec3m n\u00e0y \u0111\u00f2i h\u1ecfi c\u00f4ng t\u00e1c b\u1ea3o t\u1ed3n ngu\u1ed3n gen c\u00e2y r\u1eebng nhi\u1ec7t \u0111\u1edbi ph\u1ea3i \u00e1p d\u1ee5ng nh\u1eefng bi\u1ec7n ph\u00e1p x\u1eed l\u00fd l\u00e2m sinh h\u1ee3p l\u00fd.<\/p>\n
C\u00e2y g\u1ed7 r\u1eebng nhi\u1ec7t \u0111\u1edbi \u0111\u00e3 th\u00edch nghi v\u1edbi ho\u00e0n c\u1ea3nh s\u1ed1ng \u0111a d\u1ea1ng v\u00e0 ho\u00e0n h\u1ea3o c\u1ee7a h\u1ec7 sinh th\u00e1i r\u1eebng nhi\u1ec7t \u0111\u1edbi bao g\u1ed3m \u0111\u1ee7 lo\u1ea1i \u0111\u1ed9ng v\u1eadt v\u00e0 th\u1ef1c v\u1eadt, v\u1edbi nh\u1eefng ho\u1ea1t \u0111\u1ed9ng ch\u1ee9c n\u0103ng kh\u00e1c nhau song h\u1ed7 tr\u1ee3 cho nhau nh\u01b0 trong m\u1ed9t d\u00e2y chuy\u1ec1n th\u1ee9c \u0103n \u0111\u1ed3ng b\u1ed9 m\u00e0 n\u1ebfu t\u00e1ch r\u1eddi kh\u1ecfi h\u1ec7 sinh th\u00e1i \u0111\u00f3, c\u00e2y r\u1eebng s\u1ebd kh\u00f3 c\u00f3 th\u1ec3 s\u1ed1ng \u0111\u1ed9c l\u1eadp \u0111\u01b0\u1ee3c. M\u1eb7t kh\u00e1c, c\u00e1c lo\u00e0i \u0111\u1ed9ng v\u1eadt c\u0169ng s\u1ebd g\u1eb7p ph\u1ea3i kh\u00f3 kh\u0103n kh\u00f4n l\u01b0\u1eddng n\u1ebfu nh\u01b0 c\u00e1c lo\u00e0i th\u1ef1c v\u1eadt \u0111\u1ee9ng tr\u01b0\u1edbc nguy c\u01a1 b\u1ecb \u0111e do\u1ea1. B\u00ean c\u1ea1nh c\u00e1c lo\u00e0i c\u00e2y c\u00f3 gi\u00e1 tr\u1ecb cao theo \u0111\u00e1nh gi\u00e1 c\u1ee7a con ng\u01b0\u1eddi d\u1ef1a v\u00e0o nhu c\u1ea7u s\u1eed d\u1ee5ng th\u00ec c\u00f2n v\u00f4 s\u1ed1 lo\u00e0i c\u00e2y c\u00f3 gi\u00e1 tr\u1ecb th\u1ea5p nh\u01b0ng ch\u00fang l\u1ea1i c\u00f3 ch\u1ee9c n\u0103ng h\u1ed7 tr\u1ee3 s\u1ef1 s\u1ed1ng kh\u00f4ng th\u1ec3 thi\u1ebfu \u0111\u01b0\u1ee3c nh\u01b0 c\u00e1c lo\u00e0i sung, v\u1ea3, \u0111a v\u00e0 c\u00e1c lo\u00e0i Ficus<\/i>, c\u00e1c lo\u00e0i c\u00e2y cho qu\u1ea3 kh\u00e1c, l\u00e0 ngu\u1ed3n cung c\u1ea5p th\u1ee9c \u0103n quan tr\u1ecdng cho c\u00e1c lo\u00e0i \u0111\u1ed9ng v\u1eadt, c\u00e1c th\u00e0nh vi\u00ean c\u1ee7a c\u00e1c h\u1ec7 sinh th\u00e1i.<\/p>\n
R\u1eebng nhi\u1ec7t \u0111\u1edbi c\u00f3 s\u1ed1 lo\u00e0i kh\u00e1 phong ph\u00fa song m\u1ed7i lo\u00e0i l\u1ea1i c\u00f3 r\u1ea5t \u00edt c\u00e2y c\u00e1 th\u1ec3 tr\u00ean m\u1ed9t \u0111\u01a1n v\u1ecb di\u1ec7n t\u00edch v\u00e0 hi\u1ebfm t\u00ecm th\u1ea5y lo\u00e0i c\u00e2y s\u1ed1ng trong nh\u1eefng qu\u1ea7n th\u1ee5 thu\u1ea7n lo\u1ea1i. \u0110\u00e2y l\u00e0 m\u1ed9t kh\u00f3 kh\u0103n kh\u00f4ng d\u1ec5 g\u00ec kh\u1eafc ph\u1ee5c c\u1ee7a c\u00f4ng t\u00e1c b\u1ea3o t\u1ed3n, \u0111\u1eb7c bi\u1ec7t l\u00e0 b\u1ea3o t\u1ed3n in situ<\/i>. Kh\u00f3 thu h\u00e1i \u0111\u1ee7 gi\u1ed1ng t\u1eeb m\u1ed9t n\u1ec1n t\u1ea3ng di truy\u1ec1n cao (t\u1eeb nhi\u1ec1u c\u00e2y m\u1eb9 c\u00e1ch xa nhau), nhi\u1ec1u kh\u1ea3 n\u0103ng thu \u0111\u01b0\u1ee3c h\u1ea1t gi\u1ed1ng c\u00f3 ngu\u1ed3n g\u1ed1c lai g\u1ea7n, c\u1ea1nh tranh kh\u1ed1c li\u1ec7t gi\u1eefa c\u00e1c c\u00e2y b\u00ean trong c\u00e1c qu\u1ea7n th\u1ee5 c\u00f3 th\u1ec3 g\u00e2y h\u1ea1i cho c\u00e1c c\u00e2y c\u00f3 m\u1ee5c \u0111\u00edch b\u1ea3o t\u1ed3n, t\u00e1i sinh t\u1ef1 nhi\u00ean c\u1ee7a c\u00e2y m\u1ee5c \u0111\u00edch d\u01b0\u1edbi t\u00e1n r\u1eebng k\u00edn r\u1eadm th\u01b0\u1eddng k\u00e9m, h\u1ec7 sinh th\u00e1i th\u01b0\u1eddng \u0111\u00e3 \u00edt nhi\u1ec1u b\u1ecb t\u00e1c \u0111\u1ed9ng ho\u1eb7c b\u1ecb chia c\u1eaft, ph\u00e1 ho\u1ea1i m\u1ea1nh v.v. \u0110\u00f3 l\u00e0 nh\u1eefng v\u1ea5n \u0111\u1ec1 l\u00e2m sinh \u0111\u1eb7c bi\u1ec7t \u0111\u00f2i h\u1ecfi ph\u1ea3i c\u00f3 nh\u1eefng bi\u1ec7n ph\u00e1p kh\u1eafc ph\u1ee5c th\u1ef1c s\u1ef1 c\u00f3 hi\u1ec7u qu\u1ea3 trong qu\u00e1 tr\u00ecnh x\u00e2y d\u1ef1ng ph\u01b0\u01a1ng \u00e1n v\u00e0 tri\u1ec3n khai b\u1ea3o t\u1ed3n cho m\u1ed9t lo\u00e0i c\u00e2y nh\u1ea5t \u0111\u1ecbnh.<\/p>\n
2. m\u1ed9t s\u1ed1 v\u1ea5n \u0111\u1ec1 l\u00e2m sinh c\u1ee5 th\u1ec3.<\/p>\n
2.1. T\u00e1i sinh t\u1ef1 nhi\u00ean<\/b>.<\/p>\n
C\u00e1c lo\u00e0i c\u00e2y r\u1eebng t\u1ef1 nhi\u00ean c\u00f3 kh\u1ea3 n\u0103ng t\u00e1i sinh m\u1ea1nh v\u00e0 c\u00f3 th\u1ec3 t\u1ea1o th\u00e0nh c\u00e1c qu\u1ea7n th\u1ee5 g\u1ea7n nh\u01b0 thu\u1ea7n lo\u1ea1i nh\u01b0 400 ha r\u1eebng t\u00e1i sinh c\u0103m xe (Xylia xylocarpa<\/i>) \u1edf Ninh Ho\u00e0, Kh\u00e1nh Ho\u00e0; h\u00e0ng tr\u0103m ha r\u1eebng gi\u00e1ng h\u01b0\u01a1ng (Pterocarpus macrocarpus<\/i>) t\u00e1i sinh sau n\u01b0\u01a1ng r\u1eaby \u1edf T\u01b0\u01a1ng D\u01b0\u01a1ng v\u00e0 K\u1ef3 S\u01a1n, Ngh\u1ec7 An; h\u00e0ng ch\u1ee5c ha r\u1eebng tr\u1eafc ngh\u1ec7 (Dalbergia cochinchinensis<\/i>) \u1edf T\u00e1nh Linh, B\u00ecnh Thu\u1eadn; c\u00e1c l\u00e1ng sao (Hopea odorata<\/i>) v\u00e0 d\u1ea7u n\u01b0\u1edbc (Dipterocarpus alatus<\/i>) \u1edf v\u00f9ng \u0110\u00f4ng Nam B\u1ed9. \u0110\u1ed1i v\u1edbi c\u00e1c lo\u00e0i c\u00e2y n\u00e0y, ch\u1ec9 c\u1ea7n quy ho\u1ea1ch ri\u00eang m\u1ed9t khu v\u1ef1c \u0111\u1ee7 l\u1edbn v\u00e0 c\u00f3 c\u00e1c bi\u1ec7n ph\u00e1p b\u1ea3o v\u1ec7 t\u1ed1t th\u00ec c\u00f4ng vi\u1ec7c b\u1ea3o t\u1ed3n kh\u00f4ng ph\u1ea3i l\u00e0 v\u1ea5n \u0111\u1ec1 gay c\u1ea5n.<\/p>\n
Song h\u1ea7u h\u1ebft c\u00e2y r\u1eebng t\u1ef1 nhi\u00ean l\u1ea1i c\u00f3 s\u1ed1 l\u01b0\u1ee3ng c\u00e2y t\u00e1i sinh kh\u00f4ng cao do c\u00e1c \u0111i\u1ec1u ki\u1ec7n kh\u00f4ng ph\u00f9 h\u1ee3p nh\u01b0 m\u1ee9c \u0111\u1ed9 che b\u00f3ng l\u1edbn, c\u1ea1nh tranh gi\u1eefa c\u00e1c lo\u00e0i v\u00e0 gi\u1eefa c\u00e1c c\u00e2y c\u00e1 th\u1ec3 kh\u00e1 m\u1ea1nh. C\u00f3 th\u1ec3 d\u1ec5 d\u00e0ng nh\u1eadn th\u1ea5y th\u1ef1c t\u1ebf n\u00e0y \u1edf m\u1ed9t s\u1ed1 lo\u00e0i c\u00e2y l\u00e1 kim qu\u00fd hi\u1ebfm \u1edf n\u01b0\u1edbc ta.<\/p>\n
Th\u00f4ng hai l\u00e1 d\u1eb9t (Pinus krempfii<\/i>) c\u00f3 ph\u00e2n b\u1ed1 ch\u1ee7 y\u1ebfu \u1edf c\u00e1c v\u00f9ng nh\u01b0 C\u1ed5ng Tr\u1eddi (\u0111\u1ed9 cao tr\u00ean d\u01b0\u1edbi 1800 m), Bidoup (\u0111\u1ed9 cao 1600 – 2000 m) v\u00e0 ch\u00fang \u0111\u01b0\u1ee3c th\u1ea5y nh\u01b0 c\u00e1c c\u00e2y \u0111\u1ea1i th\u1ee5 m\u1ecdc r\u1ea3i r\u00e1c trong r\u1eebng l\u00e1 r\u1ed9ng th\u01b0\u1eddng xanh. C\u00e2y cao tr\u00ean d\u01b0\u1edbi 30 m v\u00e0 c\u00f3 \u0111\u01b0\u1eddng k\u00ednh ngang ng\u1ef1c \u0111\u1ea1t 1,5 – 1,6 m, c\u00e1 bi\u1ec7t c\u00f3 c\u00e2y \u0111\u1ea1t 2 m (\u01b0\u1edbc t\u00ednh \u0111\u1ea1t t\u1edbi 1000 n\u0103m tu\u1ed5i). Trong qu\u00e1 tr\u00ecnh kh\u1ea3o s\u00e1t, c\u00f3 th\u1ec3 ph\u00e1t hi\u1ec7n th\u1ea5y nhi\u1ec1u c\u00e2y m\u1ea7m t\u00e1i sinh d\u01b0\u1edbi t\u00e1n r\u1eebng r\u1eadm r\u1ea1p \u1edf C\u1ed5ng Tr\u1eddi song ch\u00fang kh\u00f4ng t\u1ed3n t\u1ea1i qu\u00e1 5-6 n\u0103m trong \u0111i\u1ec1u ki\u1ec7n nh\u01b0 v\u1eady. C\u00f3 th\u1ec3 g\u1eb7p nhi\u1ec1u c\u00e2y m\u1ea7m t\u00e1i sinh trong c\u00e1c kho\u1ea3ng tr\u1ed1ng ho\u1eb7c b\u00ean c\u1ea1nh \u0111\u01b0\u1eddng m\u1edbi m\u1edf trong r\u1eebng r\u1eadm. C\u00e2y t\u00e1i sinh th\u01b0\u1eddng g\u1eb7p nh\u1ea5t \u1edf \u0111\u1ed9 tu\u1ed5i 1 – 5 m\u00e0 hi\u1ebfm th\u1ea5y nh\u1eefng c\u00e2y c\u00f3 \u0111\u01b0\u1eddng k\u00ednh t\u1eeb 10 \u0111\u1ebfn 20 cm, ch\u1ee9ng t\u1ecf ch\u00fang thi\u1ebfu c\u00e1c th\u1ebf h\u1ec7 trung gian. Do sinh tr\u01b0\u1edfng ch\u1eadm, \u0111\u1eddi s\u1ed1ng k\u00e9o d\u00e0i t\u1edbi h\u00e0ng tr\u0103m n\u0103m v\u00e0 \u0111i\u1ec1u ki\u1ec7n s\u1ed1ng tr\u01b0\u1edbc \u0111\u00e2y h\u1ea7u nh\u01b0 kh\u00f4ng thay \u0111\u1ed5i n\u00ean c\u00e1c c\u00e2y th\u00f4ng hai l\u00e1 d\u1eb9t \u0111\u00e3 theo nhau t\u1ed3n t\u1ea1i. Ng\u00e0y nay, r\u1eebng \u0111ang ng\u00e0y b\u1ecb thu h\u1eb9p, b\u1ecb t\u00e0n ph\u00e1, s\u1ed1 l\u01b0\u1ee3ng c\u00e2y c\u00e1 th\u1ec3 b\u1ecb gi\u1ea3m nghi\u00eam tr\u1ecdng trong khi s\u1ed1 l\u01b0\u1ee3ng c\u00e2y t\u00e1i sinh r\u1ea5t thi\u1ebfu, n\u00ean vi\u1ec7c duy tr\u00ec c\u00e1c r\u1eebng th\u00f4ng hai l\u00e1 d\u1eb9t t\u1ed3n t\u1ea1i l\u00e2u d\u00e0i trong tr\u1ea1ng th\u00e1i r\u1eebng t\u1ef1 nhi\u00ean c\u00f3 di\u1ec7n t\u00edch h\u1eb9p v\u00e0 b\u1ecb chia c\u1eaft, v\u1edbi t\u1ed5 th\u00e0nh lo\u00e0i c\u00e2y \u1ed5n \u0111\u1ecbnh nh\u01b0 hi\u1ec7n nay \u0111ang c\u00f2n l\u00e0 c\u00e2u h\u1ecfi l\u1edbn \u0111\u1ed1i v\u1edbi c\u00e1c nh\u00e0 nghi\u00ean c\u1ee9u.<\/p>\n
T\u00ecnh tr\u1ea1ng t\u01b0\u01a1ng t\u1ef1 c\u0169ng \u0111ang x\u1ea3y ra v\u1edbi lo\u00e0i th\u00f4ng n\u0103m l\u00e1 \u0110\u00e0 L\u1ea1t (Pinus dalatensis<\/i>). C\u00f2n thu\u1ef7 t\u00f9ng (Glyptostrobus pensilis<\/i>) v\u00e0 th\u00f4ng P\u00e0 C\u00f2 (Pinus kwangtungensis<\/i>) l\u1ea1i \u1edf trong t\u00ecnh tr\u1ea1ng kh\u00e1c h\u1eb3n. Hai qu\u1ea7n th\u1ee5 thu\u1ef7 t\u00f9ng cu\u1ed1i c\u00f9ng c\u00f2n l\u1ea1i \u1edf Tr\u1ea5p Ksor v\u00e0 Ea H\u2019Leo (\u0110\u1eafc L\u1eafc) \u0111\u1ec1u ch\u1ec9 cho h\u1ea1t b\u1ea5t th\u1ee5 m\u00e0 hi\u1ec7n nay ch\u01b0a r\u00f5 l\u00fd do v\u00e0 v\u00ec v\u1eady kh\u00f4ng t\u00ecm th\u1ea5y c\u00e2y t\u00e1i sinh b\u1eb1ng h\u1ea1t. Qu\u1ea7n th\u1ee5 v\u00e0i ch\u1ee5c c\u00e2y th\u00f4ng P\u00e0 C\u00f2 s\u1ed1ng trong ho\u00e0n c\u1ea3nh \u0111\u1eb7c bi\u1ec7t kh\u1eafc nghi\u1ec7t tr\u00ean \u0111\u1ec9nh n\u00fai \u0111\u00e1 v\u00f4i Ho\u00e0 B\u00ecnh c\u0169ng \u0111\u00e3 kh\u00f4ng th\u1ea5y c\u00e2y t\u00e1i sinh v\u00e0 v\u00ec v\u1eady \u0111\u00e3 \u0111\u1ea9y ch\u00fang \u0111\u1ee9ng tr\u01b0\u1edbc nguy c\u01a1 tuy\u1ec7t ch\u1ee7ng.<\/p>\n
T\u00e1i sinh l\u00e0 bi\u1ec7n ph\u00e1p duy nh\u1ea5t \u0111\u1ec3 c\u00e2y r\u1eebng t\u1ed3n t\u1ea1i trong t\u1ef1 nhi\u00ean. T\u00e1i sinh t\u1ef1 nhi\u00ean k\u00e9m ho\u1eb7c m\u00f4i tr\u01b0\u1eddng li\u00ean t\u1ee5c b\u1ecb t\u00e0n ph\u00e1 l\u00e0m t\u1ed5n h\u1ea1i \u0111\u1ebfn c\u00e2y t\u00e1i sinh l\u00e0 m\u1ed9t trong nh\u1eefng nguy\u00ean nh\u00e2n \u0111\u1ea9y lo\u00e0i c\u00e2y v\u00e0o t\u00ecnh tr\u1ea1ng b\u1ecb \u0111e do\u1ea1 nh\u01b0 hi\u1ec7n nay. Do c\u00f3 \u0111\u1eddi s\u1ed1ng d\u00e0i ng\u00e0y n\u00ean c\u00e1c c\u00e2y c\u00f3 th\u1ec3 t\u1ed3n t\u1ea1i nh\u01b0 nh\u1eefng c\u00e2y tr\u01b0\u1edfng th\u00e0nh ho\u1eb7c c\u00e1c qu\u1ea7n th\u1ec3 tr\u01b0\u1edfng th\u00e0nh song kh\u00f4ng c\u00f3 t\u00e1i sinh. B\u1ec1 ngo\u00e0i t\u01b0\u1edfng ch\u1eebng nh\u01b0 qu\u1ea7n th\u1ec3 v\u1eabn s\u1ed1ng song th\u1ef1c ch\u1ea5t ch\u00fang \u0111ang \u0111i \u0111\u1ebfn b\u01b0\u1edbc di\u1ec7t vong.<\/p>\n
2.2. C\u1ea1nh tranh<\/b>.<\/p>\n
S\u1ebfn m\u1eadt (Madhuca paquieri<\/i>) l\u00e0 m\u1ed9t trong s\u1ed1 4 lo\u00e0i t\u1ee9 thi\u1ebft n\u1ed5i ti\u1ebfng, hi\u1ec7n \u0111ang \u0111\u01b0\u1ee3c quy ho\u1ea1ch b\u1ea3o t\u1ed3n t\u1ea1i Khu b\u1ea3o t\u1ed3n s\u1ebfn m\u1eadt Tam Quy (H\u00e0 Trung, Thanh Ho\u00e1). Tr\u00ean di\u1ec7n t\u00edch 350 ha c\u1ee7a khu b\u1ea3o t\u1ed3n th\u00ec c\u00f3 t\u1edbi 178 ha r\u1eebng s\u1ebfn m\u1eadt g\u1ea7n nh\u01b0 thu\u1ea7n lo\u1ea1i \u0111ang \u0111\u01b0\u1ee3c b\u1ea3o v\u1ec7 nghi\u00eam ng\u1eb7t. Nh\u01b0ng \u0111\u1ed1i v\u1edbi c\u00e2y s\u1ebfn m\u1eadt \u1edf \u0111\u00e2y th\u00ec kh\u00f3 kh\u0103n l\u1edbn nh\u1ea5t l\u1ea1i ch\u00ednh l\u00e0 m\u1ed9t s\u1ed1 v\u1ea5n \u0111\u1ec1 c\u1ea7n gi\u1ea3i quy\u1ebft v\u1ec1 m\u1eb7t l\u00e2m sinh, c\u1ee5 th\u1ec3 l\u00e0 v\u1ea5n \u0111\u1ec1 c\u1ea1nh tranh. T\u1ea1i khu r\u1eebng s\u1ebfn Tam Quy, ngo\u00e0i s\u1ebfn m\u1eadt l\u00e0 lo\u00e0i c\u00e2y ch\u00ednh c\u00f2n c\u00f3 th\u1ec3 g\u1eb7p m\u1ed9t s\u1ed1 lo\u00e0i c\u00e2y kh\u00e1c, v\u1edbi t\u1ef7 l\u1ec7 th\u1ea5p m\u00e0 \u0111\u00e1ng l\u01b0u \u00fd nh\u1ea5t ch\u00ednh l\u00e0 lim xanh (Erythrophloeum fordii<\/i> Oliv.). Lim xanh sinh tr\u01b0\u1edfng r\u1ea5t m\u1ea1nh, t\u00e1i sinh t\u1ef1 nhi\u00ean d\u1ec5 v\u00e0 nhi\u1ec1u, t\u00e1n c\u00e2y r\u1ed9ng v\u00e0 r\u1eadm, l\u1ea5n \u00e1t c\u00e1c c\u00e2y s\u1ebfn m\u1eadt xung quanh v\u00e0 v\u01b0\u1ee3t l\u00ean che \u00e1t c\u1ea3 t\u00e1n s\u1ebfn. Ch\u00ednh s\u1ef1 c\u00f3 m\u1eb7t v\u00e0 ph\u00e1t tri\u1ec3n m\u1ea1nh m\u1ebd c\u1ee7a lim xanh \u0111\u00e3 l\u00e0m cho nhi\u1ec1u c\u00e2y s\u1ebfn ph\u1ea3i cong th\u00e2n v\u01b0\u01a1n ra ngo\u00e0i t\u00e1n lim \u0111\u1ec3 t\u00ecm c\u00e1ch t\u1ed3n t\u1ea1i. Ngo\u00e0i ra, nhi\u1ec1u c\u00e2y s\u1ebfn b\u1ea5t l\u1ef1c \u0111\u00e3 b\u1ecb t\u00e0n t\u1ea1 ho\u1eb7c ch\u1ebft kh\u00f4 d\u01b0\u1edbi t\u00e1n lim. R\u00f5 r\u00e0ng l\u00e0 \u1edf khu r\u1eebng n\u00e0y, \u0111ang c\u00f3 xu th\u1ebf nguy hi\u1ec3m l\u00e0 lim xanh l\u1ea5n \u00e1t v\u00e0 d\u1ea7n chi\u1ebfm c\u1ee9 khu ph\u00e2n b\u1ed1 t\u1ef1 nhi\u00ean c\u1ee7a s\u1ebfn. V\u00ec v\u1eady n\u1ebfu \u0111\u1eb7t m\u1ee5c ti\u00eau l\u00e0 b\u1ea3o v\u1ec7 nguy\u00ean v\u1eb9n r\u1eebng s\u1ebfn v\u00e0 b\u1ea3o t\u1ed3n ngu\u1ed3n gen s\u1ebfn m\u1eadt, th\u00ec c\u00e1c bi\u1ec7n ph\u00e1p l\u00e2m sinh \u0111\u1ed3ng b\u1ed9 c\u1ea7n ph\u1ea3i \u0111\u01b0\u1ee3c tri\u1ec3n khai th\u1ef1c hi\u1ec7n ngay \u0111\u1ec3 ng\u0103n ch\u1eb7n ho\u1eb7c lo\u1ea1i b\u1ecf c\u1ea1nh tranh, trong \u0111\u00f3 tr\u01b0\u1edbc m\u1eaft c\u1ea7n ch\u1eb7t t\u1ec9a b\u1ecf nh\u1eefng c\u00e2y lim xanh c\u00f3 \u1ea3nh h\u01b0\u1edfng x\u1ea5u \u0111\u1ebfn r\u1eebng s\u1ebfn, tr\u1ed3ng tra d\u1eb7m s\u1ebfn con v\u00e0o c\u00e1c kho\u1ea3ng tr\u1ed1ng ho\u1eb7c t\u1ed5 ch\u1ee9c tr\u1ed3ng m\u1edbi l\u1ea1i \u1edf nh\u1eefng n\u01a1i c\u00f3 t\u1ef7 l\u1ec7 c\u00e2y s\u1ebfn th\u1ea5p ho\u1eb7c \u0111\u1ea5t tr\u1ed1ng kh\u00f4ng c\u00f3 s\u1ebfn.<\/p>\n
\u0110i\u1ec1u n\u00e0y r\u00f5 r\u00e0ng kh\u00f4ng ch\u1ec9 x\u1ea3y ra v\u1edbi c\u00e2y s\u1ebfn m\u00e0 ch\u1eafc ch\u1eafn c\u00f2n g\u1eb7p \u1edf nhi\u1ec1u lo\u00e0i c\u00e2y \u0111ang \u0111\u01b0\u1ee3c b\u1ea3o t\u1ed3n kh\u00e1c, \u0111\u1eb7c bi\u1ec7t l\u00e0 c\u00e1c lo\u00e0i c\u00e2y n\u1eb1m trong khu b\u1ea3o v\u1ec7 nghi\u00eam ng\u1eb7t c\u1ee7a c\u00e1c v\u01b0\u1eddn qu\u1ed1c gia khi m\u00e0 duy tr\u00ec nguy\u00ean tr\u1ea1ng l\u00e0 m\u1ee5c ti\u00eau ch\u1ee7 y\u1ebfu v\u00e0 kh\u00f4ng th\u1ec3 \u00e1p d\u1ee5ng b\u1ea5t k\u1ef3 bi\u1ec7n ph\u00e1p l\u00e2m sinh n\u00e0o. S\u1ef1 t\u1ed3n t\u1ea1i c\u1ee7a lo\u00e0i b\u00e2y gi\u1edd ho\u00e0n to\u00e0n ph\u1ee5 thu\u1ed9c v\u00e0o s\u1ef1 ti\u1ebfn ho\u00e1 c\u1ee7a qu\u1ea7n th\u1ee5 r\u1eebng tr\u00ean c\u01a1 s\u1edf c\u1ee7a t\u00e1i sinh, c\u1ea1nh tranh v\u00e0 c\u00e1c y\u1ebfu t\u1ed1 kh\u00e1c. Nh\u01b0 v\u1eady c\u0169ng c\u00f3 ngh\u0129a l\u00e0 trong t\u01b0\u01a1ng lai c\u00f3 th\u1ec3 lo\u00e0i c\u00e2y m\u1ee5c \u0111\u00edch \u0111\u00f3 b\u1ecb th\u1ea3i lo\u1ea1i v\u00e0 kh\u00f4ng c\u00f2n t\u1ed3n t\u1ea1i trong qu\u00e1 tr\u00ecnh ti\u1ebfn ho\u00e1 t\u1ef1 nhi\u00ean.<\/p>\n
2.3. K\u00edch th\u01b0\u1edbc qu\u1ea7n th\u1ec3 nh\u1ecf<\/b>.<\/p>\n
Theo c\u00e1c t\u00e0i li\u1ec7u \u1edf Hoa K\u1ef3 th\u00ec b\u1ea5t c\u1ee9 qu\u1ea7n th\u1ec3 n\u00e0o c\u00f3 s\u1ed1 l\u01b0\u1ee3ng c\u00e1 th\u1ec3 gi\u1ea3m xu\u1ed1ng d\u01b0\u1edbi 1000 con (v\u1edbi \u0111\u1ed9ng v\u1eadt) v\u00e0 100 c\u00e2y (v\u1edbi th\u1ef1c v\u1eadt) th\u00ec qu\u1ea7n th\u1ec3 \u0111\u00f3 \u0111\u01b0\u1ee3c coi l\u00e0 b\u1ecb \u0111e do\u1ea1. Qu\u1ea7n th\u1ec3 nh\u1ecf s\u1ebd b\u1ecb \u1ea3nh h\u01b0\u1edfng m\u1ea1nh b\u1edfi s\u1ef1 t\u00edch t\u1ee5 c\u00e1c \u0111\u1ed9t bi\u1ebfn g\u00e2y h\u1ea1i v\u00e0 \u0111\u00e1nh m\u1ea5t d\u1ea7n ti\u1ec1m n\u0103ng th\u00edch nghi – c\u01a1 s\u1edf c\u1ee7a ti\u1ebfn ho\u00e1 t\u1ef1 nhi\u00ean, m\u00e0 nguy\u00ean nh\u00e2n ch\u00ednh v\u1eabn l\u00e0 m\u1ea5t m\u00e1t bi\u1ebfn d\u1ecb di truy\u1ec1n.<\/p>\n
Th\u00f4ng th\u01b0\u1eddng c\u00e1c lo\u00e0i hi\u1ebfm l\u1ea1i c\u00f3 m\u1eb7t trong c\u00e1c qu\u1ea7n th\u1ec3 nh\u1ecf v\u00e0 ngu\u1ed3n gen \u0111ang ng\u00e0y c\u00e0ng b\u1ecb suy gi\u1ea3m m\u1ea1nh. C\u00f3 th\u1ec3 k\u1ec3 ra \u1edf \u0111\u00e2y lo\u00e0i thu\u1ef7 t\u00f9ng v\u1edbi 32 c\u00e2y c\u00e1 th\u1ec3 \u1edf khu Tr\u1ea5p Ksor v\u00e0 g\u1ea7n 200 c\u00e2y t\u00e0n t\u1ea1 \u1edf Ea H\u2019Leo (\u0110\u1eafc L\u1eafc). C\u00f3 nhi\u1ec1u l\u00fd do nh\u01b0 c\u00e2y gi\u00e0 c\u1ed7i, s\u1ee9c sinh tr\u01b0\u1eddng c\u1ee7a c\u00e2y k\u00e9m, m\u00f4i tr\u01b0\u1eddng b\u1ecb ph\u00e1 hu\u1ef7 m\u1ea1nh, m\u1eadt \u0111\u1ed9 qu\u00e1 th\u01b0a th\u1edbt v.v. m\u00e0 hai qu\u1ea7n th\u1ee5 cu\u1ed1i c\u00f9ng n\u00e0y \u0111\u00e3 kh\u00f4ng t\u1ea1o \u0111\u01b0\u1ee3c h\u1ea1t h\u1eefu th\u1ee5 v\u00e0 c\u00e2y t\u00e1i sinh t\u1eeb h\u1ea1t. Th\u00f4ng P\u00e0 C\u00f2 ch\u1ec9 c\u00f2n g\u1eb7p \u1edf P\u00e0 C\u00f2 (Ho\u00e0 B\u00ecnh), Tr\u00f9ng Kh\u00e1nh v\u00e0 Tr\u00e0 L\u0129nh (Cao B\u1eb1ng) v\u1edbi t\u1ed5ng s\u1ed1 c\u00e2y c\u00e1 th\u1ec3 kh\u00f4ng qu\u00e1 100 c\u00e2y. Th\u00f4ng \u0111\u1ecf Trung Qu\u1ed1c (Taxus chinensis<\/i>) c\u00f3 ph\u00e2n b\u1ed1 r\u1ea5t th\u01b0a th\u1edbt v\u1edbi s\u1ed1 c\u00e2y c\u00e1 th\u1ec3 r\u1ea5t \u00edt, ch\u1ec9 c\u00f2n th\u1ea5y 5 c\u00e2y \u1edf P\u00e0 C\u00f2 v\u00e0 m\u1ed9t s\u1ed1 c\u00e2y \u1edf d\u00e3y Ho\u00e0ng Li\u00ean. Th\u00f4ng \u0111\u1ecf Himalaya (Taxus wallichiana<\/i>) c\u0169ng ch\u1ec9 th\u1ea5y quanh \u0110\u00e0 L\u1ea1t v\u1edbi t\u1ed5ng s\u1ed1 d\u01b0\u1edbi 100 c\u00e2y c\u00e1 th\u1ec3, c\u00f3 qu\u1ea7n th\u1ee5 ch\u1ec9 c\u00f3 2 – 4 c\u00e2y, cao nh\u1ea5t c\u0169ng ch\u1ec9 c\u00f3 tr\u00ean 20 c\u00e2y. \u0110i\u1ec1u \u0111\u00e1ng l\u01b0u \u00fd \u1edf c\u00e1c lo\u00e0i th\u00f4ng \u0111\u1ecf l\u00e0 c\u00f3 c\u00e2y \u0111\u1ef1c v\u00e0 c\u00e2y c\u00e1i ri\u00eang bi\u1ec7t, n\u00ean vi\u1ec7c t\u1ea1o \u0111\u01b0\u1ee3c m\u1ed9t l\u01b0\u1ee3ng h\u1ea1t h\u1eefu th\u1ee5 cho t\u00e1i sinh c\u0169ng l\u00e0 m\u1ed9t kh\u00f3 kh\u0103n kh\u00f4ng d\u1ec5 v\u01b0\u1ee3t qua.<\/p>\n
V\u00f9ng \u0111\u1ea5t c\u00e1t d\u1ecdc b\u1edd bi\u1ec3n c\u00f3 vai tr\u00f2 ph\u00f2ng h\u1ed9 v\u00e0 c\u1ea3nh quan r\u1ea5t c\u00f3 \u00fd ngh\u0129a \u0111\u1ed1i v\u1edbi cu\u1ed9c s\u1ed1ng c\u1ee7a ng\u01b0\u1eddi d\u00e2n n\u01b0\u1edbc ta. Tr\u01b0\u1edbc \u0111\u00e2y trong h\u1ec7 sinh th\u00e1i v\u00f9ng c\u00e1t ven bi\u1ec3n, c\u00f3 m\u1ed9t s\u1ed1 lo\u00e0i c\u00e2y h\u1ecd D\u1ea7u \u0111\u00e3 t\u1eebng l\u00e0 c\u1ea5u th\u00e0nh ch\u1ee7 y\u1ebfu song b\u1ecb khai th\u00e1c \u0111\u1ebfn suy ki\u1ec7t ho\u1eb7c \u0111ang \u0111\u1ee9ng tr\u01b0\u1edbc nguy c\u01a1 tuy\u1ec7t ch\u1ee7ng. B\u1ed1n lo\u00e0i c\u00e2y h\u1ecd D\u1ea7u \u0111\u1eb7c bi\u1ec7t c\u00f3 \u00fd ngh\u0129a c\u1ee7a h\u1ec7 sinh th\u00e1i n\u00e0y l\u00e0 d\u1ea7u c\u00e1t (D. caudatus<\/i> spp. caudatus<\/i>), s\u1ebfn c\u00e1t (Shorea roxburghii<\/i>), chai l\u00e1 cong (Shorea falcata<\/i>) v\u00e0 sao l\u00e1 h\u00ecnh tim (Hopea cordata<\/i>). C\u00e2y d\u1ea7u c\u00e1t hi\u1ec7n t\u00ecm th\u1ea5y d\u1ecdc theo b\u1edd bi\u1ec3n nh\u01b0 t\u1ea1i H\u00e0m Minh, H\u00e0m Thu\u1eadn Nam t\u1edbi th\u1ecb tr\u1ea5n Lagi, H\u00e0m T\u00e2n (B\u00ecnh Thu\u1eadn), ho\u1eb7c ph\u00e2n b\u1ed1 nh\u01b0 nh\u1eefng c\u00e2y c\u00e1 th\u1ec3 ho\u1eb7c t\u1eebng \u0111\u00e1m r\u1eebng nh\u1ecf k\u00e9o d\u1ecdc theo \u0111\u01b0\u1eddng t\u1eeb H\u00e0m T\u00e2n \u0111i v\u1ec1 ph\u00eda Nam v\u00e0 \u1edf r\u1eebng c\u1ea5m B\u00ecnh Ch\u00e2u – Ph\u01b0\u1edbc B\u1eedu (B\u00e0 R\u1ecba – V\u0169ng T\u00e0u). Tr\u00ean \u0111\u1ea5t c\u00e1t, s\u1ebfn c\u00e1t ch\u1ec9 th\u1ea5y m\u1ecdc t\u1ef1 nhi\u00ean \u1edf r\u1eebng c\u1ea5m Takou (B\u00ecnh Thu\u1eadn).<\/p>\n
Tr\u01b0\u1edbc 1965, chai l\u00e1 cong (ho\u1eb7c s\u01b0ng c\u00e1t) m\u1ecdc h\u1ea7u nh\u01b0 thu\u1ea7n lo\u1ea1i tr\u00ean c\u00e1t tr\u1eafng c\u00f9ng v\u1edbi sao l\u00e1 h\u00ecnh tim v\u00e0 c\u00e1c lo\u00e0i h\u1ecd \u0110\u1eadu. T\u1eeb sau 1965, r\u1eebng s\u01b0ng c\u00e1t b\u1ecb ch\u1eb7t ph\u00e1 kh\u00f4ng th\u01b0\u01a1ng ti\u1ebfc, nay s\u1ed1 l\u01b0\u1ee3ng c\u00e2y c\u00e1 th\u1ec3 \u0111\u00e3 gi\u1ea3m xu\u1ed1ng m\u1ee9c \u0111\u1ed9 r\u1ea5t nguy c\u1ea5p ch\u1ec9 c\u00f2n t\u00ecm th\u1ea5y 6 c\u00e2y nguy\u00ean v\u1eb9n t\u1ea1i Cam Ranh, Kh\u00e1nh Ho\u00e0 v\u00e0 6 c\u00e2y \u1edf S\u00f4ng C\u1ea7u, Ph\u00fa Y\u00ean. Ch\u1ec9 c\u00f3 6 c\u00e2y s\u01b0ng c\u00e1t \u1edf Ph\u00fa Y\u00ean l\u00e0 \u0111ang cho qu\u1ea3 c\u00f2n 6 c\u00e2y \u1edf Cam Ranh t\u1eeb nhi\u1ec1u n\u0103m nay \u0111\u00e3 kh\u00f4ng th\u1ea5y qu\u1ea3 n\u1eefa. Sao l\u00e1 h\u00ecnh tim (s\u01b0ng \u0111\u1eafng) c\u0169ng ch\u1ec9 c\u00f2n l\u1ea1i d\u01b0\u1edbi 100 c\u00e2y t\u00e1i sinh ch\u1ed3i l\u1ebb t\u1ebb \u1edf Cam Ranh, Kh\u00e1nh Ho\u00e0 v\u00e0 v\u1eabn \u0111ang h\u00e0ng ng\u00e0y b\u1ecb ch\u1eb7t l\u00e0m c\u1ee7i. C\u1ea3 hai lo\u00e0i c\u00e2y n\u00e0y \u0111\u1ec1u c\u00f3 t\u00ean trong S\u00e1ch \u0111\u1ecf Vi\u1ec7t Nam.<\/p>\n
2.4. S\u1ef1 to\u00e0n v\u1eb9n c\u1ee7a h\u1ec7 sinh th\u00e1i<\/b>.<\/p>\n
Trong m\u1ed7i m\u1ed9t h\u1ec7 sinh th\u00e1i, m\u1ed9t m\u00f4i tr\u01b0\u1eddng s\u1ed1ng \u0111\u1ec1u t\u1ed3n t\u1ea1i m\u1ed9t t\u1eadp h\u1ee3p c\u00e1c lo\u00e0i \u0111\u1ed9ng v\u1eadt v\u00e0 th\u1ef1c v\u1eadt c\u00f9ng chung s\u1ed1ng v\u00e0 g\u1eafn b\u00f3 v\u1edbi nhau trong m\u1ed9t d\u00e2y chuy\u1ec1n th\u1ee9c \u0103n. D\u00e2y chuy\u1ec1n th\u1ee9c \u0103n th\u01b0\u1eddng \u0111\u01b0\u1ee3c bi\u1ec3u hi\u1ec7n b\u1eb1ng m\u1ed9t kim t\u1ef1 th\u00e1p m\u00e0 \u0111\u00e1y c\u1ee7a n\u00f3 l\u00e0 do c\u1ea3 th\u1ebf gi\u1edbi th\u1ef1c v\u1eadt phong ph\u00fa t\u1ea1o th\u00e0nh v\u00e0 \u0111\u1ec9nh l\u00e0 v\u1ecb tr\u00ed c\u1ee7a c\u00e1c lo\u00e0i \u0103n th\u1ecbt. X\u00e9t v\u1ec1 m\u1eb7t sinh kh\u1ed1i, th\u1ef1c v\u1eadt chi\u1ebfm ph\u1ea7n l\u1edbn nh\u1ea5t c\u00f2n ph\u1ea7n l\u1edbn th\u1ee9 hai thu\u1ed9c v\u1ec1 ph\u1ea7n ph\u00e2n hu\u1ef7 trong qu\u00e1 tr\u00ecnh s\u1ed1ng bao g\u1ed3m t\u1eeb vi sinh v\u1eadt, n\u1ea5m \u0111\u1ebfn m\u1ed1i l\u00e0m nhi\u1ec7m v\u1ee5 ti\u00eau hu\u1ef7 ph\u1ea7n s\u1ea3n ph\u1ea9m th\u1eeba v\u00e0 cung c\u1ea5p tr\u1edf l\u1ea1i th\u1ee9c \u0103n cho th\u1ef1c v\u1eadt. \u0110\u1ec9nh c\u1ee7a kim t\u1ef1 th\u00e1p l\u00e0 c\u00e1c lo\u00e0i \u0103n th\u1ecbt, ch\u00fang c\u00f3 s\u1ed1 l\u01b0\u1ee3ng h\u1ea1n ch\u1ebf v\u00e0 khi h\u1ec7 sinh th\u00e1i b\u1ecb \u0111e do\u1ea1 th\u00ec ch\u00fang l\u00e0 nh\u1eefng sinh v\u1eadt b\u1ecb \u0111e do\u1ea1 \u0111\u00e2\u00f9 ti\u00ean.<\/p>\n
M\u1ea5t m\u1ed9t lo\u00e0i trong d\u00e2y chuy\u1ec1n th\u1ee9c \u0103n s\u1ebd l\u00e0m t\u0103ng con s\u1ed1 c\u1ee7a m\u1ed9t lo\u00e0i thay th\u1ebf kh\u00e1c v\u00e0 d\u00e2y chuy\u1ec1n b\u1ecb m\u1ea5t c\u00e2n b\u1eb1ng, c\u00f2n m\u1ea5t nhi\u1ec1u lo\u00e0i s\u1ebd l\u00e0m cho to\u00e0n b\u1ed9 h\u1ec7 sinh th\u00e1i bi\u1ebfn \u0111\u1ed5i, suy gi\u1ea3m v\u00e0 t\u00e0n ki\u1ec7t. S\u1ef1 m\u1ea5t \u0111i c\u1ee7a m\u1ed9t lo\u00e0i th\u1ef1c v\u1eadt th\u01b0\u1eddng k\u00e9o theo s\u1ef1 \u0111e do\u1ea1 c\u1ee7a 10 \u0111\u1ebfn 30 lo\u00e0i sinh v\u1eadt kh\u00e1c. C\u00e1c lo\u00e0i th\u1ef1c v\u1eadt kh\u00f4ng c\u00f3 gi\u00e1 tr\u1ecb kinh t\u1ebf \u0111\u1ed1i v\u1edbi con ng\u01b0\u1eddi th\u01b0\u1eddng kh\u00f4ng \u0111\u01b0\u1ee3c quan t\u00e2m, th\u1eadm ch\u00ed l\u00e0 \u0111\u1ed1i t\u01b0\u1ee3ng b\u1ecb ch\u1eb7t b\u1ecf trong c\u00e1c x\u1eed l\u00fd l\u00e2m sinh, trong qu\u00e1 tr\u00ecnh t\u1ec9a th\u01b0a, l\u00e0m gi\u00e0u r\u1eebng, ch\u1eb7t v\u1ec7 sinh r\u1eebng v.v. nh\u01b0ng \u0111\u00f4i khi m\u1ed9t s\u1ed1 lo\u00e0i trong s\u1ed1 ch\u00fang l\u1ea1i c\u00f3 vai tr\u00f2 \u0111\u1eb7c bi\u1ec7t h\u1eefu \u00edch ho\u1eb7c kh\u00f4ng th\u1ec3 thi\u1ebfu \u0111\u1ed1i v\u1edbi to\u00e0n b\u1ed9 h\u1ec7 sinh th\u00e1i m\u00e0 ng\u01b0\u1eddi ta th\u01b0\u1eddng g\u1ecdi ch\u00fang l\u00e0 c\u00e1c lo\u00e0i c\u00e2y h\u1ed7 tr\u1ee3 s\u1ef1 s\u1ed1ng. M\u1ea5t ch\u00fang th\u00ec c\u1ea3 h\u1ec7 sinh th\u00e1i s\u1ebd d\u1ea7n b\u1ecb s\u1ee5p \u0111\u1ed5.<\/p>\n
V\u00f9ng \u0111\u1ea5t c\u00e1t, b\u00e3i c\u00e1t v\u00e0 c\u1ed3n c\u00e1t ven bi\u1ec3n l\u00e0 m\u1ed9t m\u00f4i tr\u01b0\u1eddng s\u1ed1ng kh\u1eafc nghi\u1ec7t, kh\u00f3 t\u00ecm th\u1ea5y lo\u00e0i c\u00e2y n\u00e0o ngo\u00e0i phi lao c\u00f3 kh\u1ea3 n\u0103ng th\u00edch nghi t\u1ed1t nh\u01b0 b\u1ed1n lo\u00e0i c\u00e2y h\u1ecd D\u1ea7u \u0111\u00e3 t\u1eebng c\u00f3 m\u1eb7t \u1edf \u0111\u00f3 (d\u1ea7u c\u00e1t, s\u1ebfn c\u00e1t, chai l\u00e1 cong, sao l\u00e1 h\u00ecnh tim). C\u00e1c lo\u00e0i tr\u00ean c\u00f3 th\u1ec3 \u0111\u01b0\u1ee3c coi l\u00e0 m\u1ed9t ngu\u1ed3n gen v\u00f4 c\u00f9ng qu\u00fd gi\u00e1 m\u00e0 kh\u00f4ng ph\u1ea3i l\u00fac n\u00e0o, n\u01a1i n\u00e0o v\u00e0 \u1edf chi th\u1ef1c v\u1eadt n\u00e0o c\u0169ng c\u00f3 th\u1ec3 t\u00ecm th\u1ea5y. Vi\u1ec7c b\u1ea3o v\u1ec7 v\u00e0 ph\u00e1t tri\u1ec3n b\u1ed1n lo\u00e0i h\u1ecd D\u1ea7u tr\u00ean c\u00e1c l\u1eadp \u0111\u1ecba c\u00e1t ven bi\u1ec3n l\u00e0 r\u1ea5t c\u00f3 \u00fd ngh\u0129a v\u00e0 \u0111\u00e1ng \u0111\u01b0\u1ee3c \u0111\u1ea7u t\u01b0, \u0111\u1eb7c bi\u1ec7t l\u00e0 trong ho\u00e0n c\u1ea3nh hi\u1ec7n nay khi ch\u00fang v\u1eabn \u0111ang ti\u1ebfp t\u1ee5c b\u1ecb khai th\u00e1c, nhu c\u1ea7u tr\u1ed3ng r\u1eebng tr\u00ean \u0111\u1ea5t c\u00e1t r\u1ea5t l\u1edbn v\u00e0 nhu c\u1ea7u \u0111a d\u1ea1ng ho\u00e1 lo\u00e0i c\u00e2y tr\u00ean \u0111\u1ea5t c\u00e1t \u0111ang tr\u1edf n\u00ean c\u1ea5p b\u00e1ch.<\/p>\n
Nh\u1eefng k\u1ebft qu\u1ea3 \u0111i\u1ec1u tra g\u1ea7n \u0111\u00e2y v\u1ec1 m\u1ed9t s\u1ed1 lo\u00e0i \u0111\u1ed9ng v\u1eadt \u0111\u00e3 c\u1ea3nh b\u00e1o nguy c\u01a1 \u0111e do\u1ea1 \u0111\u1ed1i v\u1edbi nhi\u1ec1u lo\u00e0i \u0111\u1ed9ng v\u1eadt k\u00edch th\u01b0\u1edbc l\u1edbn \u1edf n\u01b0\u1edbc ta. B\u00f2 x\u00e1m \u0111\u00e3 kh\u00f4ng c\u00f2n t\u00ecm th\u1ea5y \u1edf Vi\u1ec7t Nam. T\u00ea gi\u00e1c m\u1ed9t s\u1eebng hi\u1ec7n ch\u1ec9 c\u00f2n 5 – 7 con trong m\u1ed9t \u0111\u00e0n duy nh\u1ea5t \u1edf C\u00e1t L\u1ed9c. H\u1ed5 \u0110\u00f4ng D\u01b0\u01a1ng c\u0169ng ch\u1ec9 c\u00f2n tr\u00ean d\u01b0\u1edbi 100 con v\u00e0 \u0111\u00e0n voi c\u0169ng \u0111\u00e3 gi\u1ea3m xu\u1ed1ng t\u1edbi m\u1ee9c \u0111\u1ed9 b\u00e1o \u0111\u1ed9ng. Ph\u00e1 r\u1eebng, ph\u00e1 ho\u1ea1i m\u00f4i tr\u01b0\u1eddng s\u1ed1ng v\u00e0 khai th\u00e1c qu\u00e1 m\u1ee9c l\u00e0 nh\u1eefng nguy\u00ean nh\u00e2n ch\u00ednh g\u00e2y n\u00ean t\u00ecnh tr\u1ea1ng nghi\u00eam tr\u1ecdng nh\u01b0 hi\u1ec7n nay.<\/p>\n
3. K\u1ebft lu\u1eadn.<\/p>\n
Ng\u01b0\u1eddi ta th\u01b0\u1eddng coi h\u00ecnh t\u01b0\u1ee3ng b\u1ea3o t\u1ed3n nh\u01b0 m\u1ed9t t\u1ea3ng b\u0103ng tr\u00f4i m\u00e0 ph\u1ea7n n\u1ed5i tr\u00ean m\u1eb7t n\u01b0\u1edbc m\u1edbi ch\u1ec9 l\u01b0u gi\u1eef \u0111\u01b0\u1ee3c m\u1ed9t ph\u1ea7n nh\u1ecf \u0111a d\u1ea1ng di truy\u1ec1n l\u00e0 b\u1ea3o t\u1ed3n ex situ<\/i>; ph\u1ea7n n\u1eb1m ngay d\u01b0\u1edbi m\u1eb7t n\u01b0\u1edbc c\u00f3 kh\u1ea3 n\u0103ng l\u01b0u gi\u1eef nhi\u1ec1u h\u01a1n \u0111\u00f3 l\u00e0 b\u1ea3o t\u1ed3n in situ<\/i> t\u1ea1i c\u00e1c v\u01b0\u1eddn qu\u1ed1c gia v\u00e0 khu b\u1ea3o t\u1ed3n thi\u00ean nhi\u00ean; c\u00f2n ph\u1ea7n l\u1edbn nh\u1ea5t, ph\u1ea7n ch\u00ecm s\u00e2u trong n\u01b0\u1edbc, \u0111\u00f3 l\u00e0 quy ho\u1ea1ch b\u1ea3o t\u1ed3n trong k\u1ebf ho\u1ea1ch t\u1ed5ng th\u1ec3 c\u1ee7a qu\u1ea3n l\u00fd r\u1eebng t\u1ef1 nhi\u00ean, bao g\u1ed3m c\u1ea3 c\u00f4ng t\u00e1c b\u1ea3o t\u1ed3n \u1edf r\u1eebng s\u1ea3n xu\u1ea5t.<\/p>\n
Qu\u1ea3n l\u00fd r\u1eebng b\u1ec1n v\u1eefng bao g\u1ed3m c\u00e1c bi\u1ec7n ph\u00e1p khai th\u00e1c v\u00e0 b\u1ea3o v\u1ec7 h\u1ee3p l\u00fd, k\u1ebft h\u1ee3p v\u1edbi c\u00e1c bi\u1ec7n ph\u00e1p b\u1ea3o t\u1ed3n th\u00edch h\u1ee3p ch\u00ednh l\u00e0 con \u0111\u01b0\u1eddng \u0111i c\u1ea7n thi\u1ebft c\u1ee7a n\u01b0\u1edbc ta hi\u1ec7n nay. B\u1ea3o t\u1ed3n \u0111\u00f2i h\u1ecfi \u00e1p d\u1ee5ng c\u00e1c bi\u1ec7n ph\u00e1p x\u1eed l\u00fd l\u00e2m sinh ph\u00f9 h\u1ee3p v\u00e0 qu\u1ea3n l\u00fd r\u1eebng \u0111\u00f2i h\u1ecfi \u00e1p d\u1ee5ng c\u00e1c bi\u1ec7n ph\u00e1p b\u1ea3o t\u1ed3n \u0111\u1ed3ng b\u1ed9, c\u00f3 nh\u01b0 v\u1eady m\u1edbi \u0111\u1ea1t \u0111\u01b0\u1ee3c m\u1ee5c ti\u00eau “b\u1ea3o t\u1ed3n \u0111\u1ec3 ph\u00e1t tri\u1ec3n v\u00e0 ph\u00e1t tri\u1ec3n \u0111\u1ec3 b\u1ea3o t\u1ed3n”.<\/p>\n
Some silvicultural problems in the in-situ gene conservation of forest tree species<\/b><\/p>\n
Summary<\/b><\/p>\n
In the process of in-situ gene conservation of forest tree species in the tropics there are some silvicultural problems that directly effect the objectives and results of the conservation. Adequate solutions to these problems are needed. The problems are the fewness of the individuals of the species the gene conservation of which is needed, weak or poor regeneration, drastic competition between the tree species in the population. Without the interference of man, these can all result in the elimination of the species that need conservation. In addition to the species targeted by conservation, some species with supporting function, supplying food for other members of the ecological system also need proper protection.<\/p>\n
****************************************<\/p>\n","protected":false},"excerpt":{"rendered":"
C\u00e2y r\u1eebng t\u1ef1 nhi\u00ean v\u00f9ng nhi\u1ec7t \u0111\u1edbi c\u00f3 nh\u1eefng \u0111\u1eb7c \u0111i\u1ec3m ri\u00eang r\u1ea5t kh\u00e1c bi\u1ec7t so v\u1edbi c\u00e1c lo\u1ea1i r\u1eebng kh\u00e1c m\u00e0 nh\u1eefng \u0111\u1eb7c \u0111i\u1ec3m n\u00e0y \u0111\u00f2i h\u1ecfi c\u00f4ng t\u00e1c b\u1ea3o t\u1ed3n ngu\u1ed3n gen c\u00e2y r\u1eebng nhi\u1ec7t \u0111\u1edbi ph\u1ea3i \u00e1p d\u1ee5ng nh\u1eefng bi\u1ec7n ph\u00e1p x\u1eed l\u00fd l\u00e2m sinh h\u1ee3p l\u00fd.
\nC\u00e2y g\u1ed7 r\u1eebng nhi\u1ec7t \u0111\u1edbi \u0111\u00e3 th\u00edch nghi v\u1edbi ho\u00e0n c\u1ea3nh s\u1ed1ng \u0111a d\u1ea1ng v\u00e0 ho\u00e0n h\u1ea3o c\u1ee7a h\u1ec7 sinh th\u00e1i r\u1eebng nhi\u1ec7t \u0111\u1edbi bao g\u1ed3m \u0111\u1ee7 lo\u1ea1i \u0111\u1ed9ng v\u1eadt v\u00e0 th\u1ef1c v\u1eadt, v\u1edbi nh\u1eefng ho\u1ea1t \u0111\u1ed9ng ch\u1ee9c n\u0103ng kh\u00e1c nhau song h\u1ed7 tr\u1ee3 cho nhau nh\u01b0 trong m\u1ed9t d\u00e2y chuy\u1ec1n th\u1ee9c \u0103n \u0111\u1ed3ng b\u1ed9 m\u00e0 n\u1ebfu t\u00e1ch r\u1eddi kh\u1ecfi h\u1ec7 sinh th\u00e1i \u0111\u00f3, c\u00e2y r\u1eebng s\u1ebd kh\u00f3 c\u00f3 th\u1ec3 s\u1ed1ng \u0111\u1ed9c l\u1eadp \u0111\u01b0\u1ee3c. <\/p>\n","protected":false},"author":2,"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\/276"}],"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\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/vafs.gov.vn\/vn\/wp-json\/wp\/v2\/comments?post=276"}],"version-history":[{"count":3,"href":"https:\/\/vafs.gov.vn\/vn\/wp-json\/wp\/v2\/posts\/276\/revisions"}],"predecessor-version":[{"id":19388,"href":"https:\/\/vafs.gov.vn\/vn\/wp-json\/wp\/v2\/posts\/276\/revisions\/19388"}],"wp:attachment":[{"href":"https:\/\/vafs.gov.vn\/vn\/wp-json\/wp\/v2\/media?parent=276"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/vafs.gov.vn\/vn\/wp-json\/wp\/v2\/categories?post=276"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/vafs.gov.vn\/vn\/wp-json\/wp\/v2\/tags?post=276"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}