CAJ | 학술논문

为了探明北桑寄生在秦岭南坡林区的分布式样及危害状况，对陕西省宝鸡市凤县林区进行全面踏查及典型样地调查。结果表明，北桑寄生在凤县林区主要寄主为锐齿栎，在锐齿栎林中呈中心辐射状分布，多寄生于成过熟林木上，树龄在40～50年的锐齿栎被侵染的数量最大。被侵染植株总数为样地内各树种总株数的29.03%，被侵染的锐齿栎为样地内锐齿栎总数的36.90%。受害锐齿栎一级分枝平均感染率为49.53%，被寄生枝干呈明显衰退趋势，分枝末端甚至死亡。受害严重寄主生长状况较差。单丛寄生植株最大直径达160 cm，多寄生于寄主冠部偏南。寄生植株平均最大直径与寄主年龄呈线性正相关。北桑寄生目前未对凤县林区造成严重危害，但对部分寄主个体的生存造成威胁。近年来随着“天保工程”的实施，秦岭南坡锐齿栎种群密度及其种子主要传播者种群数量逐渐增加，北桑寄生的种群数量有可能随之增加，由此带来对森林的潜在危害。
위료탐명북상기생재진령남파림구적분포식양급위해상황，대합서성보계시봉현림구진행전면답사급전형양지조사。결과표명，북상기생재봉현림구주요기주위예치력，재예치력림중정중심복사상분포，다기생우성과숙림목상，수령재40～50년적예치력피침염적수량최대。피침염식주총수위양지내각수충총주수적29.03%，피침염적예치력위양지내예치력총수적36.90%。수해예치력일급분지평균감염솔위49.53%，피기생지간정명현쇠퇴추세，분지말단심지사망。수해엄중기주생장상황교차。단총기생식주최대직경체160 cm，다기생우기주관부편남。기생식주평균최대직경여기주년령정선성정상관。북상기생목전미대봉현림구조성엄중위해，단대부분기주개체적생존조성위협。근년래수착“천보공정”적실시，진령남파예치력충군밀도급기충자주요전파자충군수량축점증가，북상기생적충군수량유가능수지증가，유차대래대삼림적잠재위해。
Loranthus tanakae,one of the most common parasitic seed plants,mainly infests oak trees in the South Slope of Qinling Mountains. To explore the distribution pattern and damage status of L. tanakae,a comprehensive survey and typical sample investigation were conducted in Fengxian County. The results revealed that Quercus aliena var. acutiserrata Maxim. ex Wenz. was the preferential host of L. tanakae. L. tanakae radially distributed from the center of the oak forest,mainly infested mature and over mature oak trees of 40-to 50-years-old and prefered the southern aspect of the canopy. The maximum diameter of a cluster of L. tanakae could reach 160 cm and the diameter had a linear positive correlation with the host ages. Parasitism rate in the plots was 29. 03% of all kind of tree species and 36. 90% of Q. aliena var. acutiserrata. Furthermore,parasitism rate on the primary branches of the all infected trees was 49. 53%. With seriously affected by L. tanakae,growth and vigor of the infected hosts were clearly harmed,resulting in death of the distal branches. Populations of L. tanakae had been increased with its host density in virtue of the implementation of the Natural Forest Protection Project. Although only parts of the hosts were threatened,potential ecological damage and large scale eruption of L. tanakae should not be overlooked.