Hedychium menghaiense (Zingiberaceae), a new species from Yunnan,China

Abstract Hedychium menghaiense X. Hu & N. Liu, a new species of the Zingiberaceae from Yunnan Province, China, is described and illustrated. The new species is currently known only from its type locality, Nannuoshan Mountain, Menghai County, growing under evergreen broad‐leaved forests at altitudes of 1400–1700 m. It is similar to Hedychium forrestii Diels, but differs in its narrower and emarginate labellum folded inwards lengthwise, narrower staminodes, and scarlet stamen. The recognition of the new species is supported by the results from analysis of sequence‐related amplified polymorphism markers.     

择伐对阔叶红松林主要组成树种种内、种间竞争的影响

以择伐37 年后的阔叶红松林为对象,研究择伐对林内主要树种种内、种间竞争的影响.结果表明：择伐对阔叶红松林主要树种的种群结构、分布格局和竞争指数均产生了极显著影响.各树种的竞争指数变化值与其耐荫性指数存在极显著负相关关系(r=-0.8821).种内竞争强度与聚集强度、个体数呈极显著线性关系,择伐区内枫桦、紫椴等阳性树种的聚集强度最大,种内竞争强度远大于种间竞争,有利于树种之间的共存.择伐降低了红松对其伴生树种的竞争,而阳性树种对其他树种的竞争压力有所上升.择伐37 年后,红松所受的竞争压力变化较小,有利于红松的稳定生长;由于自疏作用,枫桦、紫椴的优势度将有所下降;冷杉所受的竞争压力有所减弱,有利于其种群数量的恢复.