---

作 者 ：焦菊英,张振国,贾燕锋,王宁,白文娟

期 刊 ：生态学报 2008年 28卷 7期 页码：2981~2997

关键词：植物分布区类型；植物生活型；水分生态型；植物群落类型；TWINSPAN分类；

Keywords:plant areal-types, plant life-form, hydrological ecological types, plant community types, TWINSPAN classification,

摘 要 ：采用样带调查与TWINSPAN分类等方法，对陕北丘陵沟壑区延安、安塞和吴旗174个撂荒地样方的物种组成、出现频率与盖度、及群落类型进行了统计与分类。植被组成结构的统计结果表明：该区自然恢复的植被几乎一半是由禾本科、菊科、豆科和蔷薇科的物种组成，北温带、旧世界温带、世界与泛热带分布成分占到总物种数近75%，且以中旱生、中生和旱生的草本类植物为主，具有典型的温带地面芽植物气候特征。植被的数量分类表明：调查样方基本包括了该区自然恢复的主要植被类型，延安、安塞和吴旗的植被在1年生草本群落到多年生蒿禾类草本群落阶段，依次均以猪毛蒿（Artemisia scoparia）、赖草（Leymus secalinus）、长芒草（Stipa bungeana）、达乌里胡枝子（Lespedeza davurica）、铁杆蒿（Artemisia gmelinii）、茭蒿（Artemisia giraldii）、白羊草（Bothriochloa ischaemun）等为主要优势物种构成的不同组合的植物群落，且这些物种具有较高的盖度和频度；但在植被演替后期，不同植被带及阴阳坡的演替方向却发生了明显的变化。以延安为代表的森林带，阴坡可形成黄刺玫（Rosa xanthina）、三角槭（Acer buergerianum）、辽东栎（Quercus liaotungensis）等为优势种的群落，阳坡可形成狼牙刺（Sophora viciifolia）、侧柏（Platycladus orientalis）等为优势种的群落；以安塞为代表的森林草原带，阴坡可形成黄刺玫、紫丁香（Syringa julianae）、虎榛子（Ostryopsis davidiana）等为优势种的群落，阳坡可形成白羊草（Bothriochloa ischaemun）、狼牙刺等为优势种的群落；而以吴旗为代表的草原带，阴阳坡植被分异不明显，为多年生蒿禾类草本群落。这些演替后期的灌乔优势物种均为高位芽植物，在阴坡为中生，在阳坡为旱生、中旱生，虽具有比较高的盖度，但分布仅仅是零散出现，并不是目前黄土丘陵沟壑区的主要植被类型。

Abstract:The species composition, frequency and cover of species, and vegetation types of natural vegetation in Yan′an, An′sai and Wuqi in a transect of 174 samples in the abandoned lands in the hilly-gullied region of the North Shaanxi Province were analyzed and classified using TWINSPAN. The analysis of species composition shows that almost half of the species belong to the gramineae, compositae, leguminoseae and rosaceae, and nearly 75% of species belong to the north temperate, old world temperate, cosmopolitan and pantropic groups, the hydro-ecological types are mainly xerophytic-mesophytic, mesophytic and xerophytic, and the main life form is the hemicryptophyte. The TWINSPAN analysis shows the main vegetation types of the area. In the earlier stages of succession from annual to perennial herbs in Yan′an, An′sai and Wuqi, the main plant communities include the dominant species Artemisia scoparia, Leymus scalinus, Lespedeza davurica, Stipa bungeana, Artemisia gmelinii, Artemisia giraldii and Bothriochloa ischaemun in different combinations, and these species have higher cover and frequency. However, in the later stages of succession, the vegetation of different zones, aspect and slope changes significantly. In the forest zone in the Yan′an area, the vegetation of shady slopes is Rosa xanthina, Acer buergerianum, Quercus liaotungensis dominated communities, and the vegetation of sunny slopes is Sophora viciifolia and Platycladus orientalis dominated communities. In the forest-steppe zone in the An′sai area, the vegetation of shady slopes is Rosa xanthina, Syringa julianae, Ostryopsis davidiana dominated communities, and on sunny slopes is Bothriochloa ischaemun and Sophora viciifolia dominated communities. In the steppe zone in the Wuqi area, the vegetation variation between sunny and shady slopes is not obvious and the main vegetation types consist of perennial herbs. The shrub and tree species in the later stages are all phaenerophytes, and the species of sunny slopes are mainly xerophytic and mesophytic, and of shady slopes are mainly mesophytic, with higher cover but occurring only sporadically, and are not the main vegetation types in the hilly-gullied region of the North Shaanxi Province.

---