Mountain pastures and grasslands in the SW Tien Shan, Kyrgyzstan — Floristic patterns, environmental gradients, phytogeography, and grazing impact

Abstract

Vast grasslands are found in the walnutfruit forest region of southern Kyrgyzstan, Middle Asia. Located above the worldwide unique walnutfruit forests and used for grazing, they play a pivotal role in the mixed mountain agriculture of local farmers. Accordingly, these pastures are subject to an increasing utilization pressure reflecting the changing political and social conditions in the transformation process from a Soviet republic to an independent state. A first detailed analysis of mountain pasture vegetation in the Ferghana Range answers the following questions: What are the main plant community types among Kyrgyzstan's mountain pastures? What are the main environmental gradients that shape their species composition? Which phytogeographical distribution types are predominant? How does grazing affect community composition and species richness in these grasslands? Species composition was classified by cluster analysis; underlying environmental gradients were explored using DCA. A dataset of 395 relevés was used for classification, and a subset of 79 relevés was used in a DCA to analyze the correlation between vegetation, environment, and grazing impact. The investigated pastures were classified into four distinctive plant communities. The site factors altitude, heat load, inclination and grazing impact were found to be the major determinants of the vegetation pattern. A significant overlap between floristic composition and structural and spatial properties was shown. The majority of the species pool consisted of Middle Asian endemics and Eurosiberian species. However, disturbance-tolerant species played a significant role with respect to species composition and coverage of the herbaceous layer in vast areas of southern Kyrgyzstan's mountain pastures. In general, an intense grazing impact is clearly reflected by both species composition and structural variables of plant communities. The highly diverse and unique ecosystem is modified by an increasing utilization pressure. In order to maintain vital processes and functioning of this valuable ecosystem -in both economical and ecological terms -, it is indispensable to adopt appropriate pasture management strategies.

Classification of tall-forb vegetation in the Pamir-Alai and western Tian Shan Mountains (Tajikistan and Kyrgyzstan, Middle Asia)

“…Dactylis glomerata-Karatavia kultiassovii and Nepeta mariae-Aconogonon coriarium) in the Aksu-Jabagly Nature Reserve in the western Tian Shan. Other pasture vegetation communities were revealed in the research of Borchardt et al (2011), where they proposed a variation of tall-forb communities (Aconogono coriarium-Prangos pabularia-Galium aparine and Ligularia thomsoni-Dactylis glomerata communities). However, these studies did not aggregate the communities into higher-level units and rationalise them with the known orders and classes.…”

Recent responses of grassland net primary productivity to climatic and anthropogenic factors in Kyrgyzstan

“…Under the Soviet government, large amounts of chemical fertilizer, artificial fodder and grazing subsidies severely impacted the sustainability of ecological and economic systems (Ludi, 2003). Vegetation degradation was a serious concern in the 1970s when more than one third of pastures were invaded by shrubs and unpalatable species (Borchardt, Schickhoff, Scheitweiler, & Kulikov, 2011). After the dissolution of the Soviet Union in 1991, Kyrgyzstan became an independent country and its economic system changed substantially.…”

Mountain pastures of Qilian Shan: plant communities, grazing impact and degradation status (Gansu province, NW China)

“…This process is amplified on the dry south-facing slopes, which are exposed to greater soil erosion and to soil compaction by animal trampling (cf. Blackburn 1984, Borchardt et al 2011.…”