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Ramet recruitment from different bud types along a grassland degradation gradient in Inner Mongolia, China

Qian J., Busso C. A., Wang Z., Liu Z.

Polish Journal of Ecology

2015

Vol. 63, nr 1

38–-52

Since the contribution of total belowground bud bank and different bud types to community regeneration has rarely been explored, the vegetative offspring recruited from different belowground bud types was investigated in four plant communities along a grassland degradation gradient in northeastern China (Inner Mongolia). This gradient, between 1000 and 1500 m a.s.l., has been caused by overgrazing. It is a Leymus chinensis steppe which occupies about 3.0×105 ha. Recruitment from tiller buds was dominant (>80%) in determining the total vegetative offspring density along the whole grassland degradation gradient. However, the proportional contribution of tiller-ramets to total ramet recruitment was significantly greater (P <0.05) during earlier than later stages of grassland degradation, while that of rhizome-ramets showed an opposite pattern. While the percentage contribution and density of root-derived ramets to total ramet density increased significantly (P <0.05) during the late stages of grassland degradation, those of bulb-ramets kept relatively constant along the whole grassland degradation gradient. The relative contribution of hemicryptophytes [i.e., Achnatherum sibiricum, Cleistogenes squarrosa, Festuca ovina, Koeoleria cristata, Poa annua, Stipa grandis] to total plant species richness decreased, while that of geophytes [i.e., Agropyron cristatum, Carex korshinskyi. Leymus chinensis, Allium anisopodium, A. bidentatum, A. tenuissimum, Astragalus galactites, Cymbaria dahurica, Iris tenuifolin, Potentilla acaulis, P. bifurca, Pulsatilla turczaninovii, Serratula chinensis, Thalictrum aquilegifolium] increased with the increases of grassland degradation. Our results showed that as grassland degradation increased, changes in the proportion of tiller-, rhizome- and root-derived ramets with respect to total ramet density determined in turn changes in the proportion of hemicryptophytes and geophytes in the study plant communities.

Variation of colchicine and metal content in Colchicum autumnale L.(Liliaceae) corms in relation to edaphic environment

Mróz L.

Polish Journal of Ecology

2008

Vol. 56, nr 3

431-441

Corms of Colchicum autumnale L. (meadow saffron) from plants growing on soils developed from five parent materials (melaphire, serpentine, sandstones, limestone and marls) were collected and analysed to evaluate their colchicine content as well as metal levels (Fe, Mn, Zn, Cu, Pb, Co, Cd, Ni and Cr). For all locations, (mountainous regions in SW Poland far from pollution sources) where corms were collected, soil samples were taken. In the soil samples, the concentration of elements (Fe, Mn, Zn, Cu, Pb, Co, Cd, Ni and Cr) was analyzed and also soil pH, organic matter content and sand, silt and clay content were determined. The results of principal component analysis (PCA) showed that the concentrations of metals in melaphire (except Cr), sandstone and serpentine soils were higher than those in limestone and marl soils. Meadow saffron corms tended to take up a higher amount of Fe and a lower amount of Co and contained in their tissues a higher amount of colchicine in melaphire soil and some sandstone soils than those in limestone and some marl soils. The concentrations of Co, Mn and Zn in corms at limestone site and Ni and Cd in corms at serpentine site and some marl sites were higher than those in other sites. The results of stepwise regression analysis showed that colchicine corm concentration as well as corm Fe content increased with increasing soil Fe, Mn, Zn, Co, Cu, Pb and Cd contents and that corm Fe content has a positive effect on the production of colchicine, whereas corm Co, Mn, Zn, Ni and Cd negative. The corm Fe, Mn, Zn, Co, Ni and Cd concentrations appeared to be the main factors determining the variation pattern of colchicine in C.autumnale corms. The variation explained by these selected variables was higher (79%) than those explained by selected soil variables (53%).