Classification and ordination of plant communities along an altitudinal gradient on the Presidential Range,New Hampshire,USA

An analysis of vegetation along an altitudinal gradient on the Presidential Range, New Hampshire, USA, using the Braun–Blanquet approach followed by multivariate data analysis is presented. Twelve main plant communities have been distinguished. Floristic information is presented in twelve tables and one appendix. The relationships of the communities to complex environmental gradients are analyzed using Correspondence Analysis. Floristic composition and community structure are controlled primarily by the altitudinal gradient (temperature, precipitation), and by mesotopographic conditions (snow accumulation, exposure and cryoturbation, slope position, and soil moisture).     

Soft-water vegetation (Littorellion) in Spanish mountains

This paper presents a systematic review of Spanish high mountain soft water communities based on 46 phytosociological relevés. Using a numerical analysis with ordination (correspondence analysis—CA) and classification (Jaccard index and complete-linkage clustering) three groups corresponding to the phytosociological associationsIsoeto lacustris-Sparganietum borderei, Sparganio angustifolii-Isoetetum echinospori andSparganio angustifolii-Callitrichetum font-queri have been defined. SpanishLittorellion communities are characterized by boreal-alpine and endemic elements. The boreal-alpine elements probably spread via the Pyrenees-Iberian System through to the mountains of the western peninsula during a cold period, thus sharing the habitat with the Ibero-Atlantic flora which was able to adapt to the changing climatic conditions.