A first inventory of gypsum flora in the Palearctic and Australia

Abstract

Abstract. Gypseous substrates are well-recognised as supporting distinctive and unique flora assemblages, including numerous gypsum endemic (gypsophile) species. Along with these, others are also frequent although their presence is not restricted to gypsum; they show a clear preference for them (gypsocline). While this phenomenon (gypsophily) has been studied regionally, and various hypotheses put forward to explain it, there has been little global synthesis. We present a preliminary check-list on the gypsophile and gypsocline flora of the Palaearctic and Australian areas as a part of a project to develop a global checklist of the World's gypsophytes, which can broaden our ecological and biogeographical understanding of these unique environments. The database contains 935 taxa spanning 54 countries. The Irano-Turanian region -and to a lesser extent the Mediterranean region-emerged as the richest territories in terms of gypsophile species; this richness was much reduced in the SaharoArabian and, especially in the Eurosiberian regions. The factors that can modulate the richness of gypsophytes in a region are discussed and have been distributed into four groups: a) geological and edaphic factors; b) factors linked to the insular nature of outcrops; c) climatic variables and their interaction with the soil; d) biogeographical factors. The importance of those factors linked to insularity and, especially, to water availability is emphasized. Because the soil structure of many gypsum outcrops reduces water ability to plants, such outcrops can be regarded as "dry-islands" surrounded by less xeric substrates. The fact that gypsophytes can be grouped within a few major flowering plant clades across continents, confirms their pre-adaptations to these harsh and unique environments. Our work provides a preliminary database for exploring ecological and biogeographic issues relating to gypsophily, and we hope it will stimulate global interest in these valuable ecosystems. Keywords: edaphism; global check-list; gypsicolous; gypsophile; gypsophyte; gypsophily. Un primer inventario de la flora gipsícola del Paleártico y de AustraliaResumen. Los sustratos yesíferos son sobradamente conocidos por presentar cortejos florísticos peculiares y exclusivos, lo que incluye a numerosos endemismos (especies gipsófilas). Junto a estas especies, aparecen otras también muy frecuentes cuya presencia no se restringe al yeso, pero hacia el que muestran una clara preferencia (gipsoclinas). Mientras que este fenómeno (gipsofilia) ha sido estudiado regionalmente, y se han sugerido varias hipótesis para explicarlo, apenas existen síntesis globales sobre el mismo. Aquí se ofrece un inventario preliminar de la flora gipsófila y gipsoclina de los territorios paleártico y australiano como parte de un proyecto que pretende desarrollar una checklist mundial, de manera que se contribuya a ampliar el conocimiento ecológico y biogeográfico de este ambiente único. Este inventario incluye 935 taxa distribuidos por 54 países. La región irano-turaniana -y en meno...

A Review of C4 Plants in Southwest Asia: An Ecological, Geographical and Taxonomical Analysis of a Region With High Diversity of C4 Eudicots

“…They composed a wide range of communities from pure C 4 communities to C 4 patches occurring in microhabitats of C 3 dominated communities: a) Dry marly or clayey hills with varying salt and gypsum composition are often dominated by xerohalophytic and gypsophytic C 4 Chenopods. In Iran such habitats are sparsely vegetated by xerohalophytic and gypsohalophytic shrubs like Anabasis eugeniae ( Figure 8F), Anabasis calcarea, Anabasis firouzii ( Figure 10B), Halothamnus auriculus, Halothamnus lancifolius, Xylosalsola arbuscula, Noaea mucronata, Caroxylon verrucosum, Suaeda dendroides, Kaviria tomentosa, K. aucheri, and K. zedzadii (Akhani, 2006;Peŕez-Garcıá et al, 2018). In Israel similar saline chalk and marl slopes are dominated by communities of Suaeda asphaltica, Hammada negevensis, and Caroxylon tetrandrum (Danin and Orshan, 1999).…”

Application of UAV-Based Methodology for Census of an Endangered Plant Species in a Fragile Habitat

“…Another important example is gypsophile endemism [32]. Gypsum (calcium sulfate) substrates occur over large areas in many semi-arid and arid parts of the world and support a unique and highly diverse assemblage of many hundreds of endemic plant species [33,34]. Many of these gypsophile endemics are species of conservation concern [35].…”

A formal classification of the Lygeum spartum vegetation of the Mediterranean Region

“…fruticosa and Stipagrostis ciliata , occur profusely in this unit. At the same time, the occurrence of Anarrhinum brevifolium, Anabasis oropediorum, Diplotaxis harra, Helianthemum lippii and Matthiola capiomontana points to gypsum‐rich substrates (Le Houérou, ; Musarella et al., ; Pérez‐García et al., ).…”