Orchid diversity: Spatial and climatic patterns from herbarium records

Abstract

AimWe test for spatial and climatic patterns of diversification in the Orchidaceae, an angiosperm family characterized by high levels of species diversity and rarity. Globally, does orchid diversity correlate with land area? In Australia, does diversity correlate with herbarium collecting effort, range size, or climate niche breadth? Where are Australia's orchids distributed spatially, in protected areas, and in climate space?LocationGlobal, then Australia.MethodsWe compared orchid diversity with land area for continents and recognized orchid diversity hotspots. Then, we used cleaned herbarium records to compare collecting effort (for Australian Orchidaceae vs. all other plant families, and also among orchid genera). Spatial and climate distributions were mapped to determine orchids’ coverage in the protected area network, range sizes, and niche breadths.ResultsGlobally, orchid diversity does not correlate with land area (depauperate regions are the subantarctic: 10 species, and northern North America: 394 species). Australian herbarium records and collecting effort generally reflect orchid species diversity (1,583 spp.), range sizes, and niche breadths. Orchids are restricted to 13% of Australia's landmass with 211 species absent from any protected areas. Species richness is the greatest in three biomes with high general biodiversity: Temperate (especially southwest and southeast Australia), Tropical, and Subtropical (coastal northern Queensland). Absence from the Desert is consistent with our realized climate niche—orchids avoid high temperature/low rainfall environments. Orchids have narrower range sizes than nonorchid species. Highly diverse orchid genera have narrower rainfall breadths than less diverse genera.Main conclusionsHerbarium data are adequate for testing hypotheses about Australian orchids. Distribution is likely driven by environmental factors. In contrast, diversification did not correlate with increases in range size, rainfall, or temperature breadths, suggesting speciation does not occur via invasion and local adaptation to new habitats. Instead, diversification may rely on access to extensive obligate symbioses with mycorrhizae and/or pollinators.

Phytogeographical Analysis and Ecological Factors of the Distribution of Orchidaceae Taxa in the Western Carpathians (Local study)

“…Research carried out in the Slovak Republic and other countries confirms that significant factors of distribution are the geological conditions of the area, which has a considerable impact on their occurrence and overall phytogeographical distribution of these species, as well as indicative values of populations, their communities and spatio-temporal changes in occurrence; these claims can be defined on the basis of the relationship to the environment and the influence of environmental factors. Similar research has been carried out in the Western Carpathians [ 6 ] and in Europe by several authors [ 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 ].…”

Automated conservation assessment of the orchid family with deep learning

“…There are approximately 29,000 orchid species on all continents except Antarctica with a variety of life forms, from terrestrial to epiphytic (Givnish et al 2016). Many orchid species are local endemics and their distributions are constrained by edaphic environments and by their relationships with mycorrhizal fungi and specialist pollinators (McCormick & Jacquemyn 2014;Gaskett & Gallagher 2018). Orchids are economically important in horticulture and in the floral, pharmaceutical, and food industries (Subedi et al 2013;Hinsley et al 2018) and many species face immediate threats by land conversion and illegal harvesting (Hinsley et al 2017;Fay 2018).…”

Automated conservation assessment of the orchid family using deep learning

“…These centers of orchid extinction risk coincide well with known areas of endemism, and hence small range sizes, for all plants (Kier et al 2009). The North American Orchid flora is surprisingly depauperate given its large area (Gaskett & Gallagher 2018), and we found that few species in this region are Possibly Threatened (Fig. 1, Fig.…”

“…There are approximately 29,000 orchid species (Givnish et al 2016) on all continents except Antarctica with a variety of life forms, from terrestrial to epiphytic (Cribb et al 2003;Givnish et al 2016). Many orchid species are local endemics and their distributions are constrained by edaphic environments and by their relationships with mycorrhizal fungi and specialist pollinators (McCormick & Jacquemyn 2014;Gaskett & Gallagher 2018). Orchids are economically important in horticulture and in the floral, pharmaceutical, and food industries (Subedi et al 2013;Hinsley et al 2018) and many species face immediate threats by land conversion and illegal harvesting (Hinsley et al 2017;Fay 2018).…”