Geographical Distribution and Relationship with Environmental Factors of Paphiopedilum Subgenus Brachypetalum Hallier (Orchidaceae) Taxa in Southwest China

Abstract

The determination of the geographic distributions of orchid species and their relationships with environmental factors are considered fundamental to their conservation. Paphiopedilum subgenus Brachypetalum is one of the most primitive, ornamental, and threatened groups of Orchidaceae. However, little is known about the distribution of Brachypetalum orchids and how they are influenced by environmental factors. In this study, we developed a database on the geographical distribution of Brachypetalum orchids based on a large-scale field investigation in the Guangxi, Guizhou, and Yunnan provinces of southwest China (2019–2020). Using this database, we first adopted the nonparametric Mann–Whitney U test to analyze the differences in the geographical distributions and growth environments of Brachypetalum orchids. In addition, we also used the method of principal component analysis (PCA) to explore distribution patterns of Brachypetalum orchids in relation to environmental factors (topography, climate, anthropogenic disturbance, productivity, and soil) in southwest China. Our results indicated that Brachypetalum orchid species were mainly distributed in the karst limestone habitats of southwest China. In general, there were 194 existing localities with the occurrence of seven target orchids in the investigated area. Of the discovered species in our study, 176 locations (~90.7%) were distributed primarily in the karst habitat. Among them, the range of 780–1267 m was the most concentrated elevation of Brachypetalum orchids. In addition, the findings also suggested that the distribution of Brachypetalum orchids in southwest China was relatively scattered in geographical space. However, the density of the distribution of Brachypetalum orchids was high, between 104° and 108° E and between 25° and 26° N. The results of the Mann–Whitney U test revealed that there are obviously different geographical distributions and growth environments of Brachypetalum in southwest China. More specifically, we found some extremely significant differences (p < 0.001) in elevation, mean diurnal range, precipitation of coldest quarter, solar radiation, and exchangeable Ca2+ between the provinces of southwest China. The PCA analysis revealed that elevation, solar radiation, temperature (mean diurnal range, annual temperature range) and precipitation (precipitation seasonality, precipitation of the warmest quarter) were found to be the most significant factors in determining Brachypetalum orchids’ distribution. These findings have implications in assessing conservation effectiveness and determining niche breadth to better protect the populations of these Brachypetalum orchid species in the future.

A comparative analysis of the past and present occurrences of some species of Paphiopedilum (Orchidaceae) in northeastern India using MaxEnt and GeoCAT

“…These orchids are becoming increasingly rare mainly due to over collection from the wild, rising urbanization causing habitat destruction and also global warming (Swarts & Dixon 2009;Seaton et al 2010;Barman & Devadas 2013;Ye et al 2021). Favorable climatic conditions, access to wild habitat sites, and a conducive environment are important for the survival of plants (Hulme 2005;Ballantyne & Pickering 2015;Wraith & Pickering 2018;Li et al 2020;Ye et al 2021). The comparison of environmental requirements of the distribution of Paphiopedilum over the years imparts an understanding of the adaptability of these orchids with changing environmental conditions.…”

Fungal community characteristics of the last remaining habitat of three paphiopedilum species in China

“…Southwest China is the origin and differentiation center of Paphiopedilum and the distribution hotspot of Paphiopedilum. However, according to a recent survey of wild Paphiopedilum plants, the plants of Paphiopedilum in Southwest China are suffering devastating damage, especially Paphiopedilum armeniacum (P. armeniacum), Paphiopedilum wenshanense (P. wenshanense) and Paphiopedilum emersonii (P. emersonii), which are the most endangered [17]. At present, fewer than 10 natural distribution sites of these three Paphiopedilum species have been found, and the latter habitats are at risk of degradation and loss.…”

Isolation of Tulasnella spp. from Cultivated Paphiopedilum Orchids and Screening of Germination-Enhancing Fungi

“…To conserve and restore the population of Paphiopedilum , studies of population geographical distribution [ 6 ], embryo development [ 7 , 8 ], in vitro tissue culture [ 9 , 10 ], ex situ seed baiting [ 11 ], and mycorrhizal fungi associated with Paphiopedilum [ 12 ] have been carried out. At the same time, in situ/ex situ conservation of Paphiopedilum orchids has also been implemented [ 3 ].…”