Inferring the Potential Geographic Distribution and Reasons for the Endangered Status of the Tree Fern, Sphaeropteris lepifera, in Lingnan, China Using a Small Sample Size

Abstract

In this study, we investigated suitable habitats for the endangered tree fern, Sphaeropteris lepifera (J. Sm. ex Hook.) R.M. Tryon, based on fieldwork, ecological niche modeling, and regression approaches. We combined these data with the characterization of spore germination and gametophytic development in the laboratory to assess the reasons why S. lepifera is endangered and to propose a conservation strategy that focuses on suitable sites for reintroduction and accounts for the ecology and biphasic life cycle of the species. Our methods represent an integration of process- and correlation-based approaches to understanding the distributional patterns of this species, and this combined approach, while uncommonly applied, is a more robust strategy than either approach used in isolation. Our ecological niche models indicated that cold temperature extremes, temperature stability over long- and short-terms, and the seasonality of precipitation were among the most important abiotic environmental factors affecting the distribution of S. lepifera among the variables that we measured. Moreover, distribution of this fern species is also strongly influenced by the timing of development of male and female gametes. Additionally, we observed that slope aspect, specifically south-facing slopes, facilitates more incoming sunlight for mature trees, and simultaneously, provides greater, much-needed shade for fiddleheads on account of the canopy being denser. We believe that our study can provide important guidance on the restoration of S. lepifera in the wild. Specifically, potential restoration areas can be screened for the specific environmental factors that we infer to have a critical impact on the survival of the species.

Complete chloroplast genome molecular structure, comparative and phylogenetic analyses of Sphaeropteris lepifera of Cyatheaceae family: a tree fern from China

“…Environmental factors, such as solar radiation and temperature, can affect mutation rates, metabolism and growth rates 58 . Previous studies have shown that cold temperature extremes, temperature stability over long- and short-terms, and the seasonality of precipitation were among the most important abiotic environmental factors affecting the distribution of S. lepifera 13 . Photosynthetic organisms generally have a much larger number of genes, usually 30,000, and many of these genes act in the photosynthetic leaf tissue 59 .…”

“…The capture and utilization efficiency of S. lepifera is higher than those of Alsophila spinulosa and A. podophylla 12 . Niche models indicate that extremely low temperatures, long-term and short-term temperature stability, and precipitation seasonality are important abiotic environmental factors affecting the distribution of S. lepifera 13 . After the leaves of S. lepifera fall, toxic substances such as p -coumaric acid and (-)-3-hydroxy- β -ionone can be decomposed and released to inhibit the growth of other woody plants in tropical forests 14 .…”

Distribution model and prediction of the tree fern Alsophila costularis Baker (Cyatheaceae) in China

“…Ultraviolet radiation can cause injuries to aboveground organs of organisms and limit their distribution (Wu et al., 2021 ). Tree ferns generally grow within light gaps in the canopy to avoid the effects of Ultraviolet (Wei et al., 2021 ). Of the five most important environmental factors, temperature annual range was a decisive factor (contribution rate of 44.9%).…”

Neglected and Underutilized Plant Species in Horticultural and Ornamental Systems: Perspectives for Biodiversity, Nutraceuticals and Agricultural Sustainability

“…Wei et al [9] investigated the characteristics of suitable habitats for the endangered tree fern, Sphaeropteris lepifera (J. Sm. ex Hook.)…”