A review of frameworks for using bryophytes as indicators of climate change with special emphasis on Sri Lankan bryoflora

Cryptogams as bio-indicators for ecosystem monitoring in Sri Lanka: a comprehensive review and recommendations

Cryptogams, encompassing algae, fungi, lichens, bryophytes, and pteridophytes play essential roles in soil formation, nutrient cycling, and ecological stability. Sri Lanka faces numerous environmental challenges, including habitat loss, climate change, and pollution and there is an urgent need for effective monitoring programs to assess and mitigate these changes. This comprehensive review compiles existing literature on the importance of cryptogams and their responses to various environmental stressors and highlights the specific characteristics that make cryptogams valuable bio-indicators, such as their sensitivity to pollution, climate change, and land-use changes in habitats such as forests, agricultural lands, and urban areas, as well as their ability to accumulate and retain pollutants over time. The diversity of cryptogams is integral to their effectiveness as bio-indicators, providing a comprehensive picture of ecosystem health. Furthermore, recommendations for the development of monitoring programs are provided for different areas in the country. These recommendations include establishing baseline data for cryptogam diversity and abundance and incorporating the integration of modern molecular techniques such as DNA barcoding which are widely used in biodiversity monitoring programs to track the responses of cryptogams to environmental changes. This review seeks to emphasize the importance of cryptogams in ecosystem health assessment raising awareness among policymakers, researchers, and conservationists in Sri Lanka. Through the implementation of effective monitoring programs, we can enhance our understanding of local ecosystem dynamics, improve conservation efforts, and contribute to the sustainable management of Sri Lanka's natural resources in the face of ongoing environmental changes.

Exploring the distribution and habitat preferences of Polytrichaceae (Bryophyta) in Tibet, China

The Qinghai-Tibet Plateau stands as one of the most ecologically fragile and biodiversity-rich regions globally. Understanding the distribution of different taxa and their relationship with environmental factors is crucial for effective conservation and sustainable management. Polytrichaceae, a significant bryophyte family widely distributed in Tibet, displays distinct structural, morphological, and phylogenetic traits compared to other mosses. Despite its importance, the distribution of Polytrichaceae in Tibet and its correlation with environmental factors have yet to be explored. In this study, we used an optimized Maximum Entropy (MaxEnt) model to explore the potential suitable habitats of Polytrichaceae in Tibet, aiming to clarify their geographic distribution pattern as well as the key environmental influence factors. The model had high accuracy with an average Area Under the Curve (AUC) of 0.933 and True Skill Statistics (TSS) value of 0.789. The results showed that the potential suitability habitats of Polytrichaceae were mainly located in southeastern Tibet, and the low suitable, moderately suitable, and highly suitable habitats accounted for 12.53 %, 6.84 %, and 3.31 % of the total area of Tibet respectively. Unsuitable habitats were mainly located in northwestern Tibet, accounting for about 77.32 %. In Tibet, temperature factors (Mean Temperature of Coldest Quarter (Bio11) and Annual Mean Temperature (Bio1)) played a pivotal role in determining the potential suitable habitats for Polytrichaceae, and elevation, precipitation, and vegetation coverage also had an important influence. The family preferred warm, moist and densely vegetated habitats in Tibet. This study enriched our ecological understanding of bryophyte ecology in this region and provided data-driven support for biodiversity conservation and ecosystem management in Tibet.

Impact of changing climate on bryophyte contributions to terrestrial water, carbon, and nitrogen cycles

Bryophytes, including the lineages of mosses, liverworts, and hornworts, are the second-largest photoautotroph group on Earth. Recent work across terrestrial ecosystems has highlighted how bryophytes retain and control water, fix substantial amounts of carbon (C), and contribute to nitrogen (N) cycles in forests (boreal, temperate, and tropical), tundra, peatlands, grasslands, and deserts. Understanding how changing climate affects bryophyte contributions to global cycles in different ecosystems is of primary importance. However, because of their small physical size, bryophytes have been largely ignored in research on water, C, and N cycles at global scales. Here, we review the literature on how bryophytes influence global biogeochemical cycles, and we highlight that while some aspects of global change represent critical tipping points for survival, bryophytes may also buffer many ecosystems from change due to their capacity for water, C, and N uptake and storage. However, as the thresholds of resistance of bryophytes to temperature and precipitation regime changes are mostly unknown, it is challenging to predict how long this buffering capacity will remain functional. Furthermore, as ecosystems shift their global distribution in response to changing climate, the size of different bryophyte-influenced biomes will change, resulting in shifts in the magnitude of bryophyte impacts on global ecosystem functions.

Stress, senescence, and specialized metabolites in bryophytes

Life on land exposes plants to varied abiotic and biotic environmental stresses. These environmental drivers contributed to a large expansion of metabolic capabilities during land plant evolution and species diversification. In this review we summarize knowledge on how the specialized metabolite pathways of bryophytes may contribute to stress tolerance capabilities. Bryophytes are the non-tracheophyte land plant group (comprising the hornworts, liverworts, and mosses) and rapidly diversified following the colonization of land. Mosses and liverworts have as wide a distribution as flowering plants with regard to available environments, able to grow in polar regions through to hot desert landscapes. Yet in contrast to flowering plants, for which the biosynthetic pathways, transcriptional regulation, and compound function of stress tolerance-related metabolite pathways have been extensively characterized, it is only recently that similar data have become available for bryophytes. The bryophyte data are compared with those available for angiosperms, including examining how the differing plant forms of bryophytes and angiosperms may influence specialized metabolite diversity and function. The involvement of stress-induced specialized metabolites in senescence and nutrient response pathways is also discussed.