BRIOLOGY: HISTORY, OBJECT OF STUDY AND RESEARCH - BIOLOGY - 2025

The briología is the discipline that is responsible for the study of bryophytes (liverworts, mosses and antóceras). Its name comes from the Greek bryon, which means moss. This branch of biology has its origin in the mid-18th century, considering the German Johann Hedwig as her father for her contributions in defining the concept of bryophyte and for her contribution to the group's innovmatics.

The most recent studies in bryology have focused on various fields. Among these, those related to the conservation of this group of plants and their ecological behavior stand out. Likewise, research carried out in the area of ​​systematics and floristics is of great importance.

History

Prehistoric uses of bryophytes

There is evidence of the use of some mosses by ancient civilizations. There are records that in the Stone Age the inhabitants of present-day Germany collected the moss Neckera crispa, and that humans took advantage of species of the genus Sphagnum found in peatlands.

Because Sphagnum generates environmental conditions that prevent the decomposition of the animal body, mummified human bodies up to 3,000 years old have been found.

Of special interest is the one known as Tollund man, discovered in 1950 in a bog in Denmark, dating from the 4th century BC (Iron Age).

Tollund man. Source: Sven Rosborn, from Wikimedia Commons

Greco-Roman period

The first references to bryology correspond to the Greco-Roman period. However, at that time bryophytes were not recognized as a natural group.

Greco-Roman herbalists coined the term "liverworts" to these plants in reference to the Marchantia species. They believed that the marchantia thallus lobes (similar to a liver) could cure liver ailments.

18th and 19th century

Briology as a formal discipline began to develop in the 18th century. However, the authors of this time included within the same group the bryophytes and the lycopodiophytes.

The first descriptions of bryophytes were made by the German Johann Dillenius in 1741. This author published the work Historia muscorum, where he recognizes 6 genera of mosses and presents 85 engravings.

Later, Carolus Linneaus in 1753 makes interesting contributions to bryology by recognizing 8 genera within bryophytes.

British botanist Samuel Gray, in 1821, was the first to recognize bryophytes as a natural group. Its classification recognizes the Musci (mosses) and Hepaticae (liverworts) as two large groups.

The father of bryology is considered to be the German botanist Johann Hedwig. This author at the end of the 18th century establishes the concept of bryophyte that we know today. He published the book Species Moscorum, where the bases of the bryophyte systematics are established.

Johann Hedwig. Source: See page for author, via Wikimedia Commons

For a long time, only two groups were recognized within bryophytes; liverworts and mosses. It was not until 1899 when the North American botanist Marshall Howe separated the Anthocerotae from the liverworts.

20th and 21st century

During the early twentieth century, studies regarding the morphology and life cycle of bryophytes became important. Likewise, many floristic studies in different parts of the world were relevant.

These investigations contributed to understanding the great diversity of bryophyte species. Investigations were also started regarding the ecology of these species and their function within ecosystems.

With the development of molecular techniques, bryology made great strides in evolutionary studies. Thus, it has been possible to determine the phylogenetic position of these within plants and their role in the colonization of the terrestrial environment.

In the 21st century, bryologists have focused primarily on phylogenetic and ecological studies. Today, bryology is a consolidated discipline, with numerous experts in different fields throughout the world.

Object of study

Bryophytes are characterized by not presenting conductive tissues and depending on water for sexual reproduction. Furthermore, the gametophyte (haploid generation) is dominant and the sporophyte (diploid generation) depends on it.

Among some of the fields that bryology studies is the study of the life cycles of mosses, liverworts and hornworts. This aspect is of great importance, since it has allowed us to recognize different species.

Red moss. Source: The original uploader was Vaelta at English Wikipedia., via Wikimedia Commons

Likewise, bryologists have given great importance to systematic studies, because it is considered that bryophytes were the first plants to colonize the terrestrial environment.

On the other hand, bryology has focused on ecological studies of mosses, a group capable of growing in extreme environmental conditions associated with a particular ecological behavior.

He has also addressed the study of the biochemistry and physiology of bryophytes. Likewise, it has been of interest for a group of bryologists to determine the species richness of bryophytes in different regions of the planet.

Recent Research Examples

In recent years, bryology research has been focused on conservation, ecological, floristic and systematic aspects.

Conservation

In the area of ​​conservation, studies have been carried out on the genetic variability and ecological factors of bryophytes.

In one of these investigations, Hedenäs (2016) studied the genetic variability of 16 species of mosses in three European regions. It was found that the genetic composition of the populations of each of the species was different in each region. Due to their genetic differences, it is necessary to protect populations in each of the studied regions.

Likewise, the importance of freshwater bodies for the development of bryophyte communities has been studied. In a work carried out in Europe, Monteiro and Vieira (2017) found that these plants are sensitive to the speed of water currents and the type of substrate.

The results of these investigations can be used to define priority areas for the conservation of these species.

Ecology

In the field of ecology, studies are being carried out on the tolerance to desiccation of bryophytes. For example, Gao et al. (2017) have studied the transcriptomes (transcribed RNA) involved in the drying processes of the moss Bryum argenteum.

It has been possible to know how RNA is transcribed during the desiccation and rehydration of this moss. This has allowed a better understanding of the mechanisms involved in the tolerance to desiccation of these plants.

Floristics and biogeography

Studies of bryophyte species present in different geographic regions are quite frequent. In recent years they have become relevant in order to determine the biodiversity of various areas.

Studies carried out on the flora of the Arctic stand out. Lewis et al. (2017) found that bryophytes are particularly abundant in this area of ​​the planet. In addition, they have great ecological importance, due to their ability to survive in these extreme environments.

Another region where numerous floristic studies have been carried out is Brazil. In this country there is a great diversity of environments where bryophytes can develop.

Among these, the study carried out by Peñaloza et al. (2017) on the bryophyte flora in soils with high iron concentrations in southeastern Brazil stands out. Ninety-six species were found, growing in different substrates and microhabitats. Furthermore, the diversity of this group is very high compared to other areas with similar environments.

Taxonomy and phylogeny

In a study carried out by Sousa et al. In 2018, the monophyly (group formed by an ancestor and all its descendants) of bryophytes was verified. Likewise, it is proposed that this group corresponds to an evolutionary branch other than tracheophytes (vascular plants) and that they are not their ancestors, as had been previously proposed.

Likewise, studies have been carried out in some problem groups, in order to define their systematic position (Zhu and Shu 2018). Such is the case of a species of the Marchantiophyta, which is endemic to Australia and New Zealand.

After carrying out molecular and morphological studies, it was determined that the species corresponds to a new monospecific genus (Cumulolejeunea).

References

1. Fram J (2012) Two centuries of Systematics of Bryophytes - What will bring the future? Archive for Bryology 120: 1-16.
2. Gao B, X Li, D Zhang, Y Liang, H Yang, M Chen, Y Zhang, J Zhang and A Wood (2017) Desiccation tolerance in bryophytes: the dehydration and rehydration transcriptomes in the desiccation-toleran bryophyte Bryum argenteum. Nature Scientific Reports 7.
3. Hedenäs L (2016) Intraspecific diversity matters in bryophyte conservation - internal transcribed spacer and rpl16 G2 intron variation in some European mosses. Journal of Bryology 38: 173-182
4. Lewis L, SM Ickert-Bond, EM Biersma, P Convey, B Goffinet, Kr Hassel, HKruijer, C La Farge, J Metzgar, M Stech, JC Villarreal and S McDaniel (2017) Future directions a priorities for Arctic bryophyte research Arctic Science 3: 475-497
5. Monteiro J and C Vieira (2017) Determinants of stream bryophyte community structure: bringing ecology into conservation. Freshwater Biology 62: 695-710.
6. Peñaloza G, B Azevedo, C Teixeira, L Fantecelle, N dos Santos and A Maciel-Silva (2017) Bryophytes on Brazilian ironstone outcrops: Diversity, environmentalfiltering, and conservation implications. Flora: 238: 162-174.
7. Sousa F, PG Foster, P Donoghue, H Schneider and CJ Cox (2018) Nuclear protein phylogenies support the monophyly of the three bryophyte groups (Bryophyta Schimp.) New Phytologist
8. Vitt D (2000) The classification of mosses: two-hundred years after Hedwig. Nova Hedwigia 70: 25-36.
9. Zhu R and L Shu (2018) The systematic position of Microlejeunea ocellata (Marchantiophyta: Lejeuneaceae), an extraordinary species endemic to Australia and New Zealand. The Bryologist, 121: 158-165.