Bryophyte

(1) The diversity of bryophytes in China

The bryophytes of China are diverse. There are about 23,000 species in the world and about 2,200 species in China, i.e., about 9% of the total.

The characteristics of China' s bryophytes are：

a. Rich in endemic taxa. There are about 35 bryophyte genera, either distributed only in China (Chinese endemics), or distributed in East Asia (East-Asian endemics, chiefly distributed in China, but a few of which occur in neighbouring regions). The 35 account for about 7.09% of the total bryophytic genera of China. They include 48 species, subspecies and forms, accounting for 2.2% of the total bryophytes species of China (Table 1). There are three distribution centres of these bryophytes genera and species, i. e., Southwestern Hengduan Mountains, the mountain region of the middle course of the Yangtze River Watershed and the mountain region along the southeastern coast of China (Table 2)

Table 1 The geographical distribution of endemic species of bryophytes in china

Species	Distribution
Ascidiota blepharophylla var. Blepharophylla	Shaanxi, Yunnan
Bellybarbula obtusicuspis	Yunnan
Brachymeniopsis gymnostoma	Yunnan
Dendrocyathophorum herzogii	Yunnan
Ditrichopsis gymnostoma	Sichuan
Microdendron sinense	Yunnan
Pseudotrichum spinosissimum	Yunnan
Pseudopleuropus morrisonensis	Taiwan
Pseudopterobryum laticuspis	Yunnan
Pseudopterobryum tenuicuspis	Yunnan
Scabridens sinensis	Guizhou, Sichuan, Yunnan
Sciaromiopsis brevifolia	Sichuan, Yunnan
Sinocalliergon satoi	Shanxi
Trichocoleopsis tsinlingensis	Shaanxi

b. Many taxa occupy critical positions in phylogeny. For example, the Takakiales is the most primitive order and the Takakiaceae has two species, i. e., Takakia lepidozioides and T. ceratophylla which occur in the high and cold mountainous areas of southeastern Tibet (Xizang).

c. Tropical and subtropical elements dominate.

Table 2 The geographical distribution of endemic bryophyte genera in China and East Asia in the Hengduan Mountains and the mountainous region along the southeast coast of China

Genus	Hengduan Mountains	Southeastern mountainous regions
Actinothuidium	+
Bellibarbula	+
Brachymeniopsis	+
Bryonoguchia	+
Dendrocyathophorum	+
Ditrichopsis	+
Dolichomitra		+
Dolichomitriopsis		+
Dozya	+
Eurohypnum	+	+
Giraldiella	+
Macvicaria	+	+
Meteoriella	+	+
Microdendron	+
Miyabea		+
Neobarbella		+
Neodolichomitra	+	+
Neotrichocolea		+
Okamuraea		+
Pilotrichopsis	+	+
Pseudopterobryum	+
Plagiochilion		+
Sciaromiopsis	+
Scabrodens	+
Trichocoleopsis		+

(2) Threats to bryophyte taxa in China

China’s bryophytes face severe threats. The threats mainly come from air pollution, forest felling, capital construction and other environmental changes induced by human activities. Forest felling changes the original dark and damp habitat and, thus, has a great influence on tropical rain forests. Many important bryophytes such as Colura (cf. Lejeuneaceae) and Pleurozia (cf. Pleuroziaceae), were distributed in the tropical rain forests of Hainan Island but, now, alter forest-felling, can not be found.

Recently, vigorously developing tourism has impacted the distribution of bryophytes at many scenic spots in China. For example, the mosses Actinothuidium hookeri and Hylocomium splendens, distributed near the peak of Mount Emei, Sichuan Province, and species of Andreaea at Mount Huang, Anhui Province, are faced with extinction under the influence of too many tourist incursions.

In addition, along with the development of horticulture, especially of flowers and plants, the cropping of Sphagnum spp. in China has been expanded dramatically, so that this resource has also become reduced.

It is estimated that there are more than 30 species of bryophytes either threatened or endangered in China (Table 3). At least 5 species have been verified lost. These are: Ascidiota Blepharophylla var. blepharophylla, Brachymeniopsis gymnostoma, Ditrichopsis clausa, D. gymnostoma and Sinocalliergon satoi.

Table 3 The rare and endangered bryophytes of China

Amblystegiaceae	Neobarbella comes
Sciaromiopsis brevifolia	N. pilifera
S. sinensis	Neckeraceae
Andreaeaceae	Dolichomitra cymbifolia var. Subinte-gerrima
Andreaea mamillosula	Pinnatella intralimbata
Brachytheciaceae	P. mariei
Pseudopleuropus morrisonensis	Orthotrichaceae
Cephaloziellaceae	Groutiella tomentosa
Zoopsis liukiuensis	Zygodon obtusifolius
Cryphaeaceae	Pleuroziaceae
Schoenobryum concavifolium	Pleurozia gigantea
Dicranaaceae	P. giganteoides
Braunfelsia enervis	Polytrichaceae
Diphysciaceae	Microdendron sinense
Theriotia lorifolia	Pottiaceae
Hypnaceae	Bellibarbula kurziana
Hondaella brachytheciella	B. obtusicuspis
Pylaisiopsis speciosa	Pterobryaceae
Lejeuneaceae	Pseudopterobryum laticuspis
Caudalejeunea circinata C. reniloba Colura karstenii C. ari C. conica C. corynephora Diplasiolejeunea brachyclada D. rudolphiana	Rhytidiaceae
	Okamuraea hakoniensis var.
	ussuriensis
	O. hakoniensis f. multiflagellifera
	Sematophyllaceae
	Bryowijkia ambigua
	Thuidiaceae
	Miyabae rotundifolia
	Trichocoleaceae
Meteoriaceae	Neotrichocolea bissetii

(3) Conservation of bryophytes in China

Apart from their scientific value, bryophytes also have an important economic value. Bryophytes have been used as antipyretic and detoxicants for hundreds of years in China. During the Ming Dynasty, Polytrichum commune and Rhodobryum giganteum and others were recorded in Li Shizhen’s Synopsis of Herbals, and R. giganteum has been called “Hui Xin Cao” and can be used to cure cardiovascular system diseases.

Traditionally, either Sphagnum plants or peat are the best wrapping material for cultivating and transplanting flowers, and seedlings, and can be used as a horticulture fertilizer; they can not, as yet, be replaced by other materials.

China is one of the major gallnut exporting countries. Chinese scientists have shown that bryophytes, as the winter hosts of aphids, are one of the indispensable links in the production cycle of gallants. Now, at least five species of bryophytes have been identified as the winter hosts of gallnuts in China.

Bryophytes are also good indicator plants of air pollution. Both bryophytes and lichens are very sensitive to SO₂, CO and HF pollution. The epiphytic mosses, Venturiella sinensis, Glyphomitrium daviesii and frullania muscicola, distributed on the bark of trees, are all common in China. They are sensitive to atmospheric pollution and can be used in environmental monitoring.

In short, the bryophytes have close relationships with Man and we must pay more attention to their protection.