# The Role of Cryptogams in Soil Property Regulation and Vascular Plant Regeneration: A Review
## 3 Effects of Cryptogam on Vascular Plants Regeneration  
Cryptogams have important and complex effects on vascular plant regeneration. In [PERSON]'s study, vascular plant coverage was significantly positively correlated with lichen coverage and negatively correlated with moss coverage, which seems to indicate that lichen is conducive to vascular plant regeneration, whereas moss obstructs its regeneration [6]. [PERSON] et al. found that _Primulina tabacum_ had better regeneration status in the area covered by the bryophyte _Gymnostomiella longinervis_[83]. It has also been shown that moss bedding has no significant effect on seed germination [84]. Research has found that the cryptogam \begin{table}
\begin{tabular}{c c c c c c c c} \hline \hline \multirow{2}{*}{**Geomorphic Feature**} & **Cryptogam** & \multicolumn{3}{c}{**Cryptogams Covered Soil Fertility Percent Change Compared with Bare Soil (\%)**} & \multirow{2}{*}{**Reference**} \\  & **Species** & & & & & & \\ \hline Sandland & Moss-dominated & & & & & & \\  & crust & & & & & & \\ The Loess Plateau & Moss crust & +1011\(\rightarrow\)398 & — & +189 & ns & — & [15] \\ Desert & Moss crust & +789.2 & — & +233.3 & +73.7 & +830.8 & [19] \\ Karst & Moss crust & & +47.1 & +63.9 & +19.0 & — & [20] \\ Desert & Moss crust & +183.5 & — & +47.4 & — & — & [25] \\ Greenhouse in desert & Moss crust & +748.4 & — & — & — & [26] \\ Burned forest and & Natural moss & & +375\(\rightarrow\)281 & — & — & — & [28] \\ sand mine & layer & & & & & & \\ Abandoned pyrite & _Campylopus_ & +46.4 & — & — & — & [53] \\ mine tailings & _schmidii_ & & & & & & \\ Sandland & Moss crust & — & +460 & +364 & +40 & — & [55] \\ Karst & Moss crust & — & ns & +102.8 & +83 & — & [61] \\ The Loess Plateau & Moss crust & — & +160.8 & +49.7 & +12.3 & — & [77] \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Effect of cryptogams on soil fertility. promotion of the regeneration of vascular plants increases the seed germination rate [85], promotes the establishment and growth of seedlings [86; 87], and improves seedling survival rates [88]. The inhibitory effect on vascular plant regeneration was primarily demonstrated to be a reduced seed germination rate [89; 90; 91], prolonged germination time [92; 93; 94], and inhibited seedling growth [95]. Other studies have found that bryophytes can not only reduce germination rate and prolong germination time but also lead to the deterioration of seed water state [96], thus reducing seed germination potential. [PERSON] et al. also found that lichen crusting reduces the ability of seedling roots to penetrate the soil [92], leading to seedling death due to a lack of access to water and nutrients. Some studies have found that the same cryptogams have completely opposite effects on the seed germination and seedling growth of the same vascular plant. [PERSON] et al. found through greenhouse experiments that the crust of cyanobacteria, lichens, and mosses inhibited the germination of _Ceratoides latens_ and _Setaria viridis_ seeds but promoted their seedling growth [97]. A study in the desert also found that biological crusts inhibited the germination of _Agriophyllum squarrosum_, _Eragrostis minor_, and _Grubovia dasphyllla_ seeds but promoted seedling growth. The inhibitory effect of crust on seed germination can be alleviated by proper sand burial treatment [98]. Bryophytes have a \"filtrating function\" for the regeneration of native and exotic plant species. Some studies have shown that bryophytes have no effect on the seed germination of native vascular plants but significantly inhibit exotic species germination [99]. [PERSON]'s research also showed that moss crust does not limit the emergence of native plants but can effectively resist the emergence of exotic species [100]. Under high soil moisture content in greenhouse conditions, the lichen-moss crust was found to inhibit the seed germination of both native plants and exotic plants.