Abstract: The growth and photosynthetic characteristics of four edible fern species including Matteuccia struthiopteris (L.) Todaro, Athyrium multidentatum(Doll.) Ching, Osmunda cinnamomea (L.) var.asiatica Fernald, and Pteridium aquilinum(L.) Kuhn var.latiusculum (Desy.) Underw. ex Heller were examined under three shading conditions (35%, 13% and 8% of full sunlight). The results showed that plant height  of the four species decreased, while specific leaf area (SLA) and leaf water content (LWC) increased with the enhanced shading degree. The net photosynthetic rate (P_n), stomatal conductance (G_s) and transpiration rate (T_r) of the four species decreased and the intercellular CO₂ concentration (C_i) increased with the enhanced shading degree. The maximal photochemistry efficiency of PSⅡ (F_v/F_m) of the four species under the three shading treatments varied between 0.7 and 0.8. The nonphotochemical quenching coefficient (NPQ) decreased with enhanced shading degree. The chlorophyll (Chl) content, especially chlorophyll b content (Chl b) of the four species increased with the enhanced shading degree except for P. aquilinum var. latiusculum, which decreased at 8% of full sunlight. P. aquilinum var. latiusculum had higher SLA, P_n, Φ_PSⅡ, but lower NPQ and Chl a/b compared with other species. In summary, the four fern species were suitable to grow under 35% of full sunlight. Although they had certain tolerance to lower light conditions, their growth was restrained to some extent, and P. aquilinum var. latiusculum had the maximum shade tolerance capacityamong the four species. Our results provide scientific basis for the cultivation, management, and utilization of the four fern species.

Key words: crustacean zooplankton, community structure, redundancy analysis, environmental factor.