Research On Zostera Marina L. Transplanting Technology In The Typical Lagoon Of The Northern China

In this paper, eelgrass were planted with three transplanting methods (staple,TERFS, and sandwiched) to select the appropriate method in the typical lagoon of thenorthern China. Approaches of experimental ecology were used to compare the effectsof the three methods to transplant Zostera marina L. on its survival, establishment,along with the density and biomass of the eelgrass patches. Meanwhile, influencefactors, economical cost, transplanting result and the suitable environments of thethree methods were analyzed. The findings of the research are expected to provideinformation, theory basis and support for the large-scale restoration of seagrass bedsby shoot transplanting. The main results are summarized as follows:1. Excluding some months, the survival rate of the eelgrass after transplanting ofthe three methods are more than60%. As the transplanting methods are different, thetime required for establishment of the eelgrass after transplanting is also different. Thestaple method needed the least time, then the TERFS method, and the sandwichedmethod needed the most. They needed to take36±6,54±15and69±27d forestablishment, respectively. According to the variation of the morphological indexes,transplanting operation shocked the growth of the transplanting eelgrass to someextent. The morphological indexes of the transplanting eelgrass, such as shoot height,leaf length and sheath length were less than those of natural ones, especially the onestransplanting in spring.2. Following a long-term growth and succession, all the three transplanting methodshave successfully created eelgrass patches. According to the monitoring results of theshoot density and the biomass of the patches created by the three methods fromAugust to October, the staple are least, the TERFS are largest and the sandwiched takethe second place, the average of those monitoring are197.3±24.4shoots/m2and108.5±1.2g/m2,329.1±21.1shoots/m2and181.0±0.4g/m2,272.7±24.7shoots/m2and 177.3±1.0g/m2,respectively.3. The fixed carbon is about55.6,103.4and98.3g/m2in the patches created by thestaple, TERFS and sandwiched method, respectively. According to the economicalanalysis of the three transplanting methods (Staple, TERFS and Sandwiched method),their total expenses are about10076,10534and10445Yuan/Mu in the shallowwaters comparing with about16604,15598and16557Yuan/Mu in the deep waters,respectively. In shallow waters, as the sandwiched method cost the least and thematerial it used had little negative effect to the marine environment, so it is suitablefor promotion and application as if in appropriate environmental conditions. In deepwaters, the TERFS method cost the least, and needed less underwater operations andlabor intensity, in addition, the frame itself can also protect eelgrass from uprootingand bioturbation. It could be retrieved for reuse, leaving behind dense patches ofeelgrass, and it is extremely effective to the creation of patches of eelgrass bed and itscost is slightly higher than other two methods. So the TERFS method is suitable forapplication and promotion in deep waters as if in appropriate environmentalconditions. According to this study, to make a design of seagrass transplantingprogram, the environmental conditions of the transplanting sites and thecharacteristics (cost, effect and time) of various transplanting methods should betaken into consideration, what’s more, a pre-experiment to validate the feasibility andeffectiveness of transplanting methods in the candidate site is needed.