The Bioturbation Of Helice Tientsinensis On Suaeda Salsa

Helice tientsinensis often becomes the dominant species in boreal Chinese coastal wetlands.Its biological and ecological impact are enormous,especially in the eutrophic estuary.The effect of borrowing and foraging on landscape pattern of H.tientsinensis is tremendous.In this study,the typical Suaeda salsa wetland in Liao River Estuary was selected to study ecological interactions between the both widely distributed species,field investigation sampling and indoor experiments were carried out then.The behavior and the biological disturbance mechanism of the H.tientsinensis were studied.he population distribution of the H.tientsinensis and S.salsa was monitored.The characteristics of stomach contents,burrow morphology and bio-sedimentation of H.tientsinensis were studied.Put it into a nutshell,the bioturbation of H.tientsinensis on the coastal wetland was evaluated with special reference to the halophilic S.salsa in order to study the ecological interaction between H.tientsinensis and S.salsa.In this paper,a series of experimental methods,such as field investigation,in-situ video recording,indoors imitated experiments were combined to study effects of the biological disturbance of crabs in Panjin Red Beach area on the survival state of the S.salsa.The main results were listed as follows:1)In order to understand the feeding effect of dominant H.tientsinensis on S.salsa in Panjin Red Beach.Field and indoor experiments were conducted to simulate the feeding of the H.tientsinensis on S.salsa.It was found that the H.tientsinensis was feeding through the jaw,and it was found that the remnant of the erosive plant was found by the field gastric capacitive microscopic examination.The size of stomach contents had no obvious effect on the feeding quantity.The feeding intensity of S.salsa plants was found to be random through indoor simulation.In addition,mechanical damage was caused by the first jaw foot to the tender bud of the fin,and the damage and feeding of the spring in the spring were observed in the wild in the field.The results of laboratory simulation showed that H.tientsinensis in the plant of S.salsa generally had preferential feeding behavior to S.salsa.In general,the feeding effect of H.tientsinensis on S.salsa was not obvious,and it was not the main reason of Red Beach degeneration.2)The ecological investigation of the H.tientsinensis and S.salsa in the Panjin Red Beach area showed that the larvae of H.tientsinensis grew fast,and there were significant relationships among morphological parameters.The sex ratio was 3.6,the aggressive behavior in H.tientsinensis mainly occurred between different genders,and death occurs.The S.salsa plants were sprout in early April,and flourishing from July to September.In the period of rapid growth of S.salsa in early July,the plant density in the flourishing area was about three times of that in the degraded area,and the transplanting of S.salsa was carried out in some seriously degraded areas was not effective.3)Population distribution of H.tientsinensis and S.salsa were different in different landscapes.Six different types of wetland were selected for this experiment: tidal creek,bare ground,mudflat,reed area,flourishing vegetated area and degrading vegetated area.The differences of burrow morphology in bare area and S.salsa area were studied by epoxy resin method.The burrow morphology of H.tientsinensis was affected by soil properties,seawater and other environmental conditions.In Panjin Red Beach Wetland,H.tientsinensis built and maintained semi-permanent,nearly vertical burrows,which vary with the location of waterlines,tidal creeks,and vegetation communities.The density of burrows in S.salsa area was high,but the ratio of length to width,volume and number of branches of each burrow were low,the burrow in bare land area was just the opposite.H.tientsinensis excavated larger ones with huge water storage at the burrow bottom.H.tientsinensis excavated in the bare soil had a larger volume,greater depth,greater length and width ratio and greater curvature than that in the both vegetated area,defending themselves against the avian preys.Further analysis showed that the undergrounded roots had an obvious effect on the burrow morphology.4)H.tientsinensis might play a positive role in the improvement of sediment through biological disturbance.Burrows of H.tientsinensis had a positive effect on beach reduction by bringing large amounts of bio-sediments,enhancing the exchange between surface and sediment,increasing organic energy,and promoting biological deposition and soil fertility.It was calculated that the descend of beach was about 15.03 mm by excavation,and the sediment turnover time was 271.14 days averagely.The burrowing effect of H.tientsinensis was to improve the wetland environment,even to promote the colonies of S.salsa and the developments of tidal creeks.Conclusively,the ecosystem engineer H.tientsinensis in the Red Beach Wetland was not the dominant reason for the deforestation of S.salsa,but reduces the salinity,increases the water content,and promotes the decomposition of the material through bioturbation in the mud.Dominant S.salsa can protect H.tientsinensis from the predation,ameliorate the erosions by tide,and,indirectly impacts influence the burrow characterizations through the underground biomass.Their ecological interaction can be summarized as mutualism.