不同环境要素影响下大型海藻碎屑分解研究

发布时间：2018-06-30 02:11

本文选题：大型海藻 + 海藻碎屑　；参考：《上海海洋大学》2017年硕士论文

【摘要】：水生植物凋落物是生态系统中的重要组成部分,参与物质循环和转化的基础,是海底沉积物或水体养分等的重要来源,让生态系统中养分得以恢复和增加,进而提高生态系统中的生产力,为维持海洋生态系统等物质和能量循环有着密切联系。凋落物的分解就是将无机营养元素从有机物质中释放出来的过程,也是生态系统中物质循环和能量流动的重要环节之一,对生态系统的功能和结构起重要作用。岛礁海域的海藻场生态系统中,海藻场生态系统中约10%的初级生产力是通过直接摄食作用而进入食物网,剩余90%通过碎屑或溶解有机质进入食物链。碎屑除了以初级生产者身份进入碎屑食物网这一途径,未被摄食者利用的碎屑自身受环境影响会不断自溶或被分解者分解进入到海域环境,同时伴随水流潮汐作用使得海藻碎屑和底栖微藻等小颗粒物质会随海流扩散至周围浅海沙滩或是岩礁潮间带或是深海处等各种不同生境处,海藻碎屑进入不同海域环境内,受到不同海域环境条件差异进而影响其分解和营养元素释放或吸收量差异。本论文主要探究不同环境要素(温度、光照强度、溶解氧)影响下海藻碎屑分解规律,并对不同大型海藻的碎屑分解进行比较分析,同时还对有无微生物作用对海藻碎屑分解差异进行了研究。结果表明:(1)不同温度、光强、溶解氧条件下,瓦氏马尾藻碎屑质量损失率在2个月的实验周期内皆大于60%,瓦氏马尾藻碎屑剩余物质干重和分解速率受光照强度影响显著(P0.05);在温度25.15℃、光强3200 lx,氧充足条件更有利于瓦氏马尾藻碎屑分解,瓦氏马尾藻碎屑剩余物质干重最小,实验末期海藻碎屑失重率可达84.70%,平均分解速率为0.08d-1;温度对瓦氏马尾藻碎屑分解释放氮磷营养盐影响不显著(P0.05);在同一温度(25.15℃)条件下,有无光照条件对水体正磷酸盐浓度影响显著(P0.05);光照强度对水体内铵态氮和正磷酸盐浓度变化具有显著影响(P0.05),溶解氧浓度差异对氨氮、磷酸盐和硅酸盐浓度变化影响显著(P0.05);在不同环境要素影响下单位瓦氏马尾藻碎屑对氮、磷、硅的营养盐贡献度为溶解无机氮(DIN)1.51~3.81mg·g-1,溶解性磷酸盐(DIP)7.72~10.14mg·g-1,活性硅酸盐(SiO42-)1.09~4.78 mg·g-1。研究表明,瓦氏马尾藻碎屑分解释放活性磷酸盐(DIP)贡献量最大,溶解无机氮(DIN)、活性硅酸盐贡献量次之。(2)铜藻碎屑在2个月的分解实验周期里失重率均高于60%,且随温度升高、光照强度增大,溶解氧浓度升高,海藻碎屑的失重率为78.29%,富氧条件下铜藻碎屑分解速率可达0.03d-1,均高于光照强度和温度实验中铜藻碎屑分解速率;铜藻碎屑分解过程中,氮、磷、硅三项无机营养盐含量变化受温度、光照强度影响显著(P0.05),随培养时间的延长对无机营养盐的浓度变化也有显著影响(P0.05),溶解氧对氨氮和硅酸盐浓度差异影响显著(P0.05),对硝酸盐、亚硝酸盐和正磷酸盐浓度变化影响不显著(P0.05);不同环境要素影响下,铜藻碎屑分解对氮、磷、硅生源要素贡献度差异较大,单位海藻碎屑在29.5℃温度条件下对DIP的贡献度为2.44~12.93 mg·g-1,高于光照条件和溶解氧环境下DIP贡献量;DIN在光照强度影响下单位铜藻碎屑释放趋势大,累积贡献量为-0.94~0.80 mg·g-1;硅酸盐释放易于在富氧(5~9mg/l)条件下,单位累积释放量可达25.20 mg·g-1。铜藻碎屑分解对硅酸盐贡献量最大,磷酸盐次之,对DIN总体呈现吸收状态。(3)将有氯仿的微生物抑制剂作为实验组,无添加氯仿的为对照组。结果表明:有微生物抑制剂的实验组海藻碎屑分解速率是对照组的1.53倍,且实验组和对照组的海藻碎屑失重率分别为81.5%、75.27%;海藻碎屑分解初期实验组和对照组中氨氮释放量均出现显著降低,但在第7天后实验组氨氮有上升趋势,并一直高于对照组,对照组氨氮释放量一直维持稳定的较低释放量,氨氮释放趋势与硝酸盐-氮释放趋势恰好相反;实验组磷酸盐一直持续较高且稳定的趋势,碎屑分解期间释放的最高值达到3.89 mg·L-1,而对照组海藻碎屑释放磷酸盐含量一直持续降低,直到实验末期仅为1.43 mg·L-1;硅酸盐含量在海藻碎屑分解过程中呈现持续上升趋势,在实验结束含量最高为9.26 mg·L-1,而在对照组硅酸盐释放量微小,且实验末期硅酸盐含量仅为0.03 mg·L-1。在海藻碎屑分解实验中,微生物抑制剂对海藻碎屑分解释放氮、磷、硅营养盐有差异,单位海藻碎屑在实验组中DIN、DIP、SiO42-累积释放量是对照组的1.21倍、1.16倍、2.31倍,微生物抑制剂在海藻碎屑分解过程中对溶解无机磷(DIP)影响最小,对硅酸盐(SiO42-)影响最大,有无微生物作用对海藻碎屑分解释放营养元素起到重要调节作用。
[Abstract]:Aquatic plant litter is an important part of the ecosystem. It is an important part of the circulation and transformation of material. It is an important source of marine sediment or water conservation. It makes the ecosystem in the ecosystem recover and increase, and then improve the productivity in the ecosystem, so as to maintain the circulation of the marine ecosystem and other materials and energy. The decomposition of litter is the process of releasing inorganic nutrients from organic matter. It is also one of the important links of material circulation and energy flow in the ecosystem. It plays an important role in the function and structure of the ecosystem. In the algae field ecosystem of the island reef sea, about 10% of the primary productivity in the algae field ecosystem. To enter the food network by direct feeding, the remaining 90% enters the food chain through detritus or dissolved organic matter. In addition to the entry into the detrital food network as a primary producer, the detritus that the detritus is not used by the feeding person will continue to dissolve or decompose into the marine environment, accompanied by the flow of water. The tidal effects make the small particles such as algae debris and benthic microalgae spread to the surrounding shallow sea sand or the intertidal zone of the reef or the deep sea and other different habitats. The algae debris enters the different marine environment, and is affected by the differences in the environmental conditions of different sea areas and the release of nutrient elements or the difference of absorption. This paper mainly explores the decomposition rules of seaweed fragments under the influence of different environmental factors (temperature, light intensity, dissolved oxygen), and analyses the decomposition of debris from different large algae, and studies the decomposition difference of seaweed fragments without microorganism. The results show: (1) under different temperatures, light intensity, and dissolved oxygen, tile The mass loss rate of Sargassum detritus was greater than 60% in the 2 month experimental period. The dry weight and decomposition rate of the residue of Sargassum valsalam were significantly affected by the light intensity (P0.05). At 25.15 C, the light intensity was 3200 LX, and the oxygen sufficient conditions were more conducive to the decomposition of the debris of the valsargasus, and the dry weight of the debris residue of Sargassum waglis was the smallest. The end stage weight loss rate of the algae debris can reach 84.70%, the average decomposition rate is 0.08d-1, and the effect of temperature on the decomposition and release of nitrogen and phosphorus nutrients of the debris of Sargassum waghl is not significant (P0.05). Under the same temperature (25.15 degrees C), there is no light condition on the concentration of phosphate (P0.05), and the intensity of light is on the ammonium and orthophosphate in the water body. The change of salt concentration had significant influence (P0.05), and the difference of dissolved oxygen concentration had a significant effect on the changes of ammonia, phosphate and silicate concentration (P0.05). The contribution of the unit to nitrogen, phosphorus and silicon was dissolved inorganic nitrogen (DIN) 1.51~3.81mg. G-1, and dissolved phosphate (DIP) 7.72~10.14mg. G-1 under the influence of different environmental factors. The active silicate (SiO42-) 1.09~4.78 mg / g-1. studies showed that the contribution of the detrital release active phosphate (DIP) of Sargassum vwis (DIP) was the largest, the dissolved inorganic nitrogen (DIN) and the active silicate contributed the second. (2) the weight loss rate of the copper algae debris in the decomposition experiment period of 2 months was higher than 60%, and the light intensity increased and the dissolved oxygen concentration increased with the increase of temperature. The weight loss rate of algae debris was 78.29%, and the decomposition rate of copper algae was up to 0.03d-1 under the condition of oxygen enrichment, which was higher than the decomposition rate of copper algae in the light intensity and temperature experiments. In the process of decomposition of copper algae, the changes of three inorganic nutrients in nitrogen, phosphorus and silicon were affected by temperature and light intensity (P0.05), with the prolongation of culture time. The concentration changes of inorganic nutrients were also significantly affected (P0.05). The effects of dissolved oxygen on the concentration of ammonia nitrogen and silicate were significant (P0.05), and the effects on nitrate, nitrite and orthophosphate concentration were not significant (P0.05); the contribution degree of the decomposition of copper algae to nitrogen, phosphorus and silicon source was greatly different under the influence of different environmental factors. The contribution of detritus to DIP at 29.5 C was 2.44~12.93 mg. G-1, which was higher than the light conditions and DIP contribution in the dissolved oxygen environment. Under the influence of illumination intensity, the release trend of the unit copper algae was large, the cumulative contribution was -0.94~0.80 mg. G-1, and the release amount of the unit was 25 under the condition of oxygen enrichment (5~9mg/l), and the cumulative release of the unit could reach 25. The decomposition of.20 mg / g-1. copper algae is the largest contribution to silicate, phosphate is the second, and the total absorption of DIN is present. (3) there will be chloroform microbial inhibitors as experimental group, no chloroform as the control group. The results show that the decomposition rate of algae debris in the experimental group with microbial inhibitors is 1.53 times that of the control group, and the experimental group and the pair The weight loss rate of algae debris in the group was 81.5%, 75.27%, respectively, and the ammonia nitrogen release in the early experiment group and the control group decreased significantly, but in the seventh days, the ammonia nitrogen in the experimental group increased, and was always higher than the control group. The ammonia nitrogen release rate of the control group remained low, the ammonia nitrogen release trend and nitric acid were in the control group. The trend of salt nitrogen release is just the opposite; in the experimental group, the highest and stable trend of phosphate continues to reach 3.89 mg. L-1 during the detrital decomposition, while the content of phosphate release phosphate in the control group continues to decrease until the end of the experiment is only 1.43 mg. L-1; silicate content is held in the decomposition process of seaweed detrital. At the end of the experiment, the highest content was 9.26 mg. L-1, while the silicate released in the control group was small, and the silicate content was only 0.03 mg. L-1. at the end of the experiment. The microbial inhibitors disassembled nitrogen, phosphorus and silicon nutrients for the decomposition of seaweed debris, and the unit algae debris in the experimental group was DIN, DIP, SiO4. The cumulative release of 2- was 1.21 times, 1.16 times and 2.31 times of the control group. Microbial inhibitors had the least influence on dissolved inorganic phosphorus (DIP) during the decomposition of seaweed detritus, and had the greatest influence on the silicate (SiO42-), and the microbial effect played an important role in the release of nutrients to the decomposition and release of algae.
【学位授予单位】：上海海洋大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：S917.3

【参考文献】