摘要
决定潮间带藻类分布的因素是极其复杂的。潮间带与潮下带比较,潮间带有些生态因子的变化比较剧烈,例如潮间带的石沼,会因下雨或天晴而引起盐度和温度的剧烈变化,潮汐所形成的藻体周期性暴露而引起干旱失水,石沼中藻类的光合作用和呼吸作用引起海水pH值的改变等等。因此研究潮间带藻类的生命活动和藻类的分布的时候,必须考虑这些潮间带的生态因子变化的特点。
The factors affecting the distribution of marine algae in the intertidal zone are very complex.Ecological factors such as the changes in the osmotic pressure of sea water in tide pools,after long expossure to air at low tides,may be of great importance in the distribution of algae in this particular zone.Therefore,it is of interest to study the tolerance of algae to changes in osmotic pressure of surrounding sea water and their physiological functions in sea water of various osmotic pressures,especially in relation to their distribution.The materials used for the present work were collected from the intertidal zone of Taiping Chiao,Tsingtao,in mid-August to mid-Octocber 1962,the most common forms being Cladophora sp.,Enteromorpha spiralis Tseng et Chang,E.intestinalis(L.)Link,Ulva lactuca L.and Sargassum Thunbergii(Mert.)O.Kuntze etc.The association and distribution of these algae appeared to be quite stable during this period.Determinations of temperature,pH value,chlorinity and osmotic pressure of sea water in various tide pools of intertidal zone were made and the osmotic physiology in relation to distribution of algae studied.(1)Cladophora sp.and E.spiralis distributed in small but deep tide pools of supralittoral zone,sea water being replenished by wave spray.The salinity could be lowered to 2.88‰and the osmotic pressure of the sea water to 2.12 atm.by rains.The temperature of the sea water in raining days might be as much as 10℃lower than that in clear days,and within a single low tide period,the temperature might vary 2.3℃,and salinity 1.63‰.However,the algae were not exposed to air,but bathed in sea water all the time.Thus,in the tide pools of supralittoral zone,the algae grew under an environmental condition characterized by sea water of lower osmotic pressure caused by precipitation.Ecological factors varied less in the littoral zone than in the supralittoral zone.Sar-gassum Thunbergii grew luxuriantly in practically all the tide pools of the littoral belt,where it was the dominant species.E.intestinalis grew on the muddy bottom of the tide pools in the lower littoral zone,together with U.lactuca.The thalli of U.lactuca also grew on rock,exposed at times to air,apparently capable of drought resistance.Very little variation of ecological factors existed in the infralittoral zone where Sargassum and Ulva were distributed.(2)The ability of the algae to tolerate changes of osmotic pressure,maintaining their normal structure were determined by the plasmolytic method.It was found that Cladophora sp.and E.spiralis were able to tolerate 2.6-32.1 and 2.6-39.8 atm.of osmotic pressure of sea water respectively.Both of them showed resistance to changes of lower osmotic pressure,of which the lowest limit was 2,6 atm.,very close to that of the sea water in the tide pools where these algae were found.The tolerance of U.lac-tuca and E.intestinalis to osmotic pressure changes was found to be from 14.3-48.4 atm.and 11.1-42.5 atm.respectively.Apparently,the ability of U.lactuca to tolerate higher osmotic pressures better than lower ones enabled it to extend its distribution to rocks subjected to long expossure to air.The paraphyses cells of the male conceptacles of Sargassum Tkunbergii tolerated from 1.32-45.4 atm.of osmotic pressure very likely,it was this ability to tolerate wide ranges of osmotic changes that made possible the wide distribution of this Sargassum,markedly predominant in the tide pools of the intertidal zone.(3)The contents of bound water of algal thalli were determined by the Dumonsky method.U.lactuca which distributed at the lower littoral 2one contained 0.13-0.45%of bound water(mostly about 0.3%).The bound water contents of S.Thunbergii from the lower littoral zone were 0.61%,from the middle 0.62%,and from the upper littoral zone 1.00%,showing that samples from the highest position had the highest bound water content.A certain correlation appeared to exist between the bound water contents and the distribution of algae.
作者
方同光
张学明
赵学武
FANG TUNG-KWANG;CHANG HSÜEH-MING;CHAO HSÜEH-WU(Department of Biology,Shangtung College of Oceanology)
出处
《海洋与湖沼》
1964年第1期85-96,共12页
Oceanologia Et Limnologia Sinica
