The Influence Of U Ditch On Juvenile Amphibian And Its Ecological Parameter Determination In Changbai Mountains

Amphibians with important values are influenced by global climate change,environment pollution,habitat fragmentation,human disturbance,Its biodiversity and population decline dramatically,Among them,Along with human activities(graff engineering,reserve development,urbanization)produce concrete drainage channel is one of the important factors lead to the decline.U ditch's lateral wall is vertical and smooth lead to the internal water environment changes dramatically,excessive accumulation of pollutants,conductive to invasive species,cause of habitat fragmentation and isolation,a serious threat to amphibians live.So we select juvenile Pelophylax nigromaculatus and Bufo gargarizans as research object,In amphibian exercise capacity(jumping height and distance,airborne time)as the breakthrough point,Preliminary interpretation juvenile amphibian through the U ditch's behavior strategy,Adopt the behavior control experiment,Study of U ditch in humid conditions,body length,body weight influence on hibian athletic ability.Analysis of the isolation effect and U ditch ecological parameters threshold size,Expect this study not only for the ecological restoration of U ditch and provide theoretical basis for design,at the same time to provide technical support for the establishment of amphibians protection strategy.Research on the following three aspects.(1)The influence of U ditch's humid habitat conditions on the juvenile amphibian movement ability.The experiment combined with the historical meteorological data,In view of the Changbai Mountain U ditch temperature humidity numerical dynamic change rule,Divided into three periods of temperature and humidity environment conditions,22:00-05:00 low temperature and high humidity of the habitat(16~19?,75%~85%);05:00-09:00,17:00-22:00 normal temperature and normal humidity,09:00-17:00 high temperature and low humidity,To study the influence on amphibian exercise capacity,under the condition of normal temperature and normal humidity juvenile amphibian have the strongest exercise ability,This period of time is the important time to amphibians foraging,back and forth through the U ditch of high frequency,and low temperature and high humidity,high temperature and low humidity their exercise ability is weaker.(2)Amphibians are influenced by biological factors,the size of its type,and the body length,body weight as the characterization of the size of the differences in both behavior and exercise capacity are different.With the same quality of juvenile Pelophylax nigromaculatus body length(L)is more slender than juvenile Bufo gargarizans.And the former do more continuity jump,The latter size is hypertrophy,like crawling,when stimulated and avoid adverse environment do jumping movement;In the same habitat conditions,the juvenile Pelophylax nigromaculatus exercise ability is stronger than the juvenile;Amphibian exercise ability enhanced with the increase of body weight?body length ratio,The jumping ability with complete degree of abnormal development gradually enhanced.(3)The directly affect of U ditch is width and depth on amphibians isolation effect.and its behavioral strategy(J strategy: by the ditch side jump to another side;success by individuals under the distance and the angle and the ditch wide decision;C strategy: jump from the bottom up,success is influence by individual biggest leap and ditch depth),U ditch ecological parameters experiments show: according to the local amphibians jumping height and distance confirm the U ditch width and depth ecological parameters.In this study,if meet the full juvenile Pelophylax nigromaculatus through smoothly,the wide should not be more than 13.7cm,deep should not be more than 2.4cm;if meet the full juvenile Bufo gargarizans through smoothly,the wide should not be more than 7.9cm,deep should not be more than 2.2cm.The U ditch parameters is difficult to implement in practical construction,Its visible that the effect of U ditch is great,serious threat to amphibians migration and proliferation.But still get valuable experience and cognition,The smaller width and depth,the greater in shape,the isolation effect is smaller.The sidewalls of the trapezoidal ditch with its angle have better ecological protection function.