种子和果实的扩散是维持生态系统结构与功能的关键过程。对大部分植物而言，种子和果实的扩散是其生命周期中唯一能够实现个体迁移的阶段。与动物传播相比，依靠风力传播的植物更容易受到气候变化的影响，因为动物活动会将种子或果实运送到更适宜动植物生活的地方（定向传播）。早渐新世是“冷室气候”的起点，欧亚大陆植被从晚始新世的亚热带常绿阔叶林转变为温带落叶混交林。这一时期植物种子和果实的主要扩散方式是什么？欧亚大陆 ...

PRAGUE, July 15 (Xinhua) -- The Czech Republic will not join the purchase of U.S. weapons for Ukraine at this time, Czech Prime Minister Petr Fiala said on Tuesday. U.S. President Donald Trump announc ...

PRAGUE, July 4 (Xinhua) -- A major power outage that struck the Czech Republic on Friday was caused by a technical fault, Czech Prime Minister Petr Fiala told reporters at a press conference, noting ...