气候变化对高原鱼类生活史的潜在影响研究

Climate change has altered the planet's ecosystems severely. As one of the three major ecosystems, freshwater is more vulnerable to climate change than terrestrial and marine ecosystems because it is relatively isolated and physically fragmented within a largely terrestrial landscape, and it is already heavily exploited by humans for the provision of 'goods and services'. Many studies have been carried out in China on climate change affecting on freshwater ecosystems. Unfortunately, most of them focused on the responses of physical and chemical characteristics to climate change, and biological characteristics were insufficiently studied. As an important role in maintenance of freshwater ecosystems function, fish has been extensively used to assess the effect of climate change on biological characteristics. Many studies found that climate change affected the fish community and population through altering its life history which was the key point for fish adapting to climate change. Therefore, studying the climate change on fish life history is an efficiency way to understand the influence of climate change on freshwater ecosystems. The Qinghai-Xizang Plateau, the most susceptible place to global climate change, is selected as the study area. The fishes which inhabit in the highland and adapt to different temperature and survival regimes are selected to study the effect of climate change on the life history. The natural environmental gradient along the altitudinal is used as a surrogate for climate change. We study the potential influence of climate change on life history of the plateau fish through three aspects: (1) investigate how climate affects life history traits and strategy of different adaptation regimes species along an altitudinal gradient; (2) determine the sensitivity of different adaptation regimes species to climate change; (3) identify the main climate factors influencing the life history and how they change with the different adaptation regimes species. The aim of this project is to investigate the potential impacts of climate change on different adaptation regimes species to understand the mechanisms how climate change influence fishes comprehensively. The research is also important for human recognizing the mechanisms how climate change affects freshwater ecosystems. In addition, the project will provide the basic data and theoretical basis for managers developing protection strategy of freshwater ecosystems in the Qinghai-Tibet Plateau to alleviate the damage of climate change.

气候变化对全球的生态系统产生了巨大影响。淡水生态系统与陆地生态系统、海洋生态系统并列为地球上的三大生态系统，但是淡水生态系统较陆地和海洋生态系统更易受到气候变化的影响。鱼类是维持淡水生态系统平衡的关键类群，其生活史是决定物种能否适应气候变化的关键因素。本项目选取气候变化敏感区青藏高原为研究地区，不同温度和生存适应机制的高原鱼类作为研究对象，采用空间代替时间的研究方法，对比研究不同适应机制物种的生活史在海拔梯度的变动规律及其气候驱动机制，评估未来气候变化对我国高原鱼类及高原淡水生态系统的潜在影响。该研究对探讨气候变化对淡水生态系统影响过程和机制有重要意义。同时，在气候背景下，为制定青藏高原地区淡水生态系统的保护策略提供理论基础和数据支撑。

气候变化已经对全球生态环境、生物多样性以及人类经济社会发展产生了深远的影响。水生生态系统对气候变化的响应尤为明显。青藏高原被认为是全球气候变化最为敏感的地区之一。本项目选取不同演化级别高原鱼类以及生存适应机制显著不同的外来鱼类作为研究对象，对比研究了其生活史特征和策略在海拔梯度的变化规律及其潜在的气候驱动因子。.生活史特性随海拔梯度变化的研究表明：海拔梯度的变化影响了拉萨裸裂尻鱼的存活（寿命）和繁殖特性（相对繁殖力）、异齿裂腹鱼的生长特性（最大体长）、双须叶须鱼的存活（寿命）和繁殖特性（最小性成熟体长）、鲫生长（最大体长）、存活（寿命）和繁殖（卵径）特性以及麦穗鱼繁殖特性（卵径，最小性成熟体长）。.生活史策略随海拔梯度变化的研究表明：拉萨裸裂尻鱼生活史策略的变化与海拔呈负相关，表明海拔的梯度变化最终会影响其生活史策略；麦穗鱼的生活史策略与最湿月份降水量呈显著负相关，表明降雨是影响麦穗鱼生活史策略的重要因素。.30种裂腹鱼类种间生活史特性与环境因子分析表明：裂腹鱼类体长，寿命和性比受环境影响；影响体长的关键环境变量为年均温和降水量季节性变化；影响寿命和性比的关键环境变量为温度的季节性变化。研究证实了气候变化对于裂腹鱼类生活史的形成具有重要作用。.拉萨裸裂尻鱼和尖裸鲤的生长指数年表结果表明：年均温对两种鱼类的生长产生了显著的负面影响，而年径流量则呈微弱的正向影响。结合年均气温与径流量关系分析，气候变化更可能是通过改变鱼类食物资源可获得性影响到鱼类的生长，而不是通过改变其生理适应性影响其生长。.26种雅鲁藏布江鱼类的生活史策略分析表明：高原鳅属鱼类多属于机会主义策略，即个体小、生命周期短、初次性成熟早、单次产卵数量较少、卵径小。裂腹鱼类多属于周期性策略个体大、生命周期长、初次性成熟晚、绝对繁殖力高、卵径较大。