Saura-Mas S, Lloret F
CREAF (Center for Ecological Research and Forestry Applications) and Unit of Ecology, Department of Animal and Plant Biology and Ecology, Autonomous University of Barcelona, E-08193 Bellaterra, Barcelona, Spain.
Ann Bot. 2007 Mar;99(3):545-54. doi: 10.1093/aob/mcl284. Epub 2007 Jan 19.
Post-fire regeneration is a key process in Mediterranean shrubland dynamics, strongly determining the functional properties of the community. In this study, a test is carried out to determine whether there is co-variation between species regenerative types and functional attributes related to water use.
An analysis was made of the seasonal variations in leaf relative water content (RWC), leaf dry matter content (LDMC), leaf moisture (LM) and live fine fuel moisture (LFFM) in 30 woody species of a coastal shrubland, with different post-fire regenerative strategies (seeding, resprouting or both).
RWC results suggest that the studied resprouters have more efficient mechanisms to reduce water losses and maintain water supply between seasons. In contrast, seeders are more drought tolerant. LDMC is higher in resprouters over the course of the year, suggesting a more efficient conservation of nutrients. The weight of the phylogenetic constraint to understand differences between regenerative strategies tends to be important for LDMC, while it is not the case for variables such as RWC.
Groups of species with different post-fire regenerative strategies (seeders and resprouters) have different functional traits related to water use. In addition to the role of phylogenetical constraints, these differences are also likely to be related to the respective life history characteristics. Therefore, the presence and abundance of species with different post-fire regenerative responses influence the functional properties of the communities.
火灾后的再生是地中海灌木丛动态变化中的一个关键过程,它在很大程度上决定了群落的功能特性。在本研究中,开展了一项试验,以确定物种再生类型与水分利用相关功能属性之间是否存在协变关系。
对一个沿海灌木丛中30种具有不同火灾后再生策略(播种、萌蘖或两者皆有)的木本植物的叶片相对含水量(RWC)、叶片干物质含量(LDMC)、叶片湿度(LM)和活细燃料湿度(LFFM)的季节变化进行了分析。
RWC结果表明,所研究的萌蘖植物具有更有效的机制来减少水分流失并在不同季节维持水分供应。相比之下,播种植物更耐旱。在一年中,萌蘖植物的LDMC更高,这表明其养分保存效率更高。系统发育限制对理解再生策略差异的影响在LDMC方面往往很重要,而对于RWC等变量则并非如此。
具有不同火灾后再生策略的物种组(播种植物和萌蘖植物)具有与水分利用相关的不同功能特征。除了系统发育限制的作用外,这些差异也可能与各自的生活史特征有关。因此,具有不同火灾后再生反应的物种的存在和丰度会影响群落的功能特性。