López-Soria Luis, Castell Carles
Department de Biologia Animal, de Biologia Vegetal i d'Ecologia, Universitat Autònoma de Barcelona, 08193, Bellaterra Barcelona, Spain.
Centre de Recerca Ecològica i Aplicacions Forestals, Facultat de Ciències, Universitat Autònoma de Barcelona, 08193, Bellaterra Barcelona, Spain.
Oecologia. 1992 Oct;91(4):493-499. doi: 10.1007/BF00650321.
Using data from three fires in northeastern Spain, we tested a condition necessary to support the idea that fire has been a factor in the evolution of the resprouting habit: populations of all resprouting species within a community should show high levels of genet survival after fires and show a low coefficient of variation. Species with high mean survival values were:Quercus ilex L.,Phillyrea latifolia L., andViburnum tinus L., with 88, 86 and 83% survival respectively; these groups had resprouts emerging from rootcrowns. Then followedArbutus unedo L. (75%),Pistacia lentiscus L. (73%),Erica arborea L. (77%),Erica multiflora L. (57%) andJuniperus oxycedrus L. (55%). This last group had resprouts from lignotubers or burls. These two groups also differed in the variability around the mean: the first showed a lower coefficient of variation, 6-12, and the second ranged from 19 to 26. Slope exposure had no significant influence on the process of resprouting, but soil depth did, with precipitation as a covariate. In the shallow soil category, the difference in genet survival between southern and northern exposures was 14% (71% vs. 57%); while the difference in the deep soil category was low, 5% (87% vs. 82%). There was no significant interaction. The component of variance for soils was larger than that for species-specific effects; substantial overlap of the within-species variance indicated that species responded as if they were a single hypothetical population, in which most of the variation in chances of survival was due to the soil conditions. The possession of the resprouting habit did not ensure a high performance. Hence, we find weak support for fire as a factor in the evolution of the resprouting habit.
利用西班牙东北部三场火灾的数据，我们检验了一个条件，该条件有助于支持火灾是萌生习性进化中的一个因素这一观点：群落内所有萌生物种的种群在火灾后应具有较高的基株存活率，且变异系数较低。平均存活率较高的物种有：冬青栎（Quercus ilex L.）、阔叶杨桐（Phillyrea latifolia L.）和地中海荚蒾（Viburnum tinus L.），存活率分别为88%、86%和83%；这些类群从根颈处萌发出新芽。接下来是草莓树（Arbutus unedo L.）（75%）、乳香黄连木（Pistacia lentiscus L.）（73%）、树状欧石南（Erica arborea L.）（77%）、多花欧石南（Erica multiflora L.）（57%）和刺叶 Juniperus oxycedrus L.（55%）。最后一组从木质块茎或树瘤处萌发出新芽。这两组在均值周围的变异性也有所不同：第一组变异系数较低，为6 - 12，第二组则在19至26之间。坡面朝向对萌生过程没有显著影响，但土壤深度有影响，将降水量作为协变量。在浅层土壤类别中，南坡和北坡基株存活率的差异为14%（71%对57%）；而在深层土壤类别中差异较小，为5%（87%对82%）。没有显著的交互作用。土壤的方差分量大于物种特异性效应的方差分量；物种内方差的大量重叠表明，物种的反应就好像它们是一个单一的假设种群，其中存活机会的大部分变异是由土壤条件造成的。拥有萌生习性并不能确保有高的表现。因此，我们发现火灾作为萌生习性进化中的一个因素的证据不足。
