The Effects of Winter Exposure to Acid Soil Conditions on the Subsequent Survival and Growth of Herbaceous, Forest Perennials: a Preliminary Investigation

For many plant species, growth is limited in acid soils, whichare characterized by high levels of potentially-toxic elementsand low nutrient availability. Although plant-soil interactionsare traditionally studied during the growing season, the highestconcentrations of toxic elements in the soil may occur duringthe winter months. The present study investigated the effectsof a 3-month exposure to either an acid or a reference soil,at temperatures fluctuating around freezing point, on subsequentsurvival and growth of eight herbs (Brachypodium sylvaticum,Carex pilulifera, Geum urbanum, Luzula pilosa, Mycelis muralis,Silene dioica, Stellaria nemorum, Veronica officinalis).Theplants were exposed to ambient weather conditions from Decemberto March, after which they were replanted in fresh referencesoil and transferred to a glasshouse. Their biomass was measured5 weeks later. The plant species differed in their responsesto the soils, in a manner reflecting their natural field distributions.All plants of the most acid-tolerant species survived in bothtreatments, whereas the more sensitive species showed lowersurvival rates after growth in the acid than in the referencesoil. Similar results were found for the regrowth:C. piluliferaandL.pilosa, the most acid-tolerant species, were unaffected by thesoil treatments (ratios between biomass in acid compared toreference soils were 0.8 and 1.1, respectively), whereasG. urbanum,M. muralis, S. nemorumandV. officinaliswere negatively affected(ratios 0.3–0.5). Effects on above- and below-ground biomasswere broadly similar. This preliminary evidence indicates thatsoil chemistry during the winter can be important for both survivaland growth during the vegetative period that follows.Copyright1998 Annals of Botany Company. Acids soils, toxicity, vascular plants, winter exposure.