Analysis of the seed regeneration process in a

Abstract

IntroduzioneLe norme tecniche e legislative che regolano le modalità di utilizzazione dei boschi cedui hanno subito, negli ultimi anni, numerose modifiche, che rispondono soprattutto alla esigenza di adeguare, per quanto possibile, questa tradizionale forma di uso del suolo a nuove istanze, emerse negli ultimi decenni, relative alla mitigazione di alcuni effetti ritenuti negativi dal punto di vista paesaggistico e idrogeologico ed alla tutela della biodiversità. Le modifiche recepite da gran parte delle legislazioni regionali, hanno interessato, in particolare, il campo di variazione di età in cui è ammesso il taglio di ceduazione (compreso tra il turno "minimo" e l'età alla quale il ceduo è considerato in fase di avviamento all'alto fusto), la dimensione e la contiguità delle tagliate, la matricinatura.Per quest'ultimo aspetto la discussione si è concen- it).Abstract: Analysis of the seed regeneration process in a Quercus pubescens Willd. coppice in the province of Florence over twenty years after cutting. The technical standards and regulations ruling coppicing procedures have been changed in recent years, and they mainly focused on the minimal rotation age of the coppice woodland, on the size and contiguity of area to be coppiced, and on the standard trees. For the latter, the discussion concerned almost exclusively the number, characteristics and spatial distribution of standards whereas the traditionally reported role played by them in term of future gamic regeneration process, as well as the characteristics and dynamics of the long term process itself, is far to be studied and clarified. The objective of this work, carried out in a Quercus pubescens coppice woodland in the province of Florence, Central Italy, is to analyze the dynamics of the population of seedlings since the time of felling in 1980 over the next 20 years. This work examined changes in number of seedlings, the age of seedlings, the development of agamic regeneration. Main results: (a) in about 20 years since felling any of the survived seedling grew to sapling; (b) mortality rate of seedlings was initially very high, gradually decreasing over the years; (c) spatial distribution varies in space and time, and is related to the presence either absence of the standard trees; (d) over the years, there was a severe selection among the coppice stumps and among the coppice shoots, some of which die, without however be replaced by seed-born trees. It emerged the marginal role of the populations of seedlings, both in terms of replacement of died stumps, and in recruitment of the new standards ("allievi"). This conclusion calls into question the term "natural regeneration" by which even in technical either scientific terminology about coppice woodlands often refers to a set of seedlings present, which is theoretically assigned a role that definitively they cannot really play. Keywords: Coppice, Quercus pubescens, Standard trees, Seed regeneration, CompetitionReceived: Nov 30, 2011; Accepted: Feb 10, 2012; Published online: Feb 28, 2012 Citation: ...