Although the presence of root anatomical structures of young Pinus ponderosa seedlings grown in containers of contrasting volume (164 vs. 7000 cm3) was similar, seedlings reared 60 days in the large container had more vascular cambium although the xylem thickness was similar. In addition, seedlings in large containers had nearly twice as many resin ducts within the vascular cambium as their cohorts in small containers. Taproot length closely matched container depth. Though lateral root emission rates were similar between container sizes, large container seedlings had more than 2X the number of lateral roots as those from small containers. These differences in morphophysiological characteristics may be important to seedling establishment on sites that experience dry summer conditions, or for seedlings destined to drier, harsher sites. Further work to elucidate the ramifications of these morphophysiological differences on seedling establishment is warranted.

In forestlands on steep slopes, where the shallow soil can be considered a non-renewable resource, erosion is of special concern. The vegetation covers, at both soil and canopy level, provides essential protection to the soil against the rainfall erosivity and reduces considerably the water erosion rate. Consequently vegetation management may affect soil erosion. We focused our attention on old coppice beech forest growing on a steep slope (28-32°) and subjected to conversion to high stand. With the aim of obtaining information on surface water flow and the mineral soil loss, three runoff-erosion plots (10 m long ´ 3 m wide) were installed in catchments in Lombardy Alps (Intelvi Valley, Como) at three stands: a coppice 40 years old (CpS 1968) and two conversions from coppice to high forest respectively cut in 1994 (CvS 1994) and 2004 (CvS 2004). Water run-off and sediment losses were collected from June to October 2008 and from May to October 2009 together with stand characteristics, LAI, soil surface cover, canopy cover and fine-root traits. Our results showed that the conversion practices significantly affect the water runoff and soil erosion with the younger conversion CvS 2004 showing the highest erosivity. This was due to the lower values of tree density, canopy cover, soil surface cover and fine-root biomass and length. The old coppice stand (CpS 1968) together with the older conversion stand (CvS 1994) showed comparable values of soil erosion. Therefore, the major role in protecting soil from erosion played by old coppice stand is recovered by the conversion stand after a number of years since harvesting. Our study highlights that abandoned old coppice stand plays an important role in protecting soil from erosion and claims consideration in forest management of steep forestland stands.

Increased summer drought and wildfires as a consequence of continuing climate change are expected to lead to disturbance of Mediterranean ecosystems. Seedlings recruitment is sensitive to both stresses and, therefore, any adaptation and restoration strategy devised to protect these forests should take into account a careful study on their effects on seedling development. As a substantial fraction of net primary productivity of forested ecosystems is channelled in the belowground compartments, the knowledge of how roots behave under stressful conditions becomes of primary importance to select the right management strategy to be implemented. This work tries to enlighten the events occurring in the fine root portion of the root system in young seedlings of three co-existing oak species (Quercus ilex, Quercus trojana and Quercus virgiliana) under controlled conditions. We have made a comparative analysis of the effect of these two stresses, alone or in combination, with the aim to evaluate the tolerance level of these seedlings and, therefore, to obtain an indication of their recruitment potential in the field. The parameters investigated were biomass and a number of morphological traits. Data obtained suggest that a decrease in diameter could be part of a tolerance strategy in all three oaks tested together with a reduction of root length. In addition, tolerance to water shortage could require a reduction of carbon allocated belowground, in particular in the very fine roots, which leads to an overall reduction of the root system dimension. Q. trojana seedlings seem to be the fastest in resuming growth after stress interruption but a good recovery was also found for the remaining two oak species. Although our study provides interesting information regarding a possible tolerance strategy taking place in the fine root compartment when seedlings of these three oak species undergo water stress and fire treatment, more information is needed before any suggestion can be made as to which species would be best suited to make these forests more resistant to global changes.