Forests2015, 6(4), 957-972; doi:10.3390/f6040957 (registering DOI) - published 31 March 2015 Show/Hide Abstract
Abstract: Reptile habitats are described using various indices. The definitions of such indices are crucial, as they are applied to habitat modelling for numerous species on local to continental scales. We examined the Leaf Area Index (LAI) for its value as a tool for determining reptile habitat. During measurements carried out in spring and summer months between 2011 and 2013, LAI values were assessed and surveys were conducted on reptile fauna at 11 survey sites in the Solska Forest and Roztocze National Parks areas in Eastern Poland. In total, six Squamata reptiles occurring in Poland were found. We determined that LAI can be utilized as a reptile habitat index, with reptile species associated with LAI seasonal variability as well as LAI range. Moreover, we found that the higher the LAI median value, the greater the variety of reptile species. These findings are useful for development of spatial models of habitats based on LAI as they point to the importance of its seasonal variation.
Forests2015, 6(4), 929-956; doi:10.3390/f6040929 - published 30 March 2015 Show/Hide Abstract
Abstract: With the current climate changes, it is essential to understand the mechanisms that govern floods and flow regimes and their effects on the dynamics of riparian forests. The aim is to assess the effects of new hydrological conditions (increase in flood frequency) on forest stands subject to frequent floods. The sampling sites (total of 94 quadrats) are located in riverine woodlands, and the choice of location corresponds to the boundaries of the flood-risk zones established by official government maps. Our study shows that there are significant differences in the composition and diversity of forest communities following differences in the flood recurrence zones. In the active floodplains (i.e., recurrence interval of 0–20 years), the tree population stands are clearly distinguished from other intermediate flood zones (interval of 20–100 years). Differences are also noted in the structure of the communities, in particular in the frequent flood zones, which are characterized by a low renewal rate, low density and less-diversified forest stands. The frequent floods risk forest stand rejuvenation and creating decline as a result of increased tree mortality and the low renewal rate. With the expected increases in the number of flood events in the coming decades, there may be greater tree mortality and a gradual disappearance of the forest communities.
Forests2015, 6(4), 914-928; doi:10.3390/f6040914 - published 27 March 2015 Show/Hide Abstract
Abstract: In the black-spruce clay-belt region of Western Québec, soil nutrients are limited due to paludification. Under paludified conditions, nutrient subsidies from decomposing surface coarse woody material (CWM) may be important particularly during the later stages of ecosystem development when deadwood from senescent trees has accumulated. For soil organisms, CWM can alter microclimatic conditions and resource availability. We compared abundance and species richness of oribatid mites below or adjacent to CWM across a chronosequence which spans ca. 700 years of stand development. We hypothesized that oribatid abundance and richness would be greater under the logs, particularly in later stages of forest development when logs may act as localized sources of carbon and nutrients in the paludified substrate. However, oribatid density was lower directly under CWM than adjacent to CWM but these differences were attenuated with time. We suggest that oribatids may be affected by soil compaction and also that such microarthropods are most likely feeding on recently fallen leaf litter, which may be rendered inaccessible by the presence of overlying CWM. This may also explain the progressive decline in oribatid density and diversity with time, which are presumably caused by decreases in litter availability due to self-thinning and Sphagnum growth. This is also supported by changes of different oribatid trophic groups, as litter feeders maintain different numbers relative to CWM with time while more generalist fungi feeders only show differences related to position in the beginning of the succession.
Forests2015, 6(4), 903-913; doi:10.3390/f6040903 - published 24 March 2015 Show/Hide Abstract
Abstract: In recent years, Austria has experienced highly variable forest fire activity with new record values regarding the number of fires and sizes of burned areas. Single seasons in 2011, 2012 and 2013 showed 20-year-peaks and significant differences regarding fire activity. A statistical overview of datasets from Austria, Switzerland, Italy and Slovenia is given, allowing a preliminary comparison between the Alpine countries. Higher temperatures in combination with local dry weather conditions are hypothesized as reasons for the observed anomalies. Further analysis will be done with new climatic data in high spatial resolution from the “AgroDroughtAustria” project to confirm these preliminary findings.
Forests2015, 6(4), 879-902; doi:10.3390/f6040879 - published 24 March 2015 Show/Hide Abstract
Abstract: Planted forests of Sitka spruce, a non-native species from north-west America, are the major forest type in Great Britain and Ireland. Standard management involves even-aged stands, rotations of 40–50 years and a patch clear-felling system with artificial regeneration. However, forest policies support managing these forests for multifunctional objectives with increased diversity of species composition and stand structure. Continuous cover forestry (CCF) is an alternative silvicultural approach used to provide such diversity, but the amount of CCF forest is under 10% of the forest area, and less in Sitka spruce forests; This paper reviews research carried out in the last two decades to support the implementation of CCF in Sitka spruce planted forests; Stand structures and microclimate favouring natural regeneration are understood. Harvesting systems have been adapted for use in CCF stands, a single-tree growth model has been calibrated, comparative costs and revenues have been determined, and operational trials established. The interaction between thinning and wind stability in irregular stands is problematic, together with the lack of suitable species for growing in mixture with Sitka spruce; Introduction of an alternative silvicultural approach may take decades and must overcome technical challenges and cultural resistance.
Forests2015, 6(4), 859-878; doi:10.3390/f6040859 - published 24 March 2015 Show/Hide Abstract
Abstract: As European forest policy increasingly focuses on multiple ecosystem services and participatory decision making, forest managers and policy planners have a need for integrated, user-friendly, broad spectrum decision support systems (DSS) that address risks and uncertainties, such as climate change, in a robust way and that provide credible advice in a transparent manner, enabling effective stakeholder involvement. The Sim4Tree DSS has been accordingly developed as a user-oriented, modular and multipurpose toolbox. Sim4Tree supports strategic and tactical forestry planning by providing simulations of forest development, ecosystem services potential and economic performance through time, from a regional to a stand scale, under various management and climate regimes. Sim4Tree allows comparing the performance of different scenarios with regard to diverse criteria so as to optimize management choices. This paper explains the concept, characteristics, functionalities, components and use of the current Sim4Tree DSS v2.5, which was parameterized for the region of Flanders, Belgium, but can be flexibly adapted to allow a broader use. When considering the current challenges for forestry DSS, an effort has been made towards the participatory component and towards integration, while the lack of robustness remains Sim4Tree’s weakest point. However, its structural flexibility allows many possibilities for future improvement and extension.