High Forest Systems Research Articles

Assessing Forest Structural and Topographic Effects on Habitat Productivity for the Endangered Apennine Brown Bear

Any forest management potentially affects the availability and quality of resources for forest-dwelling wildlife populations, including endangered species. One such species is the Apennine brown bear, a small and unique population living in the central Apennines of Italy. The conservation of this relict bear population is hampered by the lack of knowledge of the fine-scale relationships between productivity of key foods and forest structure, as this prevents the design and implementation of effective forest management plans. To address this issue, we sampled the main structural stand attributes within the bear’s range and used multivariate generalized linear mixed models in a Bayesian framework to relate forest structural attributes to proxies of productivity of key bear foods. We found that hard mast was positively associated with both forest typology and high forest system, but negatively related to both the time elapsed since the last forest utilization and the amount of deadwood. The availability of soft-mast producing species was positively related to past forestry practices but negatively associated with steep slopes historically managed with high tree densities and a low silvicultural disturbance. Our findings also suggest that herb cover was negatively affected by terrain steepness and basal area, while herb productivity was positively affected by northern and southern exposure. Additionally, richness of forest ants was associated with forests characterized by low volume and high density. Our findings confirm that the productivity of natural bear foods is strongly affected by forest structural and topographical characteristics and are relevant as preliminary information for forest management practices to support the long-term conservation of Apennine bears.

Stato dell’arte e analisi statistica della pianificazione a livello comunale in Basilicata

This work has the purpose to define current level of Basilicata Region’s forest management planning (PAF) and to collect different data concerning to municipal agro-silvo-pastoral properties, administrated until today, and about the planning level reached. In order to allow a correct comparison about different forest populations, the acquired data have been aggregated into homogeneous categories. According to PAF information in this paper are listed: working circle types, main forest system used type, main and dominant species and age-class distribution. Data analysis were based on a comparative analysis about of spatial impact of managed areas if related to analyzed factors, in order to evaluate the areal distribution of collected information. In both provinces (Potenza and Matera), according to data analysis, the working circles that appear to be more frequent have productive and protective functions, while the most extensive type of management forms is high forest system. The comparison between tree factors like main species, managed area and provinces show that in Matera Province the dominant species is the Turkey oak (Quercus cerris L.); instead beech (Fagus sylvatica L.) is the most widespread one in province of Potenza. Moreover Quercus is the most represented genus on the regional territory, if you add mixed oak woods to the Turkey oak. Age-class distribution is an another factor which make a difference between Potenza and Matera provinces: while in Matera is easier to found young forests, uneven-aged management is typical of Potenza’s area, and in both cases we found high forest system. The connection between main species and forest system show us that simple coppice system is typical of mixed oak woods instead beech or Turkey oak pure stand are previously managed as high forest system. In a large quantity of cases, Basilicata Regions coppices are however aged, as shown by the age-class distribution analysis. Finally this work try to understand the relationship between forest management and forest fires.

Does management improve the state of chestnut (Castanea sativa L.) on Belasitsa Mountain, southwest Bulgaria?

Chestnut forests in the Belasitsa Mountain region of southwest Bulgaria were traditionally intensively managed as orchard-like stands for nut production. More recently, management intensity has been sharply reduced as a result of rural abandonment, which combined with the effects of chestnut blight has led to marked structural changes in these forests. The focus of this paper is on the seed-based regeneration potential and seedling survival of chestnut in mixed stands managed over the past 15 years. Results suggest that management of stands under a high-forest system is appropriate, and regeneration from seed has advantages over coppicing if competing species can be controlled. An investigation into “sanitation cutting” performed since the 1990s shows that this had not a successful response to blight infestations.

Growth, regeneration and shade tolerance of the Wild Service Tree (Sorbus torminalis (L.) Crantz) in aged oak coppice forests

Sorbus torminalis L. (Crantz) is a rare species in Central European forests with very limited quantitative information on its regeneration and growth dynamics. Since coppicing is no longer practiced in the most parts of Central Europe, it is unclear whether S. torminalis, which has usually a shorter end height than companion species, can persist in high forest systems. Here, we quantified species frequency on three 1 ha sample plots of former oak coppice forest. To determine whether S. torminalis regenerated continuously and how it might compete with oaks, the age of 80 trees was determined, and diameter and height growth were reconstructed for the 20 largest trees by stem analysis. To assess its shade tolerance, photosynthesis was measured for leaves located in high and low light conditions. Dendrochronological data demonstrated that, over the last 80 years, continuous recruitment of S. torminalis occurred. Growth patterns and photosynthesis measurements suggest that S. torminalis is a highly shade-tolerant species. We conclude that abandonment of coppicing in these forests does not threaten the status of S. torminalis, which can persist beneath the canopy of oaks.

Coppice-with-standards with an overmature coppice component enhance saproxylic beetle biodiversity: A case study in French deciduous forests

Until its replacement by high forest systems in the 19th centuries, coppicing had been practiced in the deciduous broad-leaved forests of Central Europe for many centuries, serving as a source of fuel wood, charcoal and tan-bark for the local populations. Nowadays, some coppice-with-standards (CWS) stands have been converted to high forest by singling (sprout thinning), but many others were simply abandoned, resulting in CWS stands with an overmature coppice component. Little knowledge exists on the biodiversity hosted by such abandoned CWS. In this study, we compared stand features and saproxylic beetle biodiversity in CWS stands with a mature (20-year-old) coppice component to those in stands with an overmature (60-year-old) coppice component. For our study area, we selected 29 plots in 12 oak-hornbeam forests in five regions in northern France. We show that extending rotation age increases the amount of woody debris and alters the deadwood profile. The older the trees and the stands, the more coarse woody debris was created; this includes debris resulting from natural disturbance events. We demonstrated that overmature CWS stands have a higher saproxylic beetle richness than mature CWS. Moreover, even though we found few red-listed beetle species, their number tended to increase in the overmature CWS stands. These results are in line with the observed shift in deadwood profile. Indeed, the increase in deadwood volume along the maturity gradient seems to positively affect saproxylic beetle diversity. Consequently, we conclude that conserving CWS stands with an overmature coppice component can be a useful tool in biodiversity restoration management, in addition to set aside areas.

Un exemple de l’effet du régime sylvicole sur l’humus et la richesse du sol en éléments nutritifs

Les facteurs de la pédogénèse et ceux de la fertilité des sols sont connus. Les effets des traitements sylvicoles sur le sol le sont moins, comme par exemple le passage du régime du taillis-sous-futaie à la futaie. Le taillis épuiserait davantage la fertilité minérale du sol que la futaie par suite de l’exportation de biomasse, à l’inverse la futaie pourrait conduire à des humus plus dégradés qu’en taillis. Cet article présente un exemple pris en chênaie ligérienne et pose la question générale de l’effet des monocultures fussent-elles feuillues, et celle des perturbations des écosystèmes, sur la fertilité minérale des sols.

Pour mobiliser la ressource de la forêt française. Résumé du rapport du groupe de travail sur l’insuffisante exploitation de la forêt française

La forêt française s’est beaucoup étendue et enrichie. Son extension atteint le double, 16 millions d’hectares, de celle d’il y a 180 ans, et elle s’est aussi considérablement enrichie depuis par les conversions de taillis en futaie, par les reboisements des terrains en montagne (RTM) depuis un siècle et par ceux du Fonds forestier national (FFN) depuis un demi-siècle. Sa production est maintenant de 103 millions de m3/an. Parallèlement, la récolte connue, qui représentait environ les deux tiers de cette production il y a trente ans, stagne aujourd’hui à la moitié seulement (soit 50 millions de m3/an). Cette divergence certaine est préoccupante. Avec cette capitalisation, nous bénéficions d’une ressource qu’il serait dommage de ne pas valoriser. Il nous faut aujourd’hui une politique ambitieuse de la forêt et encore plus de l’utilisation du bois. À l’occasion des récentes “Assises de la forêt”, le Ministre Michel Barnier a annoncé qu’il faudrait augmenter la récolte de 10 millions de m3/an d’ici 2010 et de 20 d’ici 2020.

Management driven changes (1967–2005) in soil acidity and the understorey plant community following conversion of a coppice-with-standards forest

Forest management regimes influence plant diversity and soil properties. Many European forests were traditionally managed as coppice-with-standards of which the majority are nowadays being converted to or have been converted to high forest systems. To evaluate the impact of these changes on abiotic and biotic characteristics, long-term data are needed. Here results are presented from the 245 ha Tournibus forest (Belgium) where soil acidity was determined and vegetation records were made in 1967 and 2005 for 246 semi-permanent plots. In 1967 most of the forest was managed as coppice-with-standards, whereas in 2005 stands were managed as high forest (either uneven-aged high forest, even-aged high forest with Quercus spp., or even-aged high forest with Fagus spp.). We determined if soil acidity (at 5 and 45 cm depth) and understorey vegetation related characteristics changed between 1967 and 2005 for the whole forest and if conversion types differentially influenced these variables. Each conversion type was also characterised in terms of canopy and forest floor/topsoil derived factors. Soil acidity at 5 cm depth increased and the magnitude depended on conversion type and initial soil acidity. No soil acidification was observed at 45 cm. Significant overall increases were found for: α-diversity (i.e. plot species richness), the proportion of ruderal species and Ellenberg indicator values for soil moisture, soil reaction and soil nitrogen. On the contrary, β-diversity (i.e. the degree of change in species identities among plots) and the proportion of competitive and stress-tolerant species on average decreased significantly. Moreover, conversion type differentially affected the magnitude of change for all variables, except α-diversity. Conversion to even-aged high forest led to larger departures from the 1967 situation than conversion to uneven-aged high forest. Most changes were interpreted as abiotic or biotic homogenization, which are likely not independent: increased convergence of abiotic factors within a conversion type (mainly even-aged high forest) most likely has led to biotic homogenization.

Detecting local establishment strategies of wild cherry (Prunus avium L.)

BackroundP. avium, a pioneer tree species that colonizes early forest successional stages, is assumed to require an effective strategy allowing stably repeatable rounds of local establishment, dispersal and local extinction. Consequently, the early replacement of cherry by climax tree species makes the establishment of several local generations very unlikely, especially in central European continuous cover forests. This has to be seen in connection with the mixed reproduction system involving asexual reproduction as a complementary adaptational strategy. Tests of the local establishment of wild cherry must therefore consider the possibility of first generation establishment via seedling recruitment potentially followed by an asexual generation (root suckering). Successful establishment can therefore be determined only among adult individuals with the option of detecting vegetative reproduction at these stages. To test the implied suggestion about local establishment strategies of wild cherry, nuclear microsatellites were used to analyse patterns of asexual propagation among adult stages that have been subjected to one of two major types of forest management. These management types, the historical "coppice with standards system" (CWS) and the "high forest system" (HFS), can be reasonably assumed to have affected the reproduction system of P. avium.ResultsClear differences were found in the reproduction pattern between two stands representing the two forest management types: 1) Clonal propagation is observed in both management systems, but with a distinctly higher frequency in the CWS. Hence, sexual recruitment as a first local generation is followed by a second asexual generation in both, whereas in the CWS there is evidence for an additional clonal generation. 2) The estimation of amounts of clonal reproduction critically depends on the assumptions about multilocus gene associations. This is revealed by the application of newly developed methods of quantifying gene associations. 3) Haplotype diversities are higher in the CWS and found to be associated with a large degree of heterozygosity for the second largest clonal group. 4) Seed set was sparse over the last eight years of observation in the CWS stand.ConclusionThis study provides useful guidelines for more comprehensive investigations, particularly on the interrelationships between degrees of cloning and capacity of sexual reproduction, amounts of multilocus gene associations, effects of heterozygosity on cloning success, and sustainability of different forest management types.

L'aménagement forestier entre conjoncture et temps long, rupture et continuité//Long and short-term in forest management

By trying to en sure continuity by applying a long term policy while integrating renewed social needs, forest management transposes on forestry space some choices fixed at a certain moments. Our paper contrasts the time of relative certainties defined primarily by tree conversions to a high forest system and the expansion of coniferous tree plantations with the time of the present forest realities characterized by a new definition of the balance between wood production, increasing opening of forests to services, and sustainable development.

Sustainable management of planted forests: some comparisons between Central Europe and the United States

Following the introduction of planned forestry and the regular high forest system more than 250 years ago, forests in Central Europe became increasingly shaped by plantation silviculture. Many natural woodlands were replaced by planted forests, and forest plantations are still being established through afforestation of extensive land areas. Nowadays, forests are managed for many different purposes, including wood production, recreation, ecological, cultural, and amenity values, biodiversity, and soil and groundwater protection. This brings new challenges to forest management and silviculture. To reach a sustainable forestry, in the sense of Brundtland (WCED 1987), we are now reshaping European forestry toward a more nature oriented silviculture. Maybe forestry in the United States and elsewhere can benefit from the mistakes made in Europe during the last two centuries and take a shortcut toward sustainable forestry.