C1f: Silviculture and management of deciduous broadleaved 08:30 - 10:30 Wednesday, 2nd October, 2019 Venue R08 - WING 2 Congress Theme C. Forests and Forest Products for a Greener Future Presentation Types Oral Chair Magnus Prof

Temperate broadleaved forests are common throughout Eurasia, Americas and elsewhere where they are of outstanding importance for and they provide many ecosystem services. For example, some oaks can harbor nearly 500 species of flora and fauna and in many countries these tree species are managed for high quality timber, firewood, wine barrels, truffles, building materials, mushrooms, cork, fodder production etc. There are many tree species included in this group of which some are relatively unknown from ecological and management perspectives. Temperate broadleaved forests are many times located near urban areas connected to agricultural fields and water. They are therefore among our most preferred forest habitats for recreation purposes and are connected to esthetical and cultural/historical values. Sustainable management of these forests is a global issue and is connected to many environmental and developmental strategies, and large amounts of governmental funding is involved for protection and management with conservation purposes. The main objective of this session is to review different management options applied for sustainable management in these types of forests. The session is organized through a cooperation between IUFRO unit 1.01.06 (Ecology and Silviculture of Oak) and Ignacio Diaz-Maroto. Our intention with this session is to promote a discussion on temperate broadleaved forests between researchers, decision-making authorities and other stakeholders.

08:30 - 08:45

C1f MANAGING REGENERATION POTENTIAL TO SUSTAIN OAK FORESTS IN NORTH AMERICA

Daniel Dey US Forest Service, Columbia, USA

Abstract

Today in North America, there is a well-accepted recognition of oak regeneration failure and the widespread loss of oak forests. Similar observations are being reported around the world. Regeneration potential of a species is the probability that the species will be competitive through regeneration and stand development to prevail in the mature stand. It is the summation of a species regeneration potential from all modes of reproduction, including current seed, seed bank, new seedlings that establish after a regeneration disturbance, advance reproduction, and vegetative reproduction from stump sprouting, root sprouting and layering. Regeneration potential has been quantified for some oak species. Large, competitive oak advance reproduction and stump sprouts are essential to sustain oak forests. Regeneration potential is influenced by initial floristics, site quality, competing vegetation, herbivores, and level of management. Oak regeneration potential in modern forests is commonly too low to sustain oak stocking at current levels. Recommendations are given for silvicultural prescriptions designed to increase oak regeneration potential to sustain oak forests. 08:45 - 09:00

C1f A Review of Research-based Methods for Managing Deer Herbivory of Hardwood Regeneration

Caleb Redick1, Douglass Jacobs2 1Purdue University, WEST LAFAYETTE, USA. 2Purdue University, West Lafayette, USA

Abstract

Pervasive ungulate herbivory poses a major obstacle to forest regeneration in many regions. Various deer species threaten to shift existing forest composition in North America and Europe as they preferentially browse oaks and other high value hardwoods. Herbivory thereby presents a challenge to foresters who want to maintain oak dominated forests. Herbivory also impedes successful of abandoned agricultural or mined lands. Population control can be difficult to implement, and even small populations of deer can have negative effects. Methods other than to manage deer browse are required until populations are reduced on a regional level. Forest landowners and managers attempting hardwood forestation have come up with many creative solutions to deal with wildlife damage, ranging from fences and shelters, to repellents. Many empirical studies on browse management methods have been published in the scientific literature and results can be generalized. Fences are effective, yet require maintenance. Shelters, though expensive, have been shown to be effective in increasing growth and survival in many cases and promote seedling growth to free-to-grow status. Repellents are a common alternative to physical barriers, but their usefulness is short- lived so reapplication is necessary. In addition, there is much variability in effectiveness depending on the repellent type and local deer population. Systemic repellents have been tested, but success is sporadic and depends upon uptake of the chemical. This literature review catalogs research on browse management methods in the presence of high deer populations and compares the effectiveness of such methods. 09:00 - 09:15

C1f Potential of prescribed fire as a management tool for natural oak regeneration in temperate Europe

Linda Petersson1, Daniel Dey2, Annika Felton1, Emile Gardiner3, Magnus Löf1 1Swedish University of Agricultural Sciences, Alnarp, Sweden. 2USDA Forest Service, Columbia, USA. 3USDA Forest Service, Stoneville, USA

Abstract

Oak-dominated forests provide ecosystem services and harbor biodiversity. However, rapidly changing land- use and disturbance regimes have reduced suitable regeneration niches and unsuccessful natural oak regeneration have caused concern in Europe and North America for over a century. In eastern North America, a fire-oak hypothesis has been developed which attributes some oak regeneration problems to effective fire suppression. Prescribed burns are used to regenerate oak-dominated ecosystems, often combined with thinning to increase light and control competing vegetation. In temperate Europe the role of fire is not clear, but fire suppression is widespread. Our study investigates if the fire-oak hypothesis can be applied to European temperate oaks (Q. robur and Q. petraea). A field experiment combining effects of light (high-low), browsing (fence-no fence), and fire (burn-no burn) in a complete block design was established in 2016 at five oak- dominated forests in Sweden. We recorded survival and growth of 2357 naturally regenerated oak seedlings. Two growing season following burn treatment, oak seedling survival ranged from 52% in low-light*no- fence*burn-treatment to 96% in high-light*fence*no burn-treatment. For all burn treatments, 93% of surviving oaks had re-sprouted. This is the first field study to investigate use of a low-intensity prescribed fire as a management tool in European temperate oak forests. The initial results are positive in that we demonstrate the high sprouting capacity of naturally established oak seedlings that experienced a low-intensity prescribed fire. Our results also highlight the importance of investigating combined effects of multiple factors, continued research will further explore these interactive effects. 09:15 - 09:30

C1f The Status quo and scope for future development of oak in

Xiuling Guan1, Wenhui Zhang2 1Chinese Soceity of Forestry, Beijing, China. 2North West Agriculture and Forestry University, Yangling, China

Abstract

China boasts rich diversity of oak species (Quercus spp.) with a wide distribution. According to the 8th forest resources inventory of China, the total area of oak is 16.10 million ha, accounting for 13.7% of natural forests. Importance of oaks will be going to increase because China is prioritizing mixed forests of native species than monoculture of exotic species to increase resilience of forests. Oaks have been underestimated in China for long, often being used as fuel , whereas its economic, ecological and cultural values have been ignored. Since 2015, the CSF has initiated promotion of oak forestry and industry in China. In last three years, apart from involving oak experts from abroad, the CSF has also facilitated the management of secondary forests of oak in over 10 provinces in northern China. The Oak Division of the CSF and China Innovation Alliance of Oak were established in 2018. At present, oak industry is attracting increasing attention from forest departments at different levels, stepping on the path of industry-education-research and coordinated development under the guidance of the CSF. In this presentation, I will present a comprehensive picture of current oak forestry in China and future potentials.

Key words: Quercus, Oak silviculture, oak ecology, sustainable , secondary forests, , oak wood industry 09:30 - 09:45

C1f Regeneration and Conservation of Oaks in Western Himalayan forest of Uttarakhand, India

Manisha Thapliyal, Namitha NK, Pravin Rawat Forest Research Institute, Dehradun, India

Abstract

Oak forests are one of the oldest vegetation types of the Himalayan region and a climax community. They have great social and ecological relevance in the Western Himalayan region providing many important ecosystem services like retention and enriching soil, sustaining the hydrological regime of hills. Oaks are also highly valued economically in the region as they are closely linked with hill agriculture and sustenance as an important source of fodder for livestock, litter for compost, fire wood and timber. Owing to the intense anthropogenic pressure, recurrent forest fires and poor acorn production at times, regenerative capacity of oaks is declining in the Himalayan region. The regeneration of Quercus leucotrichophora and Q. semecarpifolia was studied in Kedarnath Forest Division, of Uttarakhand state. In Q. semecarpifolia forests, there are large number of old trees but establishment of sapling and low girth class trees was hampered due to poor acorn production, disturbances like grazing, trampling, etc. In case of Q. leucotrichophora poor regeneration was observed due to poor acorn setting, weevil attack, acorn predation, browsing damage to seedlings, lopping, forest fire, etc. Natural regeneration of both the species was poor both in disturbed and undisturbed forests in the study area. Existing Oak forests need to be conserved through active involvement of the community in protection and planting of oak, restricting anthropogenic activities and also planting of other fodder species by the Forest department and Self Help Groups to reduce the people’s dependence on oak. 09:45 - 10:00

C1f The impact of admixing rich litter tree species on the vitality and growth of pedunculate oak forests

Ellen Desie1, Leon van den Berg2, Bart Nyssen2, Maaike Weijters3, Arnold van den Burg4, Gert-Jan van Duinen5, Jan den Ouden6, Karen Vancampenhout7, Bart Muys1 1KU Leuven, Leuven, Belgium. 2Bosgroep Zuid Nederland, Heeze, . 3B-Ware, Nijmegen, Netherlands. 4Stichting BioSFeer, Otterlo, Netherlands. 5Bargerveen, Nijmegen, Netherlands. 6Wageningen University, Wageningen, Netherlands. 7KU Leuven Campus Geel, Geel, Belgium

Abstract

Due to the combined effects of land use changes since the Neolithic and more recent atmospheric deposition, many West-European forests are located on degraded and acidified soils. The adverse effects of soil acidity are far reaching, and have resulted in hampered ecosystem functioning and lower delivery of ecosystem services. Forest management, by altering the overstory tree species composition, can accelerate or counteract soil acidification through the quantity and quality of litter input. The admixture of tree species with nutrient rich litter is hypothesized to be a successful soil restoration intervention improving forest vitality, productivity and resilience. The positive impact of rich litter on the soil nutrient status and belowground ecosystem functioning has already been evidenced in common gardens of monocultures. Given the increasing relevance of mixed forests in a context of climate change adaptation, we aimed to evaluate whether the rich litter effect is substantial enough to also improve the soil nutrient status in mixed forest stands and, moreover, whether it can improve aboveground ecosystem functioning. We studied the effect of admixture of black cherry (Prunus serotina) in pedunculate oak (Quercus robur) stands on the belowground ecosystem functioning and on the vitality of oak trees. This was done by pairwise comparison of individual oaks in black cherry neighbourhoods with oaks in monospecific neighbourhoods located over Belgium, The Netherlands and . Results of this study allow to better understand the underlying mechanisms of rich litter admixture and make more applied recommendations for forest management. 10:00 - 10:15

C1f Ecology and management of young Hungarian oak (Quercus frainetto Ten.) stands in the south of

Valeriu-Norocel Nicolescu1, Valentina Aga1, Ecaterina-Maria Chirteș1, Adrian-Vasile Chirteș1, Alexandru-Sorin Stainbok1, Adina-Elena Nicola1, Cătălin Matei2, Constantin Mitrică2, Marinela Ioniță2, Beatrice-Maria Ușurelu1 1Faculty of Silviculture and Forest Engineering, Transylvania University of Brasov, Brasov, Romania. 2Olt County Branch, National Forest Administration ROMSILVA, Slatina, Romania

Abstract

Hungarian oak (Quercus frainetto Ten.) is one of the six oaks in Romania, where it covers ca. 130,000 ha. The species is found chiefly in the south and west of the country, where its occurrence is mostly soil-controlled, as being especially adapted to heavy acidic soils. In the south of Romania (Seaca-Optășani Forest, the largest block of Hungarian oak in the entire native range, ca. 1,560 ha), the species grows under difficult site conditions: local climate specific to a forest steppe zone (mean annual temperature 10.8 oC; mean annual precipitation 559.8 mm; mean annual evapotranspiration 685 mm; mean aridity index 26.9), with heavy soils (Vertisols, developed on loess, marl and clay). Since 1890's, Hungarian oak is managed as high forest, regenerated by seed following the application of group shelterwood cuttings. The resulting young stands are monospecific, highly stocked, with tall and slender trees, and show a high level of mortality (up to 60% of number of trees at 10-15 years of age). Cleaning-respacing interventions - first when mean dbh is ca. 5 cm, second when it reaches 8-9 cm -, carried out in two adjacent Hungarian oak sub-compartments in 2018, have improved the vertical structure and quality of residual stands by performing interventions across the canopy (but mostly from below) and eliminating dead, dying, bent-over, wounded trees, as well as those individuals competing strongly with potential final crop trees, selected based on the vigor-quality-distribution criteria. 10:15 - 10:30

C1f Pre-commercial thinning in naturally regenerated stands of European beech (Fagus sylvatica L.): effects of thinning pattern, stand density and pruning on tree growth and stem quality

Ditlev Otto Juel Reventlow1, Thomas Nord-Larsen1, Jens Peter Skovsgaard2 1Department of Geosciences and Natural Resource Management, University of Copenhagen, Frederiksberg C, Denmark. 2Southern Swedish Forest Research Centre, Swedish University of Agricultural Sciences, Alnarp, Sweden

Abstract

Pre-commercial thinning in naturally regenerated stands of European beech is often expensive and must be justified by improved development of the remaining crop. Based on a field experiment established in two 14- year-old naturally regenerated beech stands in Denmark, we investigated some effects of pre-commercial thinning and pruning on future crop tree growth and stem quality. The treatments included (1) no thinning, (2) moderate to heavy strip thinning, with or without subsequent selective thinning, and (3) extremely heavy strip thinning in two perpendicular directions (checkerboard thinning), with or without subsequent selective thinning and with or without pruning. The resulting residual stand densities ranged from 105 to only 200 ha-1. Treatment effects were evaluated at age 32 on one potential future crop tree for every 100 m2. Total crop tree height was reduced by checkerboard thinning. Stem diameter increased with decreasing stand density but was reduced by pruning. The lower live branch was positioned lower with heavy strip thinning and with checkerboard thinning without pruning. Forks were more frequent and at a lower position in checkerboard thinning. Stem tilt and stem straightness were unaffected by thinning. However, pruned trees tilted less and had straighter stems. Extremely heavy thinning increased the formation of epicormic branches, but these did not reemerge after pruning. In summary, moderate to heavy pre-commercial thinning had no effect on stem quality, while extremely heavy thinning without pruning resulted in unacceptably low stem quality. No-thinning resulted in acceptable growth and stem quality of the crop trees and remains an alternative.