Does size matter?: On the importance of various dead wood fractions for fungal diversity in Danish beech forests

The importance of different fractions of coarse wood debris (cwd) for species diversity of wood-inhabiting fungi was investigated in near-natural Danish beech stands. Species number per tree increased significantly with increasing tree size, pointing out large trees to be most valuable for fungal diversity if single samples are compared. Rarefaction curves, evaluating the importance of different cwd fractions in a cumulative space, revealed a different and more complex picture. Rarefaction curves based on wood volume showed small trees and branches to host more species per volume unit than larger trees and logs, respectively, while snags were the most species-poor fraction. Surface-based curves showed species density to be rather similar among cwd types, though species density still decreased slightly with tree size. These results are interpreted to reflect a combination of two factors: firstly, small diameter cwd represent a larger surface area per volume and hence more space for fungal sporocarps, than large diameter cwd. This ‘surface area factor’ explains the high degree of similarity of the surface-based rarefaction curves. Secondly, a collection of small diameter cwd involves more separate units than an equal volume of large diameter cwd, and represents thereby more individual cases of fungal infection and, most likely, more variation in environmental conditions. The effect of this ‘number of item factor’ is reflected in the slightly increasing species density per surface area with decreasing tree size. Richness patterns of red-listed and non-red-listed species were found to be strikingly similar across cwd types, and a general preference for large logs among red-listed species was hence absent. An individual look at the most frequent encountered red-listed species revealed substrate preference patterns to occur in three of six species, of which one, the heart-rot agent Ischnoderma resinosum, preferred large logs. Based on these results, it would be obvious to conclude that local fungal species diversity is most efficiently increased in managed forests if small diameter cwd is prioritised for natural decay. However, small diameter wood appear to be unable to support heart-rot agents and other species depending on a long and diverse infection history and thus the integrity of saproxylic communities may be seriously undermined if only small diameter cwd is left for decay. Therefore, we strongly recommend that whole, naturally dead trees, representing the full range of cwd habitats, are prioritised for natural decay in managed forests whenever possible.     

At which spatial scale are plant species composition and diversity affected in beech forests?

• Context  

Landscape structure is crucial for forest conservation in regions where the natural forest is fragmented. Practical conservation is currently shifting from local stands to a landscape perspective, although few studies have tested the relative effects of different spatial scales on plant species composition and diversity in forests.     

Estimating “autotrophic” belowground respiration in spruce and beech forests: decreases following girdling

Seasonal fluxes of CO₂ from soil and the contribution of autotrophic (root + mycorrhizal) to total soil respiration (SR) were estimated for a mixed stand of European beech (Fagus sylvatica) and Norway spruce (Picea abies) in Central Europe. Mature trees of each species were girdled in August 2002 to eliminate carbohydrate allocation to roots. SR was measured at distances of 0.5, 1.0, and 1.5/2.0 m from the bole of each tree at 1–2 weeks intervals throughout the fall of 2002 and monthly during the spring and summer of 2003. The contribution of roots and mycorrhizae to total SR was estimated by the decrease in SR compared to ungirdled control trees to account for seasonal patterns evident in controls. SR decreased with soil temperature in the fall 2002 and increased again in 2003 as soil warmed. During most of the study period, SR was strongly related to soil temperature. During the dry summer of 2003, however, SR appeared to be uncoupled from temperature and was strongly related to soil water content (SWC). Mean rates of SR in beech and spruce control plots as well as root densities did not show a clear pattern with distance from the bole. SR decreased to levels below controls in beech within a few days after girdling, whereas spruce did not show a significant decrease until October 2002, 6 weeks after girdling. In both beech and spruce, decreased SR in response to girdling was greatest closest to the bole, possibly reflecting increased mycorrhizal activity close to the bole. Autotrophic respiration was estimated in beech to be as much as 50% of the total SR in the stand. The contribution of autotrophic respiration was less certain for spruce, although close to the bole, the autotrophic fraction may contribute to total SR as much as in beech. The large fraction of autotrophic respiration in total SR requires better understanding of tree level stresses that affect carbon allocation below ground.     

Herb-layer diversity in deciduous forests: Raised by tree richness or beaten by beech?

Where natural production capacity permits, modern silvicultural management in Central Europe frequently aims at the development of mixed broadleaved stands, instead of pure European beech (Fagus sylvatica) stands. It is crucial to study the effects of these tree-layer diversity variations on herb-layer vegetation, since herb-layer vegetation contributes significantly to ecosystem functioning in forests. In Hainich National Park (Thuringia, Germany), we conducted observational research in deciduous stands to investigate whether herb-layer diversity was related to canopy-layer diversity, and to ascertain possible causal mechanisms. We found that herb-layer vegetation of deciduous forest stands rich in canopy species appeared to be more diverse than herb-layer vegetation of beech-dominated stands. We surmise that herbaceous understorey diversity was indirectly influenced by canopy tree species through the medium of the altered environmental factors soil pH and litter layer thickness. Apparently, lower beech proportion had a more profound effect than the number of secondary tree species. There were no correlations between herb-layer diversity and light transmissibility of the canopy layer, indicating that the light factor was not crucial for herb-layer diversity. At least for the Hainich research sites, our results indicated that small-scale light and soil heterogeneity is insignificant for herb-layer diversity. We found several herb-layer species whose occurrence was particularly correlated with tree-layer diversity and environmental factors. Remarkably, all species positively correlated with soil pH were important for the phytosociological classification of the research sites. Beech-dominated research sites showed high tree-layer volumes, whereas research sites with high tree-layer diversity tended to feature lower tree-layer volumes. These findings could be the result of differing former silvicultural systems and varying soil clay contents affecting tree species composition. In contrast, herb-layer biomass was positively correlated with tree-layer diversity. Herb-layer productivity might be promoted in more diverse research sites by increased nutrient supply and base saturation. It is also possible that greater beech proportion interfered with herb-layer productivity. However, herb-layer biomass was also positively correlated with herb-layer diversity. Hence, our study hints that positive diversity-functioning relationships might occur in the herb-layer of the deciduous forest under investigation.     

Fruits from shade trees in coffee: how important are they?

Agroforestry systems often receive attention and support in the literature for what is perceived as the benefits from multiple products associated with the trees that create the “forest” component of the setting. A comparison of small coffee growers’ use of fruits derived from the coffee agroforestry holding in Guatemala and Peru reveals that significant differences exist between these groups—not merely in the importance of the fruits themselves, but in the ways they are used. The overall importance of fruits from the coffee system accounts for a relatively small portion of the total value coming from the coffee area (about 10%), but the consumption and sales of the various products do generate needed income or sustenance for most farmers. The fate of fruits shows significant differences between the two countries. Whether at the farm level or on a per hectare basis, Guatemalan coffee farmers are more linked into a market economy and sell significantly more fruits than Peruvian farmers. The opposite is the case when on-farm consumption (use value) of the fruits is compared. While the potential value of these products may be quite large (from 95 to95 to 270/ha), we find that little gets consumed or sold, resulting in tremendous loss of potential benefits that could flow from these sources. Both groups lose more fruits than are sold or used, with Guatemalans foregoing more than three times the dollar value per hectare than Peruvians (151/ha vs.151/ha vs. 44/ha). Data about the economic context within which these growers and the fruits from coffee are found reveal possible reasons as to why we see the differences in use and exchange values realized in the two countries.     

To what extent is altitudinal variation of functional traits driven by genetic adaptation in European oak and beech?

The phenotypic responses of functional traits in natural populations are driven by genetic diversity and phenotypic plasticity. These two mechanisms enable trees to cope with rapid climate change. We studied two European temperate tree species (sessile oak and European beech), focusing on (i) in situ variations of leaf functional traits (morphological and physiological) along two altitudinal gradients and (ii) the extent to which these variations were under environmental and/or genetic control using a common garden experiment. For all traits, altitudinal trends tended to be highly consistent between species and transects. For both species, leaf mass per area displayed a positive linear correlation with altitude, whereas leaf size was negatively correlated with altitude. We also observed a significant increase in leaf physiological performance with increasing altitude: populations at high altitudes had higher maximum rates of assimilation, stomatal conductance and leaf nitrogen content than those at low altitudes. In the common garden experiment, genetic differentiation between populations accounted for 0-28% of total phenotypic variation. However, only two traits (leaf mass per area and nitrogen content) exhibited a significant cline. The combination of in situ and common garden experiments used here made it possible to demonstrate, for both species, a weaker effect of genetic variation than of variations in natural conditions, suggesting a strong effect of the environment on leaf functional traits. Finally, we demonstrated that intrapopulation variability was systematically higher than interpopulation variability, whatever the functional trait considered, indicating a high potential capacity to adapt to climate change.     

Remunerating nature conservation in central European forests: scope and limits of the Faustmann–Hartman approach

The elementary method based on Faustmann's analysis and extended by Hartman is used for the design of payment schemes inciting forest owners to manage their assets in a way more conducive to nature conservation. It is not aimed at extending the elementary theory but rather, to elicit its most important empirical implications. It is taken for granted that the conservation benefit of a forest increases linearly with time. Linearity is not only in sufficient agreement with ecological facts but also makes it easy to derive important conditions, in particular the minimal payment inducing owners never to harvest. The theory is applied to a German beech forest model (Fagus sylvatica). It is found that inciting owners to delay cutting cannot be recommended. The instrument should be used for the objective of abandoning cutting altogether which, however, demands that the conservation objective, as expressed in its present value, is granted a very high value by society. In the sequel, various aspects as to the scheme's practicability are discussed, including the need to capitalise annual payments into one single sum, the choice of a discount rate, the allowance for current costs in forestry and the likely approval of payments in the political arena. Although the discussion identifies several obstacles to the practical application of the scheme, there appears to exist no principal reason why a conservation policy based on the Faustmann–Hartman approach should not work in forestry.     

Rehabilitation of Nothofagus pumilio forests in Chilean Patagonia: can fencing and planting season effectively protect against exotic European hare browsing?

New Forests - In forests affected by heavy fires and continuous grazing of exotic herbivorous mammal species, Nothofagus pumilio (lenga) cannot recover naturally. The main factors that hinder the...     

China's role in the global forest sector: how will the US recovery and a diminished Chinese demand influence global wood markets?

Over the last decade, while the size of China's economy more than doubled, China has simultaneously become a major producer and exporter of forest products. Although China's domestic supply of wood is significantly constrained both by a limited natural supply and by conservation-oriented policies, the country is increasingly regarded as the world's “wood workshop.” Furthermore, China is the largest driver of demand for the trade in tropical logs and is becoming a significant driver of demand for trade in coniferous logs. In this paper, we describe a spatial equilibrium model adapted to study forest sector markets and policies that affect them. We present the model and the result of two alternative future scenarios. The first scenario analyzes the impact on global forest products markets of a US recovery in wood markets. The second scenario examines the effect on global forest products markets of decelerating growth in Chinese demand for wood products. Through these two scenarios, the modeling output sheds light on the role China's wood products markets have on resource supply and trade around the world. The trade model shows substantial potential changes in global prices, production, and trade activity associated with the recovery in domestic demand in the USA.     

Could artificial reforestations provide as much production and diversity of fungal species as natural forest stands in marginal Mediterranean areas?

The aim of this work was to study and describe fungal communities in different habitats in dry Mediterranean areas. The objective was to determine whether artificial reforestations can develop fungal communities as productive and diverse as those found in natural stands. The results could provide ecological and economical implications for forest management in marginal areas, in order to recover the original forest dominated by Quercus, establishing as intermediate stage new forest stands dominated by Pinus which might play an essential role in restoring some type of degraded or marginal areas.     

Environmental impacts and aspects in the forest industry: What kind of picture do corporate environmental reports provide?

Despite its good environmental track record, the Finnish forest industry nonetheless causes harmful environmental impacts. This paper studies corporate environmental reports within the Finnish forest industry to determine the environmental performance of the industry at large. Fifteen years of environmental reports from the three biggest Finnish forest industry companies are analysed. The majority of these reports focus on inputs needed for production (especially energy) and unwanted outputs (especially air and water emissions) in the industry. The environmental impacts in areas of the industry taking place outside of mills, however, are less often reported and appear to be less important to the companies. This paper makes five contributions to the literature: First, the forest industry's reporting, as a less researched field, is studied in detail. Second, the forest industry's environmental reporting is diverse, comprised of multiple indicators and units of measurement. Third, the energy indicator reporting is both established and diversified. The diversity makes the reports as a weak source of comparison of environmental performance. Fourth, the case companies seldom report the environmental performance of their supply chains. Fifth, while the prior literature has analysed multiple environmental impacts of the forest industry, the case companies report on very few of them. The paper concludes by stating that future environmental reporting should especially address supply chains and multiple environmental impacts caused by the industry.     

Long-term changes of structure and tree species composition in Dinaric uneven-aged forests: are red deer an important factor?

Uneven-aged silver fir-European beech forest stands were studied to (1) analyse the dynamics of diameter structure and tree species composition in the past two centuries and (2) determine the impact of red deer on the regeneration and recruitment of silver fir. The study used current data on forest stands, archival data from old forest management plans for the period 1789–2004, and red deer harvesting records for the period 1907–2006. During the observation period, the silver fir population aged and silver fir and European beech alternated in dominance. The study revealed a strong impact of red deer on the composition and recruitment of tree regeneration, especially on silver fir regeneration. The drastic changes in red deer density (from extermination up to 5.8 animals km⁻²) and past forest management practices were apparently the main factors driving the population dynamics of silver fir (regeneration, recruitment, and diameter structure) in the study area during the past two centuries.     

Growing common plantation tree species in Kenya for sale of carbon and wood supply: what is the best bet?

The introduction of carbon finance as an incentive in forestry farming has a potential of increasing the amount of carbon sequestered. However, this has created a daunting task among investors in forestry to optimise the joint production of wood and carbon sequestration. For instance, investors might find it profitable to give up some timber returns in exchange for carbon credits. This study evaluated expected income from growing Cupressus lusitanica Mill., Pinus patula Schiede ex Schltdl. & Cham., Eucalyptus saligna Sm. and Juniperus procera Hochst. ex Endl. for wood and/or the carbon market in central Kenya. The global average unit price of carbon and stumpage royalty were used to estimate expected returns from sale of carbon credits and wood, respectively. There were significant differences (p < 0.01) in the expected amount of income from sale of carbon and wood among the four species. Specifically, at economic rotation of 30 years with stand density of 532 trees ha^?1 P. patula and C. lusitanica yielded US$28 050 and US$23 650, respectively, from sale of carbon compared with US$59 000 and US$51 000, respectively, from sale of wood. This was twice the value investors receive from clear-felling as compared with sales from carbon. Similarly, at economic rotation of 33 years with stand density of 150 trees ha^?1, a forest investor in E. saligna would earn US$15 400 from sale of carbon compared with US$33 000 from sale of wood. Overall, the amount expected to be realised from sale of carbon was lower compared with that from sale of wood. This demonstrates that the price dynamics of carbon offsets in the voluntary and the compliance markets need to remain competitive and attractive for the forest owners to give up some timber returns in exchange for carbon income or to modify forest management regulation in order to increase carbon sequestration.     

Breeding and scientific advances in the fight against Dutch elm disease: Will they allow the use of elms in forest restoration?

New Forests - Elms (Ulmus spp.) were once dominant trees in mixed broadleaf forests of many European territories, mainly distributed near rivers and streams or on floodplains. Since ancient times...     

Correction to: Breeding and scientific advances in the fight against Dutch elm disease: Will they allow the use of elms in forest restoration?

New Forests - Author had ordered for open access after the article went online in Springer link. The article was changed to open access article.     

Correction to: How does light availability affect the aboveground biomass allocation and leaf morphology of saplings in temperate mixed deciduous forests?

New Forests - The original version of this article was inadvertently published without the acknowledgements section.     

European beech (Fagus sylvatica L.) and silver fir (Abies alba Mill.) rotation in the Carpathians—A developmental cycle or a linear trend induced by man?

A detailed historical survey was made to assess the impact of humans on fir–beech forests in the northern Carpathians. Research findings are compared with results from repeated tree layer measurements in eight of the most well-preserved reserves of fir–beech stands in the region. Documentary evidence is provided showing that the historical and contemporary spontaneous development of fir–beech stands throughout the northern Carpathians is identical. The replacement of beech by fir occurred predominantly in the period from the 15–18th centuries, primarily due to grazing and litter raking. Starting in the 19th century, fir was replaced predominantly by beech under the influence of changing social conditions, since the dieback of the “grazing” fir generation had not yet been completed. Air pollution damage and other factors in the fir dieback were only secondary accelerating phenomena. These changes of tree species cannot be interpreted as the natural rotation of two beech generations within the life cycle of one fir generation, as has been the previous explanation. The development is rather a linear trend induced by man, which has occurred simultaneously throughout the northern Carpathians. The current dynamics of spontaneous development are affected by the high stock of hoofed game and by the absence or reduced numbers of predators.     

Modelling the management of fragmented forests: Is it possible to recover the original tree composition?: The case of the Maulino forest in Central Chile

In the fragmented Maulino forest (in Central Chile), differences in the relative frequencies of species between seedlings and mature trees are strong indicators of a changing replacement dynamics in the community. Stationary Markov chain models predict that the future tree composition such Maulino forest fragments will differ from that of continuous, intact forest. We found that the persistence probability was highest for Aristotelia chilensis and lowest for Nothofagus glauca. These two tree species are the most affected by fragmentation, and changes in their abundances appear to be the main drivers of the long-term change in stand composition. The aim of our study was to test if the management of just these two species would be sufficient to avoid long-term changes in the composition of forest fragments or would recover their composition toward a state more similar to the continuous forest. For this purpose, we constructed a Markov matrix model from published information, and calculated the future stable stand composition under different management simulations: (1) reduction of A. chilensis recruitment, (2) increased recruitment of N. glauca, and (3) a combined treatment. To evaluate the effectiveness of management treatments, the future composition of fragments was compared with the composition expected for continuous (i.e., undisturbed) Maulino forest. We performed a sensitivity analysis of the stable composition in order to assess the intensity of changes in the future composition driven by the treatments, and to determine to what extend the recruitment of other coexisting species contributes to changes in relative frequencies of A. chilensis and N. glauca.     

Community-based forestry and community forestry enterprises in quintana roo,mexico and petén,guatemala: how have policies,history, and culture shaped their trajectories?

ABSTRACT

The Mayan Biosphere Reserve in the region of Petén, Guatemala and the state of Quintana Roo, Mexico have well-established experiences of community-based forestry and community forestry enterprises within the area known as the Mayan forest. Context has been a key factor shaping the trajectories of these two cases. Several scholars have highlighted the usefulness of understanding the role of context in the emergence and functioning of common property regimes. However, scholarship has been dominated by the mainstream school of common property, which sees these regimes as arising out of voluntary, rational action with the main intent of conserving a common-pool natural resource. This paper seeks to answer the call for more research on context for common property regimes. The article discusses how policies, history, and culture have shaped the trajectory of community forestry in both countries. Policies present choices, opportunities, and constraints, while history and culture can facilitate or hinder taking advantage of such opportunities. Communities have agency not only to react, but also to adapt. These two cases present overriding themes that strengthen the alternative literature on common property regimes and also offer lessons to policy makers, practitioners, nongovernmental organizations, and communities practicing forestry.