Diversity and spatio-temporal dynamics of dead wood in a temperate near-natural beech forest (<Emphasis Type="Italic">Fagus sylvatica</Emphasis>)

The diversity, spatial patterns and temporal dynamics of dead wood were examined within the near-natural beech forests (Fagus sylvatica) of Serrahn (North-eastern Germany). Data were collected in an 8 ha sample plot and in two permanent plots (0.36 and 0.25 ha) that had been established at the end of the 1960s. The mean volume of dead wood was 94 m³ ha⁻¹, amounting to 14% of the total volume of all trees. The dead wood displayed a large variation in dead wood type, tree size and decay class. Standing dead wood accounted for about one-third of the total dead wood volume. The densities of standing dead trees were about 10% of the densities of the living trees over a wide range of diameters. The overall spatial distribution of dead trees exhibited a random pattern. Among the different dead wood types, standing entire dead trees and uprooted trees deviated from this pattern by displaying a significantly aggregated pattern. In the permanent plots a high mortality of overstorey trees was observed (1.3% year⁻¹) and the average amount of dead wood increased greatly from 2.9 to 111.6 m³ ha⁻¹ over the 35-year observation period. The near-natural beech forests of Serrahn have experienced a long period of low human interference. Nevertheless, our results suggest that the structure and dynamics of dead wood are strongly affected by the last major disturbance events that took place at the end of the Middle Ages. Information about the forest history is therefore a basic requirement when interpreting the results obtained in near-natural forests.     

Accumulation of dead wood in abandoned beech (Fagus sylvatica L.) forests in northwestern Germany

Currently, there is much debate about what strategy is most suitable for increasing old-growth attributes in forests that have been managed intensively for wood production in the past. Passive restoration, i.e. cessation of forestry interventions, should be considered when the old-growth attributes desired can be restored within a feasible period of time.Our study focuses on standing and lying coarse dead wood (≥20 cm diameter) in beech-dominated forests in northwestern Germany. We analyzed monitoring data of 545 sample plots (sized 500-1000 m²) from 12 strict forest reserves (SFRs). The SFRs had been without forestry intervention for up to 28 years.Both, number of dead objects and volume of dead wood (m³ ha⁻¹) increased significantly with ongoing time since abandonment from forestry interventions. The mean amount doubled from 9 to 18 m³ ha⁻¹ within 10 years. The proportion of standing dead wood was about 40% of the total dead wood pool ≥20 cm diameter.With mixed linear modeling we showed that dead wood increased by a mean net rate of about 1 m³ ha⁻¹ a⁻¹. Therefore, after three decades critical values for restoring the dead wood pool could be reached. We hypothesized that the rate of dead wood input is mainly determined by disturbance driven tree mortality such as oak decline, bark beetle infestations and storms.A comparison with primeval forests or reserves abandoned more than 100 years ago showed that the SFRs studied are at the beginning of a long process of dead wood accumulation.Based on our results, the abandonment of forest activities in harvestable pure and mixed beech stands is an effective strategy for restoring the dead wood pool.     

Impact of silviculture on dead wood and on the distribution and frequency of tree microhabitats in montane beech-fir forests of the Pyrenees

In forest ecosystems, the level of biodiversity is strongly linked to dead wood and tree microhabitats. To evaluate the influence of current forest management on the availability of dead wood and on the abundance and distribution of microhabitats, we studied the volume and diversity of dead wood objects and the distribution and frequency of cavities, dendrothelms, cracks, bark losses and sporophores of saproxylic fungi in montane beech-fir stands. We compared stands unmanaged for 50 or 100 years with continuously managed stands. A total of 1,204 live trees and 460 dead wood objects were observed. Total dead wood volume, snag volume and microhabitat diversity were lower in the managed stands, but the total number of microhabitats per ha was not significantly different between managed and unmanaged stands. Cavities were always the most frequent microhabitat and cracks the least frequent. Dendrothelm and bark loss were favored by management. Beech (Fagus sylvatica) carried many more microhabitats than silver fir (Abies alba), especially cavities, dendrothelms and bark losses. Fir very scarcely formed dendrothelms. Secondary tree species played an important role by providing cracks and bark losses. The proportion of microhabitat-bearing trees increased dramatically above circumference thresholds of 225 cm for beech and 215 cm for fir. Firs with a circumference of less than 135 cm did not carry microhabitats. In order to conserve microhabitat-providing trees and to increase the volume of dead wood in managed stands, we recommend conserving trees that finish their natural cycle over 10–20% of the surface area.     

Spatiotemporal Availability of Dead Wood in Protected Old-growth Forests: A Case Study from Boreal Forests in Eastern Finland

Spatiotemporal patterns of standing and fallen dead trees were examined in two protected Scots pine ( Pinus sylvestris L.)-Norway spruce ( Picea abies (L.) Karst.) forests in eastern Finland (Pahkavaara and Pönttövaara). In Pahkavaara the volume of standing dead trees was 10 m 3 ha -1 and the volume of fallen logs was 66 m 3 ha -1 , and in Pönttövaara the values were 48 m 3 ha -1 and 107 m 3 ha -1 , respectively. The areas differed with respect to the tree species composition, whereas the proportion of different decay stages was similar. Decay stage and dendrochronological analyses revealed the continuity of dead wood formation. The spatial pattern of standing dead trees was usually towards clustered. The volumes of fallen logs showed a spatial autocorrelation up to distances of 10-20 m. The results also suggest that the current amount and diversity of dead wood is rather high, but that forest succession is likely to lead to a less diverse state in the future.     

Deadwood volume in strictly protected,natural, and primeval forests in Poland

Standing and downed deadwood at different stages of decay provides a crucial habitat for a wide range of organisms. It is particularly abundant in unmanaged forests, such as strictly protected areas of national parks and nature reserves. The present work used the available data for such sites in Poland, analyzing a total of 113 studies concerning 79 sites to determine the causes contributing to variation in deadwood volume based on the duration of conservation, changes in deadwood volume over time (for those sites which were examined multiple times), elevation above sea level, forest type, stage of forest development, input of dead trees from the years preceding deadwood measurements, live tree volume, and the proportion of downed to standing deadwood). Depending on species composition and site altitude, most tree stands fell into one of four categories: subalpine spruce forests, montane beech-fir forests, low altitude beech-fir forests, or oak-hornbeam and riparian forests. The mean deadwood volume for all forest types amounted to 172.0 m³/ha. The mean volume of deadwood in montane beech-fir forests (223.9 m³/ha) was statistically significantly greater than in the other three forest types, for which it ranged from 103.5 to 142.5 m³/ha. A direct effect of the duration of conservation on deadwood volume was not identified. Nevertheless, analysis of repeated measurements on the same sample plots at 10-year intervals showed a consistent rise in mean deadwood volume. A linear regression model for all the analyzed factors reported from montane beech-fir forests and subalpine spruce forests showed that in addition to site altitude, another statistically significant variable was the input of dead trees (R²?=?63.54%).     

Habitat factors for land snails in European beech forests with a special focus on coarse woody debris

Analyses of land snails and habitat factors in acid beech forests were conducted in southern Germany (northern Bavaria). The objectives were to study the effects of habitat characteristics on snail density and species richness. Habitat structures were determined for 37 plots in one big forest. We found a significant relationship between the number of snail species and individuals and the following set of habitat factors coverage of herbaceous layer, growing stock, mean diameter at breast height of the three largest trees (DBHmax), stand age, total dead wood volume per ha, and advanced decomposed dead wood volume per ha. We use maximally selected rank statistics to estimate cutpoints separating stands with low densities, from stands with high snail densities. Here, we define cutpoints for a significant higher snail density at a stand age of 187 years, 57 m³/ha dead wood, 40 m³/ha advanced decomposed dead wood, 63 cm DBHmax and more than 1% herbaceous layer. For species richness, cutpoints are estimated at 338 m³/ha stand volume, 170 years stand age, 50 m³/ha total dead wood amount, 15 m³/ha advanced decomposed dead wood and 56 cm DBHmax. The microhabitat analysis shows a higher pH value and a higher Calcium content at the bottom of large snags and under large lying dead wood pieces in comparison to litter, upper mineral soil and at the bottom of vital living trees. Snail species and individual density are significantly linked to these patterns of chemical parameters. The identified cutpoints are a good base for ecological management decisions in forest management.     

Assemblages of wood-inhabiting fungi related to silvicultural management intensity in beech forests in southern Germany

Current silvicultural treatments in beech forests are aimed at achieving thick logs without discoloured hardwood. Therefore intensive thinning is applied already in younger stands with the objective of large-sized trunks at an age of 100 years. However, this approach bears the risk that dead wood structures and broken trees are completely removed from the forest. The impact of three different silvicultural management intensity levels on wood-inhabiting fungi over decades was investigated in a large beech forest (>10,000 ha) in southern Germany in 69 sampling plots: A Intensive Thinning and Logging with high-value trees, B Conservation-Oriented Logging with integration of special structures such as dead wood and broken trees and C Strict Forest Reserves with no logging for 30 years. The analysis of community showed marked differences in the fungus species composition of the three treatments, independent of stand age. The relative frequencies of species between treatments were statistically different. Indicator species for naturalness were more abundant at sites with low silvicultural management intensity. Fomes fomentarius, the most common fungus in virgin forests and strict forest reserves, is almost missing in forests with high-management intensity. The species richness seemed to be lower where intensive thinning was applied (P = 0.051). Species characteristic for coarse woody debris were associated to low management intensity, whereas species with a significant preference for stumps became more frequent with increasing management intensity. A total amount of dead wood higher than 60 m³/ha was found to enable significantly higher numbers of species indicators of naturalness (P = 0.013). In conclusion, when applying intensive silvicultural treatment, the role of dead wood needs to be actively considered in order to maintain the natural biocoenosis of beech forests.     

德国巴伐利亚州近自然森林经营成效研究

近自然森林经营发源于德国巴伐利亚州,是当今国际公认的一种先进的森林经营方法。以德国巴伐利亚州4次森林资源连续清查成果为依据,从森林结构、枯木状况、森林近自然度、森林蓄积量4个方面对近自然森林经营成效进行分析评价。结果表明,1971—2012年的41年间,巴伐利亚州阔叶树种占比由22%提高到35.7%,针阔混交林和阔叶混交林已占乔木林面积的64.1%,复层林已占乔木林面积的77.4%,森林年龄结构基本实现了均衡分布;林内枯木数量达22 m³/hm²,为野生动物提供了栖息场所和营养来源;自然林和近自然林已占乔木林面积的42.6%,比德国全境高6.8个百分点;单位面积森林蓄积量396 m3/hm2,在全球处于领先地位。建议我国在营造林工程项目中加大近自然森林经营的推广应用力度,建好示范样板,并进一步探索近自然森林经营的技术和方法。     

Carbon and nitrogen in forest soils: Potential indicators for sustainable management of eucalypt forests in south-eastern Australia

Soil organic matter (SOM) has been adopted as an indicator of soil fertility based on the rationale that SOM contributes significantly to soil physical, chemical, and biological properties that affect vital ecosystem processes of forests in Australia. A study was undertaken to evaluate the utility of SOM as an indicator of SFM at two long-term experimental sites in native eucalypt forests, including Silvertop Ash (E. sieberi L. Johnson) and Mountain Ash (E. regnans F. Muell.) in Victoria. This study examines the relative contributions made by various sources of carbon in soil profiles (0–30 cm) of forest soils, viz. mineral soil (<2 mm), plant residues, charcoal (>2 mm), and rock fragments (>2 mm). The long-term changes in these fractions in response to management-induced soil physical disturbance and fire (unburnt, moderate and high intensity) were evaluated. After 10 years, carbon levels in the fine soil fraction (soil <2 mm including fine charcoal) were similar across the range of fire disturbance classes in Mountain Ash forest (20–25 kg/m²) and Silvertop Ash forest (7–8 kg/m²). Likewise differences in carbon associated with other fractions, viz. microbial biomass, labile carbon, plant residues and rock fragments were comparatively small and could not be attributed to fire disturbance. Burning increased the charcoal carbon fraction from 5 to 23 kg/m² in Mountain Ash forest and from 1 to 3 kg/m² in Silvertop Ash forest. Taking into account, the percentage area affected by fire, increases in total soil carbon in these forests were estimated at 25 and 7 t/ha, respectively.

The effects of physical disturbance of soils were examined at one site in Mountain Ash forest where soil cultivation was used as site preparation rather than the standard practice of burning of logging residues. Total carbon in soil profiles decreased from 29 to 21 kg/m² where soil disturbance was severe, i.e. topsoil removed and subsoil disturbed. This was mainly due to a decrease in charcoal carbon from 6.8 to 1.7 kg/m² but severe soil disturbance also increased the amount of carbon associated with rock fragments from 1.6 to 3.5 kg/m².

Management-induced fire increased the coarse charcoal content of soil profiles substantially, thus increasing total carbon content as well as the proportion of recalcitrant carbon in SOM. In contrast, there was little change in the carbon content of the fine soil fraction including the labile and biologically active fractions indicating that these SOM fractions most relevant to ecosystem processes showed little long-term impact from soil disturbance and fire. Conventional sampling of the fine soil fraction (<2 mm) only represented between 50% and 70% of total carbon in the soil profiles. In contrast, total nitrogen in this fraction represented between 75% and 90% of the nitrogen in soil profiles and was less affected by changes in the contributions of N made by coarse fractions. Monitoring of soil N rather than C as an indicator of soil fertility and SFM may be more appropriate for forest soils with significant charcoal content.     

Modelling dead wood islands in European beech forests: how much and how reliably would they provide dead wood?

Dead wood is an important element of forests both for biodiversity and ecosystem functions. Due to intensive silviculture, however, dead wood usually is strongly underrepresented in European forests. Forest reserves cannot fully compensate for this because they comprise only a small proportion of forested areas and are often isolated. Retaining a certain number of dead trees in managed forests is important, but may cause safety problems for lumbermen and visitors and still does not necessarily lead to an amount and incidence (i.e., probability of occurrence) of dead wood that might be required for many species and certain ecosystem functions. Our studies concentrate on a third and complimentary dead wood management strategy: dead wood islands, i.e. small unmanaged islands distributed throughout managed forests. As an example, we focus on European beech forests (Fagus sylvatica). An important question related to this strategy is: how do amount, quality, and incidence of dead wood depend on the island’s size? To provide an answer, we use the spatially explicit, rule-based simulation model BEFORE-CWD that was developed to analyse dead wood dynamics in natural beech forests. This model and its predecessor, BEFORE, are well-verified and validated. They reproduce a suite of observed patterns and generate valid secondary and independent predictions. We found that islands that are too small, i.e. smaller than 0.33 and 0.08 ha for standing and lying dead wood, respectively, can fail to provide dead wood for several decades. The shape of the islands has only a minor effect. Extreme storm events temporarily increase and then decrease the amount of standing dead wood. In terms of the amount and incidence of dead wood, it makes no difference if one big or several small islands are set aside from management, unless the islands are not too small. We conclude that even relatively small unmanaged islands within managed forests can reliably provide dead wood and therefore should be considered as a management option. Our results can be used, for example by using metapopulation models of species of interest, to develop management plans for creating networks of dead wood islands.     

Burning of Amazonian forest in Ariquemes, Rondônia, Brazil: biomass, charcoal formation and burning efficiency

Biomass burning in tropical forests – the normal practice to prepare land for agriculture and ranching – has been a major source of CO₂ emitted to the atmosphere. Mass transformations by burning are still little studied in the tropics. The present study estimated parameters, such as the stock of carbon contained in the biomass, burning efficiency and the formation of charcoal and ashes in a tropical moist forest. Two sets of plots arranged in the form of ‘stars' (720 m² total) were installed in a 3.5 ha area of forest that had been felled for planting pasture at Fazenda Nova Vida, Ariquemes, Rondônia. Each ‘star' had six rays measuring 2 m × 30 m; alternating rays were designated for pre-burn and post-burn measurements. All above-ground biomass present in the plots was weighed directly before the burn in the pre-burn rays and after the burn in the post-burn rays. Pieces of wood with diameter ≥10 cm also had their biomasses estimated from volume estimates, using line-intersect sampling (LIS) in order to increase the area of sampling and to allow volume loss to be estimated as an increment based on individual pieces measured before, and after, the burn at the same point (as opposed to inferring change as a difference between independent estimates of stocks). The initial above-ground biomass (dry weight) before the burn was estimated at 306.5 ± 48.6 (mean ± SE) Mg ha⁻¹, with an additional 4.5 Mg ha⁻¹ for trees left standing. Carbon stock in the initial biomass (including trees left standing) was 141.3 (Mg C) ha⁻¹. After burning, carbon stock was reduced by 36.8% (burning efficiency). The stocks of charcoal and ash formed in the burn were, respectively, 6.4 ± 2.7 and 5.7 ± 1.0 Mg ha⁻¹. The destructive and nondestructive (LIS) methods did not differ significantly (t-test, p > 0.05) in estimating post-burn stocks of wood and charcoal. The results of this study contribute to improving the estimates of parameters needed for global carbon calculations and point to ways in which estimates of these parameters could be further improved.     

Future development of the Leningrad region forests under nature-oriented forest management

Russian forests are of high importance for the Russian economy, the European wood market, for nature conservation, and for carbon sequestration. However, the ongoing changes in forest management and administration in Russia led to uncertainty about forest ownership, wood harvesting levels, and long-term impacts of alternative management plans. Therefore, better insight in their current and future state is highly desirable. We present a study for the Leningrad region forests in which alternative management regimes for wood production and nature conservation values are balanced in varying ways. The total forest land area in the Leningrad region forest fund is 4.8 million ha. Coniferous species dominate and due to the natural succession occurring, the forests are divers in vertical structurally.

A timber assessment model was used to project the forest until 2040. Five forest management scenarios were run. Special attention was paid to a scenario that simulates recovery of the Russian forest sector in combination with the incorporation of a ‘set-aside for nature conservation’ policy. All scenarios showed that recovery of the forest sector in the Leningrad region is biologically feasible. A sustainable continuous annual production of 10.6 million m³ per year (2.8 m³ ha⁻¹ per year) by 2040 was found. The ‘Recovery with Nature Conservation’ scenario showed that recovery of the forest sector in combination with the establishment of set-aside areas is very well feasible. It was possible to set aside 28% of the forest area for nature conservation while still developing a forest sector to a production level higher than that achieved in the late eighties.

The timber assessment model applied was not specifically designed to incorporate nature-oriented forest management. We, therefore, discuss ways of improving the required methodology to analyse long-term effects of nature-oriented forest management in Europe.     

浙江省林业应对气候变化成效及措施研究

在全球气候变化大背景下,森林碳汇能力成为国际社会公认的减缓气候变暖的重要措施之一。文章总结了近年来浙江省林业应对气候变化成效:森林蓄积量从2005年的1.72亿m~3提高到2019年的3.61亿m~3,全省森林植被总碳储量达到2.8亿t;2006-2019年全省共完成造林更新41.2万hm²,共实施中幼林抚育面积约181.47万hm²;建立了中国绿色碳汇基金会浙江碳汇基金,募集社会资金大力实施公益性林业碳汇项目,共营造碳汇林9786.67hm²。同时,分析了当前浙江省林业应对气候变化存在宜造林地严重不足、森林质量总体不高、松材线虫病形势严峻、对林业碳汇认识不足等问题,提出了应切实提高森林增汇能力、努力减少森林碳排放量、加强林业碳汇建设与交易、加大林业科技支撑力度和强化组织领导和科普宣传等发展对策。     

3种皆伐方式对毛竹林更新生长的影响

研究了不同面积规模的全面皆伐(2.0 hm²和3.33 hm²)、带状皆伐(带长均为60 m,带宽分别为3m、6 m和9 m)和块状皆伐(25 m²、100 m²和400 m²)对毛竹林更新生长的影响。结果显示:3种皆伐方式对竹林更新生长影响不同,其中全面皆伐后的竹林长势较差,生物量较低,且皆伐面积越大,竹林更新生长越差;带状皆伐,皆伐带宽为3 m和6 m的竹林更新生长状况均较好,以带宽为6 m时综合效果最好;在块状皆伐中,皆伐面积为25 m²的竹林更新生长最好。此外,皆伐后对毛竹伐桩进行施肥,能够促进竹林的恢复生长;竹林的坡向也影响林分的更新生长,阴坡林分通常在皆伐后2年即能恢复到皆伐前状态,而阳坡林分的恢复则需要3年以上。     

Red-listed wood-inhabiting fungi in natural and managed forest landscapes adjacent to the timberline in central Sweden

Many wood-inhabiting fungi are today threatened as modern forestry practices drastically reduce the amount of dead wood available in various forest ecosystems. We investigated whether the occurrence of red-listed wood-inhabiting fungi differed between natural and managed forest landscapes adjacent to the timberline in the middle part of Sweden. We assessed whether environmental variables such as the degree of human impact, length of forest roads, dead wood volume and quality affected species richness and abundance. The effects of forestry on wood-inhabiting fungi have been assessed in several studies in lowland Swedish forests. Few studies have, however, been conducted in forest landscapes adjacent to the timberline in Sweden. This is potentially important since forests close to the Swedish mountains have been pointed out as one of few intact forest landscapes in Fennoscandia and they are subjected to increasing logging pressure. Similar to other studies, species numbers and abundances were positively correlated with larger volumes of logs in various decay stages. However, never shown previously, the length of forest roads was negatively correlated with species abundance and occurrence of red-listed species. We suggest that a low amount of forest roads can be used as a conservation indicator to localize still-intact forest landscapes.     

Effect of intervention and type of forest management on quality and quantity characteristics of dead wood in managed and reserve forests: A case study

We compared the dead wood (DW) conditions of Cheshmeh-sar forest and Sardab forest with different management history,including reserve forest and harvested forest. The First forest took 100% inventory from all the available DW. Also dead trees were compared interms of species, shape, location and quality of fracture in both forests.Volumes of dead wood in Cheshmeh-sar and Sardab forests were 207.47and 142.74 m3, respectively. Due to this significant difference, impact onthe management level was determined. In Cheshmeh-sar forest, 42% ofdead trees were standing and 58% were fallen type while in Sardab forest 38.6% were standing and 61.4% fallen. But the difference was not statistically significant between them (p = 0.0587). In terms of quality, dead trees of hard, soft and hollow had the highest frequency, respectively.However, 71.5% of DW was seen as hard dead in Cheshmeh-sar forestwhile hard dead trees in Sardab forests were 54.2%. Soft quality degree ofdead trees which formed in Cheshmeh-sar and Sardab forest were calculated as 26.6% and 43.4% respectively. Also 30% of the dead trees of Sardab forest were eradicated while in Cheshmeh-sar this amount was reduced to 12%. Due to this significant difference ((Р=0/018), it is concluded that the type of management and human interference are affecting the quality of dead trees and makes us to think the human interferences could effect on the ecosystem of touched forests.     

Stand characteristics of mixed oriental beech (<Emphasis Type="Italic">Fagus orientalis</Emphasis> Lipsky) stands in the stem exclusion phase,northern Iran

The structure of forest stands changes through developmental phases. This study is carried out in the unmanaged, oriental beech (Fagus orientalis Lipsky) stands in the north of Iran. The aim of this research was to quantify structural characteristics of stands in the stem exclusion phase using common structural indices, which include mingling, tree–tree distance, stem diameter, and tree height differentiation. According to our measurements from three stands, naturally regenerated stands tend to be mixed in species composition have slightly heterogeneous diameter distributions and uniform tree height. The average distance between trees was 3.3 m. Stocking volume of the stands had an average of 540 m³ ha^?1 and 412 stem ha^?1. Dead wood volume was 24 m³ ha^?1, and as a standing volume, the most frequent species in dead wood pool was oriental beech (F. orientalis) (48 %). The common form of dead trees was snag (41 %). The mean value of mingling and tree-to-tree interval indices revealed that beech was mixed intensively with hornbeam and appears to be a more successful competitor for space and light compared with hornbeam; moreover, we found relatively high evidence of inter-species competition in this phase. A better understanding of stand characteristics in the stem exclusion phase as a critical part of the natural dynamics of forest ecosystems could facilitate predictions about the future changes within the stand.     

Timber harvesting as ongoing disturbance in a landscape of diverse ownership

Although the northeastern US includes extensive areas of aggrading forest, uncertainty regarding the intensity and pattern of forest harvesting hampers an understanding of important ecological processes and characteristics such as carbon and nitrogen storage, habitat quality, and forest dynamics, and impedes regional conservation and management planning. Due to the complex ownership pattern dominated by thousands of non-industrial private forest (NIPF) owners and the difficulty of detecting selective logging using remote sensing, details of the harvesting regime remain largely unknown to the scientific and policy communities. To examine the value of statewide regulatory data for Massachusetts as a unique source of this critical information, we analyzed 17 years of timber harvest data gathered for regulatory purposes for a 168,000 ha forested landscape in Massachusetts that is the focus of concerted conservation planning and intensive study of landscape and ecosystem pattern and process. The North Quabbin Region is heavily wooded with a complicated ownership pattern dominated by over 2500 NIPF owners, three state agencies, and diverse conservation and municipal holdings.

The extent and intensity of harvesting were surprising, with an annual disturbance rate of 1.5% and a mean intensity of 44.7 m³ ha⁻¹ (approximately one-fourth of average stand volume). The predominant form of harvesting was selective removal of commercially valuable tree sizes, grades and species (e.g., Quercus rubra and Pinus strobus). The spatial pattern of logging was random with regards to major physical, biological, or cultural factors. However, logging was strongly related to landowner class. NIPF owners control 60% of the forest area and were responsible for 64.1% of harvest area, but the highest logging intensity (volume per area harvested; 69.3 m³ ha⁻¹) among major landowners was conducted by the state agency responsible for managing southern New England’s largest conservation property, the watershed of Boston’s drinking reservoir.

This regime of chronic disturbance is occurring over the entire landscape and exerting a major influence on forest composition, dynamics, and habitat quality. However, dispersed selective harvesting is largely unnoticed by residents, is routinely overlooked by ecologists and conservationists, and would remain unrecognized in the absence of this previously unused regulatory data. These results identify the value of regional regulatory spatial information to estimate ecological trends and to assist in conservation planning. Given similarities among ownership and forest patterns for much of the northeastern US, we expect that the broad findings of this study to have regional application.     

Modelling the economically viable wood in the crown of European beech trees

Long-term forest development programs in Germany aim on an increase of close-to-nature broadleaf forest stands. This means that the economic importance of European beech is expected to increase. The economic potential of a tree basically consists of the stem as well as the economically viable wood volume in the crown. Due to the high morphological variability of European beech crowns, taper models are often not satisfactory for predicting the economically viable wood volume arising from crowns. Prediction models with a higher precision are recently still lacking. Aim of this study is thus the development of prediction model for the economically viable crown wood volume of European beech trees.We determined the distribution of the wood volume in the crown over the branch diameters using the multistage ‘randomized branch sampling’ method (RBS). The tree-specific wood volume distribution on the branch diameters were used to cluster all sampled trees into 3 groups. Additionally, we developed a method able to distinguish between economically viable and unviable crown branches. Basing on the RBS measurements as well as revenues and processing costs, we modeled the economically viable wood volume from the crown for each tree. To calculate the wood volume under bark, we parameterized a bark thickness function from disk samples of the trees.We showed that the European beech crowns could be clustered into 3 groups differing in their wood volume distribution. The economically viable wood volume in the crown significantly depended on this grouping parameter as well as diameter at breast height (DBH). By contrast, the total amount of wood in the crown only depended on DBH. The differing viable wood volumes in the crowns were thus explained by different wood distributions and not by differing total crown wood volume. To make the results applicable in practice forestry, the modelling results were used to develop a regression formula able to predict the economically viable wood volume in the crown depending on the DBH and the crown type. As the crown type can also be predicted via measurable tree covariates, the regression model of the viable wood volume in the crown can be used as a support tool for the management of European beech stands. Sensitivity analysis quantifies how harvest revenues and costs translate into different viable tree volume.     

The abundance and distribution of rattan over an elevation gradient in Sulawesi, Indonesia

The rattan flora of Central Sulawesi is abundant, species rich and patchily distributed in lowland and montane forests. I recorded the abundance and distribution of rattan on five randomly established 10 m × 1000 m transects between 830 and 1330 m elevation and associated changes in forest canopy heights, photosynthetically active radiation (PAR) and soil characteristics. Rattans were observed at all sites and elevations (100% of 10 m × 10 m sample plots in the transects contained rattan), but exhibited the greatest diversity (species richness) between 1180 and 1280 m elevation. Overall (all species and elevations), there was an average of 314 mature rattan genets per hectare. The two most prominent rattans in terms of size, abundance and distribution, Calamus zollingeri and Daemonorops robusta, averaged 62 and 40 genets/ha overall, respectively. Several other rattans, including C. leiocaulis, C. leptostachys, and C. ornatus occurred on all transects and all elevations. In contrast, C. didymocarpus, C. minahassae, C. symphysipus and Korthalsia celebica were patchily distributed, and C. didymocarpus and C. sp. (‘kalaka’) were restricted to higher elevations. Resident cane collectors differentiate C. zollingeri and D. robusta into low and high elevation forms on the basis of morphological and growth characteristics, but this distinction is not discernable in sterile specimens. Based on local classification, lowland forms of C. zollingeri and D. robusta were replaced by high elevation forms over less than 200 m vertical elevation which corresponds to the transition from upper lowland to montane forests. The mean canopy height of upper lowland forest between 900 and 1000 m was significantly greater than that of montane forests between 1100 and 1300 m (30.0 and 21.2 m, respectively). Soils in upper lowland forests had significantly higher concentrations of NO₃ and P, significantly lower organic matter levels and higher pH than montane soils in both O and A/E soil horizons. PAR levels did not vary significantly by forest type. Most large diameter rattans are marketed under a single trade name and cannot be distinguished by cane characteristics. These findings have significance for biodiversity conservation and management because rattan harvesting is widespread and unmanaged, and the Sulawesi rattan flora remains poorly known taxonomically and ecologically.