Forest Compartments Research Articles

Time-stability of soil water through boreal (60–68°N) gradient

Summary The time-stability concept suggests that the spatial pattern of the soil water content does not change with time when the observations are ranked according to the magnitude of the soil water. The time-stability holds for soils in agricultural fields and forest compartments, yet broader scale effects of boreal climate on time-stability are poorly understood. We studied the spatial persistence of soil water through the boreal climatic gradient (60–68°N) on the Baltic Shield using multi-year (2002–2010) automatic monitoring at sites (up to 18 in number) with diverse soil texture and land use. We found that the soils exhibited significant time-stability, Spearman’s rank correlation coefficients rs = 0.94–0.95, p

Linking safe sites for recruitment with host-canopy heterogeneity: The case of a parasitic plant, Viscum album subsp. austriacum (Viscaceae).

• Premise of the study: Canopies are ecologically relevant compartments of forests. Multiple sources of heterogeneity interact within forest canopies due to their structural complexity, which exert major influences on the structure and composition of epiphyte communities. Here, we explore canopy environmental heterogeneity of a Mediterranean pine forest, identifying the key biotic and abiotic factors determining mistletoe (Viscum album subsp. austriacum) recruitment at coarse and fine spatial scales.• Methods: Through field experiments, we assessed the range of suitable host species for V. album subsp. austriacum (hereafter, V. a. austriacum). We characterized the variation in abiotic factors at a fine spatial scale on the host species. Finally, we examined the effects of biotic (predation) and abiotic (light, temperature) factors on the fate of mistletoe seeds and seedlings along host branches.• Key results: We confirmed the tight specificity of V. a. austriacum to pine species, in particular to P. nigra at the local scale. Biotic constraints increased toward the branch interior, with minor effects on apical locations due to the positive effect of pine-needle coverage. Contrarily, abiotic constraints increased toward branch extremities, harming mistletoe seeds by encouraging their desiccation.• Conclusions: Biotic and abiotic variables exert a strong, nonrandom filter on V. album regeneration, resulting in recruitment hotspots at the periphery of the branches and sites with a high probability of recruitment failure at thicker and more exposed locations. The narrow range of suitable host species and the scarcity and spatially restricted recruitment hotspots for V. a. austriacum leads to the clumping of mistletoe populations at the finer spatial scale.

Приклади метризації і прогнозування біомаси соснових деревостанів у Польщі

In the article there are presented examples of metrication of stands biomass with a predominance of pine (Pinus sylvestris L), such as: hand-held measuring of trees biomass in the forest; average data for forest compartments, selected from the Computer System of State Forests; data from hemispheric photos; data from Terrestrial Laser Scanning (TLS) and Aerial Laser Scanning (ALS). Collected and measured data was inserted into the FORKOME model, which predicted the biomass dynamics of pine stands for the period of 100 years. Key words: biomass, pine stands, metrication, prediction.

Species richness estimation from probabilities of observing new species

A new species richness estimator applicable to probability sampling with fixed-area (a) plots in a finite-area (A) population is presented and tested in simulated sampling from three stem-mapped forest compartments, and from six large collections of forest inventory data. The estimator of richness is the average number of species per plot times the sum—over the N = A/n plots in a population—of the probability (pm) of observing a new species in the mth plot (m = 1,…, N). A Cauchy distribution function is used to capture trends in pm. The parameters of the Cauchy distribution were estimated by optimizing a weighted maximum likelihood function. In comparison to five presumed best alternative estimators, the new estimator was ‘average’ with respect to bias, but best in terms of average root mean squared error. Taking the average of the estimates of richness produced by the five alternate and the new estimator would, generally, keep bias below 15 %. With relatively large sample sizes, the bias is moderately small (<10 %).

Butterfly Community Composition Across a Successional Gradient in a Human‐disturbed Afro‐tropical Rain Forest

AbstractKnowledge of the recovery of insect communities after forest disturbance in tropical Africa is very limited. Here, fruit‐feeding butterflies in a tropical rain forest at Kibale National Park, Uganda, were used as a model system to uncover how, and how fast, insect communities recover after forest disturbance. We trapped butterflies monthly along a successional gradient for one year. Traps were placed in intact primary forest compartments, heavily logged forest compartments with and without arboricide treatment approximately 43 years ago, and in conifer‐clearcut compartments, ranging from 9 to 19 years of age. The species richness, total abundance, diversity, dominance, and similarity of the community composition of butterflies in the eight compartments were compared with uni‐ and multivariate statistics. A total of 16,728 individuals representing 88 species were trapped during the study. Butterfly species richness, abundance, and diversity did not show an increasing trend along the successional gradient but species richness and abundance peaked at intermediate stages. There was monthly variation in species richness, abundance, diversity and composition. Butterfly community structure differed significantly among the eight successional stages and only a marginal directional change along the successional gradient emerged. The greatest number of indicator species and intact forest interior specialists were found in one of the primary forests. Our results show that forest disturbance has a long‐term impact on the recovery of butterfly species composition, emphasizing the value of intact primary forests for butterfly conservation.

Modelling the Potential Distribution of Three Climate Zonal Tree Species for Present and Future Climate in Hungary

Abstract The potential distribution and composition rate of beech, sessile oak and Turkey oak were investigated for present and future climates (2036-2065 and 2071-2100) in Hungary. Membership functions were defined using the current composition rate (percentage of cover in forest compartments) of the tree species and the long-term climate expressed by the Ellenberg quotient to model the present and future tree species distribution and composition rate. The simulation results using the regional climate model REMO showed significant decline of beech and sessile oak in Hungary during the 21st century. By the middle of the century only about 35% of the present beech and 75% of the sessile oak stands will remain above their current potential distribution limit. By the end of the century beech forests may almost disappear from Hungary and sessile oak will also be found only along the Southwest border and in higher mountain regions. On the contrary the present occurrences of Turkey oak will be almost entirely preserved during the century however its distribution area will shift to the current sessile oak habitats.

Combining double sampling for stratification and cluster sampling to a three-level sampling design for continuous forest inventories

We extend the well-known double sampling for stratification sampling scheme by cluster subsampling to a three-level design and present corresponding estimators based on the infinite population approach in the first phase. After stratification of the sample points (phase I), a second-phase sample is drawn independently among the first-phase points within each stratum. On level III, clusters are formed of those phase II points and a sample of clusters is finally drawn without replacement. We used the forest planning units compartment and subdistrict as clusters and moreover formed clusters with a heuristic for the vehicle routing problem. The precision of the new estimator was compared to that achieved with classical double sampling for stratification in a case study. The results indicate that the expected increase in sampling errors caused by clustering cannot be compensated by the reduced inventory costs under the conditions given in the case study.

Impact of Collaborative Forest Management on Forest Status and Local Perceptions of Contribution to Livelihoods in Uganda

This study assessed the impacts of Collaborative Forest Management (CFM) initiatives on forest status of Budongo Forest reserve in Uganda and perceptions of the participating communities on the contribution of CFM towards their livelihood. Impact on conservation was assessed by applying a Participatory community based Forest Resource Assessment (PFRA) method to examine population structure, dynamics, and incidences of human disturbance across two forest compartments under CFM and comparing these with the status in two compartments without CFM, but otherwise similar to the former in terms of forest type, history of resource use-patterns, silvicultural management practices and location (in the production zone of the forest and close proximity to local communities). Impact on local livelihoods was examined through a survey that involved ten focus group discussions and semi-structured interviews among 140 randomly selected forest neighbours. With the exception of tree regeneration, CFM improved forest status in terms of more live stems of timber, pole tree species, trees with harvestable logs, merchantable volume, and lowered incidences of human disturbances. However, local people do not perceive CFM to have contributed to their livelihoods because whereas CFM created opportunities for income generation particularly through bee keeping, the in-forest activities it halted were superior sources of livelihood. As a result, nearly 50% of the respondents explicitly reported dissatisfaction with the CFM arrangements. Other reasons for dissatisfaction included the inability of CFM to deliver benefits as promised in the signed agreements, local people were frequently not consulted or involved in making key management decisions, and inequality in sharing CFM benefits amongst members of the local community. CFM at Budongo forest reserve has thus contributed to improving forest status, but is perceived to have had limited benefits to local livelihoods.

Rapid assessment of wind storm-caused forest damage using satellite images and stand-wise forest inventory data

Abstract: This paper introduces a method for rapid forest damage assessment using satellite images and stand-wise forest inventory data. Two Landsat 5 Thematic Mapper (TM) images from June and September 2010 and data from a forest stand register developed within the frameworks of conventional stand-wise forest inventories in Lithuania were used to assess the forest damage caused by wind storms that occurred on August 8, 2010. Satellite images were geometrically and radiometrically corrected. The percentage of damage in terms of wind-fallen or broken tree volume was then predicted for each forest compartment within the zone potentially affected by the wind storm, using the non-parametric k-nearest neighbor technique. Satellite imagery-based difference images and general forest stand characteristics from the stand register were used as the auxiliary data sets for prediction. All auxiliary data were available from existing databases, and therefore did not involve any added data acquisition costs. Simultaneously, aerial photography of the area damaged by the wind storm was carried-out and color infrared (CIR) orthophotos with a resolution of 0.5 x 0.5 m were produced. A precise manual interpretation of the effects of the wind storm was used to validate satellite image-based estimates. The total wind damaged volume in pine dominating forest (~1.180.000 m3) was underestimated by 2.2%, in predominantly spruce stands (~233.000 m3) by 2.6% and in predominantly deciduous stands (~195.000 m3) by 4.2%, compared to validation data. The overall accuracy of identification of wind-damaged areas was around 95-98%, based solely on difference data from satellite images gathered on two dates.

Changes in the forest cover after intense logging in southern taiga of the russian federation

Specific features of the forest cover formation after industrial timber cutting during a period of 50 years in southern taiga spruce forests (Kostroma oblast) are described. The statistical analysis of the forest use intensity, the forested area, and the dynamics of the age and species structure of forests was performed. Plans of forest stands obtained for five inspections and taxation databases of 1954 and 1997 were also used. The potentialities of analyzing the structure of forest mapping units using means of overlay in the geoinformation system are considered. Parameters for distinguishing forest compartments were calculated. The dynamics of these parameters reflect the natural development of forest, effects of adverse environmental factors, economic history of the region, and specific features of individual interpretation of the survey materials in forest management.

Estimation of winter leaf area index and sky view fraction for snow modelling in boreal coniferous forests: consequences on snow mass and energy balance

AbstractLeaf area index (LAI) and canopy coverage are important parameters when modelling snow process in coniferous forests, controlling interception and transmitting radiation. Estimates of LAI and sky view factor show large variability depending on the estimation method used, and it is not clear how this is reflected in the calculated snow processes beneath the canopy. In this study, the winter LAI and sky view fraction were estimated using different optical and biomass‐based approximations in several boreal coniferous forest stands in Fennoscandia with different stand density, age and site latitude. The biomass‐based estimate of LAI derived from forest inventory data was close to the values derived from the optical measurements at most sites, suggesting that forest inventory data can be used as input to snow hydrological modelling. Heterogeneity of tree species and site fertility, as well as edge effects between different forest compartments, caused differences in the LAI estimates at some sites. A snow energy and mass balance model (SNOWPACK) was applied to detect how the differences in the estimated values of the winter LAI and sky view fraction were reflected in simulated snow processes. In the simulations, an increase in LAI and a decrease in sky view fraction changed the snow surface energy balance by decreasing shortwave radiation input and increasing longwave radiation input. Changes in LAI and sky view fraction affected directly snow accumulation through altered throughfall fraction and indirectly snowmelt through the changed surface energy balance. Changes in LAI and sky view fraction had a greater impact on mean incoming radiation beneath the canopy than on other energy fluxes. Snowmelt was affected more than snow accumulation. The effect of canopy parameters on evaporation loss from intercepted snow was comparable with the effect of variation in governing meteorological variables such as precipitation intensity and air temperature. Copyright © 2012 John Wiley &amp; Sons, Ltd.

Improving the Precision of Tree Counting by Combining Tree Detection with Crown Delineation and Classification on Homogeneity Guided Smoothed High Resolution (50 cm) Multispectral Airborne Digital Data

A method of counting the number of coniferous trees by species within forest compartments was developed by combining an individual tree crown delineation technique with a treetop detection technique, using high spatial resolution optical sensor data. When this method was verified against field data from the Shinshu University Campus Forest composed of various cover types, the accuracy for the total number of trees per stand was higher than 84%. This shows improvements over the individual tree crown delineation technique alone which had accuracies lower than 62%, or the treetop detection technique alone which had accuracies lower than 78%. However, the accuracy of the number of trees classified by species was less than 84%. The total number of trees by species per stand was improved with exclusion of the understory species and ranged from 45.2% to 93.8% for Chamaecyparis obtusa and C. pisifera and from 37.9% to 98.1% for broad-leaved trees because many of these were understory species. The better overall results are attributable primarily to the overestimation of Pinus densiflora, Larix kaempferi and broad-leaved trees compensating for the underestimation of C. obtusa and C. pisifera. Practical forest management can be enhanced by registering the output resulting from this technology in a forest geographical information system database. This approach is mostly useful for conifer plantations containing medium to old age trees, which have a higher timber value.

Soil temperatures during prescribed burning and the occurrence of Rhizina undulata Fr

Rhizina undulata is a postfire fungus. The ascospores germinate after heating over 35°C. The prescribed burning of one forest compartment was done in the purpose to investigate the effects of forest fire to atmosphere at Hyytiala Forestry Field Station in Southern Finland. The soil temperature measurements were one part of that research. One year after burning, the ascocarps of R. undulata appeared offering the possibility to use temperature data for studying the ecology of the species. The soil temperature was measured with 21 iButton sensors. Before and during the burning, all sensors were at 7 cm depth in the burned area. After burning, 10 sensors were moved to the unburned control area. The ascocarps were inventoried from 40 systematically located 10 m2 plots. On average 6 ascocarps were found in one plot. Ascocarps were present on 75% of plots. Most ascocarps were found on spots for seeding with bare mineral soil visible. The fungus has not killed germlings of pine but 43% of planted seedlings were dead. The temperature during the burning reached 35°C in 10 points. In 4 points, the temperature was over 60°C, which could be too high temperature for spores to survive. It seems that the ascospores could exist in the soil in 2 to 10 cm depth if they can germinate. The temperatures after burning did not reach 35°C in 7 cm depth. More measurements are needed to show if the temperature in the surface of burned area reached critical point after burning. Key words: Postfire fungus, forest fire, ascocarps.

Estimating forest timber volume by means of “low-cost” LiDAR data

The main purpose of the present research is to verify whether medium resolution LiDAR data, not forest-specific, can be used to carry out statistical models for estimating timber volume. LiDAR data with different characteristics, and taken in different seasons (winter and summer) on the same forest area (Foresta di Paneveggio, Trentino, Italy), were processed, and an estimation model using winter low-resolution data was performed. Such model was then applied to a different territory, having similar forest characteristics. Moreover, LiDAR and ground data, surveyed during the management plan inventory, were integrated. The final model allows to obtain good volume estimates with fair precision if applied at forest compartments level, and can produce detailed timber volume maps, very useful when

Canopy gaps and the natural regeneration of Matang mangroves

Canopy opening or gap creation by lightning strike is an important form of exogenous disturbance in the mangroves of Matang in Malaysia. The almost circular shaped canopy gaps consist of a group of standing dead trees which decay simultaneously with the growth of new trees. This characteristic is chiefly different with terrestrial forests where canopy gaps are normally created by tree-falls. Lightning strike disturbance in mangroves has created a means for natural regeneration whereby dormant seedlings growing underneath the canopies have had the opportunity to progress and ultimately replacing the canopies of the dead trees. Historical and recent aerial photographs of the Virgin Jungle Reserve of Pulau Kecil in Matang were analysed to measure gap turnover rate and to calculate canopy turnover. The average (±SD) canopy turnover is 25.5±6.9years. This finding shows that the continuous dynamics of gap creation and closure have sustainably maintained the condition of the forest. The finding also supports the hypothesis that this disturbance prevents mangroves from reaching more senescent stage, thus, canopy gap creations are justified to be the key driver in the natural regeneration of the tropical Rhizophora-dominated mangroves. Curiously compared, the average turnover is almost similar to the existing 30-year rotation cycle system adopted by the Forestry Department for the management of forest compartments in Matang.

Modelling of the natural chlorine cycling in a coniferous stand: implications for chlorine-36 behaviour in a contaminated forest environment

Considered as one of the most available radionuclide in soil–plant system, 36Cl is of potential concern for long-term management of radioactive wastes, due to its high mobility and its long half-life. To evaluate the risk of dispersion and accumulation of 36Cl in the biosphere as a consequence of a potential contamination, there is a need for an appropriate understanding of the chlorine cycling dynamics in the ecosystems. To date, a small number of studies have investigated the chlorine transfer in the ecosystem including the transformation of chloride to organic chlorine but, to our knowledge, none have modelled this cycle. In this study, a model involving inorganic as well as organic pools in soils has been developed and parameterised to describe the biogeochemical fate of chlorine in a pine forest. The model has been evaluated for stable chlorine by performing a range of sensitivity analyses and by comparing the simulated to the observed values. Finally a range of contamination scenarios, which differ in terms of external supply, exposure time and source, has been simulated to estimate the possible accumulation of 36Cl within the different compartments of the coniferous stand. The sensitivity study supports the relevancy of the model and its compartments, and has highlighted the chlorine transfers affecting the most the residence time of chlorine in the stand. Compared to observations, the model simulates realistic values for the chlorine content within the different forest compartments. For both atmospheric and underground contamination scenarios most of the chlorine can be found in its organic form in the soil. However, in case of an underground source, about two times less chlorine accumulates in the system and proportionally more chlorine leaves the system through drainage than through volatilisation.

Polypore communities in broadleaved boreal forests

The cover and extent of boreal broadleaved forests have been decreasing due to modern forest management practices and fire suppression. As decomposers of woody material, polypores are ecologically important ecosystem engineers. The ecology and conservation biology of polypores have been studied intensively in boreal coniferous forests. However, only a few studies have focused on the species living on broadleaved trees. To increase knowledge on this species group we conducted polypore surveys in 27 broadleaved forests and 303 forest compartments (539 ha) on the southern boreal zone in Finland and measured dead wood and forest characteristics. We detected altogether 98 polypore species, of which 13 are red-listed in Finland. 60% of the recorded species are primarily associated with broadleaved trees. The number of species in a local community present in a broadleaved forest covered approximately 50 species, of which 30–40 were primarily associated with broadleaved trees. The size of the inventoried area explained 67% of the variation in the species richness, but unlike in previous studies conducted in coniferous forests, dead wood variables as well as forest structure had very limited power in explaining polypore species richness on forest stand level. The compartments occupied by red listed Protomerulius caryae had an especially high volume of living birch, but otherwise the occurrences of red-listed species could not be predicted based on the forest structure.

GIS-Based Evaluation and Analysis of Windthrow Hazarel in Liangshui Nature Reserve

Forest ecosystems provide a lot of service functions which are not only sustainable conditions for life, but also the material foundation and guarantee for human survival and socio-economic development. Therefore, these years more and more attention has been paid to forest health and health assessment has become extraordinarily important. This study is primarily based on the evaluation criteria prescribed by Continuous Forest Inventory Technique, combining with site, geography, climate conditions and so on in Liangshui nature reserve to define the evaluating indicators. In this thesis, windthrow hazarel is divided into four grades: zero, mild, moderate and severe. The data of forest resource inventory in Liangshui nature reserve in 2009 is used to calculate the accumulation of different forest compartment and species of wind fallen trees. And based on ARCGIS, windthrow hazarel geodatabase, disaster distribution, volume distribution of wind fallen trees of Liangshui nature reserve are built and mapped. Then with the combination of aspect, slope and stand density distribution, this thesis is to analyze the factors which influence the disaster grade and distribution, to propose target-oriented prevention measures and treatment strategies. The results demonstrate that in Liangshui nature reserve, forest compartments in mild disaster are the most with the total number of 21, those in moderate disaster are 4, in zero degree disaster are 4 and in severe are 2. And the area of forest compartments whose main variety of wind fallen tree is pinus koraiensis takes up over 45% of the total forest zone, the area of forest compartments whose main varieties are fir and spruce takes up approximately 40%, and the areas of forest compartments whose main varieties respectively are poplar and basswood takes up about 10% and 5%.

Silviculture as a disturbance regime: the effects of clear-cutting, planting and thinning on polypore communities in mixed forests

The structure of modern forest landscapes is profoundly affected by human-caused disturbances, particularly forest management; however, the effects and prospects of individual silvicultural techniques are insufficiently understood. This study distinguishes the effects of clear-cutting, planting and thinning on species richness and community composition of polypore fungi. In 2008–2009, 181 forest compartments (ranging from naturally regenerated deciduous stands to planted Picea abies stands and 0–137 years post clear-cutting) were explored in a hemiboreal landscape subjected to even-aged management. Altogether 104 polypore species were recorded. For species richness, time since clear-cutting was the most influential factor at both stand and landscape scales, followed by thinning. Clear-cuts had distinct polypore communities (including several red-listed species) whose species richness declined in time. Following 20 years post clear-cutting, species richness started to increase along different community–composition pathways determined by regeneration type. The communities developed after planting were moderately species rich at stand scale but homogeneous over larger areas. Thus, at landscape scale, mature unmanaged naturally regenerated stands hosted most species; thinning reduced species richness by approximately 15%, and among thinned stands, planted areas had a further 9–22% fewer species than naturally regenerated areas. In such variably managed landscape, silviculture appeared to create particularly distinct communities in young stands on nutrient-rich soils, which naturally provide polypores with a rich supply of small deciduous snags absent from stands artificially planted with P. abies and intensively thinned.

Post-logging recovery time is longer than expected in an East African tropical forest

Uncertainty in recovery times of tropical forests can lead to mismanagement, such as in setting inappropriate harvesting rates or failing to achieving conservation targets. We use long-term plot data (17 y) to estimate recovery times of separate forest compartments, which experienced different levels of timber extraction within Kibale National Park, Uganda. We estimate that structural recovery (basal area) of heavily logged and moderately logged compartments will take respectively 112 and 95 y, when compared to adjacent mature forest. Our data suggests that recovery in terms of species composition will take significantly longer. Our estimates of structural recovery are derived from rates of change of diameter at breast height and basal area measurements which have been used traditionally as indicators of forest growth and productivity. Our results suggest that the severity of the logging has an impact on the rate of recovery, with current recovery rates estimated at 0.32 m 2 ha −1 y −1 in a moderately logged compartment and 0.25 m 2 ha −1 y −1 in heavily logged areas, highlighting the possible benefits of reduced impact harvesting in increasing long-term yields. We investigate how some representatives of the wildlife community were affected by differential recovery times and find that recovery times of frugivorous primate's forest habitats were 2.5 times slower when compared with folivorous primates.