High-quality Forest Research Articles

Forest density and orchard classification in Hyrcanian forests of Iran using Landsat 8 data

Satellite-based remote sensing is of crucial importance to provide timely and continuous thematic maps for practical forestry tasks. There is currently no existing remote sensing-based, large-scale inventory of canopy cover classes (and also adjacent orchards) on the full range of Hyrcanian forests. We used the freely available and large-scale coverage of Landsat 8 imagery acquired in 2014 to classify three forest density classes as well as non-forest and orchards. The supervised classification and support vector machine classifier were selected based on a pre-classification of three representative pilot regions. Classified final maps were validated by means of a two-stage sampling and 1,852 field samples. The total areas of the dense, semi-dense, sparse forests and orchards were 45, 36, 19 and 1.9% of the total studied area, respectively. The overall accuracy and Kappa coefficient of classified maps were 94.8 and 90%, respectively. The methodology introduced to map forest cover in Hyrcanian forests is concluded to enable providing a high quality forest database for further research, planning and management.

Edge Effects, Invasion, and the Spatial Pattern of Herb-Layer Biodiversity in an Old-Growth Deciduous Forest Fragment

Habitat loss and fragmentation are major threats to global biodiversity, altering both habitat structure and availability. Small preserves nested within landscapes dominated by human commerce can serve as long-term storehouses of biodiversity, yet they are vulnerable to threats such as exotic plant invasion and disturbance. The Drew Woods State Nature Preserve (DWSNP) in Darke County, Ohio, provided an opportunity to understand the capacity of a small old-growth preserve for maintaining regional floristic biodiversity and assessing ecological threats. A series of six approximately biweekly herbaceous layer samplings were conducted across 32 1-m2 circular plots within DWSNP, and percent vegetative cover was estimated for each herbaceous species identified. The vascular flora of this 6-ha site was inventoried and used for a Floristic Quality Assessment. Spatial patterns were visualized using ArcGIS software, and linear regression analyses and non-metric multidimensional scaling were used to test for relationships between measures of diversity and cover and environmental variables. A total of 176 species were identified across 124 genera and 67 families, and the majority of species were native (89.2%). Characteristic native herb species included Jeffersonia diphylla (twinleaf), Trillium sessile (toad trillium), Allium tricoccum (wild leek), and Erythronium americanum (trout lily), all of which are indicative of high-quality forest. A north—south gradient of species richness was found across all samplings, with the southernmost plots tending to be most species-rich (P < 0.01, r2 ≤ 0.42). This pattern appeared to be linked with gradients of light and temperature that are likely driven by edge effects. Old-growth forests are known for their resiliency, a trait that was evident in the high-quality flora of DWSNP; however, they are not immune to invasion by exotic species. We discovered a significant, nascent, invasion of Alliaria petiolata (garlic mustard), which has the potential to negatively impact the biological integrity of the site if left unchecked. Small forest fragments in agricultural landscapes can act as important reservoirs of biodiversity, but effective preservation and management of these sites requires an understanding of the threats to their ecological integrity as well as environmental drivers of diversity.

Spatial and Temporal Variation in Heterophil-to-Lymphocyte Ratios of Nestling Passerine Birds: Comparison of Blue Tits and Great Tits

Environmental factors affecting trophic conditions act as stressors on nestling altricial birds. Access of parental birds to a sufficient supply of food in a limited period of the nestling stage differ in time and space, depending on nesting habitat, prey density and weather conditions. Heterophil-to-lymphocyte ratio (H/L) is considered as a reliable indicator of prolonged stress reaction in birds. In this study we examine if variation in H/L shows consistent spatio-temporal patterns in nestlings of two parids, blue tit Cyanistes caeruleus and great tit Parus major. We found that blue tit nestlings had on average higher H/L than great tit nestlings, which corresponds with the ecological sensitivity of these species. In both species H/L was higher in a poor parkland habitat than in a high quality forest habitat. In nestling blue tits, higher H/L values occurred in years characterized by more extreme weather conditions and worse caterpillar availability. Such consistent patterns of variation in the H/L ratio of nestling blue tits and great tits suggest that, when age-dependent effects are controlled, the ratio can be used as an indicator of physiological stress that is generated by food-related stressors differing in space and time. In particular, elevated H/L ratios are indicative of human-induced changes in the structure of breeding habitats.

Wood energy fuel cycle optimization in beech and spruce forests

A novel synergistic approach to reducing emissions from residential wood combustion (RWC) is presented. Wood energy fuel cycle optimization (FCO) aims to provide cleaner burning fuels through optimization of forestry and renewable energy management practices. In this work, beech and spruce forests of average and high quality were modelled and analysed to determine the volume of fuel wood and its associated bark fraction produced during typical forestry cycles. Two separate fuel wood bark production regimes were observed for beech trees, while only one production regime was observed for spruce. The single tree and stand models were combined with existing thinning parameters to replicate existing management practices. Utilizing estimates of initial seedling numbers and existing thinning patterns a dynamic model was formed that responded to changes in thinning practices. By varying the thinning parameters, this model enabled optimization of the forestry practices for the reduction of bark impurities in the fuel wood supply chain. Beech forestry cycles responded well to fuel cycle optimization with volume reductions of bark from fuel wood of between ∼10% and ∼20% for average and high quality forest stands. Spruce, on the other hand, was fairly insensitive to FCO with bark reductions of 0–5%. The responsiveness of beech to FCO further supports its status as the preferred RWC fuel in Switzerland. FCO could easily be extended beyond Switzerland and applied across continental Europe and North America.

Current trends in the Russian Far East forest sector

Having vast areas of high-quality forests, Russia tries to attract more investments in the forest sector for domestic timber processing in order to fill in regional and federal budgets to have more funds available for forest protection and rehabilitation. Comprising over 70% of total forestlands in Russia, forests of the Russian Far East (RFE) are distributed unevenly across provinces. Larch, pine and spruce are the dominant conifer tree species in this vast region, while substantial amounts of forest area and timber volumes can be attributed to oak and ash species. Forest area and tree species distribution are mainly a result of long-lasting natural and anthropogenic impacts, such as forest fires, pest outbreaks, territory development, land-use change, timber harvesting and forestry activities. Mature conifer stands are the most important source of timber both in Russia and in the RFE. Over decades, a predominance of mature conifer species in forest composition became a key strategic factor of timber industry development including domestic consumption and export, mainly roundwood (logs). During the last few decades, the RFE and Siberia forests have been a significant source of timber for domestic use and export to the Asia-Pacific region, mainly, the People's Republic of China, Japan and the Republic of Korea. Current administrative and legislative reforms, introduction of a new Forest Code of the Russian Federation (2006), governmental decisions on the forest sector including an increase of export tariffs on raw timber, a decrease of import tariffs on wood-processing equipment and some other measures have initiated changes in the forest sector of the RFE. New Russian Forest Code empowered provincial authorities for more practical actions, including initiation of investment projects in major forested provinces of Russia. The article examines major challenges occurring in the Russian forest sector from the following positions: forest resources and impacts on them, timber available for harvesting and availability of forest resources in the RFE to meet growing demands in the future, efforts to increase volumes of wood products of higher value added via the export-import policy, and a reaction of the wood products market to these changes. The conclusion is that the steps undertaken by the Russian Government in order to increase revenue from forest sector are beginning to bring their first results.

Reliable forest carbon monitoring – systematic reviews as a tool for validating the knowledge base

SUMMARY With global carbon credits valued at over US$100 billion/year, accounting under REDD will drive demand for high quality forest monitoring systems. The choice of system to adopt should be guided by good science. The adequacy and comparability of different national systems for forest carbon measurement under REDD have not been fully evaluated. There is a growing body of scientific and technical information on ground-based and remote-sensing methods of carbon measurement. This extensive, often conflicting, knowledge base has not been systematically reviewed in the transparent, readily-repeatable manner consistent with evidence-based practice. This paper argues that such an approach, regarded in medicine as the gold standard for evidence evaluation, is long overdue in forestry generally and carbon monitoring and assessment specifically. Preliminary findings from an international project set up to scope the potential for a systematic review approach indicate that this evidence-based approach would add ...

Analysis of forest reservation modes and development countermeasures

封山育林能快速、经济地恢复和增加林草植被, 形成的植被群落稳定, 是深远山区生态建设的重要途径。河北省在生态环境建设中, 实施封山育林, 在充分利用自然环境自我修复能力的同时, 采取必要的人工促进措施, 加快封山育林成林速度, 提高封山育林质量, 促进山区生态产业发展。本文总结提出了河北省封山育林中应用的自然封育、飞封结合、封造结合、封改结合、封保结合等主要山区生态建设模式, 并分析了封山育林效益和存在的主要问题, 提出了增加投入、落实政策等加快封山育林的对策措施。

Ecological thresholds in herb communities for the management of suburban fragmented forests

Fragmentation is a major cause of biodiversity loss. The relationship between fragmentation and biodiversity might be non-linear, due to the presence of ecological thresholds; however, the application of the threshold concept on the conservation of herb biodiversity has received limited attention. We assessed the relationship between a pool of woodland indicators and features of forest fragments (area, isolation, shape), and we evaluated whether ecological thresholds might provide guidelines for conservation. We performed our study in a human dominated area of northern Italy. In order to obtain a group of floristic indicators, we chose perennial herbs characteristic of the phytosociological syntaxa Fagetalia sylvaticae, Carpinion betuli and Erythronio-Carpinion, with suitable Landolt L and H index, obtained from previous relevés in reference and high-quality forests. Subsequently, we analyzed the relationship between richness of indicators and patch features recorded in a highly fragmented landscape. Generalized linear models showed that the number of forest indicators was positively related to fragment size and connectivity. Generalized Additive Models showed that the relationship between indicator richness and fragment size was non-linear, with the presence of two thresholds. The number of forest indicators increased until 35–40ha; above this size the richness remained constant. Fragments above this threshold should be the target of conservation. Furthermore, the relationship between area and number of indicators was less steep in patches smaller than 1–1.5ha. Patches between these two thresholds can be optimal targets of management actions, as small size increases can greatly improve their value for biodiversity. The identification of two thresholds in the relationship between patch area and indicators suggests an abrupt response to changing landscape features and provide quantitative targets for conservation.

Applying spatial conservation prioritization software and high-resolution GIS data to a national-scale study in forest conservation

We apply a recently developed conservation prioritization method (Zonation algorithm) to a national-scale conservation planning task. The Finnish Forest and Park Service (Metsähallitus) was given the mandate to expand the current protected areas in southern Finland by 10 000 ha. The question is which areas should be selected out of the total area of 1 760 000 ha. The data available include a nation-wide GIS data set describing general features of forests at the resolution of 25 m × 25 m for entire Finland and another data set about biodiversity features within the current state-managed conservation areas. Ecologically, the key information includes forest age and the volume of growing stock for 20 forest types representing different productivity classes and dominant tree species. Our analysis employs four different connectivity components to identify forest areas that are (i) locally of high quality and internally well connected, (ii) well connected to surrounding high-quality forests, (iii) well connected to existing conservation areas, and (iv) large enough to allow efficient implementation. Expert evaluation of the results suggested that the present quantitative analysis was helpful in identifying areas with high conservation value systematically across southern Finland. Our analysis also showed that the highest forest conservation potential in Finland is located on privately owned land. The present techniques can be applied to many large-scale planning and management projects.

THE USE OF TREE-MOUNTED ARTIFICIAL SHELTERS TO INVESTIGATE ARBOREAL SPIDER COMMUNITIES IN NEW ZEALAND NATURE RESERVES

Spiders have been advocated as valuable bio-indicators of forest ecosystem ''health.'' However, the numbers and types of spiders that are recorded at a site will usually be highly dependent on the sampling method employed. The use of lethal, indiscriminate invertebrate sampling techniques is undesirable when investigating rare species, or sampling within areas of high conservation status. There- fore we used non-lethal artificial tree-mounted shelters to monitor arboreal spiders in nature reserves near Christchurch, New Zealand. After three months, over 60% of the shelters had been used by spiders, increasing to 91% after twelve months. There were significant differences in the numbers of spiders found in the shelters at the different sites. However, factors such as the species of tree the shelter was attached to, ground vegetation, and levels of incident light did not affect the likelihood of a shelter being occupied. The species composition of the spider faunas in those sites regarded as high quality forest remnants was dissimilar to the faunas found in the low quality reserves. However, although spiders were more abundant in the high quality sites compared with the poorest stands of woodland, they were not more species rich. The shelters are inexpensive and easy to manufacture and are useful for long-term non-lethal monitoring of spider communities. They also have good potential as a tool for studying spider phenology, population dynamics, behavior, and as a collection/carriage device for live specimens used in conservation translo- cations.

Experimental evidence of 'floaters' in two isolated populations of an Afrotropical forest bird

We studied the presence of 'floaters', i.e. non-territorial individuals roaming occupied territories awaiting future breeding opportunities, in two separate White-starred Robin (Pogonocichla stellata) populations at the Taita Hills, Kenya, using a removal experiment. Previous vegetation analyses at this site had showed that 'population Ngangao' occupied a high-quality forest fragment, and 'population Chawia' occupied a low-quality one. Using a combination of radio telemetry, dawn calls, visual observations and targetted playbacks in one 16ha plot per fragment, 52 individuals of different territorial status were identified. Ngangao hosted 14 resident and 13 floating males, while Chawia hosted eight residents and two floaters. Population Chawia (but not Ngangao) hosted unmated territorial males. Floating males in Ngangao took over three of seven (i.e. 43%) vacated territories within a few days of the residents' removal. In both populations, no resident neighbouring males expanded their territories or moved to take over the vacant territories following experimental removal of resident males. These results suggest that (1) territorial behaviour is an important factor limiting the number of breeders in Population Ngangao; (2) other factors such as poor habitat quality and female scarcity, most likely associated with the lower bird densities in Population Chawia, can limit numbers of breeders before territorial exclusion becomes a concern.

Mammal and Land Bird Studies on Camiguin Island, Philippines: Background and Conservation Priorities

Camiguin Island, with an area of ca. 265 km2 and maximum elevation of ca. 1620 m, lies about 10 km north of Mindanao but is isolated from Mindanao by a deep (385 m) channel. It originated from volcanic activity as a dryland island not earlier than 1 million years ago, but most growth of the island has occurred within the past 340,000 years. Current landforms are dominated by large, scenic volcanic peaks, several of which are active. Lowland rain forest originally occurred up to about 1100 m elevation, with montane rain forest from 1100 m to about 1350 m and mossy forest from 1350 m to the peaks. By the mid-1990s, deforestation had removed most natural vegetation below about 600 m, with degree of disturbance to forest decreasing with elevation and ending at about 1250 m. The climate is tropical, with rainfall of 2–3 m per year in the lowlands and probably about 7.5 m near the peaks. Mammal and/or bird specimens are available from 18 sites from the 1960s and 1990s; these sites are here located and described to the extent possible. Given the presence of two endemic species of mammals (one described in this volume), one endemic bird (described in this volume), and previously described endemic plants and a frog, Camiguin is one of the smallest but most distinctive centers of biodiversity in the Philippines and should be a priority site for conservation. The remaining forest on Camiguin is essential habitat for these unique species, but it is also essential for watershed protection and control of floods and landslides, and it contributes significantly to the tourism trade that provides substantial income on the island. Deforestation for logging and agriculture and overhunting are current threats. A protected area on the island should include the full range of original habitat diversity, which would encompass both the existing high-quality forest at upper elevations and also significant tracts of disturbed but natural lowland forest, especially along rivers and streams, that should be allowed to regenerate in the future.

Invasion Pattern of Herb Garlic Mustard (Alliaria petiolata) in High Quality Forests

The invasion of non-indigenous plant species poses a severe threat to native plant communities. Garlic mustard (Alliaria petiolata) is a naturalized European biennial herb that has spread rapidly through the eastern US and adjacent Canada. To determine garlic mustard rate of spread, eleven permanent plots (50×25 m) were located in seven high quality (relatively undisturbed) forests in the early stages of invasion. Garlic mustard presence was recorded within six 50×2 m permanent belt transects, and density and percent cover by age class were recorded in 36 permanent 1 m2 quadrats, between 1989 and 1992, and again in 1997. Garlic mustard spread at an average rate of 5.4 m per year between 1989 and 1992, in all plots combined. Within individual plots rate of spread varied substantially, with location of the front increasing up to 36 m and decreasing as much as 18 m between years. While the front alternately advanced and retreated, over time garlic mustard consistently advanced through all forests. Rate of spread was influenced by establishment of satellite populations, and disturbance (wind-throw and flooding). The pattern of spread within plots was one of a ragged advancing front, supplemented by establishment of satellite populations 6–40 m distant from the front, which then coalesced with the main population. Garlic mustard presence between 1989 and 1997 increased significantly within all plots, and in each age class within each plot. The greatest increases occurred in plots where this plant was initially rarest. Garlic mustard cover and density varied nonsignificantly during the same time period. These results indicate that after garlic mustard invades a forest it becomes a permanent part of the community, annually increasing in presence but fluctuating in cover and density. Garlic mustard maintains a low profile under low disturbance conditions, but increases rapidly with periodic disturbance. This study monitored garlic mustard invasion in high quality relatively undisturbed forests, and may underestimate the rate of spread in low quality highly disturbed forests.

Improvement and Evaluation of the Feller-Buncher Head

The high quality forest machines have recently become very popular in Japan. Many improvements on these machines have been made to fit the Japanese forests. This report describes the improvement and evaluation of the feller-buncher head of the prototype machine: FG-35. This head is mounted on the telescopic and knuckle-boom carrier. The prototype machine was improved to cut the trees, felled down on the ground or felled side ways by the storm as in the Kyushu district. And also the machine was improved so that it could be driven well without crashing the chainsaw-bar by the beginners. The testing operation of this machine carried out in Sumita-chou in Iwate and in Kuzu-chou in Oita. The productivity of the machine can be estimated at about 20 m3/h. The results of the improvement on the machine can be said to be good.

An investigation of operation aptitude among operators of high quality forest machines

An investigation of operation aptitude among operators of high quality forest machines

Emergence of Eucalyptus marginata (jarrah) from seed in Mediterranean‐climate forest in response to overstorey, site, seedbed and seed harvesting

Abstract The effects of overstorey, type of site, seedbed, seeding date and seed harvesting by vertebrates and invertebrates on the emergence of Eucalyptus marginata (jarrah) seedlings were studied experimentally in the northern jarrah forest of Western Australia. Seed harvesting by small vertebrates substantially reduced emergence, whereas invertebrates only slightly reduced emergence. Ninety per cent of seed was removed within 1 day when it was on the soil surface and in the open, whereas seed removal was insignificant when the seed was covered by soil. Vertebrates harvested seed more effectively when the understorey and litter were removed and the seed was more visible on the soil surface. Seed harvesting by small vertebrates had less impact on a site where there had been bauxite mining, possibly because the surrounding area was being revegetated with large numbers of seed and the area afforded poor cover for vertebrates. Emergence was less where the overstorey was removed compared to where it was retained, and on the rehabilitated bauxite mined site compared to the forest sites. There was no difference in emergence between the low and high quality forest sites and so the emergence phase could not fully explain the variation in abundance off. marginata seedlings on different quality sites. Post emergence events are likely to be important in explaining this difference between low and high quality sites.

Reptile and frog utilisation of rehabilitated bauxite minesites and dieback-affected sites in Western Australia's Jarrah Eucalyptus marginata forest

Alcoa of Australia Limited rehabilitate bauxite mined areas in the southwest of Western Australia. One of the aims of the revegetation programme is to promote the return of fauna species which inhabit areas prior to mining. This paper discusses the extent to which reptile and frog species utilise revegetated bauxite minesites. It was shown that 4–6 year old revegetated sites support similar numbers of reptile species as unmined sites, although densities are comparable to values recorded in poorer quality forest. Species utilisation of revegetated sites depended largely on the particular species microhabitat preferences. Comparison of community composition in various sites demonstrated high degrees of similarity between some rehabilitated sites and high quality forest sites. The effects of jarrah dieback disease on reptile and frog populations was also assessed. From the results, it is possible to assess the likely combined impact of dieback and mining on the longer term conservation of jarrah forest reptile and frog species.

Growth rate of jarrah(Eucalyptus marginata)in relation to site quality in cut-over forest, Western Australia

Summary The growth rate of jarrah was measured in 47 plots situated in high and low quality cut-over forest between Mundaring and Collie. Mean growth increments per decade for jarrah in high and low quality forest respectively were: diameter, 1.7 and 1.0 cm; basal area, 1.9 and 0.6 m2ha−1; volume, 11.8 and 2.0 m3ha−1. In high quality forest, diameter increment varied inversely with initial basal area whereas basal area increment and volume increment varied directly with initial number of stems per hectare. In low quality forest, basal area increment varied directly with initial basal area and initial number of stems per hectare. From diameter growth curves calculated with these data the average diameter attained by trees in high or low quality forest after 400 years would be about 70 cm or 50 cm respectively. When only trees with above average increments are considered, 70 cm diameter would be attained after 250 years in high quality forest and 310 years in low quality forest. If only the 25% of the trees...