Unproductive Forests Research Articles

Assessing and mitigating systematic errors in forest attribute maps utilizing harvester and airborne laser scanning data

Cut-to-length harvesters collect useful information for modeling relationships between forest attributes and airborne laser scanning (ALS) data. However, harvesters operate in mature forests, which may introduce selection biases that can result in systematic errors in harvester data-based forest attribute maps. We fitted regression models (harvester models) for volume (V), height (HL), stem frequency (N), above-ground biomass, basal area, and quadratic mean diameter (QMD) using harvester and ALS data. Performances of the harvester models were evaluated using national forest inventory plots in an 8.7 Mha study area. We estimated biases of large-area synthetic estimators and compared efficiencies of model-assisted (MA) estimators with field data-based direct estimators. The harvester models performed better in productive than unproductive forests, but systematic errors occurred in both. The use of MA estimators resulted in efficiency gains that were largest for HL (relative efficiency, RE = 6.0) and smallest for QMD (RE = 1.5). The bias of the synthetic estimator was largest for N (39%) and smallest for V (1%). The latter was due to an overestimation of deciduous and an underestimation of spruce forests that by chance balanced. We conclude that a probability sample of reference observations may be required to ensure the unbiasedness of estimators utilizing harvester data.

Diameter growth performance and estimated carbon stock of Shorea spp. at KHDTK Haurbentes, Bogor

Shorea leprosula Miq. and Shorea selanica (Lam.) Blume are fast growing plant and they can be used as a rehabilitation plant. Plant adaptability can be seen from the growth in diameter. Furthermore, rehabilitation plants have the potential to store carbon stocks which can support Indonesia's Forestry And Other Land Use (FOLU) Net Sink 2030 program. This study aims to analyze diameter growth and estimate carbon stocks stored in 8-year-old S. leprosula and S. selanica species in unproductive forest area KHDTK Haurbentes, Bogor. Furthermore, the data collection of diameter was conducted by census while carbon stock estimation used allometric equations. The diameter distribution of S. leprosula and S. selanica was normally distributed. The normal diameter distribution is defined as the highest number of frequencies around the mean value. The results of the normality test of S. leprosula and S. selanica have normal diameter distribution data which indicate that these species have good adaptability in unproductive forest areas. Moreover, the incremental growth of S. leprosula diameter is 1.38 cm while the diameter increment of S. selanica is 1.19 cm. The carbon stock of S. leprosula is 4.72 tons/ha while S. selanica is 8.32 tons/ha. S. leprosula and S. selanica have good adaptability. Thus, they can be used as plants to rehabilitate unproductive forests and store potential carbon stocks.

Juniperus L. for Restoration of Degraded Forest Lands in Turkey

Degraded forests are among of the most important environmental and commercial problems around the world. Turkey has 22.74 million hectares of forest area, out of which 9.656 million ha (42%) are unproductive. To transform these unproductive forests into productive ones, forest restoration including rehabilitation is one of the best actions. In this sense, juniper species play an important role for degraded lands because they are drought-tolerant and withstand aridity and poor soils better than most timber species grown in Turkey. Therefore, this review presents the ecological considerations for the restoration of degraded forest lands in Turkey under the conditions of climate change. Within this framework, it focuses on the production of planting stock of juniper species, the significance of site-species matching, and post-planting site maintenance for successful rehabilitation.

Tree regeneration on industrial linear disturbances in treed peatlands is hastened by wildfire and delayed by loss of microtopography

The world’s forests are highly fragmented by linear disturbances, and many forests have failed to recover decades after abandonment. Lack of recovery is common in unproductive forests, such as treed peatlands, because of conditions that limit tree growth, including simplification of microtopography (loss of microsites). The persistence of these features affects biodiversity, but of particular concern in Canada is the detrimental effects on threatened woodland caribou. Although natural regeneration of trees in peatlands occurs in some places, it is not an effective recovery strategy for restoring the habitat of woodland caribou. This has led to restoration activities with costs exceeding CAD$12 500/km. However, current restoration does not consider wildfires, which can destroy planted trees but also initiate early seral conditions that favor natural regeneration. Here we compared tree regeneration on seismic lines and adjacent forest controls for burnt (75 sites) and unburnt (68 sites) treed peatlands in northeast Alberta, Canada. Tree regeneration (stems with a DBH < 1 cm/ha) varied from 28 500 in burnt lines, 11 440 in unburnt lines, and 18 210 in burnt forest, to 9520 in unburnt forest. Wildfires promoted denser regeneration in sites with a greater proportion of serotinous species and water table depth. Microtopography and terrain wetness explained regeneration on burnt lines, but not unburnt lines. In burnt and unburnt lines, sunlight, microtopography, and depth of water table most affected tree regeneration patterns.

Alucra Orman İşletme Şefliği Içindeki Nüfus Dinamiğinin Arazi Kullanım Değişimlerine Olan Etkisinin Belirlenmesi

Aim of study: This study is done to monitor temporal land use/land cover changes in a typical mountain watershed covering an area of 135441.0 ha in North Eastern of Turkey based on rural demographic dynamics and forest management plans belonging to the years 1987 and 2013 coupled by GIS analyses. It also investigates changes in the shape of land use class (LUC) over the period.Material and Methods: The changes occurring time wise and positional on the base of the local LUC was examined by benefiting from the forest management plans from 1987 to 2013. Moreover, the change of LUC around these areas has been examined with the 1000 m zones thrown around the settlement areas and correlated with the fast decrease of the population recent years. Demographic dynamics (increase or decrease) affect the usage of forest lands, as well.Main results: While there was an increase in the productive forest lands (pure coniferous and deciduous, and mixed forest) between 1987 and 2013. In the same periods there was a decrease in agricultural and sandy areas. The increase of patches in the productive forest lands mostly resulted from afforestation works conducted in the unproductive forest lands, and forestry maintenance activities. Another reason for this increase of forest patches is why people have immigrated to urban areas in the last years.Research Highlights: It can be said that one of the most important causes in the rise of the forest resources in the Alucra Forest Planning Units (FPU) is the time wise changes of social structure. Furthermore, the forestry activities in the study between 1987 and 2013 are also the other significant factor in this increase of forest resources.

Evaluating scenarios of landscape change for Sunda clouded leopard connectivity in a human dominated landscape

The forests of Borneo support some of the highest biodiversity in the world, yet have experienced among the world's highest rates of deforestation. Such rapid forest loss and associated fragmentation reduces the availability of suitable habitat for wildlife and creates dispersion barriers. Understanding the prevalence and impacts of this anthropogenic disturbance, and developing ways in which to mitigate such changes, is thus critical to the conservation of Borneo's wildlife. Here, we applied a path selection function with conditional logistic regression and used it to develop a resistance surface for a population of Sunda clouded leopards (Neofelis diardi) residing within a fragmented and human dominated landscape in Malaysian Borneo. We used cumulative resistant kernel and factorial least-cost path analysis to predict how connectivity may change in response to four future scenarios involving conversion of remaining unproductive forest to palm oil plantations, conversion of unproductive palm oil back to forest, and restoration of a riparian buffer zone along the river, and combination of the two forest restoration scenarios. We showed that Sunda clouded leopard movement is facilitated by forest canopy cover and resisted by non-forest vegetation, particularly recently cleared/planted and underproductive (flooded) plantation areas with low canopy closure. By combining resistant kernel and factorial least-cost path modelling we mapped core areas and the main linkages among them, and identified several key pinch points that may limit regional connectivity of the population. We predict that Sunda clouded leopard connectivity in the region can be greatly enhanced through the protection of privately owned forest patches and the reforestation of underproductive oil palm plantation areas, and creation of a forested buffer zone along the river. Conversely, we show that if the region's unprotected forests were to be converted to plantations then connectivity across the Kinabatangan floodplain would be significantly reduced.

General over-view of forest establishment in Turkey

Turkey has 9.64 million hectares of unproductive forests 43% of the total forest area according, to 2016’ forest inventory. Forest establishment including afforestation, reforestation, rehabilitation and private plantation is the most important method to convert unproductive forest into productive ones, and also to increase present productivity of product forest by improved seed and seedling materials. Turkish forest establishment is examined based on past, present, and future perspectives according to forest inventory from 1946 to 2015 in the present study to contribute present and future establishment.

Monitoring Forest Recovery Following Wildfire and Harvest in Boreal Forests Using Satellite Imagery

In the managed boreal forest, harvesting has become a disturbance as important as fire. To assess whether forest recovery following both types of disturbance is similar, we compared post-disturbance revegetation rates of forests in 22 fire events and 14 harvested agglomerations (harvested areas over 5–10 years in the same vicinity) in the western boreal forest of Quebec. Pre-disturbance conditions were first compared in terms of vegetation cover types and surficial deposit types using an ordination technique. Post-disturbance changes over 30 years in land cover types were characterized by vectors of succession in an ordination. Four post-disturbance stages were identified from the 48 land thematic classes in the Landsat images: “S0” stand initiation phase; “S1” early regeneration phase; “S2” stem exclusion phase; and “S3” the coniferous forest. Analyses suggest that fire occurs in both productive and unproductive forests, which is not the case for harvesting. Revegetation rates (i.e., rapidity with which forest cover is re-established) appeared to be more advanced in harvested agglomerations when compared with entire fire events. However, when considering only the productive forest fraction of each fire, the revegetation rates are comparable between the fire events and the harvested agglomerations. The S0 is practically absent from harvested agglomerations, which is not the case in the fire events. The difference in revegetation rates between the two disturbance types could therefore be attributed mostly to the fact that fire also occurs in unproductive forest, a factor that has to be taken into account in such comparisons.

Nest tree selection by the brahminy kiteHaliastur indusin aRhizophoramangrove forest

Despite the vast range of the brahminy kite Haliastur indus in the Indian subcontinent, Southeast Asia, and Australian regions, the species is little studied. The aim of this study was to evaluate the effect of nine forestry and habitat variables on nest number of a dominant raptor (brahminy kite) at six distance buffers in a Rhizophora mangrove forest. Field observations were made during the breeding season from March to May 2012 within the Matang Mangrove Forest Reserve. The average height of nest trees (19.2 ± 2.2 m) was significantly higher than adjacent trees (8.4 ± 6.8 m) (p < 0.05). On average, active nests were 16.7 ± 4.2 m above the ground, and 1.8 ± 1.1 m below the top of trees. Active nest trees had an average diameter of 21.2 ± 6.4 cm and were located very close to open water (2.7 m ± 4.9 SD). Aggregated nest number at different distance classes had significant correlation with all environmental variables of restricted production and unproductive forests, protective forests, clear-cutting area...

Richness and Density of Birds in Timber Nothofagus pumilio Forests and their Unproductive Associated Environments

Research on forest management impact focuses mainly on timber stands, and leaves out the unproductive forest environments. These stands are spatially mixed with timber forests. The objective was to evaluate richness and density of birds in timber Nothofagus pumilio forests and their unproductive associated environments, and discuss forest management implications. These stands showed significant differences in their forest structure, which generate a great variety of ecological environments. A total of 1881 individuals belonging to 30 bird species were observed during the sampling, in spring and summer seasons. These species were mainly migratory and insectivores, Passeriforms being the most important group. From 12 to 17 birds/ha were found, which varied with the forest environments and seasons. Timber stands of Nothofagus pumilio support a low number of bird species. Most of them are opportunistic and a few prefer these woods over other forested or afforested areas. Low bird density and richness characterize these austral forests, which share their diversity with a high variety of ecosystems along Patagonia. Timber N. pumilio forests has a marginal value for bird species conservation, considering its richness, density and the percentage of this forest in the total forested landscape of Tierra del Fuego (Argentina).

Turkey's Wood Reserves, Potential Trends and Future Perspectives of Wood Use

Wood is the major source of energy in rural Turkey. Forests and wooded land cover 20.2 million hectares (ha) of Turkey's 77 million ha and are 99 percent state owned and managed. As a result of destructive use, productive forests cover only about 6.6 million ha, equivalent to 8.5 percent of land area. The remaining 2.2 million ha consist of degraded unproductive forest cover and 11.3 million ha of wooded land. The total forest potential of Turkey is around 935 million m3 with an annual growth of about 28 million m3. Fuel wood is most likely the most important commodity coming from the forests. Fuel wood is the fourth largest source of energy in Turkey. In Turkey, fuel wood production is 17.6 mtoe, in 1999. Turkey is decreasing its consumption from 5177 Goe to 5512 Goe in 1995.

Whole-catchment liming at Tjønnstrond, Norway: An 11-year record

In June 1983 a whole-catchment liming experiment was conducted at Tjonnstrond, southernmost Norway, to test the utility of terrestrial liming as a technique to restore fish populations in remote lakes with short water-retention times. Tjonnstrond consists of 2 small ponds of 3.0 and 1.5 ha in area which drain a 25-ha catchment. The area is located at about 650–700 meters above sea-level in sparse and unproductive forests of spruce, pine and birch with abundant peatlands. A dose of 3 ton/ha of powdered limestone were spread by helicopter to the terrestrial area. No limestone was added to the ponds themselves. The ponds were subsequently stocked with brown and brook trout.

Carbon and nitrogen cycling in North American boreal forests

A model of boreal forest dynamics was adapted to examine the factors controlling carbon and nitrogen cycling in the boreal forests of interior Alaska. Empirical relationships were used to simulate decomposition and nitrogen availability as a function of either substrate quality, the soil thermal regime, or their interactive effects. Test comparisons included black spruce forests growing on permafrost soils and black spruce, birch, and white spruce forests growing on permafrost-free soils. For each forest, simulated above-ground tree biomass, basal area, density, litterfall, moss biomass, and forest floor mass, turnover, thickness, and nitrogen concentration were compared to observed data. No one decay equation simulated forests entirely consistent with observed data, but over the range of upland forest types in interior Alaska, the equation that combined the effects of litter quality and the soil thermal regime simulated forests that were most consistent with observed data. For black spruce growing on permafrost soils, long-term simulated forest dynamics in the absence of fire resulted in unproductive forests with a thick forest floor and low nitrogen mineralization. Fires were an important means to interrupt this sequence and to restart forest succession.