Knowledge of forest change type and timing is required for forest management, reporting, and science. Time series of historic satellite data (e.g. Landsat) have resulted in an invaluable record of ...changes in forest conditions. Natural resource management and reporting typically operate at an annual time step, yet the recent addition of data streams from compatible satellites (e.g., Sentinel-2) offer the possibility of generating frequent, management-relevant forest status assessments and maps of change. Analytical approaches that rely on a time series of observations to identify change often struggle to provide reliable estimates of change events in terminal years of the time series until subsequent, additional observations are available. Methods to meaningfully integrate observations from compatible satellite platforms can provide short-term information to augment and refine estimates of change area and type in those terminal years of the time series. In this research we fuse Landsat-8 and Sentinel-2A and -2B data streams to capture, with reduced latency, stand replacing forest change (harvest and wildfire), tagged to a temporal window of occurrence over an ~10,000 km2 area of central British Columbia, Canada. We introduce a new algorithm, SLIMS (Shrinking Latency in Multiple Streams), to rapidly and reliably detect change, and then use an established Bayesian approach to meaningfully combine changes detected in the Landsat and Sentinel data streams. Our results indicate that the type and timing of stand-replacing disturbances can be identified in these forests with high accuracy. Overall, 13.9% of the study area was disturbed between the end of 2016 and the end of 2017, with the majority of disturbed area attributable to wildfire and a smaller amount attributed to forest harvesting, mostly in the winter 2016–2017 with some limited summer harvest also occurring. Overall accuracy of the change, assessed using independent validation data, was 95% ± 2.3%. The capacity of these change results to augment a trend-based assessment of change for 2017 was also demonstrated and provides a framework for how short- and long-term change detection approaches provide complementary information that can increase the timeliness and accuracy of change area estimates in the terminal years of a time series. These findings also demonstrate the capacity to regard Landsat and Sentinel-2 sensors as elements of a virtual constellation to obtain forest change information in a timely (i.e., end of growing season) and reliable fashion over large areas.
•We developed a multi-sensor algorithm for rapid-response disturbance detection.•We detected fire and harvest, to the year and season level, with high accuracy.•The SLIMS algorithm is lightweight, effective, and easily understood.•BULC synthesizes information from distinct data streams for detection and typing.
Over the last decade, renewable energy expansion, driven by legislation such as the Renewable Energy Directives passed by the European Union (EU) member states has generated a surge in demand for ...sustainable feedstock alternatives, notably woody biomass in the form of wood pellets. Expansion of woody biomass harvesting in the southeastern United States (US) has raised concerns regarding removal, distribution, and spatial allocation of forest residues following harvesting, and potential ramifications for nutrient depletion, biodiversity, accelerated erosion, and water quality impairment. This study evaluated the current state of knowledge regarding the sustainability of woody biomass and wood pellet feedstock harvesting on the effects of woody residue, soil characteristics, biodiversity, carbon, and water quality. Our survey of existing literature revealed a lack of research evaluating the effects of forest residue removal across the southeastern US. Limited field studies have assessed biomass harvesting in general, and effectively no studies assessed wood pellet feedstock operations specifically. Primary recommendations include completing field studies on wood pellet feedstock harvests in the southeastern US to better understand resource utilization, changes in forest land allocation, and the potential effect on site sustainability. Current management standards such as biomass harvesting guidelines (BHGs) and best management practices (BMPs) appear effective at managing base recommended thresholds in specific regions, but should further evaluate what criteria are necessary, appropriate, and operationally feasible for sustainable biomass production. These studies should be conducted regionally to evaluate potential effects of increased residual removal for wood pellet feedstock as compared to conventional practices.
•Biomass demand can be met, but long-term influence on forest structure is unknown.•Field studies necessary to further characterize the effects of biomass harvests.•Best management practices can maintain water quality on biomass harvests.•Limited data available supporting practices past conventional application.
•Woody debris and key soil properties were modified by forest harvesting with a greater magnitude over the shorter-term.•Even-aged had stronger and longer lasting harvest effects on soil properties ...than uneven-aged management.•Soils originating from clearcutting sites had negative effects on tree seedling growth.•Forest harvesting had detrimental effects on soil fertility and productivity and impacts increased with harvest intensity.
Understanding long-lasting effects of different silvicultural systems on soil properties is critical to sustainable forest management. We determined even-aged (EA, clearcuts) and uneven-aged (UA, partial harvests; 30% by single-tree selection) management effects on soil properties 5, 15 and 30 years after harvesting, relative to unmanaged old-growth forests, in a hardwood forest in southern Quebec, Canada. In total, 198 plots were sampled in 66 randomly selected sites. We measured coarse woody debris (CWD) and examined key soil physico-chemical properties in the forest floor and mineral horizon (0–20 cm). CWD volume strongly decreased in the forest floor of EA managed forests compared to unmanaged forests; no recovery pattern was observed 30 years post-harvest. Following UA management, CWD volume only significantly decreased 5 years after harvesting. Relative to old-growth forests, sites that were subject to forest harvesting were characterized by soils with lower values for key chemical properties that drive soil fertility, including pH, available K, Ca and Mg, and base saturation. Five years after harvesting, both EA and UA managed forests had higher rates of nitrification than unmanaged forests. Overall, EA management had stronger and longer lasting harvest effects on soil chemical properties than forest sites involving UA management. We also assessed, in a greenhouse pot experiment, whether a hypothetical gradient of decreasing soil fertility would affect seedling growth of three tree species (trembling aspen, white birch, yellow birch). Soil originating from EA managed forests with lower soil fertility resulted in lower height growth rates and total dry biomass for the three species, relative to soil from the unmanaged forest (higher soil fertility). Forest harvesting can have major detrimental effects on soil fertility and productivity, over both the short- and long-term, and impacts may increase with harvest intensity.
•Compared sediment yields in the 1960s and after contemporary forest harvesting.•Pre-treatment sediment yields similar in historical and contemporary periods.•No evidence that contemporary harvesting ...affected sediment concentrations or yields.•There was no legacy effect from the historical forest harvesting activity.
Forest harvesting practices can expose mineral soils, decrease infiltration capacities of soils, disturb the stream bank and channel, and increase erosion and fine sediment supply to stream channels. To reduce nonpoint source sediment pollution associated with forest management activities and to maintain the high water quality typically provided from forests, best management practices (BMPs) were developed and implemented. While BMPs have evolved over time, the effectiveness of contemporary BMPs, particularly for harvesting practices, have not been thoroughly investigated, especially in comparison to historical practices. The objectives of this study were to (1) determine the effects of contemporary harvesting practices on suspended sediment concentrations and yields and (2) examine the legacy effects from historical harvesting on suspended sediment concentrations. The Alsea Watershed Study was an important early research site that lead to the development of contemporary forest management practices to protect water quality and fish habitat in Oregon and elsewhere. By returning to the same watersheds that were harvested in 1966, this is one of the few times that a watershed-scale study is able to directly compare and contrast the effects of historical practices with contemporary practices. The Alsea Watershed Study Revisited includes the same three watersheds as the original study. Flynn Creek (FCG, 219 ha) is an old-growth dominated reference watershed. Deer Creek (DCG, 315 ha) is an extensively managed watershed that was patch-cut during the original study. Needle Branch (NBLG, 94 ha) was clearcut harvested in the original study and again in the recent study, but with contemporary BMPs, including riparian buffers. The upper portion of Needle Branch was harvested in 2009 (Phase I), while the lower portion of the watershed was harvested in 2015 (Phase II). We monitored suspended sediments and discharge from WY 2006–2016, and analyzed this data using multiple linear regression procedures and ANCOVA. Average suspended sediment yields ranged from 55–313 Mg km−2 yr−1 in FCG, 31–102 Mg km−2 yr−1 in NBLG, and 69–127 Mg km−2 yr−1 in DCG. We found no evidence that contemporary harvesting techniques affected suspended sediment concentrations or yields. Overall, suspended sediment concentrations and yields after contemporary harvesting were similar to historical pre-treatment levels.
1. Understanding the impact of forest harvesting is critical to sustainable forest management, yet there remains much uncertainty regarding how harvesting affects soil carbon (C), nitrogen (N) and ...phosphorus (P) dynamics. 2. Here, we conducted a global meta-analysis of 808 observations from 49 studies to test the effects of harvesting on the stocks and concentrations of soil C, N and and C:N:P ratios relative to uncut control stands. 3. With all harvesting intensities combined, C stock was unaffected by harvesting in either the forest floor or mineral soil, while harvesting reduced forest floor C, N and P and C:N ratio, increased the mineral soil C and C:N ratio, but reduced mineral soil N stock. The impacts of harvesting on forest floor C and N stocks, C:P and N:P and mineral soil C and N changed from no effects by partial, stem-only and whole-tree harvesting (WTH) to significantly negative effects by the harvesting coupled with fire. Stem-only and WTH similarly reduced forest floor P. The negative effects of harvesting were most pronounced in conifer stands. Soil C, N and C:N decreased with time since harvesting, but soil P did not, resulting in an increase in forest floor N:P. 4. Synthesis and applications. Our findings highlight the importance of harvest intensity and rotation length on long-term soil nutrient availability when managing forests. Furthermore, the lag in the recovery of phosphorus concentration following harvesting may indicate a decoupling of the phosphorus cycle from those of carbon and nitrogen, and a potential concern in managed forests.
Despite the attention currently given to the potential environmental benefits of large-scale forest planting, there is a shortage of clear observational evidence regarding the effects on river flows, ...and what there is has often been contradictory or inconclusive. This paper presents three independently conducted paired-catchment forestry studies covering 66 station-years of flow measurements in the UK and Ireland. In each case coniferous evergreen trees were removed from one catchment with minimal soil disturbance while the adjoining control catchment was left unchanged. Trees were removed from 20% - 90% of the three experimental basins. Following woodland removal there was an increase in dry weather baseflow at all sites. Baseflows increased by about 8% after tree removal from a quarter of the Hore basin and by 41% for the near-total cut at Howan. But the changes were more complex for peak flows. Tree harvesting increased the smallest and most frequent peak storm flows, indicating that afforestation would lead to the suppression of such events. This was however restricted to events well below the mean annual flood, indicating that the impact of forests upon the largest and most damaging floods is likely to be limited. Whilst a forest cover can be effective in mitigating small and frequent stormflows it should never be assumed to provide protection against major flood events.
Display omitted
•Forest harvesting increased dry weather baseflows.•Forest harvesting increased the peak flows of small storm events.•Forest has limited impact on reducing peak flows in extreme large flood events.
This paper is dedicated to study the forest and the impact of its use in the native community of Chamiriari in the province of Satipo, Peru. The adequate forestry use of the forests in the area would ...allow the efficiency in the timber industry and therefore mean an economic improvement, in addition to reducing ecological damages and preserving the cultural wealth of the native Chamiriari people who inhabit the area. That is why the statistical study of how timber resources are exploited in this area of Peru was necessary. For this, plots that serve as a sample were randomly selected to study the trees distribution in Satipo. One drawback found is that due to the number of plots studied and the extension of them it is difficult to count exactly how many trees exist, even on how much land is not planted, that is why the technicians who carried out the data collection were asked to express the data in the form of intervals, where imprecision is included, but the accuracy is preserved. This way of representing the data needs to be processed with the use of Neutrosophic Statistics, which is the extension of the theory of classical statistics to cases where data or parameters are available in interval forms. The results obtained will make it possible to increase the efficiency of timber industry with a minimum of ecological damage and respecting the way of life of the Chamiriari community. It is the first time to the authors' knowledge that a study of this kind has been carried out in the province of Satipo. We concluded that the studied plots which are "non-intervened" or with few of cut out trees, have more variety in tree quality and economical interest in comparison with the "intervened" plots. KEYWORDS: Forest harvesting, floristic composition, Tukey's mean comparison test, statistical inference. MSC: 62P12, 62P30. Este artículo está dedicado a estudiar el bosque y el impacto de su uso en la comunidad nativa de Chamiriari en la provincia de Satipo, Perú. El aprovechamiento forestal adecuado de los bosques de la zona permitiría la eficiencia en la industria maderera y por ende significaría una mejora económica, además de reducir los daños ecológicos y preservar la riqueza cultural del pueblo nativo Chamiriari que habita la zona. Es por ello que se hizo necesario el estudio estadístico de cómo se explotan los recursos madereros en esta zona del Perú. Para ello, se seleccionaron aleatoriamente parcelas que sirvieran de muestra para estudiar la distribución de los árboles en Satipo. Un inconveniente encontrado es que por la cantidad de parcelas estudiadas y la extensión de las mismas es difícil contar con exactitud cuántos árboles existen, incluso en cuánto terreno no se planta, por lo que se consultó a los técnicos que realizaron la toma de datos para expresar los datos en forma de intervalos, donde se incluye la imprecisión, pero se preserva la exactitud. Esta forma de representar los datos necesita ser procesada con el uso de la Estadística Neutrosófica, que es la extensión de la teoría de la estadística clásica a los casos donde los datos o parámetros están disponibles en formas de intervalo. Los resultados obtenidos permitirán aumentar la eficiencia de la industria maderera con un mínimo de daño ecológico y respetando el modo de vida de la comunidad Chamiriari. Es la primera vez, según conocimiento de los autores, que se realiza un estudio de este tipo en la provincia de Satipo. Se concluyó que las parcelas estudiadas "no intervenidas" o con poca tala presentan la mayor variedad en calidad de los árboles y en interés económico en comparación con los espacios "intervenidos". PALABRAS CLAVES: Aprovechamiento forestal, composición florística, prueba de comparación de medias de Tukey, inferencia estadística.
Forestry equipment simulators offer opportunities for new operators to become familiar with operating logging machines as well as a promising solution to the high costs of training forestry equipment ...operators. Current literature lacks a synthesis on how best to train forestry equipment operators using simulators. The goal of this review was to identify effective ways to incorporate forestry equipment simulators into an equipment operator training curriculum. We analyzed a total of 14 independent studies in which construction and forestry equipment operators were trained on simulators and engaged in discussions with nine professionals in the field of heavy equipment operator training. In this review, traditional machine training and simulator training practices are introduced. Then, four key aspects of skill acquisition for forestry equipment operators are identified. Information collected from peer-reviewed literature and discussions with industry experts are used to consider how each aspect of skill acquisition is addressed in both traditional training using real machines and simulator-based training. Drawing on these sources, benefits and drawbacks of traditional machine training and simulator-based training for forestry equipment operators are synthesized and discussed. Finally, a model for an integrated and adaptive training curriculum that incorporates principles and technologies from both traditional machine training and simulator training is presented.
PDF
