545 research outputs found
Instance segmentation of individual tree crowns with YOLOv5: A comparison of approaches using the ForInstance benchmark LiDAR dataset
No full textFine-grained information on the level of individual trees constitute key components for forest observation enabling forest management practices tackling the effects of climate change and the loss of biodiversity in forest ecosystems. Such information on individual tree crowns (ITC's) can be derived from the application of ITC segmentation approaches, which utilize remotely sensed data. However, many ITC segmentation approaches require prior knowledge about forest characteristics, which is difficult to obtain for parameterization. This can be avoided by the adoption of data-driven, automated workflows based on convolutional neural networks (CNN). To contribute to the advancements of efficient ITC segmentation approaches, we present a novel ITC segmentation approach based on the YOLOv5 CNN. We analyzed the performance of this approach on a comprehensive international unmanned aerial laser scanning (UAV-LS) dataset (ForInstance), which covers a wide range of forest types. The ForInstance dataset consists of 4192 individually annotated trees in high-density point clouds with point densities ranging from 498 to 9529 points m-2 collected across 80 sites. The original dataset was split into 70% for training and validation and 30% for model performance assessment (test data). For the best performing model, we observed a F1-score of 0.74 for ITC segmentation and a tree detection rate (DET %) of 64% in the test data. This model outperformed an ITC segmentation approach, which requires prior knowledge about forest characteristics, by 41% and 33% for F1-score and DET %, respectively. Furthermore, we tested the effects of reduced point densities (498, 50 and 10 points per m-2) on ITC segmentation performance. The YOLO model exhibited promising F1-scores of 0.69 and 0.62 even at point densities of 50 and 10 points m-2, respectively, which were between 27% and 34% better than the ITC approach that requires prior knowledge.Furthermore, the areas of ITC segments resulting from the application of the best performing YOLO model were close to the reference areas (RMSE = 3.19 m-2), suggesting that the YOLO-derived ITC segments can be used to derive information on ITC level
Approaches for estimating stand-level volume using terrestrial laser scanning in a single-scan mode
No full textThe most efficient way to obtain stand inventory data with terrestrial laser systems (TLS) is with the single-scan mode, which involves taking one scan at a single point. With a single-scan setup, there will be a nondetection of trees in a plot and the representation of the individual trees will be incomplete. We explore how stand-level volume estimates, based on the single-scan mode, perform compared with standard inventory estimates. We base our study on 166 plots in 12 mature stands dominated by Scots pine (Pinus sylvestris L.) and Norway spruce (Picea abies L. Karst) in southern Norway. First, we compare individual-tree volume estimates from TLS with estimates from volume functions and measurements from harvesters. We show that individual-tree volumes can be estimated with high precision and accuracy with TLS in single-scan mode. Secondly, we test three approaches for correction of nondetection relying on model-based estimates of the detection probability obtained by point transect sampling estimators. We show that all three approaches adjust for nondetection and yield stand-level volume estimates that are similar to those obtained by fixed-area sampling. In conclusion, our results indicate that stand-level volume estimates, based on single-scan mode TLS data, perform well compared with standard inventory estimates.BALABU [192263]; Norwegian Research Counci
Forest Inventories in Nordic Countries
No full textBased on manuscript: Forest inventories in Nordic countries – roadmap for the future
Annika Kangas, Kari T. Korhonen, Mats Nilsson, Håkan Olsson, Jonas Fridman, Johannes Breidenbach, Rasmus Astrup, Thomas Nord-Larsen, Erik Næsset, Terje Gobakken & Matti Maltamo201
Spatio-temporal prediction of soil moisture using soil maps, topographic indices and SMAP retrievals
No full text202
Tireless in His Service: Rasmus Andersen, Pastor and Author 1878-1924
No full textOf the four founders of the Danish Lutheran Church in America in 1872, the one concerning whom the most information exists is Rasmus Andersen. Yet it has been my observation that comparatively little is known about him. A reason for this is that, to my knowledge, no comprehensive biography exists, and there is almost nothing available in the English language. Most of the material that does exist is to be found in the Danes World Wide Archives ( Udvandrerarkivet ) in Aalborg, Denmark. According to Birgit Flemming Larsen, who oversees that archive, the Andersen collection is the largest at the Aalborg archive. It consists of 104 archival boxes, filled with books, letters, diaries, memoirs, ministerial records, copies of letters sent, unpublished manuscripts and much more. The Danes World Wide Archives constitutes a treasure trove for the researcher who is interested in Rasmus Andersen
Stand recovery and self-organization following large-scale mountain pine beetle induced canopy mortality in northern forests
No full textA mountain pine beetle (MPB) epidemic is currently ravaging large areas of interior British Columbia (BC) with significant implications for ecosystem services including future timber supply and community economic stability. Information is needed on future stand dynamics in areas of impacted forests that are unlikely to be salvaged logged. Of greatest concern are stands dominated by lodgepole pine (>50% timber volume). Predicting how surviving trees in these areas respond and grow and the timing and specie composition of natural regeneration ingress is of critical importance for multiple forest values. We undertook a retrospective study in the Flathead Valley of southeastern British Columbia where an intense MPB epidemic peaked in 1979?1980. Our objective was to gain insight into stand recovery and stand selforganization as influenced by species-specific growth responses of different sized secondary structure trees (individual seedling, sapling, sub-canopy and canopy trees surviving the epidemic) and post-beetle regeneration dynamics. MPB mortality rates, the percent of basal area killed by beetles, varied from 42%to 100% with most stands between 60% and 80%. In general, all surviving secondary structure released but the extent of growth release exhibited species variability. Release of surviving canopy lodgepole pine trees was often dramatic and greatest in stands with high total stand MPB mortality rates. Ingress of natural regeneration was slow in the first few years after MPB attack but there was a strong pulse of recruitment 10?20 years post disturbance which then slowed considerably. Nearly 30 years after the MPB attack, the stocking and composition of the understories have changed dramatically. Overall, the occurrence of the MPB epidemic resulted in more structurally and compositionally diverse stands leading to multiple successional pathways different from those of even-age pine dominated stands. The recovery and self-organization of unsalvaged natural stands in the Flathead Valley was a complicated process. It has provided insights for future forest management in areas impacted by the current massive MPB epidemic ongoing for the past decade in western North America.Fil: Amoroso, Mariano Martin. Consejo Nacional de Investigaciones Científicas y Técnicas. Científico Tecnológico Mendoza. Instituto Argentino de Nivologia, Glaciologia y Ciencias. Ambientales; Argentina;Fil: Coates, K. David. Ministry of Forests, Lands and Natural Resource; Canadá; Bulkley Valley Research Centre; Canadá;Fil: Astrup, Rasmus. Bulkley Valley Research Centre; Canadá; Norwegian Institute for Forest and Landscape; Noruega
The influence of climate change, site type, and disturbance on stand dynamics in northwest British Columbia, Canada
No full textStand and disturbance dynamics are key processes that need to be assessed along withclimate-species interactions if we are to better understand the impacts of climate change on species. In this study we investigated the biotic interactions (competition) between species, the influence of disturbance type, and changes in resource availability (moisture and light) on the response of six tree species to climate change in the northwest region of central British Columbia, Canada. Two ecological models were parameterized, linked together and coupled to climate change scenarios to explore the interactions between: (1) the response of species in the regeneration phase and (2) the role of disturbance, resource availability and competition on determining stand composition and productivity. Climate change was found to reduce soil moisture availability which resulted in a decline in regeneration potential for all species on dry sites and negative to neutral responses on sites with higher water availability. Following fire, stand dynamics and composition were modeled to undergo significant changes under the 2080s climate compared to current climate conditions on dry and mesic sites. Changes in stand dynamics under climate change were marginal following bark beetle disturbances. While significant changes to stand dynamics were found on dry sites, the presented results suggest that the sites with the highest moisture availability maintain the same general stand dynamics and composition following disturbances under climate change. This study highlights the need to consider species response to climate change in interaction with existing stand conditions, disturbance type, competition, resource availability, not just temperature and precipitation.Fil: Nitschke, Craig. University of Melbourne; Australia. Bulkley Valley Research Centre; CanadáFil: Amoroso, Mariano Martin. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Provincia de Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Universidad Nacional de Cuyo. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales; Argentina. Bulkley Valley Research Centre; CanadáFil: Coates, David. Ministry of Forests, Lands and Natural Resource Operations; CanadáFil: Astrup, Rasmus. Bulkley Valley Research Centre; Canadá. Norwegian Institute for Forest and Landscape; Norueg
Perehdytysopas Pirkanmaan saneerauspalvelu Oy:lle
No full textTämän opinnäytetyön tarkoituksena on perehdytysopas toimeksiantajayritys
Pirkanmaan saneerauspalvelu Oy:n uusille työntekijöille. Yrityksellä ei ole aiemmin ollut perehdytysopasta työntekijöilleen, vaan uusien työntekijöiden perehdytys on toteutunut kokeneempien työntekijöiden toimesta työmailla. Lisäksi perehdytyksen yhteydessä yrityksen hallilla on pidetty perehdytyskierros, jolloin työnjohto on näyttänyt eri materiaalien sijainnit, kertonut lyhyesti yleisiä asioita yrityksestä ja työntekijän työtehtävistä.
Tämän opinnäytetyön tavoitteena on, että jatkossa uusien työntekijöiden töiden aloittaminen on helpompaa sekä selkeämpää. Lisäksi tavoitteena on myös vähentää työnjohdon sekä kokeneempien työntekijöiden kuormitusta uusien työntekijöiden perehdyttämisessä.
Opinnäytetyössä perehdyttämisen lisäksi työssä käsitellään rakennusalan työturvallisuutta, työsuoritteita ja niissä käytettäviä materiaaleja. Työssä tarkastellaan myös työkoneiden ja- välineiden turvallista käyttöä, Easoft-toiminnanohjausjärjestelmää sekä laadunvarmistukseen liittyviä asioita. Lopuksi pohditaan mahdollisia jatkotoimenpiteitä. Tämän perehdytysoppaan tekemiseen on kerätty tietoa kirjallisista lähteistä, haastateltu pitkään yrityksessä olleita ammattilaisia sekä tämän opinnäytetyön tekijän kokemuksia rakennusalalta.
Tulevaisuudessa perehdytysopas on tarkoitus jakaa uusille työntekijöille (työsopimusta kirjoittaessa) sekä uusille vuokratyöntekijöille. Uusien työntekijöiden sekä vuokratyöntekijöiden tulee tutustua perehdytysoppaaseen ennen varsinaisten töiden aloitusta.
Perehdytysopasta voidaan tulevaisuudessa muokata työnjohdon toimesta työntekijöiltä kerätyn palautteen perusteella. Lisäksi opasta muokataan, mikäli yrityksen toimintatavat ja työsuoritteet muuttuvat.The purpose of this thesis is an orientation guide for the new employees of the employer company Pirkanmaan Saneerauspalvelu Ltd. The company has not previously had an orientation guide for its employees, so the orientation of new employees has been implemented by more experienced workers in the workplace. In addition, during the orientation an induction tour has been held in the hall, where the supervisors have shown the locations of different materials, briefly told general things about the company and which tasks belong to whom. The objective of this thesis is to make it easier and clearer for the new employees to start working. In addition, the aim is to reduce the burden on supervisors as well as more experienced employees when orienting a new employee.
In addition to orientation, this thesis deals with construction occupational safety, work processes and the materials used. The work also examines the safe use of machines and equipment used to work, ERP system called Easoft and issues regarding quality assurance. In the end potential follow-ups are pondered. To create this orientation guide information was collected from various written sources. In addition, professionals working in the company has been interviewed and the own experiences of the author of this thesis on the construction industry has been collected.
In the future, the orientation guide will be distributed to new employees when writing an employment contract and also for new agency workers. The new employees as well as the agency workers should read the orientation guide before starting the actual work.
In the future, the orientation guide can be modified by the management based on feedback from employees. In addition, the guide will be modified according to the changes of the company's policies and processes
- …
