Single-tree detection in high-density LiDAR data from UAV-based survey

UAV-based LiDAR survey provides very-high-density point clouds, which involve very rich information about forest detailed structure, allowing for detection of individual trees, as well as demanding high computational load. Single-tree detection is of great interest for forest management and ecology purposes, and the task is relatively well solved for forests made of single or largely dominant species, and trees having a very evident pointed shape in the upper part of the canopy (in particular conifers). Most authors proposed methods based totally or partially on search of local maxima in the canopy, which has poor performance for species that have flat or irregular upper canopy, and for mixed forests, especially where taller trees hide smaller ones. Such considerations apply in particular to Mediterranean hardwood forests. In such context, it is imperative to use the whole volume of the point cloud, however keeping computational load tractable. The authors propose the use of a methodology based on modelling the 3D-shape of the tree, which improves performance w.r.t to maxima-based models. A case study, performed on a hazel grove, is provided to document performance improvement on a relatively simple, but significant, case

Hazard-rating assessment of roadside trees at UPM using geospatial tool.

Roadside trees provide benefits in the form of green landscape, human health, storm-water management, carbon storage and etc. However, they are potentially hazardous to their surroundings. Hence, there is a need to evaluate these trees as to whether they are hazardous or not. Hazard-rating assessment in the context of urban trees is the evaluation of the hazard of trees and how likely they are to fail as well as how severe in terms of damage that they could cause to their surroundings. In this study, roadside trees hazard rating was assessed automatically using a customised ArcMap TM application using Visual Basic for Applications (VBA), known as UPM-Malaysian Urban Trees Information System (UPM-MUTIS), developed by Faculty of Forestry, UPM. The study is to determine the capabilities of UPM-MUTIS in generating hazard-rating assessment. The study area covered part of UPM’s academic zone. Result depicted that out of 909 trees assessed, 99.8% (907 trees) were categorised as ‘Medium’ hazard rating and no trees with ‘Low’, ‘High’, and ‘Severe’ hazard rating. Upon deriving hazard-rating assessment, abatement activities were subsequently proposed in which was mainly various degrees and types of pruning. This paper details out the hazard-rating assessment process of roadside trees and the succeeding abatement activities proposed at the study site

Pine Pitch Canker and Insects: Regional Risks, Environmental Regulation, and Practical Management Options

Producción CientíficaPine pitch canker (PPC), caused by the pathogenic fungus Fusarium circinatum (Nirenberg and O’ Donnell), is a serious threat to pine forests globally. The recent introduction of the pathogen to Southern Europe and its spread in Mediterranean region is alarming considering the immense ecological and economic importance of pines in the region. Pines in forests and nurseries can be infected, resulting in severe growth losses and mortality. The pathogen is known to spread in plants for planting and in seeds, and results from recent studies have indicated that F. circinatum may also spread through phoretic associations with certain insects. With this review, we aim to expand the current understanding of the risk of insect-mediated spread of PPC in different parts of Europe. Through the joint action of a multinational researcher team, we collate the existing information about the insect species spectrum in different biogeographic conditions and scrutinize the potential of these insects to transmit F. circinatum spores in forests and nurseries. We also discuss the impact of environmental factors and forest management in this context. We present evidence for the existence of a high diversity of insects with potential to weaken pines and disseminate PPC in Europe, including several common beetle species. In many parts of Europe, temperatures are projected to rise, which may promote the activity of several insect species, supporting multivoltinism and thus, further amplifying the risk of insect-mediated dissemination of PPC. Integrated pest management (IPM) solutions that comply with forest management practices need to be developed to reduce this risk. We recommend careful monitoring of insect populations as the basis for successful IPM. Improved understanding of environmental control of the interaction between insects, the pathogen, and host trees is needed in order to support development of bio-rational strategies to safeguard European pine trees and forests against F. circinatum in future.European Cooperation in Science and Technology (COST Action FP1406 PINESTRENGTH)Ministerio de Economía, Industria y Competitividad - Fondo Europeo de Desarrollo Regional (project AGL2015-69370-R)Portuguese Foundation for Science and Technology (contract IF/00471/2013/CP1203/CT0001)Russian Foundation for Basic Research (grant 17-04-01486)Saint Petersburg State Polytechnical University (project 2019-0420

Effects of diameter distribution errors on stand management decisions according to a simulated individual tree detection

Key Message Tree-level forest inventory data are becoming increasingly available, which motivates the use of these data for decision-making. However, airborne inventories carried out tree-by-tree typically include systematic errors, which can propagate to objective function variables used to determine optimal forest management. Effects of under-detection focused on the smallest trees on predicted immediate harvest profits and future expectation values were assessed assuming different sites and interest rates. Management decisions based on the erroneous information caused losses of 0-17% of the total immediate and future expected income of Scots pine stands. Context Optimal decisions on how to manage forest stands can depend on the absence or presence of intermediate and understory trees. Yet, these tree strata are likely prone to inventory errors. Aims The aim of this study is to examine implications of making stand management decisions based on data that include systematic errors resembling those typically observed in airborne inventories carried out tree-by-tree. Methods Stand management instructions were developed based on theoretical diameter distribution functions simulated to have different shape, scale, and frequency parameters corresponding to various degrees of under-detection focused on the smallest trees. Immediate harvest income and future expectation value were derived based on various management alternatives simulated. Results Errors in diameter distributions affected the predicted harvest profits and future expectation values differently between the simulated alternatives and depending on site type and interest rate assumptions. As a result, different alternatives were considered as optimal management compared to the use of the error-free reference distributions. In particular, the use of no management or most intensive management alternatives became preferred over alternatives with intermediate harvesting intensities. Certain harvesting types such as thinning from below became preferred more often than what was optimal. The errors did not affect the selection of the management alternative in 71% of the simulations, whereas in the remaining proportion, relying on the erroneous information would have caused losing 2%, on average, and 17% at maximum, of the total immediate and future expected income. Conclusion The effects above might not have been discovered, if the results were validated for inventory totals instead of separately considering the immediate and future income and losses produced by the erroneous decisions. It is recommended not to separate but to integrate the inventory and planning systems for well-informed decisions.Peer reviewe

Historical land-use information from culturally modified trees

In a global perspective, the human impact on forest ecosystems varies greatly in type, frequency and magnitude. Knowledge of the history of forest use is crucial for understanding the development of forests, which in turn helps to understand how societies react to forest development. Culturally modified trees (CMTs), recorded in the western U.S., northern Scandinavia and south-eastern Australia, are features that can be dated precisely, and they bear witness to unique events of human activity. CMTs are traces from historical uses of forest resources that reflect the activities of local communities and extend far back in time, and therefore offer information not usually available from other sources. In this thesis I argue that CMTs have high potential for assessing human activity and possibly human impacts on forest ecosystems, particularly those concerning local indigenous uses. Periods of increased activity in a certain area are reflected in peaks in the distribution of CMT dates. These also show the time period and speed of abandonment of a traditional forest use in a landscape. The possibility to learn about the people, their behaviour and activities in the forest are good, but their impact on ecosystems will always be difficult to assess when only CMT data are available. Therefore, it is important to learn as much as possible about traditional customs expressed in CMTs, in combination with oral and ethnological sources, and the role of CMTs in the traditional use of the forest. In this way it is possible to estimate what the density and distribution of CMTs in the landscape actually tells us about historical impact on the ecosystem. CMTs contradict the idea of “pristine” forests but symbolize the traditional view that people are part of nature rather than separate from it

Mapping and assessment of ecosystems and their services. Urban ecosystems

Action 5 of the EU Biodiversity Strategy to 2020 requires member states to Map and Assess the state of Ecosystems and their Services (MAES). This report provides guidance for mapping and assessment of urban ecosystems. The MAES urban pilot is a collaboration between the European Commission, the European Environment Agency, volunteering Member States and cities, and stakeholders. Its ultimate goal is to deliver a knowledge base for policy and management of urban ecosystems by analysing urban green infrastructure, condition of urban ecosystems and ecosystem services. This report presents guidance for mapping urban ecosystems and includes an indicator framework to assess the condition of urban ecosystems and urban ecosystem services. The scientific framework of mapping and assessment is designed to support in particular urban planning policy and policy on green infrastructure at urban, metropolitan and regional scales. The results are based on the following different sources of information: a literature survey of 54 scientific articles, an online-survey (on urban ecosystems, related policies and planning instruments and with participation of 42 cities), ten case studies (Portugal: Cascais, Oeiras, Lisbon; Italy: Padua, Trento, Rome; The Netherlands: Utrecht; Poland: Poznań; Spain: Barcelona; Norway: Oslo), and a two-day expert workshop. The case studies constituted the core of the MAES urban pilot. They provided real examples and applications of how mapping and assessment can be organized to support policy; on top, they provided the necessary expertise to select a set of final indicators for condition and ecosystem services. Urban ecosystems or cities are defined here as socio-ecological systems which are composed of green infrastructure and built infrastructure. Urban green infrastructure (GI) is understood in this report as the multi-functional network of urban green spaces situated within the boundary of the urban ecosystem. Urban green spaces are the structural components of urban GI. This study has shown that there is a large scope for urban ecosystem assessments. Firstly, urban policies increasingly use urban green infrastructure and nature-based solutions in their planning process. Secondly, an increasing amount of data at multiple spatial scales is becoming available to support these policies, to provide a baseline, and to compare or benchmark cities with respect to the extent and management of the urban ecosystem. Concrete examples are given on how to delineate urban ecosystems, how to choose an appropriate spatial scale, and how to map urban ecosystems based on a combination of national or European datasets (including Urban Atlas) and locally collected information (e.g., location of trees). Also examples of typologies for urban green spaces are presented. This report presents an indicator framework which is composed of indicators to assess for urban ecosystem condition and for urban ecosystem services. These are the result of a rigorous selection process and ensure consistent mapping and assessment across Europe. The MAES urban pilot will continue with work on the interface between research and policy. The framework presented in this report needs to be tested and validated across Europe, e.g. on its applicability at city scale, on how far the methodology for measuring ecosystem condition and ecosystem service delivery in urban areas can be used to assess urban green infrastructure and nature-based solutions

The visual preferences for forest regeneration and field afforestation : four case studies in Finland

The overall aim of this dissertation was to study the public's preferences for forest regeneration fellings and field afforestations, as well as to find out the relations of these preferences to landscape management instructions, to ecological healthiness, and to the contemporary theories for predicting landscape preferences. This dissertation includes four case studies in Finland, each based on the visualization of management options and surveys. Guidelines for improving the visual quality of forest regeneration and field afforestation are given based on the case studies. The results show that forest regeneration can be connected to positive images and memories when the regeneration area is small and some time has passed since the felling. Preferences may not depend only on the management alternative itself but also on the viewing distance, viewing point, and the scene in which the management options are implemented. The current Finnish forest landscape management guidelines as well as the ecological healthiness of the studied options are to a large extent compatible with the public's preferences. However, there are some discrepancies. For example, the landscape management instructions as well as ecological hypotheses suggest that the retention trees need to be left in groups, whereas people usually prefer individually located retention trees to those trees in groups. Information and psycho-evolutionary theories provide some possible explanations for people's preferences for forest regeneration and field afforestation, but the results cannot be consistently explained by these theories. The preferences of the different stakeholder groups were very similar. However, the preference ratings of the groups that make their living from forest - forest owners and forest professionals - slightly differed from those of the others. These results provide support for the assumptions that preferences are largely consistent at least within one nation, but that knowledge and a reference group may also influence preferences.Väitöskirjassa tutkittiin ihmisten maisemapreferenssejä (maisemallisia arvostuksia) metsänuudistamishakkuiden ja pellonmetsitysten suhteen sekä analysoitiin näiden preferenssien yhteyksiä maisemanhoito-ohjeisiin, vaihtoehtojen ekologiseen terveyteen ja preferenssejä ennustaviin teorioihin. Väitöskirja sisältää neljä tapaustutkimusta, jotka perustuvat hoitovaihtoehtojen visualisointiin ja kyselytutkimuksiin. Tapaustutkimusten pohjalta annetaan ohjeita siitä, kuinka uudistushakkuiden ja pellonmetsitysten visuaalista laatua voidaan parantaa. Väitöskirjan tulokset osoittavat, että uudistamishakkuut voivat herättää myös myönteisiä mielikuvia ja muistoja, jos uudistusala on pieni ja hakkuun välittömät jäljet ovat jo peittyneet. Preferensseihin vaikuttaa hoitovaihtoehdon lisäksi mm. katseluetäisyys, katselupiste ja ympäristö, jossa vaihtoehto on toteutettu. Eri viiteryhmien (metsäammattilaiset, pääkaupunkiseudun asukkaat, ympäristönsuojelijat, tutkimusalueiden matkailijat, paikalliset asukkaat sekä metsänomistajat) maisemapreferenssit olivat hyvin samankaltaisia. Kuitenkin ne ryhmät, jotka saavat ainakin osan elannostaan metsästä - metsänomistajat ja metsäammattilaiset - pitivät metsänhakkuita esittävistä kuvista hieman enemmän kuin muut ryhmät. Nämä tulokset tukevat oletusta, että maisemapreferenssit ovat laajalti yhteneväisiä ainakin yhden kansan tai kulttuurin keskuudessa, vaikka myös viiteryhmä saattaa vaikuttaa preferensseihin jonkin verran. Nykyiset metsämaisemanhoito-ohjeet ovat pitkälti samankaltaisia tässä väitöskirjassa havaittujen maisemapreferenssien kanssa. Myöskään tutkittujen vaihtoehtoisten hoitotapojen ekologisen paremmuuden ja niihin kohdistuvien maisemallisten arvostusten välillä ei ollut suurta ristiriitaa. Kuitenkin joitakin eroavaisuuksia oli; esimerkiksi sekä maisemanhoito-ohjeiden että ekologisten hypoteesien mukaan säästöpuut tulisi jättää ryhmiin, kun taas ihmiset pitivät eniten yksittäin jätetyistä puista. Informaatiomalli ja psyko-evolutionaarinen teoria tarjoavat mahdollisia selityksiä uudistushakkuisiin ja pellonmetsitykseen kohdistuville preferensseille, vaikkakaan tutkimuksen tuloksia ei voida täysin selittää näillä teorioilla

Tree collections of Auckland : biodiversity and management : a thesis presented in partial fulfilment of the requirements for the degree of Master of Applied Science in Landscape Management at Massey University, Palmerston North, New Zealand

Appendix 1: Personal Communications Contact List. Page 182 has been removed. Please consult the print copy held in the Library.Recent developments in New Zealand environmental legislation and government policies are based on an economic world-view where landscape is portrayed as a 'natural' resource. This paradigm largely ignores the human-made urban landscape where the highest proportion of population live. Our national legislation pays little attention to urban vegetation in general and exotic tree collections in particular. Research therefore has a vital role in highlighting the character and values of urban vegetation, and in analysing the current models used to manage its continued existence. This study examines the importance of charting and managing biodiversity and focuses on managed amenity and scientific tree collections in the Auckland region. This regional study seeks to characterise the biodiversity of tree collections in Auckland, and describe how landscape management can best contribute to their biological and human-use values. The literature review establishes the importance and values of trees and urban vegetation as critical to the fabric of human lifestyles and the ecology of the city. It then reviews the basis for the preservation of biodiversity in managed plant collections. Management principles and systems are reviewed along with the legislative context in Auckland. No mandate is established for exotic plant collection managment under the Resource Management Act, 1991 (RMA1991). Management of this resource is found to lack the focus and funding from which natural and rural biodiversity benefit under the RMA and other national legislation. A biodiversity survey of thirty-eight collections of trees characterises the biodiversity in the collections, and a survey of twelve tree collection managers provides data about the goals, practices and tools used in the management of those collections. Results reveal the diverse and unique flora of Auckland tree collections, and establish a baseline for comparison over time. The regional mix of native and exotic species found in Auckland collections is compared with other national plant surveys, and demonstrates differences consistent with regional climatic character and a differing research focus. The largest collection of trees and the most specialist genera collections were found at the Auckland Regional Botanic Garden, while the university of Auckland provides the most extensive range of scientific plant-collection facilities. There is evidence of sequential open space acquisition for tree collections in the Auckland region. Comparison of best management practices put forward in current literature with current practices of collection managers in Auckland reveals some significant issues. There is little evidence found to suggest strategic plant acquisition goal setting. It is also of concern that only half the collection managers used computerised plant record systems such as inventories and specialised database systems. Only one third of the managers had management plans, and therefore documented collection goals. There was no significant difference in the use of best management practices between the private and publicly owned collections. Well-managed collections are characterised by high or specialist tree species diversity, clear strategic goal setting and management planning, computerised plant record systems, adequate resources, appropriate staffing and the use of monitoring tools. Discussion of these research results leads to three recommendations. Firstly, the management of specific sites is discussed in light of a proposed model for plant collection management. Secondly, management policy for the regional urban Forest is recommended. Lastly, the finding that Auckland's exotic tree collections are a valuable resource worthy of protection, currently having little status under the law, leads to the recommendation for the empowering of a national body (central agency) with a mandate for the national coordination of botanic gardens and plant collections. This research therefore charts aspects of Auckland's urban biodiversity with reference to current legislation and management models. Its findings and recommendations are of importance to reviewers of national environmental legislation, regional policymakers and tree collection managers

Agroforest diversity and ethnobotanical aspects in two villages of Berau, East Kalimantan, Indonesia

Hartoyo APP, Supriyanto, Siregar IZ, Theilade I, Prasetyo LB. 2018. Agroforest diversity and ethnobotanical aspects in two villages of Berau, East Kalimantan, Indonesia. Biodiversitas 19: 387-398. REDD+ aims to reduce emissions from deforestation and forest degradation, conservation, enhancement of forest carbon stocks, and sustainable forest management (SFM). An assessment of agroforest is important for REDD+ implementation in Indonesia. In this context, evaluation of the existing agroforests and their uses is an important issue. The objectives of this research were to characterize agroforest diversity with respect to habitat, regulation, production and information functions in Kampung Birang and Kampung Merabu, Berau, East Kalimantan. This research focused on two size classes of trees, namely medium trees (10?dbh?20 cm) and large trees (dbh>20 cm). Local community members were trained in plot establishment (60 plots, 50x50 m), tree diameter measurement, trees tagging, and herbarium collection. Local community members identified tree species by local names and listed the species uses. Results showed that agroforests as habitat obtained diversity indices (H’) of moderate category for Kampung Birang and high category for Kampung Merabu. Otherwise, Margalef’s index (Dmg) for the medium and large tree classes in Kampung Birang and Kampung Merabu were classified as high species richness category. This finding implies that enrichment planting using high economic value species is still necessary in Kampung Birang. Kampung Merabu was found to be more diverse than Kampung Birang, although soil quality in Kampung Birang was better than that in Kampung Merabu. Disturbances due to human activities that potentially impact agroforest stability were also pre-identified. The top ten tree species were classified based on importance value index (IVI) across both villages consisting of 80% shade intolerant and 20% semi-tolerant species. Agroforest showing production and information function as produces various edible fruits that are considered as key component for maintaining biodiversity sustainability and ecosystem functioning