Open field-applicable instrumental methods for structural and functional assessment of whole trees and stands

Abstract

© iForest -Biogeosciences and Forestry Introduction 1Proper management of forest ecosystems from a biological perspective is dependent on classification of the natural environment for the purposes of phytotechnology (e.g., thinning operations) and forestry management. Functional management goals may include timber production as well as other important functions of forests in the landscape, such as water sources for people, but also for control of climate, maintenance of biological diversity, recreation, etc. for which importance often increases with time. Such functions have been working automatically in the past, but serious environmental impacts on forests associated with anthropogenic activities (e.g., air pollution, soil acidification) and global climatic change became apparent at the end of the 20 th century.Therefore long-term experience of foresters should be supplemented with additional objective information, which may be used to help solve new problems. This includes application of modern electronics, computers and other technologies, as well as collection of necessary data in the field especially pertaining to ecophysiology. This review provides only a brief description of methods suitable for studies at the whole tree and stand levels (and even higher levels). The methods are applicable under open forest conditions using mobile instrumentation approaches that can be used almost everywhere. They were tested in more than 60 sites and in over 50 woody species in Europe, USA and Australia. We focused on measurement and evaluation of macrostructure and water flow, because the maximum energy flow in ecosystems goes through water and water is the most frequent natural limiting factor of tree growth and functional states of whole trees and stands (if not considering polar regions and tops of high mountains). Ecologically oriented scientific fields and practically oriented field activities in forestry, arboristics, horticulture, hydrology, remote sensing and forensic engineering use many traditional and modern methods.Annual and seasonal stem growth are probably the most frequently studied processes in forestry. Usually institutions for forest management (IFM) base their practices on this valuable data on a large scale (e.g., national), which provide crucial information about timber production and yield. A great body of literature is available on this topic. However, strategy for the management of forest ecosystems in Europe elaborated over several centuries is focused on classification of the natural environment and determining potential natural vegetation and oriented not only toward production but also on preserving other important functions of forests in the landscape. A detailed version of this approach was successfully applied for over 80 years. The eventual impact of anthropogenic activities and global climatic changes led to development of ecophysiological methods applied to evaluate the functional state and development of forest ecosystems.These methods were usually overlooked in the past because prev...

Growing season water balance of an inner alpine Scots pine (Pinus sylvestris L.) forest

“…, drought) as it was the case at our study site. Moreover, there is also evidence that when using 2 or 6 sample trees, the scaling error for estimates of Q s-mean is usually less than 12 and 7%, respectively (Cermak et al 2015).…”

A Novel Approach to Evaluate the Effect of Neighboring Trees and the Orientation of Tree Social Area on Stem Radial Increment of Norway Spruce Trees

“…Social area is an aspect of stand area associated with a sample tree that accounts for its size and the size of neighboring trees as well as the available surrounding space [38,39]. Thus, each tree has its own growing area shaped by the trees surrounding it [52].…”

“…On the other hand, as a parameter that uses the dimension and distance between neighbors to express competition, AS is a good tool for explaining current tree radial increment. In addition, calculating AS for a sample tree, according toČermák et al [38,39], presumes that basal area at breast height is the best variable for tree size expression and for weighting distances between trees in a mutual tree competition evaluation. The weighted distances were solved by Krejza et al [42] and Pelz [57] and their results confirmed our finding that basal area is the best criterion to express tree dimension in competitive environment observations.…”

“…As used here, the term social area (AS) can be commonly characterized as the area where a particular tree realizes its growth and supplies its growth demands [38,39]. The shape and orientation of AS result from the competitive strength of neighboring trees; thus, using tree AS allows researchers to estimate the apparent competitive environment surrounding a tree.…”

Estimation of Alpine Forest Structural Variables from Imaging Spectrometer Data

“…Structural attributes are crucial to determine information facilitating the management of forest ecosystems [2,3], to modify silvicultural practices [4,5], to quantify deforestation impacts on the carbon cycle and related impacts for global warming [6], and to assess productivity of forested areas in relation to forest composition [7] as well as in view of specific forest management practices [4,5]. Further, accurate estimates of structural variables are practical indicators for determining forest evolutionary history [8], monitoring forest sustainability [9], assessing insect infestation susceptibility [10,11], studying wildlife management and biodiversity [12], as well as forest water flux modeling [13]. Accordingly, there is an increasing need to generate accurate information regarding forest structural dynamics [14].…”