An assessment of hydrological functions of forest ecosystems to support sustainable forest management

We used geographical information system to analyze changes in forest ecosystem functions, structure and composition in a typical department of forest management area consisting of four forest management planning units in Turkey. To assess these effects over a 25 year period we compiled data from three forest management plans that were made in 1986, 2001 and 2011. Temporal changes in forest ecosystem functions were estimated based on the three pillars of forest sustainability: economics, ecology and socio-culture. We assessed a few indicators such as land-use and forest cover, forest types, tree species, development stage, stand age classes, crown closure, growing stock and its increment, and timber biomass. The results of the case study suggested a shift in forest values away from economic values toward ecological and socio-cultural values over last two planning periods. Forest ecosystem structure improved, due mainly to increasing forest area, decreasing non-forest areas (especially in settlement and agricultural areas), forestation on forest openings, rehabilitation of degraded forests, conversion of even-aged forests to uneven-aged forests and conversion of coppice forests to high forests with greater growing stock increments. There were also favorable changes in forest management planning approaches.

Wild ungulates as forest engineers

The development of appropriate ecological criteria and indicators for community forest conservation using participatory methods: A case study in northeastern Thailand

Drivers of global climate change and the increased frequency of extreme climate events may affect urban and periurban forest ecosystems more rapidly than natural forest ecosystems. Multi stressors of urban forest ecosystems include alterations in forest soils and to the diversity and composition of forest ecosystem, as well as higher temperatures during heat waves periods and increasing carbon dioxide content due to high traffic issue. Global conservation targets and management practices of urban forest ecosystems in Romania requires adequate novel monitoring methodology for monitoring the dynamics changing status. Ground-based measurements are valuable tools with limited spatial footprints. Multispectral and multitemporal satellite remote sensing data allow detailed information on forest structure and can deliver ecologically relevant, long-term datasets suitable of vegetation phenology for analyzing changes in periurban and urban forest ecosystem areas, structure and function at temporal and spatial scales relevant to forest dynamics monitoring. The aim of this paper was to evaluate and characterize forest changes for selected test area Cernica –Branesti in Ilfov county located in the Eastern part of Bucharest metropolitan region, Romania, where the climate and anthropogenic stressors endanger natural and economical values of forest environment. Based on time-series Landsat 5 TM, 7 ETM+, 8 OLI/TIRS, MODIS Terra/Aqua and Sentinel 2A satellite data have been investigated urban forest land cover and forest biophysical parameters (LST, NDVI/EVI and LAI) changes over 2000-2016 period of time. Accuracy of image processing results (spectral classification) was confirmed through in-situ spectroradiometrical analysis of reflectance spectra with portable GER 2600 spectroradiometer.

Natural disturbances like wildfire, windthrow and insect outbreaks are critical drivers of composition, structure and functioning of forest ecosystems. They are strongly climate‐sensitive, and are thus likely to be distinctly affected by climatic changes. Observations across Europe show that in recent decades, forest disturbance regimes have intensified markedly, resulting in a strong increase in damage from wind, bark beetles and wildfires. Climate change is frequently hypothesized as the main driving force behind this intensification, but changes in forest structure and composition associated with management activities such as promoting conifers and increasing standing timber volume (i.e. ‘forest change’) also strongly influence susceptibility to disturbances. Here, we show that from 1958 to 2001, forest change contributed in the same order of magnitude as climate change to the increase in disturbance damage in Europe's forests. Climate change was the main driver of the increase in area burnt, while changes in forest extent, structure and composition particularly affected the variation in wind and bark beetle damage. For all three disturbance agents, damage was most severe when conducive weather conditions and increased forest susceptibility coincided. We conclude that a continuing trend towards more disturbance‐prone conditions is likely for large parts of Europe's forests, and can have strong detrimental effects on forest carbon storage and other ecosystem services. Understanding the interacting drivers of natural disturbance regimes is thus a prerequisite for climate change mitigation and adaptation in forest ecosystem management.

Alongside global warming, droughts are expected to increase in frequency, severity, and extent in the near future, which will likely result in significant impacts on forest growth, production, structure, composition, and ecosystem services. However, due to spatial and temporal characteristics, it is difficult to monitor and assess the potential effects of droughts. Remote sensing can provide an effective way to obtain real-time conditions of forests affected by drought and offer a range of spatial and temporal insights into drought-induced changes to forest ecosystem structure, function, and services. Remote sensing is rapidly developing as more satellites are launched. In situ and remotely sensed data fusion techniques have achieved notable success in assessing drought-induced damage to forests and carbon cycles. Even so, constraints still exist when using satellite data. The objectives of this review are to (1) briefly review existing data sources and methods of remote sensing; (2) synthesize current applications and contributions of remote sensing in monitoring and estimating impacts of droughts on forest ecosystems; and (3) highlight research gaps and future challenges.

Abstract. Terrestrial biosphere models (TBMs) are invaluable tools for studying plant–atmosphere interactions at multiple spatial and temporal scales, as well as how global change impacts ecosystems. Yet, TBM projections suffer from large uncertainties that limit their usefulness. Forest structure drives a significant part of TBM uncertainty as it regulates key processes such as the transfer of carbon, energy, and water between the land and the atmosphere, but it remains challenging to observe and reliably represent. The poor representation of forest structure in TBMs might actually result in simulations that reproduce observed land fluxes but fail to capture carbon pools, forest composition, and demography. Recent advances in terrestrial laser scanning (TLS) offer new opportunities to capture the three-dimensional structure of the ecosystem and to transfer this information to TBMs in order to increase their accuracy. In this study, we quantified the impacts of prescribing initial conditions (tree size distribution), constraining key model parameters with observations, as well as imposing structural observations of individual trees (namely tree height, leaf area, woody biomass, and crown area) derived from TLS on the state-of-the-art Ecosystem Demography model (ED2.2) of a temperate forest site (Wytham Woods, UK). We assessed the relative contributions of initial conditions, model structure, and parameters to the overall output uncertainty by running ensemble simulations with multiple model configurations. We show that forest demography and ecosystem functions as modelled by ED2.2 are sensitive to the imposed initial state, the model parameters, and the choice of key model processes. In particular, we show that: Parameter uncertainty drove the overall model uncertainty, with a mean contribution of 63 % to the overall variance of simulated gross primary production. Model uncertainty in the gross primary production was reduced fourfold when both TLS and trait data were integrated into the model configuration. Land fluxes and ecosystem composition could be simultaneously and accurately simulated with physically realistic parameters when appropriate constraints were applied to critical parameters and processes. We conclude that integrating TLS data can inform TBMs of the most adequate model structure, constrain critical parameters, and prescribe representative initial conditions. Our study also confirms the need for simultaneous observations of plant traits, structure, and state variables if we seek to improve the robustness of TBMs and reduce their overall uncertainties.

Climate change is one of the world's greatest challenges. which creates effects on our forest ecosystem. Sensitivity of forest ecosystem and climate significance affects the growth rate and structure of the forest, and it also have a direct impact on species composition, growth of tress, their mortality and reproduction of trees is also affected by climate change. Increase and decrease in temperature leads to change in time phenology due to which earlier burst of bud, leafing and flowering in trees is affected, this review is all about how climate change affects forest ecosystem. All direct and indirect alterations and shifts in the ecosystems are affected by change in climate. Direct alterations involve temperature changes, precipitation, sea level etc whereas Indirect alteration involves habitat loss and fragmentation, disruption of carbon and nitrogen cycles etc. Examples: Mountain pine beetle (Dendroctonus ponderosae) in north America warmer temperature have extended the breeding season of the mountain pine beetle, Artic species (e.g., Polar bear and walruses). Rise in temperature will affect respiration process due to which photosynthesis rate will also change. Disturbance in climate change. Affects carbon cycle, forest structure, composition of species and alteration in forest ecosystem. Disturbance includes; invasion in species, forest fire, insects and disease outbreaks. Disease outbreaks destroy the structure, composition and function of forest ecosystems. Forest fire also disturbs our forest ecosystem by disturbing wildlife, habitat, increase and decrease in nutrient cycling and mortality of individual. Trees frequency, size, seasonality, intensity due to fire multiplication of pests and pathogen is faster. They expand their range and invade into new regions under warmer, wetter, or carbon dioxide enriched conditions. Nutrient availability is affected by an increase in the temperature through change of organic matter decomposition and mineralization of soil nutrients, mainly nitrogen.

The structure and composition of forest ecosystems are expected to shift with climate‐induced changes in precipitation, temperature, fire, carbon mitigation strategies, and biological disturbance. These factors are likely to have biodiversity implications. However, climate‐driven forest ecosystem models used to predict changes to forest structure and composition are not coupled to models used to predict changes to biodiversity. We proposed integrating woodpecker response (biodiversity indicator) with forest ecosystem models. Woodpeckers are a good indicator species of forest ecosystem dynamics, because they are ecologically constrained by landscape‐scale forest components, such as composition, structure, disturbance regimes, and management activities. In addition, they are correlated with forest avifauna community diversity. In this study, we explore integrating woodpecker and forest ecosystem climate models. We review climate–woodpecker models and compare the predicted responses to observed climate‐induced changes. We identify inconsistencies between observed and predicted responses, explore the modeling causes, and identify the models pertinent to integration that address the inconsistencies. We found that predictions in the short term are not in agreement with observed trends for 7 of 15 evaluated species. Because niche constraints associated with woodpeckers are a result of complex interactions between climate, vegetation, and disturbance, we hypothesize that the lack of adequate representation of these processes in the current broad‐scale climate–woodpecker models results in model–data mismatch. As a first step toward improvement, we suggest a conceptual model of climate–woodpecker–forest modeling for integration. The integration model provides climate‐driven forest ecosystem modeling with a measure of biodiversity while retaining the feedback between climate and vegetation in woodpecker climate change modeling.

Nowadays, Turkish forest management philosophy has changed from timber management to ecosystem-based multiple-use forest planning (EBMUFM) with the principles of “sustainable forest management” criteria and indicators drafted in a few national and international agreements. This study analyzed the temporal changes in forest ecosystem structure and a few forest values such as tree species, distribution of age class, development stage, canopy closure, species mixture, timber volume and increment, carbon storage and oxygen production in Sacinka Forest Planning Unit in the northeast corner of Turkey. To assess the patterns during a 21-year period (1985-2006), the necessary data were obtained from forest stand maps and evaluated with Geographical Information Systems (GIS). Results showed that the decrease of agricultural and settlement areas caused the increase of productive forests and the decrease of degraded forests. Bark beetles, which have common effect in Artvin, had less effect on the vitality of Sacinka Forest Planning Unit forests compared to the neighboring forest ecosystems. This forest ecosystem vitality and integrity level was a result of the mechanic and biological interventions against the beetle damages and appropriate silvicultural prescriptions. Key words: Ecosystem based multiple use forest management planning, geographic information systems, land cover change, carbon storage, oxygen production.

We have developed a forest ecosystem model to assess the effects of climate change on the functioning and structure of boreal coniferous forests assuming that temperature and precipitation are the major variables of the niche occupied by a tree species. We specified weather patterns to a level representing the time constant of different physiological and ecological processes relevant to the survival, growth and death of trees. We thereby coupled the long-term dynamics of the forest ecosystem with climate through physiological mechanisms such as photosynthesis and respiration in terms of energy flow through the ecosystem. The hydrological and nutrient cycles couple the dynamics of the forest ecosystem with climate change through soil processes, which represent the thermal and hydraulic properties of the soil, and the decomposition of litter and humus with mineralization of nutrients. Simulations for southern Finland (62 degrees N) indicated that an increase in temperature of 5 degrees C over one hundred years could reduce soil water in Scots pine-dominated forest ecosystems. At the same time, the temperature increase could enhance photosynthesis up to 6-8% under current CO(2) concentrations (330 ppm) and up to 8-10% under elevated CO(2) concentrations (660 ppm). Because the elevated temperature and CO(2) concentration caused an increase in respiration (12-14% more than under the current climate), total stem production increased only up to 4% with a 5 degrees C increase in temperature and up to 6% when temperature and atmospheric CO(2) concentration were increased simultaneously. Because transpiration only increased up to 5% in response to elevated temperature and CO(2) concentration, the water use efficiency of Scots-pine dominated forest ecosystems increased up to 3%, particularly during the late rotation.

One of the most harmful biotic factors in forests is the bark beetle (Coleoptera: Curculionidae: Scolytinae). They might have catastrophic consequences on the coniferous forest ecosystems, killing a lot of trees in forested area. One of the most significant pests of coniferous trees, particularly pine and fir, is the silver fir bark beetle, or Pityokteines curvidens. It may cause significant tree mortality and alter the structure and composition of forest ecosystems. The invasion of bark beetles is influenced by a variety of biotic and abiotic variables. Reducing the effects of potential infestations will benefit from early diagnosis of forest stands vulnerable to bark beetle infestations. The study focused on the comparison of Pityokteines curvidens susceptibility maps using the analytical hierarchy process (AHP), and Maximum Entropi (MaxEnt) methods. The research was carried out in the fir forests of the Kastamonu regional directorate of Forestry in the Western Black Sea region of Türkiye. The eight main criteria used to produce the map were the stand structure, site index, crown closure, stand age, slope, and bioclimatic variables. The map of the infested stands was used for the models' validation. The receiver operating characteristic (ROC) curves and area under the curve (AUC) were used to determine the accuracy of the maps. This study could help decision makers to produce bark beetle susceptibility maps easily and rapidly so they can take the necessary precautions to slow or prevent infestations.

Knowledge of forest ecosystem pattern and process responses to climate change and anthropogenic pressure requires innovative tools that combine monitoring and modelling of tree growth dynamics to account for a more sustainable management of forest resources and ecosystem services. In this context, Digital Twins (DTs) emerge as powerful tool to allow a better interpretation of complex models, summarizing a large amount of data and knowledge into a comprehensive 3D visualization. A Digital Twin is an evolving and comprehensive representation of a physical object, in our case trees, which involves three key elements: a digital representation of the object, an evolving set of data and a dynamic adjustment of the object data. However, due to the structural complexity of the forest stand, and the lack of adequate growth historical data series useful to build and validate the simulations, the full potential of Digital Twin frameworks has yet to be realized in forest field. Our work aims to develop a system that simulate forest growth and spatial patterns through a process-based single tree model and represent the outputs into a 3D immersive and interactive environment, able to reproduce the stand structure of Mediterranean forests. An individual based spatially explicit model has been developed to simulate the biomass growth within a time step of one year and while an immersive 3D dynamic environment enables the user to interact with trees (e.g. tree marking, logging). Competition among trees has been modelled computing the tree influence on surroundings space using a distance-biomass dependent approach. We implemented a set of allometric equations to convert tree biomass into size attributes (e.g. stem diameter, total height) to appropriately represent the modelled forest stand in the 3D environment. The use of DTs can assist forest experts and policymakers in managing complex systems like Mediterranean forests, by simulating several management scenarios and analysing their long-term impacts on forest ecosystem dynamics. Furthermore, process-based models coupled with an immersive 3D representation could help to better understand the forest ecosystem functioning.

SummaryForest microclimate is crucial for the growth and survival of tree seedlings and understorey vegetation. This high ecological relevance contrasts with the poor functional and quantitative understanding of how the properties of forest ecosystems influence forest microclimate.In a long‐term (1998–2011) trial, we investigated how temporal patterns of microclimate below sparse and dense forest canopy related to those of nearby open areas and how this relationship was influenced by soil moisture and seasonality. Air temperature (T), vapour pressure deficit (VPD), soil matrix potential and leaf area index (LAI) were measured in a unique set‐up of below‐canopy and open‐area meteorological stations at eleven distinct forest ecosystems, characteristic of subalpine and temperate climate zones. Data from these plots were analysed for the moderating capacity of the canopy, that is, the differences between below‐canopy and open‐area microclimate, with respect to (i) long‐term means, (ii) dynamics within homogeneous moist‐ vs. dry‐soil periods and (iii) diurnal patterns.The long‐term mean moderating capacity of the canopy was up to 3.3 °C for dailyTmaxand 0.52 kPa for daily VPDmax, of which soil moisture status alone accounted for up to 1.2 °C (Tmax) and 0.21 kPa (VPDmax). Below dense canopy (LAI > 4), the moderating capacity was generally higher when soils were dry and increased during dry‐soil periods, particularly in spring and somewhat less in summer. The opposite pattern was found below sparse canopy (LAI < 4). At the diurnal level, moderating capacity below dense canopy was strongest in mid‐afternoon and during dry‐soil conditions, whereas peak moderation below sparse canopy occurred in mid‐morning and during moist‐soil conditions.Synthesis. Our results suggest a threshold canopy density, which is probably linked to site‐specific water availability, below which the moderating capacity of forest ecosystems switches from supportive to unsupportive for seedling establishment. Under supportive moderating capacity, we understand a stronger mitigation during physiologically most demanding conditions for plant growth. Such a threshold canopy density sheds new light on forest resilience to climate change. Climate change may alter forest canopy density in a way that precludes successful establishment of tree species and ultimately changes forest ecosystem structure and functioning.

Understanding the historical dynamics, composition, and environmental disturbances of forest landscapes provides a context for monitoring changes, describing trends, and establishing reference conditions. This study analyses the temporal changes in forest ecosystem structure in Artvin Forest Planning Unit (AFPU), Turkey, during 1972-2002 period based on digitized forest stand type maps using geographic information system (GIS) and interpretation of satellite data. The results showed that there was a net decrease of 450 ha in total forested areas between 1972 and 2002. Forest ecosystem structure changed over time depending on a few factors such as demographic movements, insect outbreaks, dam and road construction, unregulated management actions, and social pressure. In conclusion, temporal changes and the factors affecting these changes should be determined for sustainable management of natural resources.