Zoran Nesic

• M.A.Sc.
• University of British Columbia at University of British Columbia

The shortage of decades‐long continuous measurements of ecosystem processes limits our understanding of how changing climate impacts forest ecosystems. We used continuous eddy‐covariance and hydrometeorological data over 2002–2022 from a young Douglas‐fir stand on Vancouver Island, Canada to assess the long‐term trend and interannual variability in...

Arctic wetlands are known methane (CH4) emitters but recent studies suggest that the Arctic CH4 sink strength may be underestimated. Here we explore the capacity of well-drained Arctic soils to consume atmospheric CH4 using >40,000 hourly flux observations and spatially distributed flux measurements from 4 sites and 14 surface types. While consumpt...

Quantifying the emissions of the three main biogenic greenhouse gases (GHGs), carbon dioxide (CO2), nitrous oxide (N2O) and methane (CH4), from agroecosystems is crucial. In this study continuous measurements of N2O, and CH4 emissions from potato and pea crops in southwest British Columbia, Canada were made using the eddy‐covariance (EC) technique....

Recent evidence suggests that the relationships between climate and boreal tree growth are generally non‐stationary; however, it remains uncertain whether the relationships between climate and carbon (C) fluxes of boreal forests are stationary or have changed over recent decades. In this study, we used continuous eddy‐covariance and microclimate da...

Rewetting of disturbed peatlands is an important restoration strategy for climate change mitigation. Previous work primarily focuses on the biogeochemical processes altered by rewetting and few studies have investigated the biophysical impacts, which can diminish or amplify biogeochemical effects beyond the ecosystem scale. We used a paired flux to...

Photosynthetic light use efficiency (LUE) determines the ability of a plant to assimilate atmospheric carbon dioxide to biomass and is known to be controlled by environmental conditions, light regimes and forest age. The photochemical reflectance index (PRI), derived from leaf or canopy remotely sensed spectra, has been shown to be an effective and...

We propose a gap-filling model for carbon dioxide fluxes measured by eddy covariance (EC) that combines the flux variance similarity (FVS) partitioning approach with the artificial neural network (ANN) technique (FVS–ANN). 18 years of EC-measured net ecosystem production (NEP) of a Douglas-fir (Pseudotsuga menziesii) stand in British Columbia, Cana...

p>The following authors were omitted from the original version of this Data Descriptor: Markus Reichstein and Nicolas Vuichard. Both contributed to the code development and N. Vuichard contributed to the processing of the ERA-Interim data downscaling. Furthermore, the contribution of the co-author Frank Tiedemann was re-evaluated relative to the co...

We used, and present, robust methodologies to measure the shortwave (S) and longwave (L) spectral radiative properties (reflectivity (ρ), transmissivity (τ) and absorptivity (α)) of nine plastic films and quantified their effect, when used as mulches, on soil heat flux density (G), net radiation (Rn, above the films) and soil temperature (Ts2cm, 2-...

Agricultural fields can be significant sources of carbon dioxide (CO2), nitrous oxide (N2O) and methane (CH4), with implications for climate change. This paper reports continuous half-hourly CO2, CH4 and N2O fluxes over a conventionally-managed highbush blueberry field on Westham Island in Delta, British Columbia (BC), Canada, measured using the ed...

Evergreen conifer forests are the most prevalent land cover type in North America. Seasonal changes in the color of evergreen forest canopies have been documented with near‐surface remote sensing, but the physiological mechanisms underlying these changes, and the implications for photosynthetic uptake, have not been fully elucidated. Here, we integ...

Partitioning measured net ecosystem exchange of CO2 (NEE) into ecosystem respiration (Re) and gross primary production (GPP) is essential for understanding the biophysical controls on forest ecosystem carbon (C) dynamics. Obtaining Re and GPP accurately from NEE remains a challenge. In this study, we measured stable CO2 isotopologue signatures at e...

The FLUXNET2015 dataset provides ecosystem-scale data on CO2, water, and energy exchange between the biosphere and the atmosphere, and other meteorological and biological measurements, from 212 sites around the globe (over 1500 site-years, up to and including year 2014). These sites, independently managed and operated, voluntarily contributed their...

We studied the recovery of tree- and stand-level carbon (C) storage in a lodgepole pine (Pinus contorta Dougl. ex Loud. var. latifolia Engelm.) forest in northern British Columbia that experienced substantial (∼83%) mortality in 2006–2007 (total loss by 2013 = 86%) during a severe mountain pine beetle (MPB; Dendroctonus ponderosae Hopkins, 1902) in...

The FLUXNET2015 dataset provides ecosystem-scale data on CO2, water, and energy exchange between the biosphere and the atmosphere, and other meteorological and biological measurements, from 212 sites around the globe (over 1500 site-years, up to and including year 2014). These sites, independently managed and operated, voluntarily contributed their...

A core principle of organic farming is the reliance on internal nutrient recycling, favoring nutrient sources produced on farms (e.g.,manures) as opposed to those that are not (e.g., processed fertilizers, municipal compost). Soil fertility management varies tremendously among organic vegetable production systems, potentially with large effects on...

Douglas-fir (Pseudotsuga menziesii) forests in the Pacific Northwest are the most productive managed forests in North America. Nitrogen (N) fertilizers are generally applied in this region to increase the rate of tree growth and consequently carbon (C) sequestration. However, the long-term effects of N fertilization on C and water exchanges of Doug...

Optimal manure management can maximize agronomic benefits and minimize environmental impacts. Field experiments were conducted in the Pacific Northwest (Vancouver, Canada) to determine how chicken and horse manures that were fall-applied to meet nitrogen crop demand affect soil ammonium (NH4⁺) and nitrate (NO3⁻), apparent net mineralization (ANM) a...

Long‐term trends in ecosystem resource use efficiencies (RUEs) and their controlling factors are key pieces of information for understanding how an ecosystem responds to climate change. We used continuous eddy covariance and microclimate data over the period 1999–2017 from a 120‐year‐old black spruce stand in central Saskatchewan, Canada, to assess...

Case study (Dresden, Wiener Platz) impact of green roofs on the thermal comfort of pedestrians, simulation results using ENVI-met 3.1

Manure‐based soil amendments (MBSAs) must be managed optimally to maximize N concentration and availability while minimizing environmental impacts (e.g., greenhouse gas [GHG]) emissions. We conducted an 83‐d incubation study to determine the effects of different moisture (60 or 120% of water‐holding capacity [WHC]) and temperature (4 or 20°C) condi...

Insect outbreaks can significantly influence carbon (C) and water balances of forests. Forest tent caterpillars (FTC) (Malacosoma disstria Hübner) are one of the most prominent insects found in aspen forests in Canada and have the potential to considerably influence regional C and water fluxes. In the summer of 2016, an FTC infestation occurred in...

The most recent mountain pine beetle (MPB) (Dendroctonus ponderosae) outbreak in British Columbia (BC), which began in the late 1990s, killed ∼54% of the mature merchantable lodgepole pine and was expected to impact gross primary productivity (GPP), ecosystem respiration (R) and thus net ecosystem productivity (NEP) of infested stands. Eddy-covaria...

Implications: We monitored the impact of rainfall protection on nutrient losses and greenhouse gas emissions during the decomposition of broiler chicken, turkey and horse manure-based soil amendments. We found large ammonium and potassium losses when amendments were exposed to rainfall, resulting in a 37-74% decrease in N inputs when compared to a...

Despite storing approximately half of the atmosphere’s carbon, estimates of fluxes between wetlands and atmosphere under current and future climates are associated with large uncertainties, and it remains a challenge to determine human impacts on the net greenhouse gas balance of wetlands at the global scale. In this study we demonstrate that the r...

The Quest Carbon Capture and Storage (CCS) project in Alberta, Canada, is a fully integrated project, as it involves the capture, transport, injection, storage of CO2, and a measurement, monitoring and verification (MMV) program. The MMV program has two key objectives: a) to ensure containment and b) to ensure conformance. Prior to the start of CO2...

Many peatlands have been drained and harvested for peat mining, agriculture, and other purposes, which has turned them from carbon (C) sinks into C emitters. Rewetting of disturbed peatlands facilitates their ecological recovery and may help them revert to carbon dioxide (CO2) sinks. However, rewetting may also cause substantial emissions of the mo...

Tree mortality due to the recent mountain pine beetle (MPB) (Dendroctonus ponderosae) outbreak in British Columbia (BC) is expected to impact evapotranspiration (E), gross primary productivity (GPP), and snow accumulation and melt, thereby influencing ecosystem hydrology. To quantify the impact on E and GPP, we have made eddy-covariance (EC) measur...

Tree mortality due to the recent mountain pine beetle (MPB) (Dendroctonus ponderosae) outbreak in British Columbia (BC) is expected to impact evapotranspiration (E), gross primary productivity (GPP), and snow accumulation and melt, thereby influencing ecosystem hydrology. To quantify the impact on E and GPP, we have made eddy-covariance (EC) measur...

A method for directly measuring carbon dioxide (CO2) emissions using a mobile sensor network in cities at fine spatial resolution was developed and tested. First, a compact, mobile system was built using an infrared gas analyzer combined with open-source hardware to control, georeference, and log measurements of CO2 mixing ratios on vehicles (car,...

Diurnal and seasonal changes of δ 13 C and δ 18 O in carbon dioxide measured by eddy covariance over an urban surface The isotopic composition of the greenhouse gas CO 2 can provide valuable information about its sources. For example , linear mixing models have been used to identify the sources of enhanced CO 2 in the urban atmosphere using urban a...

A method for directly measuring carbon dioxide (CO2) emissions using a mobile sensor network in cities at fine spatial resolution was developed and tested. First, a compact, mobile system was built using an infrared gas analyzer combined with open-source hardware to control, georeference and log measurements of CO2 mixing ratios on vehicles (car, b...

Understanding plant photosynthesis, or Gross Primary Production (GPP), is a crucial aspect of quantifying the terrestrial carbon cycle. Remote sensing approaches, in particular multi-angular spectroscopy, have proven successful for studying relationships between canopy-reflectance and plant-physiology processes, thus providing a mechanism to scale...

Stand-replacing disturbances, such as harvesting, change former forest net CO2 sinks into net sources due to significantly reduced photosynthetic uptake and continued respiratory losses. To quantify these effects, this study used data from a Fluxnet-Canada Douglas-fir chronosequence on Vancouver Island, where the most mature site (62-year-old; DF49...

Burns Bog Ecological Conservancy Area (BBECA) in Metro Vancouver is a part of a large disturbed raised bog ecosystem that is currently being managed to promote ecological recovery through rewetting. Restoration efforts aimed at raising the water table through damming of drainage structures have been in place since 2005. This study quantified summer...

Stand-replacing disturbances, such as harvesting, change former forest net CO2 sinks into net sources due to significantly reduced photosynthetic uptake and continued respiratory losses. To quantify these effects, this study used data from a Fluxnet-Canada Douglas-fir chronosequence on Vancouver Island, where the most mature site (62-year-old; DF49...

The isotopic composition (δ¹³C and δ18O) in atmospheric carbon dioxide (CO₂) originating from gasoline and diesel vehicle exhaust and from natural gas combustion was determined. Gasoline and diesel samples were taken in the exhaust of representative vehicles of the fleet in Vancouver, BC, Canada between November 2013 and May 2...

Stand-replacing disturbances, such as harvesting, have a major impact on the CO2 exchange between forested land and the atmosphere. Former forest CO2 sinks become net CO2 sources due to significantly reduced photosynthetic uptake and continued respiratory losses. Chronosequence studies have been widely used to quantify the effect of harvesting on t...

Over the past decade, British Columbia (BC), has experienced the largest mountain pine beetle (MPB) outbreak on record. This study used the eddy-covariance (EC) technique to examine the impact of the MPB attack on evapotranspiration (E) and associated canopy characteristics of two lodgepole pine stands with secondary structure (trees, saplings and...

Stand-replacing disturbances, such as harvesting, have a major impact on the exchange of carbon dioxide (CO2) between forested land and the atmosphere. The former forest CO2 sinks become net CO2 sources due to the continued respiratory losses of CO2 and to the significantly reduced photosynthetic uptake of CO2. The duration and magnitude of this ca...

This study describes a system designed to measure chloroform flux from terrestrial systems, providing a reliable first assessment of the spatial variability of flux over an area. The study takes into account that the variability of ambient air concentrations is unknown. It includes quality assurance procedures, sensitivity assessments, and testing...

The recent mountain pine beetle (MPB) outbreak has had an impact on the carbon (C) cycling of lodgepole pine forests in British Columbia. This study examines how partial harvesting as a forest management response to MPB infestation affects the net ecosystem production (NEP) of a mixed conifer forest (MPB-09) in Interior BC. MPB-09 is a 70-year-old...

The most important long-lived greenhouse gas (LLGHG) emitted during combustion of fuels is carbon dioxide (CO2), however also traces of the LLGHGs methane (CH4) and nitrous oxide (N2O) are released, the quantities of which depend largely on the conditions of the combustion process. Emission factors determine the mass of LLGHGs emitted per energy us...

The recent mountain pine beetle (MPB) outbreak has had an impact on the carbon (C) cycling of lodgepole pine forests in British Columbia. This study examines how partial harvesting as a forest management response to MPB infestation affects the net ecosystem production (NEP) of a mixed conifer forest (MPB-09) in Interior BC. MPB-09 is a 70-yr old st...

Chronosequence studies, where current different-aged stands are used to reconstruct the development of an older stand, have been used to characterize the net ecosystem productivity (NEP) at different stand ages following disturbances. Almost no replicated observations have been made within the Fluxnet community comparing the NEP of similarly aged s...

Automated measurements of forest soil CO2 efflux (F) using non-steady-state chamber systems are necessary to study the short- and long-term responses of soil respiration to temporal variations in abiotic and biotic variables. Increased use of automated chamber systems in regional flux networks results in large data sets that demand an efficient and...

Over the past decade, the mountain pine beetle (MPB) (Dendroctonus ponderosae) has killed 17.5 million ha of forest in British Columbia. The forest sector responded by increasing the annual allowable cut to salvage the beetle-killed lodgepole pine trees (Pinus contorta var. latifolia). The most common strategy is to clearcut the entire stand. This...

Abstract Disturbances play an important role in determining the C balance of North American forests. This study used the eddy covariance (EC) technique to examine the impact of mountain pine beetle (MPB) (Dendroctonus ponderosae) outbreak on the gross ecosystem photosynthesis (Pg), ecosystem respiration (Re) and net ecosystem production (NEP), of...

The eddy-covariance method has become a cornerstone in the study of the surface energy and water balances, yet the oft-reported lack of energy-balance closure adds uncertainty to its measurements of evapotranspiration. This study explores the issue of closure based on 10 years of energy and water balance measurements at seven flux-tower sites in th...

We compared the biophysical controls of soil respiration (Rs) in two different-aged (21 and 60 years old, hereafter known as HDF88 and DF49, respectively) Douglas-fir stands on Vancouver Island, Canada with the younger stand having abundant deciduous understory and a relatively thicker LFH layer. Rs in the younger stand, HDF88 was more responsive t...

The effects of climatic factors and vegetation type on evapotranspiration (E) and water use efficiency (WUE) were analyzed using tower-based eddy-covariance (EC) data for nine mature forest sites, two peatland sites and one grassland site across an east-west continental-scale transect in Canada during the period 2003-2006. The seasonal pattern of E...

The issue of fast-growing crops originally goes back to early 1970th. Fast-growing crops initially dominated as a way of obtaining the raw material for producing cellulose. In subsequent years, with the development of technology, the range of benefits of this type crops began to increase - for example crops found use in the purification of industri...

The mountain pine beetle (MPB) outbreak has had a major impact on the carbon (C) and water balances of forests in Interior BC, Canada. As a management response, the forest sector has increased the annual allowable cut to enable partial harvesting in the timber supply areas. Protecting the non-pine secondary structure provides opportunities for mid-...

Automated measurements of the net forest-floor carbon dioxide exchange (NFFE) were made in a mature (130 years-old) boreal black spruce forest over an 8-year period (2002 to 2009) with the objectives of (1) better understanding the biophysical controls on spatial patterns and multi-temporal trends of NFFE and its components, i.e. soil respiration (...

The response of net ecosystem productivity (NEP) and evaporation in a boreal aspen (Populus tremuloides Michx.) forest and a black spruce (Picea mariana (Mill.) BSP) forest in Canada was compared using a newly developed realistic model of surface-atmosphere exchanges of carbon dioxide (CO2), water vapor, and energy as well as eddy covariance flux m...

Naturally formed volatile chlorinated organic compounds (VOCl) are involved in various atmospheric processes such as ozone depletion. These compounds are present in several environmental compartments and some of them are of ecotoxicological concern. Over the past few years, a small but growing literature has focused on the emission of VOCls from te...

Eddy covariance (EC) measurements have greatly advanced our knowledge of carbon exchange in terrestrial ecosystems. However, appropriate techniques are required to upscale these spatially discrete findings globally. Satellite remote sensing provides unique opportunities in this respect, but remote sensing of the photosynthetic light-use efficiency...

An observational study was conducted during an eight-week period in the summer of 2009 at a forested site in British Columbia (``DF49'') to measure advective carbon dioxide (CO2) fluxes. The site is situated in a 35-m tall Douglas-fir forest on a 5-10 degree slope. Wind vector and CO2 concentration measurements were made at heights of 1, 2.6, 8, 20...

The volatile organic chlorinated compounds (VOCl) are important components of the global chlorine budget. The origin of VOCl in the environment was for decades thought to be strictly anthropogenic. Over the past decade, a number of studies have however shown that VOCls are naturally formed in soil, and nowadays this source is recognized as a crucia...

Plant photosynthesis is critical for understanding carbon cycling at landscape and global scales. While tower-based measurements of CO2 have enhanced our knowledge of ecosystem fluxes, scaling these measurements globally is difficult. Satellite observations provide full, global coverage and hold the potential of spatially continuous measurements of...

Components of the surface energy balance of a mature boreal jack pine forest and a jack pine clearcut were analysed to determine the causes of the imbalance that is commonly observed in micrometeorological measurements. At the clearcut site (HJP02), a significant portion of the imbalance was caused by: (i) the overestimation of net radiation (R n )...

This study investigated how nitrogen (N) fertilization with 200kg urea Nha−1 of an intermediate-aged Pacific Northwest Douglas-fir (Pseudotsuga menziesii) stand influenced forest-floor CO2 and N2O fluxes over a period of two years. Forest-floor CO2 efflux (Rs) measurements were made continuously with an automated non-steady-state chamber system as...

British Columbia (BC), Canada is experiencing a severe mountain pine beetle (MPB) (Dendroctonus ponderosae) epidemic extending over an area of 135,000 km2. The widespread mortality of lodgepole pine (Pinus contorta var. latifolia) caused by the beetle has significant implications for BC's timber supply and Canada's carbon (C) budget. This study use...

This study investigated the 2-year response to nitrogen (N) fertilization of three different-aged Douglas-fir stands on the west coast of Canada on eddy covariance (EC)-measured net ecosystem productivity (NEP), gross primary productivity (GPP), ecosystem respiration (R) and evapotranspiration (E). Fertilizer application took place in January 2007,...

An observational experiment was conducted during the summer of 2009 at the Canadian Carbon Program's British Columbia Flux Station to determine the incidence and magnitude of advective carbon dioxide (CO2) fluxes. The site is located in a tall (Zh = 35 m), dense (1100 stems/ha) Douglas-fir forest on a 5-10o slope. Katabatic flows occur within the s...

A large area of boreal jack pine (Pinus banksiana Lamb.) forest in Canada is recovering from clear-cut harvesting, and the carbon (C) balance of these regenerating forests remains uncertain. Net ecosystem CO2 exchange was measured using the eddy-covariance technique at four jack pine sites representing different stages of stand development: three p...

To download the paper go to https://circle.ubc.ca/bitstream/handle/2429/34831/Black_AGU_2008JG000912.pdf?sequence=1 use full link

A simple aerodynamic-variance method is proposed to fill gaps in continuous CO2 flux measurements in rainy conditions, when open-path analysers do not function. The method requires turbulent conditions (friction velocity greater than 0.1 ms–1), and uses measurements of mean wind speed, and standard deviations of temperature and CO2 concentration fl...

This study analyzes 9 years of eddy-covariance (EC) data carried out in a Pacific Northwest Douglas-fir (Pseudotsuga menzesii) forest (58-year old in 2007) on the east coast of Vancouver Island, Canada, and characterizes the seasonal and interannual variability in net ecosystem productivity (NEP), gross primary productivity (GPP), and ecosystem res...

We used the eddy-covariance technique to measure evapotranspiration (E) and gross primary production (GPP) in a chronosequence of three coastal Douglas-fir (Pseudotsuga menziesii) stands (7, 19 and 58 years old in 2007, hereafter referred to as HDF00, HDF88 and DF49, respectively) since 1998. Here, we focus on the controls on canopy conductance (gc...

Similar nonsteady-state automated chamber systems were used to measure and partition soil CO2 efflux in contrasting deciduous (trembling aspen) and coniferous (black spruce and jack pine) stands located within 100 km of each other near the southern edge of the Boreal forest in Canada. The stands were exposed to similar climate forcing in 2003, incl...

Fire and harvesting are major forest renewal processes in the Canadian boreal forest. The eddy covariance method was used to compare ecosystem fluxes of carbon dioxide between harvested and burned boreal forest sites in Saskatchewan, Canada. The harvest chronosequence had sites harvested in 2002 (HJP02), 1994 (HJP94) and 1975 (HJP75), whereas the f...

Plant growth and potential photosynthetic carbon uptake are strongly controlled by water availability and climatic conditions. The study of evapotranspiration (E) among a variety of terrestrial ecosystems is therefore fundamental to understand its role within the water cycle and linkage to carbon fluxes. In this study, we analyze tower-based eddy-c...

British Columbia, Canada is experiencing a severe mountain pine beetle (MPB) epidemic extending over an area of 135,000 km2. The widespread mortality of lodgepole pine caused by the beetle is having severe implications for Canada's carbon (C) budget. This study used the eddy-covariance technique to examine how the beetle is affecting the net ecosys...

Using the eddy-covariance technique, we have been measuring, since 1998, CO2, water vapour and energy exchange between the atmosphere and the ecosystem in three different-aged Westcoast Douglas-fir (Pseudotsuga menziesii) stands (9, 21 and 60 year-old in 2009, hereafter known as HDF00, HDF88 and DF49, respectively). These stands were fertilized wit...

Disturbance of forest ecosystems, an important component of the terrestrial carbon cycle, has become a focus of research over recent years, as global warming is about to increase the frequency and severity of natural disturbance events. Remote sensing offers unique opportunities for detection of forest disturbance at multiple scales; however, spati...

A simple top-down model of canopy photosynthesis (P) was developed and tested in this study. The model (referred to as the Q(e)-MM model) is P = alphaQ (e) P (max)/(alphaQ ( e ) + P (max)), alpha and P (max) are quantum-use efficiency and potential P, respectively. Q (e) is given by Q (d) (0) + kQ (b) (0), where Q (d) (0) and Q (b) (0) are the diff...

Fertilization is one of the eligible management practices for C sequestering and hence reducing CO2 emissions under Article 3.4 of the Kyoto Protocol. In the coastal regions of British Columbia, which have very little nitrogen (N) deposition from pollution sources owing to their remote location, and soils deficient in N (Hanley et al., 1996), Dougl...