Modeling potentially sustainable biomass productivity in jack pine forest stands

1998 ◽  
Vol 78 (1) ◽  
pp. 105-113 ◽  
Author(s):  
J. S. Bhatti ◽  
N. W. Foster ◽  
T. Oja ◽  
M. H. Moayeri ◽  
P. A. Arp
Keyword(s):  
Steady State ◽  
Atmospheric Deposition ◽  
Mass Balance ◽  
Forest Fire ◽  
Forest Biomass ◽  
Jack Pine ◽  
Biomass Growth ◽  
Tree Biomass ◽  
Nutrient Demand ◽  
Whole Tree

A steady-state mass balance model (ForSust), developed to simulate potentially sustainable levels of tree biomass growth and related nutrient uptake dynamics, was applied to 17 jack pine sites across Canada. The model simulates potential tree biomass growth based on nutrient inputs from estimated atmospheric deposition (N, Ca, Mg, K) and soil weathering (Ca, Mg, K), and matches the resulting nutrient supply rates with calculated nutrient demand. Nutrient demand calculations are based on nutrient concentrations in wood, bark, branches, and foliage. Specifically, the model simulates sustainable annual increment (SAI) of biomass growth for stem-only and whole-tree (aboveground biomass) harvesting, and for recurring forest fire conditions. Calculated SAI levels were compared with field-estimated mean annual increments for aboveground forest biomass (MAI). For recurring forest fires, it was found that SAI values, as simulated, corresponded with the MAI field estimates in general. For whole-tree harvesting, SAI was lower than MAI for most but not all sites. For stem-only harvesting, SAI corresponded with MAI, but there was a greater scatter between SAI and MAI values than what appeared to be the case for the recurring forest fire scenario. Key words: Jack pine; whole-tree, stem-only harvesting; steady-state mass balance; forest biomass; N, Ca, Mg, K growth limitations; atmospheric deposition

Effects of biomass harvest intensity and soil disturbance on jack pine stand productivity: 15-year results

2014 ◽  
Vol 44 (12) ◽  
pp. 1566-1574 ◽  
Author(s):  
R.L. Fleming ◽  
J.-D. Leblanc ◽  
P.W. Hazlett ◽  
T. Weldon ◽  
R. Irwin ◽  
...  
Keyword(s):  
Aboveground Biomass ◽  
Pinus Banksiana ◽  
Field Experiments ◽  
Forest Biomass ◽  
Jack Pine ◽  
Soil Disturbance ◽  
Growth Responses ◽  
Stand Productivity ◽  
Planted Tree ◽  
Whole Tree

Rising demands for forest biomass have raised concerns that the increased removal of organic residues and harvest impacts may reduce longer term site productivity. Replicated field experiments examining the effects of stem-only harvest with disc trenching (SOT), whole-tree harvest with (WTT) and without (WT) disc trenching, whole-tree harvest with forest-floor removal by blading (WTB), and blading followed by compaction (WTBC) were installed on nine sandy jack pine (Pinus banksiana Lamb.) sites in northern Ontario. At year 5, planted-tree diameters, dominant tree heights (HD), and stand aboveground biomass (jPPBio) were smaller without soil disturbance (the WT), but were otherwise similar among treatments. At year 15, planted-tree size and stand yield rankings were WTT = SOT = WT > WTB = WTBC. Biomass production by natural regeneration and total stand aboveground biomass (TotBio) treatment rankings were SOT ≥ WTT ≥ WT > WTB = WTBC. HD, jPPBio, and TotBio showed increasing divergence over time in WTB vs. WTT – SOT response, whereas statistical equivalence of the WTT and SOT treatments was shown for most tree and stand growth responses. There was some evidence of increasingly negative impacts of WTB as site index declined. Overall, negative WTB effects on tree and stand productivity have become increasingly apparent.

scholarly journals Forest biomass accumulation is an important source of acidity to forest soils: Data from Swedish inventories of forests and soils 1955 to 2010

AMBIO ◽  
2021 ◽  
Author(s):  
Erik Karltun ◽  
Johan Stendahl ◽  
Johan Iwald ◽  
Stefan Löfgren
Keyword(s):  
Atmospheric Deposition ◽  
Forest Soils ◽  
Forest Biomass ◽  
Biomass Accumulation ◽  
Net Uptake ◽  
Minor Part ◽  
Edaphic Properties ◽  
Whole Tree Harvesting ◽  
Whole Tree

AbstractThe input of acidity to Swedish forest soils through forestry between 1955 and 2010 is compared with the acid input from atmospheric deposition. Depending on region, input of acidity from forestry was the minor part (25–45%) of the study period’s accumulated acid input but is now the dominating source (140–270 molc ha−1 year−1). The net uptake of cations due to the increase in standing forest biomass, ranged between 35 and 45% of the forestry related input of acidity while whole-tree harvesting, introduced in the late 1990s, contributed only marginally (< 2%). The geographical gradient in acid input is reflected in the proportion of acidified soils in Sweden but edaphic properties contribute to variations in acidification sensitivity. It is important to consider the acid input due to increases in standing forest biomass in acidification assessments since it is long-term and quantitatively important.

A critical review of mass balance methods for calculating critical loads of nitrogen for forested ecosystems

1993 ◽  
Vol 1 (2) ◽  
pp. 145-156 ◽  
Author(s):  
L. H. Pardo ◽  
C. T. Driscoll
Keyword(s):  
Steady State ◽  
Atmospheric Deposition ◽  
Water Chemistry ◽  
Critical Load ◽  
Mass Balance ◽  
Critical Loads ◽  
Balance Method ◽  
Mass Balance Method ◽  
Basic Cation ◽  
State Water

Critical loads are used in the assessment of air pollution and regulation of the causative emissions to prevent or mitigate ecological damage. We critically review four mass balance methods for calculating critical loads for nitrogen deposition: the steady-state water chemistry method, the nitrogen mass balance method, the basic cation mass balance method, and the steady-state mass balance method. The critical loads may be calculated with respect to effects of acidification associated with nitrate leaching or effects of elevated nitrogen such as eutrophication, excess nitrate loss, and nutrient imbalances. The most useful method for calculating the critical load for nitrogen with respect to effects of elevated atmospheric deposition of nitrogen is the nitrogen mass balance method. The steady-state water chemistry method can be readily applied for regional-scale calculations because it requires only water chemistry data from synoptic surveys of surface waters and does not explicitly consider biogeochemical processes. Both of the other approaches are severely limited by lack of quantitative information on rates of mineral weathering. If weathering data were available, the steady-state mass balance method could be more effectively used to assess critical loads with respect to acidification. Similarly, the basic cation mass balance method could be used to calculate critical loads for both acidity and elevated nitrogen effects. Because of the complexity of the nitrogen cycle, it is not possible to obtain a single critical load for the whole ecosystem. Rather, one should analyze and synthesize several values of critical loads that reflect different components of the ecosystem and different ecological effects of elevated nitrogen deposition (e.g., acidification and eutrophication effects).Key words: atmospheric deposition of nitrogen, acidification, critical loads, nitrogen cycling.

Combining SAR interferometry and the equation of continuity to estimate the three-dimensional glacier surface-velocity vector

1999 ◽  
Vol 45 (151) ◽  
pp. 533-538 ◽  
Author(s):  
Niels Reeh ◽  
Søren Nørvang Madsen ◽  
Johan Jakob Mohr
Keyword(s):  
Steady State ◽  
Mass Balance ◽  
Vertical Velocity ◽  
Velocity Vector ◽  
Thickness Distribution ◽  
Vertical Surface ◽  
Horizontal Velocity ◽  
Sar Interferometry ◽  
Surface Velocity ◽  
Ice Thickness

AbstractUntil now, an assumption of surface-parallel glacier flow has been used to express the vertical velocity component in terms of the horizontal velocity vector, permitting all three velocity components to be determined from synthetic aperture radar interferometry. We discuss this assumption, which neglects the influence of the local mass balance and a possible contribution to the vertical velocity arising if the glacier is not in steady state. We find that the mass-balance contribution to the vertical surface velocity is not always negligible as compared to the surface-slope contribution. Moreover, the vertical velocity contribution arising if the ice sheet is not in steady state can be significant. We apply the principle of mass conservation to derive an equation relating the vertical surface velocity to the horizontal velocity vector. This equation, valid for both steady-state and non-steady-state conditions, depends on the ice-thickness distribution. Replacing the surface-parallel-flow assumption with a correct relationship between the surface velocity components requires knowledge of additional quantities such as surface mass balance or ice thickness.

scholarly journals Tree height integrated into pantropical forest biomass estimates

2012 ◽  
Vol 9 (8) ◽  
pp. 3381-3403 ◽  
Author(s):  
T. R. Feldpausch ◽  
J. Lloyd ◽  
S. L. Lewis ◽  
R. J. W. Brienen ◽  
M. Gloor ◽  
...  
Keyword(s):  
East Africa ◽  
Carbon Storage ◽  
Stand Structure ◽  
Forest Biomass ◽  
Small Diameter ◽  
Tree Height ◽  
Total Biomass ◽  
Guiana Shield ◽  
Tree Biomass ◽  
Continental Scale

Abstract. Aboveground tropical tree biomass and carbon storage estimates commonly ignore tree height (H). We estimate the effect of incorporating H on tropics-wide forest biomass estimates in 327 plots across four continents using 42 656 H and diameter measurements and harvested trees from 20 sites to answer the following questions: 1. What is the best H-model form and geographic unit to include in biomass models to minimise site-level uncertainty in estimates of destructive biomass? 2. To what extent does including H estimates derived in (1) reduce uncertainty in biomass estimates across all 327 plots? 3. What effect does accounting for H have on plot- and continental-scale forest biomass estimates? The mean relative error in biomass estimates of destructively harvested trees when including H (mean 0.06), was half that when excluding H (mean 0.13). Power- and Weibull-H models provided the greatest reduction in uncertainty, with regional Weibull-H models preferred because they reduce uncertainty in smaller-diameter classes (≤40 cm D) that store about one-third of biomass per hectare in most forests. Propagating the relationships from destructively harvested tree biomass to each of the 327 plots from across the tropics shows that including H reduces errors from 41.8 Mg ha−1 (range 6.6 to 112.4) to 8.0 Mg ha−1 (−2.5 to 23.0). For all plots, aboveground live biomass was −52.2 Mg ha−1 (−82.0 to −20.3 bootstrapped 95% CI), or 13%, lower when including H estimates, with the greatest relative reductions in estimated biomass in forests of the Brazilian Shield, east Africa, and Australia, and relatively little change in the Guiana Shield, central Africa and southeast Asia. Appreciably different stand structure was observed among regions across the tropical continents, with some storing significantly more biomass in small diameter stems, which affects selection of the best height models to reduce uncertainty and biomass reductions due to H. After accounting for variation in H, total biomass per hectare is greatest in Australia, the Guiana Shield, Asia, central and east Africa, and lowest in east-central Amazonia, W. Africa, W. Amazonia, and the Brazilian Shield (descending order). Thus, if tropical forests span 1668 million km2 and store 285 Pg C (estimate including H), then applying our regional relationships implies that carbon storage is overestimated by 35 Pg C (31–39 bootstrapped 95% CI) if H is ignored, assuming that the sampled plots are an unbiased statistical representation of all tropical forest in terms of biomass and height factors. Our results show that tree H is an important allometric factor that needs to be included in future forest biomass estimates to reduce error in estimates of tropical carbon stocks and emissions due to deforestation.

Investigating Fast- and Slow-settling Phosphorus Fractions in Lakes using Steady-state Modeling

2021 ◽  
Author(s):  
Hamed Khorasani ◽  
Zhenduo Zhu
Keyword(s):  
Steady State ◽  
Mass Balance ◽  
Large Scale ◽  
Hydraulic Residence Time ◽  
Simple Method ◽  
Retention Models ◽  
Mass Balance Models ◽  
Limiting Nutrient ◽  
Fast Settling ◽  
P Retention

&lt;p&gt;Phosphorus (P) is the key and limiting nutrient in the eutrophication of freshwater resources. Modeling P retention in lakes using steady-state mass balance models (i.e. Vollenweider-type models) provides insights into the lake P management and a simple method for large-scale assessments of P in lakes. One of the basic problems in the mass balance modeling of P in lakes is the removal of P from the lake water column by settling. A fraction of the incoming P into the lake from the watershed is associated with fast-settling particles (e.g. sediment particles) that result in the removal of that fraction of P quickly at the lake entrance. However, existing models considering a constant fraction of fast-settling TP for all lakes are shown to result in overestimation of the retention of P in lakes with short hydraulic residence time. In this study, we combine a hypothesis of the fast- and slow-settling P fractions into the steady-state mass balance models of P retention in lakes. We use a large database of lakes to calibrate the model and evaluate the hypothesis. The results of this work can be used for the improvement of the prediction power of P retention models in lakes and help to better understand the processes of P cycling in lakes.&lt;/p&gt;

scholarly journals Forest Fire in East Nusa Tenggara during 2015-2019: Comparison to Forest Fire in Kalimantan and Sumatera

2021 ◽  
Vol 893 (1) ◽  
pp. 012010
Author(s):  
Sumaryati ◽  
D F Andarini ◽  
N Cholianawati ◽  
A Indrawati
Keyword(s):  
Carbon Monoxide ◽  
Forest Fire ◽  
Forest Fires ◽  
Forest Biomass ◽  
Comparison Method ◽  
Atmospheric Environment ◽  
Annual Average ◽  
Statistical Comparison ◽  
Fire Area ◽  
Total Column

Abstract East Nusa Tenggara is one of the provinces in Indonesia that has big forest fires following some provinces in Kalimantan and Sumatra. However, forest fires in East Nusa Tenggara have less attention in forest fires discussion in Indonesia. This study aims to analyze forest fires in East Nusa Tenggara and their impact on reducing visibility and increasing carbon monoxide (CO) from 2015 to 2019. In this study, hotspot, forest fire area, Oceanic Niño Index, visibility, and CO total column data were used to analyze the forest fires using a statistical comparison method in East Nusa Tenggara, Kalimantan, and Sumatra. The result shows that the number of hotspots in East Nusa Tenggara less than in Kalimantan and Sumatra for the same forest fire area. The forest fires in East Nusa Tenggara do not harm the atmospheric environment significantly. East Nusa Tenggara dominantly consists of savanna areas with no peatland, hence, the forest biomass burning produces less smoke and CO. Furthermore, the forest fire in East Nusa Tenggara has not an impact on decreasing visibility and increasing CO total column, in contrast, visibility in Sumatra and Kalimantan has fallen to 6 km from the annual average, and CO total column rise three times of normal condition during peak fire.

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