scholarly journals Bayesian inference of biomass growth characteristics for sugi (C. japonica) and hinoki (C. obtusa) forests in self-thinned and managed stands

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Valérie Nicoulaud-Gouin ◽  
Marc-André Gonze ◽  
Pierre Hurtevent ◽  
Phillippe Calmon
Keyword(s):  
Bayesian Inference ◽  
Mortality Rate ◽  
Stand Density ◽  
The Self ◽  
Biomass Growth ◽  
Managed Forests ◽  
Biological Time ◽  
Evergreen Forests ◽  
Biomass Dynamic ◽  
Stand Yield

Abstract Background Forests are an important sink for atmospheric carbon and could release that carbon upon deforestation and degradation. Knowing stand biomass dynamic of evergreen forests has become necessary to improve current biomass production models. The different growth processes of managed forests compared to self-managed forests imply an adaptation of biomass prediction models. Methods In this paper we model through three models the biomass growth of two tree species (Japanese cedar, Japanese cypress) at stand level whether they are managed or not (self-thinning). One of them is named self-thinned model which uses a specific self-thinning parameter α and adapted to self-managed forests and an other model is named thinned model adapted to managed forests. The latter is compared to a Mitscherlich model. The self-thinned model takes into account the light competition between trees relying on easily observable parameters (e.g. stand density). A Bayesian inference was carried out to determine parameters values according to a large database collected. Results In managed forest, Bayesian inference results showed obviously a lack of identifiability of Mitscherlich model parameters and a strong evidence for the thinned model in comparison to Mitscherlich model. In self-thinning forest, the results of Bayesian inference are in accordance with the self-thinning 3/2 rule (α=1.4). Structural dependence between stand density and stand yield in self-thinned model allows to qualifying the expression of biological time as a function of physical time and better qualify growth and mortality rate. Relative mortality rate is 2.5 times more important than relative growth rate after about 40 years old. Stand density and stand yield can be expressed as function of biological time, showing that yield is independent of initial density. Conclusions This paper addressed stand biomass dynamic models of evergreen forests in order to improve biomass growth dynamic assessment at regional scale relying on easily observable parameters. These models can be used to dynamically estimate forest biomass and more generally estimate the carbon balance and could contribute to a better understanding of climate change factors.

scholarly journals The self as a prior for the other: social learning under paranoia

2021 ◽  
Author(s):  
Joseph M Barnby ◽  
Nichola Raihani ◽  
Peter Dayan
Keyword(s):  
Bayesian Inference ◽  
Social Interactions ◽  
Social Preferences ◽  
Value Orientation ◽  
Social Value ◽  
The Self ◽  
The Other ◽  
Social Value Orientation ◽  
Inference Process ◽  
Social Partners

To benefit from social interactions, people need to predict how their social partners will behave. Such predictions arise through integrating prior expectations with evidence from observations, but where the priors come from and whether they influence the integration is not clear. Furthermore, this process can be affected by factors such as paranoia, in which the tendency to form biased impressions of others is common. Using a modified social value orientation (SVO) task in a large online sample (n=697), we showed that participants used a Bayesian inference process to learn about partners, with priors that were based on their own preferences. Paranoia was associated with preferences for earning more than a partner and less flexible beliefs regarding a partner’s social preferences. Alignment between the preferences of participants and their partners was associated with better predictions and with reduced attributions of harmful intent to partners.

scholarly journals Data and non-linear models for the estimation of biomass growth and carbon fixation in managed forests

Data in Brief ◽  
2019 ◽  
Vol 23 ◽  
pp. 103841 ◽  
Author(s):  
Ariane Albers ◽  
Pierre Collet ◽  
Anthony Benoist ◽  
Arnaud Hélias
Keyword(s):  
Carbon Fixation ◽  
Linear Models ◽  
Biomass Growth ◽  
Managed Forests ◽  
Non Linear

scholarly journals Use of Modified Reineke’s Stand Density Index in Predicting Growth and Survival of Chinese Fir Plantations

2019 ◽  
Vol 65 (6) ◽  
pp. 776-783 ◽  
Author(s):  
Xiongqing Zhang ◽  
Quang V Cao ◽  
Lele Lu ◽  
Hanchen Wang ◽  
Aiguo Duan ◽  
...  
Keyword(s):  
Predictor Variable ◽  
Basal Area ◽  
Stand Density ◽  
Chinese Fir ◽  
The Self ◽  
Survival Models ◽  
Future Climate Change ◽  
Growth And Survival ◽  
Density Index ◽  
Stand Density Index

Abstract Stand density index (SDI) has played an important role in controlling stand stocking and modeling stand development in forest stands. Reineke’s SDI (SDI_R) is based on a constant slope of –1.605 for the self-thinning line. For Chinese fir plantations, however, it has been reported that the self-thinning slope varied with site and climate, rendering SDI_R questionable. Remeasured data from 48 plots distributed in Fujian, Jiangxi, Guangxi, and Sichuan provinces were used to develop models for prediction of stand survival and basal area, with SDI_R incorporated as a predictor variable. Also included in the evaluation were growth models based on self-thinning slopes estimated from two groups of sites (SDI_S) or from climate variables (SDI_C). Results indicated that models with climate-sensitive SDI (SDI_C) performed best, followed by SDI_S and SDI_R. The control models without SDI received the worst overall rank. Inclusion of climate-sensitive SDI in growth and survival models can therefore facilitate modeling of the relation between stand density and growth/survival under future climate-change conditions.

A Comparison of Diameter-and Volume-Based Stocking Guides for Red Alder

1989 ◽  
Vol 4 (4) ◽  
pp. 113-115 ◽  
Author(s):  
David E. Hibbs ◽  
Gary C. Carlton
Keyword(s):  
United States ◽  
Stand Density ◽  
The Self ◽  
Western United States ◽  
Alnus Rubra ◽  
Stem Density ◽  
Red Alder ◽  
Rule Based ◽  
Density Index ◽  
Stand Density Index

Abstract Stocking guides based on Reineke's stand density index concept (diameter vs stem density) and on the self-thinning rule (volume vs stem density) are currently in use in the western United States. A self-thinning rule-based guide has been developed for red alder (Alnus rubra). In this paper, we develop a Reineke-type guide for red alder and compare the growth of thinned and self-thinning stands in both systems. Stand density appears to be defined differently in the two systems, leading to differences in density management prescriptions. West. J. Appl. For. 4(4):113-115, October 1989.

scholarly journals Density Management Diagram for Northeastern Red Spruce and Balsam Fir Forests

1999 ◽  
Vol 16 (1) ◽  
pp. 48-56 ◽  
Author(s):  
Duncan S. Wilson ◽  
Robert S. Seymour ◽  
Douglas A. Maguire
Keyword(s):  
Stand Density ◽  
Maximum Size ◽  
Site Index ◽  
The Self ◽  
Red Spruce ◽  
Balsam Fir ◽  
Stand Development ◽  
Exponential Relationship ◽  
Data Set ◽  
Natural Stands

Abstract A stand-density management diagram is presented for use in northeastern red spruce and balsam fir forests. The diagram was derived from an extensive archived data set collected during the 1970s from fully stocked stands throughout northern Maine and a more recent study of precommercially thinned stands. The negative exponential relationship between mean stemwood volume per tree and stand density, commonly known as the "self-thinning rule, "was formulated to define a biological maximum stand density. The maximum size-density equation can be used to calculate the relative density of any stand and is accurate for thinned and unthinned natural stands as well as plantations. Equations for estimating quadratic mean diameter and stand top height are also derived for unthinned natural stands only. Data used to fit the self-thinning line are substantially above the A-lines on the familiar northeastern stocking guides, suggesting that these guides underestimate maximum density and thus overpredict self-thinning. Examples illustrate how to use the diagram to predict stand development under commercial and precommercial thinning scenarios, as well as natural stand development without thinning. Relevant site index and volume equations are included in an appendix. North. J. Appl. For. 16(1):48-56.

Climate-sensitive self-thinning trajectories of Chinese fir plantations in south China

2018 ◽  
Vol 48 (11) ◽  
pp. 1388-1397 ◽  
Author(s):  
Xiongqing Zhang ◽  
Lele Lu ◽  
Quang V. Cao ◽  
Aiguo Duan ◽  
Jianguo Zhang
Keyword(s):  
South China ◽  
Minimum Temperature ◽  
Stand Density ◽  
Chinese Fir ◽  
Mitigation Strategies ◽  
The Self ◽  
Maximum Temperature ◽  
Mean Annual Temperature ◽  
First Order ◽  
Stand Density Management

The self-thinning rule is fundamental in regulating maximum stocking and constructing stand density management diagrams. Chinese fir (Cunninghamia lanceolata (Lamb.) Hook.) is the most important tree species and widely distributed across subtropical China. Yet, our understanding of how the self-thinning line of Chinese fir relates to climate is limited. Longitudinal data from 48 plots distributed in Fujian, Jiangxi, Guangxi, and Sichuan provinces were used to describe self-thinning for Chinese fir in relation to climate through first-order autoregressive (AR(1)) and nonlinear mixed effects (NLME) models. Results showed that self-thinning lines had steeper slopes for Chinese fir growing in areas with larger annual precipitation and summer mean maximum temperature but flatter slopes with higher mean annual temperature, degree-days below 0 °C, and winter mean minimum temperature. Winter mean minimum temperature was the dominant climatic factor in shaping self-thinning lines, which suggests that temperature was the key climate driver that affects self-thinning of Chinese fir. In addition, differences of slopes for any two of the four sites were significant, except between the Guangxi and Sichuan sites. Our results will be useful for both the silvicultural practices and mitigation strategies of Chinese fir under climate change in south China.

scholarly journals Estimating the asphaltene critical nanoaggregation concentration region using ultrasonic measurements and Bayesian inference

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Aleksandra Svalova ◽  
David Walshaw ◽  
Clement Lee ◽  
Vasily Demyanov ◽  
Nicholas G. Parker ◽  
...  
Keyword(s):  
Bayesian Inference ◽  
Critical Concentration ◽  
Computational Cost ◽  
The Self ◽  
Dynamic Simulations ◽  
Credible Intervals ◽  
Surface Active ◽  
Self Association ◽  
Computationally Intensive ◽  
Oil Emulsions

AbstractBayesian inference and ultrasonic velocity have been used to estimate the self-association concentration of the asphaltenes in toluene using a changepoint regression model. The estimated values agree with the literature information and indicate that a lower abundance of the longer side-chains can cause an earlier onset of asphaltene self-association. Asphaltenes constitute the heaviest and most complicated fraction of crude petroleum and include a surface-active sub-fraction. When present above a critical concentration in pure solvent, asphaltene “monomers” self-associate and form nanoaggregates. Asphaltene nanoaggregates are thought to play a significant role during the remediation of petroleum spills and seeps. When mixed with water, petroleum becomes expensive to remove from the water column by conventional methods. The main reason of this difficulty is the presence of highly surface-active asphaltenes in petroleum. The nanoaggregates are thought to surround the water droplets, making the water-in-oil emulsions extremely stable. Due to their molecular complexity, modelling the self-association of the asphaltenes can be a very computationally-intensive task and has mostly been approached by molecular dynamic simulations. Our approach allows the use of literature and experimental data to estimate the nanoaggregation and its credible intervals. It has a low computational cost and can also be used for other analytical/experimental methods probing a changepoint in the molecular association behaviour.

scholarly journals Stock Assessment of Small Yellow Croaker (Larimichthys polyactis) Off the Coast of China Using Per-Recruit Analysis Based on Bayesian Inference

2021 ◽  
Vol 8 ◽  
Author(s):  
Lixin Zhu ◽  
Changzi Ge ◽  
Zhaoyang Jiang ◽  
Chunli Liu ◽  
Gang Hou ◽  
...  
Keyword(s):  
Bayesian Inference ◽  
Mortality Rate ◽  
Growth Parameters ◽  
Stock Assessment ◽  
Larimichthys Polyactis ◽  
Small Yellow Croaker ◽  
Spawning Stock ◽  
Key Factor ◽  
The Status ◽  
Spawning Potential Ratio

This paper presents a framework for quantifying uncertainty in per-recruit analysis for small yellow croaker (Larimichthys polyactis) fisheries in China, in which credible estimates of life history parameters from Bayesian inference were used to generate the distribution for a quantity of interest. Small yellow croakers were divided into five spatial groups. The status of each group was examined using a yield-per-recruit (YPR) model and a spawning stock biomass-per-recruit (SSBPR) model. The optimal length at first capture (Lcopt) was proposed to recover the biomass. The maximum observed age in the current stocks (3 years) and the maximum recorded age (≥20 years) were adopted in per-recruit analysis. Our results suggest that the framework can quantify uncertainty well in the output of per-recruit analysis for small yellow croaker. It is suited to other fish species. The SSBPR at FMSY (SSBPRMSY) is a better benchmark than the spawning potential ratio (SPR) at FMSY because SSBPRMSY had a unimodal distribution. The SSBPR analysis can lead to a more conservative Lcopt than the YPR analysis. The key factor influencing the assessment conclusions may be the growth parameters rather than the natural mortality rate for a stock with a younger maximum age. Overfishing likely occurred for all groups and recruitment overfishing may not occur if the maximum age is maintained at 3 years. Increasing lengths at first capture to the recommended values can help this population recover. However, Fcur is too high for small yellow croakers to attain the maximum recorded age. Both reducing fishing mortality rate and increasing length at first capture are needed to attain the maximum recorded age.

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