Parameterization and testing of a coupled photosynthesis-stomatal conductance model for boreal trees

A coupled photosynthesis-stomatal conductance model was parameterized and tested with branches of black spruce (Picea mariana (Mill.) B.S.P.) and jack pine (Pinus banksiana Lamb.) trees growing in the Northern Study Area of the Boreal Ecosystem-Atmosphere Study (BOREAS) in Manitoba, Canada. Branch samples containing foliage of all age-classes were harvested from a lowland old black spruce (OBS) and an old jack pine (OJP) stand and the responses of photosynthesis (A(n)) and stomatal conductance (g(s)) to temperature, CO(2), light, and leaf-to-air vapor pressure difference (VPD) were determined under controlled laboratory conditions at the beginning, middle, and end of the growing season (Intensive Field Campaigns (IFC) 1, 2, and 3, respectively). The parameterized model was then tested against in situ field gas-exchange measurements in a young jack pine (YJP) and an upland black spruce (UBS) stand as well as in the OBS and OJP stands. Parameterization showed that Rubisco capacity (V(max)), apparent quantum yield (alpha') and Q(10) for sink limitation were the most crucial parameters for the photosynthesis sub-model and that V(max) varied among different measurement series in the laboratory. Verification of the model against the data used to parameterize it yielded correlation coefficients (r) of 0.97 and 0.93 for black spruce and jack pine, respectively, when IFC-specific parameters were used, and 0.77 and 0.87 when IFC-2 parameters were applied to all IFCs. For both measured and modeled g(s), the stomatal conductance sub-model, which linearly relates g(s) to (A(n)h(s))/c(s) (where h(s) and c(s) are relative humidity and CO(2) mole fraction at the leaf surface, respectively), had significantly steeper slopes and higher r values when only the VPD response data were used for parameterization than when all of the response data were used for parameterization. Testing the photosynthesis sub-model against upper canopy field data yielded poor results when laboratory estimates of V(max) were used. Use of the mean V(max) estimated for all upper canopy branches measured on a given day improved model performance for jack pine (from a nonsignificant correlation between measured and modeled A(n) to r = 0.45), but not for black spruce (r = 0.45 for both cases). However, when V(max) was estimated for each branch sample individually, the model accurately predicted the 23 to 137% diurnal variation in A(n) for all stands for both the upper and lower canopy. This was true both when all of the other parameters were IFC-specific (r = 0.93 and 0.92 for black spruce and jack pine, respectively) and when only mid-growing season (IFC-2) values were used (r = 0.92 for both species). Branch-specific V(max) estimates also permitted accurate prediction of field g(s) (r = 0.75 and 0.89 for black spruce and jack pine, respectively), although parameterization with all of the response data overestimated g(s) in the field, whereas parameterization with only the VPD response data provided unbiased predictions. Thus, after parameterization with the laboratory data, accurately modeling the range of A(n) and g(s) encountered in the field for both black spruce and jack pine was reduced to a single unknown parameter, V(max).     

An approach to modeling the joint distribution of tree diameter and height data

Advantages of the application of bivariate distribution models to forest management cannot be overemphasized. However, there are quite a number of flexible statistical distributions not yet evaluated in their bivariate domains. Therefore, in this article, we evaluated the bivariate forms of some probability distribution models used in quantitative forestry. Six bivariate distributions were assessed: Burr XII (Burr XII-2), Dagum (Dagum-2), Kumaraswamy (Kum-2), the new Logit-Logistic-Dagum (LLD-2) distribution, Logit-Logistic (LL-2), and the much used Johnson’s S_BB. All models were constructed using the Plackett’s method except for the S_BB distribution. Appropriate constraints were imposed on the boundary parameters of the bivariate distributions using fractions derived from the Gumbel distribution. Models were fitted with maximum likelihood to the joint distribution of diameter and height data of Eucalyptus camaldulensis Dehn from 90 sample plots. Model assessment was based on negative log-likelihood (-ΛΛ), Corrected Akaike Information Criterion (AICc), Bayesian Information Criterion (BIC) and Hannan-Quinn Criterion (HQC). The result showed that the Johnson’s S_BB had the overall best performance. Their ranking order was: S_BB > LLD-2 > Burr XII-2 > Dagum-2 > LL-2 > Kum-2. These models can be used to simulate timber harvesting regime.     

核磁共振光谱和X射线光电子能谱对纤维低聚糖的分析

1H-1HCOSY和13C-1HHSQC谱对通过Bio-GelP-2柱(2.5cm×125cm)分离制备的纤维三糖、纤维四糖和纤维五糖进行分析。结果表明,在水溶液中纤维低聚糖还原末端C1位α构型与β构型之比(α/β)随聚合度增大而减小,纤维三糖主要是α构型(α/β,0.52),而纤维四糖和纤维五糖主要是β构型(α/β,分别是0.34和0.25)。X射线光电子能谱(XPS)分析表明纤维低聚糖的C1s主要有2种电子结合能,分别为284.8(C1s1,C—O)和286.1eV(C1s2,O—C—O),C1s1与C1s2之比(C1s1/C1s2)随聚合度增大而增大。     

Positive effect of forest structural diversity on aboveground stand carbon stocks for even-aged Scots pine (Pinus sylvestris L.) stands in the Sarıçiçek Forest,Northern Turkey

This study examines the relationships between forest structural diversity indices and aboveground stand carbon storage for even-aged and pure Scots pine stands located in the Sar?çiçek Forest, Northern Turkey. In the even-aged Scots pine stands, 293 sample plots were selected to represent various stand conditions such as site quality, age, and stand density. The stand structural diversity, including Shannon’s, improved Shannon, Simpson’s, McIntosh, Margalef, and Berger–Parker indices, was used to correlate the stand carbon storage values. Positive partial correlation coefficients between stand carbon storage and forest structural diversity indices, including the improved Shannon index (r?=?0.770), Shannon’s index (r?=?0.742), Simpson’s index (r?=?0.703), the Berger–Parker index (r?=?0.657), the Gini index (r?=?0.390), and the Margalef index (r?=?0.327), were found at the 0.01 level. These results offer an enhancement of theories concerning positive relationships between stand carbon storage and stand structural diversity for pure and single-species forests. Moreover, regarding biodiversity suitability and stand carbon storage as carbon sinks, the results illustrate that forest stands with higher structural diversity may be preferred when used to mitigate global warming.     

Hydraulic properties of Douglas-fir (Pseudotsuga menziesii) branches and branch halves with reference to compression wood

Douglas-fir (Pseudotsuga menziesii var. menziesii (Mirb.) Franco) branch segments were used to test the hypothesis that compression wood reduces xylem transport efficiency. Whole 3-year-old segments were first measured for specific conductivity (k(s), m(2) s(-1) MPa(-1)), then split lengthwise into upper and lower halves, the latter containing all or most of the compression wood in the segment. Halves were then remeasured for k(s) using a new technique that prevents leakage of permeating fluid during measurements. Lower branch halves had significantly lower k(s) than upper halves (6.4 +/- 0.3 versus 9.3 +/- 0.3 m(2) s(-1) MPa(-1) x 10(-4), respectively; n = 36), and despite their larger size, significantly lower hydraulic conductivity (k(h), m(4) s(-1) MPa(-1)) than upper halves. Lower branch halves had higher specific gravity (0.51 +/- 0.01 versus 0.45 +/- 0.01; n = 36), lower water content (123 +/- 2% versus 155 +/- 3%; n = 36), and larger proportions of volume occupied by both cell wall and air than upper halves. Lower halves had more tracheids per annual ring than upper halves (73 +/- 3 versus 63 +/- 2 per radial transect, respectively; n = 36), but tracheids were shorter and had narrower lumens than those of upper branch halves. Differences in hydraulic properties between upper and lower halves suggest that compression wood does reduce xylem transport efficiency. In contrast, the amount of compression wood in each sample did not explain any variation in whole unsplit sample hydraulic properties.     

6种宿根花卉植物的光合特性研究

目前,我国北方地区园林应用中宿根花卉的种类相对较少、品种单一。为了进行宿根花卉的引种栽培进而有效丰富园林宿根花卉的种类,以黑心菊、芙蓉葵、蜀葵、赛菊芋、紫茉莉、醉鱼草等6种宿根花卉为试验材料,利用CIRAS-3光合仪,研究其光合有效辐射、二氧化碳的响应以及光合速率日变化。结果表明,黑心菊、赛菊芋和醉鱼草净光合速率日变化表现为单峰曲线,未出现"午休"现象;芙蓉葵、蜀葵和紫茉莉为明显的双峰曲线,有明显的"午休"现象,且第2峰值均出现在14:00,其中黑心菊的光补偿点最低、光饱和点也较低,分别为18.69μmol/(m~2·s)和1 506.49μmol/(m~2·s),可以在遮阴环境下生长,而赛菊芋的光补偿点最高、光饱和点也较高,分别为32.45μmol/(m~2·s)和1 616.41μmol/(m~2·s),表现出较强的喜阳性。     

Parameterization and testing of a biochemically based photosynthesis model for walnut (Juglans regia) trees and seedlings

The biochemically based leaf photosynthesis model proposed by Farquhar et al. (1980) and the stomatal conductance model proposed by Jarvis (1976) were parameterized for walnut. Responses of photosynthesis to CO(2) and irradiance were used to determine the key parameters of the photosynthesis model. Concurrently, stomatal conductance responses to leaf irradiance (Q), leaf temperature (T(l)), water vapor pressure deficit at the leaf surface (D), and air CO(2) concentration at the leaf surface (C(s)) were used to parameterize the stomatal conductance model. To test the generality of the model parameters, measurements were made on leaves from a 20-year-old tree growing in the field, and from sunlit and shaded greenhouse-grown seedlings. The three key parameters of the photosynthesis model (maximum carboxylation rate V(cmax), electron transport capacity J(max), and dark respiration rate R(d)) and the key parameter of the conductance model (reference stomatal conductance, g(sref)) were linearly correlated with the amount of leaf nitrogen per unit leaf area. Unique relationships could be used to describe nitrogen effects on these parameters for leaves from both the tree and the seedlings. Our data allowed separation of the effects of increasing total photosynthetic apparatus per unit leaf area from the effects of partitioning nitrogen among different pools of this apparatus for foliage acclimation to leaf irradiance. Strong correlations were found between stomatal conductance g(s) and Q, D and C(s), whereas the relationship between g(s) and T(l) was weak. Based on these parameterizations, the model adequately predicted leaf photosynthesis and stomatal conductance when tested with an independent set of data obtained for the tree and seedlings. Total light-driven electron flows derived from chlorophyll fluorescence data obtained at different leaf temperatures were consistent with values computed by the model. The model was also tested with branch bag data acquired from a three-year-old potted walnut tree. Despite a relatively large variance between observed and simulated values, the model predicted stomatal conductance and photosynthesis reasonably well at the branch scale. The results indicate that the photosynthesis-conductance model developed here is robust and can be applied to walnut trees and seedlings under various environmental conditions where water is non-limiting.     

3种箬竹属植物光合特性的比较

为给湖南园林中运用的箬竹属植物的栽培以及园林应用提供理论依据,以5年生‘箬竹’Indocalamus tessellates(Munro)Keng f.、‘湖南箬竹’I.hunanensis B.M.Yang、‘阔叶箬竹’I.latifolius(Keng)Mc Clure为试材,研究了其光合特性及叶绿素荧光参数。结果表明:3种箬竹的净光合速率(Pn)日变化均呈单峰型曲线,峰值均出现在10:00,其中阔叶箬竹的峰值净光合速率最高,达14.79μmol/(m2·s);各个供试种的光合参数差异显著,阔叶箬竹的最大净光合速率、光饱和点(LSP)、光补偿点(LCP)较高,分别为15.16、1191.61、20.51μmol/(m2·s),箬竹的暗呼吸速率(Rd)较低,为0.461μmol/(m2·s)。叶绿素荧光参数显示湖南箬竹的电子传递速率(ETR)较高。表明阔叶箬竹的光合性能较强,相对较喜光,箬竹较耐荫,湖南箬竹的光合性能中庸。     

苏云金杆菌在森林害虫综合治理中的应用(英文)

苏云金杆菌是一种重要的微生物杀虫剂，而且能够编码几种昆虫毒蛋白基因。本文概述 了苏云金杆菌在森林害虫综合治理中的应用。苏云金杆菌HD1菌株及其衍生物被广泛用于防 治各种森林害虫，如Lymantria dispar, Choristoneura fumiferana, Thaumetopoea pityo campa, Rhyacionia buoliana和Lymantria monacha。文章提供了Bt毒蛋白基因在林木中的 构建和表达方面的研究进展并对Bt产品在森林害虫综合治理上的应用前景及限制因素进行了 初步讨论。     

东北落叶松不同器官的热值和灰分含量分析

植物热值是森林生态系统中物质循环和能量转化评价的重要指标。利用假设检验和回归分析方法,对东北落叶松不同器官的热值和灰分含量进行了研究。结果表明:林木不同器官的热值和灰分含量在统计上大都存在显著差异,去灰分热值从大到小排序为叶(21.57 kJ/g)﹥枝(20.98 kJ/g)﹥皮(20.73 kJ/g)﹥根(19.88 kJ/g)﹥干(19.51 kJ/g),灰分含量排序为叶(5.79%)﹥皮(2.48%)﹥枝(1.88%)﹥根(0.95%)﹥干(0.47%);树干热值和灰分含量随树干从下往上呈增加趋势,且上、中、下部均存在显著差异;树根热值和灰分含量从根茎、粗根到细根也呈增加趋势,且两两之间差异显著;地上部分的平均干质量热值、去灰分热值和灰分含量均大于地下部分(树根),且差异显著;不同器官的热值和灰分含量与林木直径、树高和起源等因子显著相关,但其影响程度不尽相同。     

雷州半岛地区林下栽培平菇栽培料配方试验

在雷州半岛地区进行林下平菇栽培试验,栽培料中用不同量的桉树木屑代替棉籽壳,以获得适宜林下栽培平菇的栽培料配方.结果表明:桉树木屑可以替代部分棉籽壳进行林下栽培平菇,桉树木屑52％、棉籽壳26％、米糠20％、蔗糖1％、石膏粉1％是较适宜的配方,应用该配方可以明显提高平菇的菌丝生长速度和鲜菇产量,其生物转化率为102.5％,比对照高出10.3％.     

马尾松PER同工酶与子代表型性状相关的研究

本项研究通过对马尾松亲子代针叶PER同工酶的分析,认为马尾松亲子代PER同工酶谱型相似而同一点位酶带相对含量相关不紧密。同时探讨了亲本及子代PER同工酶酶谱点位及相对含量与子代高生长的相关性,认为子代谱型与其本身高生长有一定相关性,而亲本PER同工酶谱型不能预测子代高生长,因而马尾松不能以单亲亲本针叶PER同工酶选择优良繁殖材料。     

从黄芩中微波辅助提取黄芩苷的研究

本研究运用新型分离方法微波辅助提取法(MAE)来提取黄芩中的黄芩苷.分别选用水、乙醇、氯仿、正己烷、石油醚作为萃取介质,在间歇微波辅助提取装置中,对10 g黄芩原料进行微波辅助提取实验,得出微波辅助提取的最佳工艺为:黄芩原材料粉碎粒度200目,溶剂为60%乙醇溶液,微波辐射8 min.同时还对微波辐射时间、溶剂、物料粒度等条件对黄芩苷得率的影响进行了探讨.结果表明微波辅助提取黄芩中的黄芩苷,具有质量稳定、速度快、萃取效率高等特点.     

木塑复合3D打印耗材制备研究进展

3D 打印 (3D printing, 3DP) 起源于 20 世纪 80 年代,是一种节材、节能的新兴增材制造技术, 其原理是分层制造、逐层叠加,近年来受到社会的广泛关注。文章简要介绍了 3D 打印技术的分类和常用 3D 打印材料种类,重点综述了近年来专用于 3D 打印的木塑复合材料的研究现状,指出了目前 3D 打印 用木塑复合材料存在的主要缺陷。     

Effects of leaf age and tree size on stomatal and mesophyll limitations to photosynthesis in mountain beech (Nothofagus solandrii var. cliffortiodes)

Mesophyll conductance, g(m), was estimated from measurements of stomatal conductance to carbon dioxide transfer, g(s), photosynthesis, A, and chlorophyll fluorescence for Year 0 (current-year) and Year 1 (1-year-old) fully sunlit leaves from short (2 m tall, 10-year-old) and tall (15 m tall, 120-year-old) Nothofagus solandrii var. cliffortiodes trees growing in adjacent stands. Rates of photosynthesis at saturating irradiance and ambient CO(2) partial pressure, A(satQ), were 25% lower and maximum rates of carboxylation, V(cmax), were 44% lower in Year 1 leaves compared with Year 0 leaves across both tree sizes. Although g(s) and g(m) were not significantly different between Year 0 and Year 1 leaves and g(s) was not significantly different between tree heights, g(m) was significantly (19%) lower for leaves on tall trees compared with leaves on short trees. Overall, V(cmax) was 60% higher when expressed on the basis of CO(2) partial pressure at the chloroplasts, C(c), compared with V(cmax) on the basis of intercellular CO(2) partial pressure, C(i), but this varied with leaf age and tree size. To interpret the relative stomatal and mesophyll limitations to photosynthesis, we used a model of carbon isotopic composition for whole leaves incorporating g(m) effects to generate a surface of 'operating values' of A over the growing season for all leaf classes. Our analysis showed that A was slightly higher for leaves on short compared with tall trees, but lower g(m) apparently reduced actual A substantially compared with A(satQ). Our findings showed that lower rates of photosynthesis in Year 1 leaves compared with Year 0 leaves were attributable more to increased biochemical limitation to photosynthesis in Year 1 leaves than differences in g(m). However, lower A in leaves on tall trees compared with those on short trees could be attributed in part to lower g(m) and higher stomatal, L(s), and mesophyll, L(m), limitations to photosynthesis, consistent with steeper hydraulic gradients in tall trees.     

Analysis of moisture diffusivity of larch timber during convective drying condition by using Crank＇s method and Dincer＇s method

Two analytical procedures （Crank＇s method and Dincer＇s method） for porous solid materials were reevaluated and used to determine moisture diffusion coefficients and moisture transfer coefficients for larch lumber subjected to drying. A diffusion-like equation was used to describe drying process data. The lumber was idealized in the modeling as infinite plates. The moisture transport process inside the board was assumed to be one-dimensional. The macroscopic drying kinetics curves of larch timber at particular conditions were determined experimentally. Based on these data, calculation for both the moisture diffusion coefficients and moisture transfer coefficients by the Dincer＇s analytical procedure were made. The dynamic moisture diffusion coefficients by the traditional Crank＇s method were calculated. In general, diffusion coefficients calculated by the Dincer＇s method were all higher than those by Crank＇s method. These results could be due to the differences between two analytical methods and also different characteristics between solid moisture diffusion process and heat transfer process. Therefore the analysis and solution procedures of moisture diffusion differential equations need to be adapted in the future. With drying temperature＇s increasing moisture diffusion coefficient （D） and moisture transfer coefficient （k） increases accordingly. Also the relationships between diffusion coefficients and temperature as well as material moisture contents were analyzed by using Arrhenius equation and bound water transport theory.     

Remote sensing and forest inventories in Nordic countries – roadmap for the future

The Nordic countries have long traditions in forest inventory and remote sensing (RS). In sample-based national forest inventories (NFIs), utilization of aerial photographs started during the 1960s, satellite images during the 1980s, laser scanning during the 2000s, and photogrammetric point clouds during the 2010s. In forest management inventories (FMI), utilization of aerial photos started during the 1940s and laser scanning during the 2000s. However, so far, RS has mostly been used for map production and research rather than for estimation of regional parameters or inference on their accuracy. In recent years, the RS technology has been developing very fast. At the same time, the needs for information are constantly increasing. New technologies have created possibilities for cost-efficient production of accurate, large area forest data sets, which also will change the way forest inventories are done in the future. In this study, we analyse the state-of-the-art both in the NFIs and FMIs in the Nordic countries. We identify the benefits and drawbacks of different RS materials and data acquisition approaches with different user perspectives. Based on the analysis, we identify the needs for further development and emerging research questions. We also discuss alternatives for ownership of the data and cost-sharing between different actors in the field.     

Estrogenic activity of the dichloromethane extract from Pueraria mirifica

Pueraria mirifica and its extracts are widely used as the ingredient(s) in many rejuvenating products. Up to now, the extract of P. mirifica roots that has been used in most studies, is the alcoholic extract. In the present study, we investigated the estrogenic activity using uterotropic and MCF-7 cell proliferation models of the dichloromethane extract as well as the water extract which was obtained from partitioning the ethanolic extract. The results indicated that among the three extracts, i.e. the ethanolic extract (PM1), the water extract (PM2) and dichloromethane extract (PM3), PM3 exhibited the most potent estrogenic activity in both models, followed by PM1. The extracts produced uterotropic activity associated with the increase of water content while uterotropic activity of 17beta-estradiol was related to the increase of muscle mass. The two isoflavonoids, genistein and daidzein, were not the major active phytoestrogens involving the estrogenic activity of these extracts.     

伯乐树1年生幼苗的光响应特征

采用自然全光照的16.72%(s17)、24.51%(s25)、36.49%(s36)和100%(s100)及林地下14.02%(s14)等5种光照强度,比较分析不同光照条件下的环境因子日变化、1年生幼苗成活率、生长量等指标,以期揭示幼苗对于夏季不同光照条件的光响应特征。结果表明:不同光照强度下,环境因子日变化显著不同,幼苗的成活率、形态和生理指标等均存在显著差异。极度弱光下(s17)幼苗生长迟缓;而全光照环境(s100)和较强光照下(s36)易造成幼苗的死亡;仅适度遮荫(s25)适于幼苗的生长;林下栽培(s14)的相对光照强度虽然较弱,但其各种小气候因子均明显优于无林地的其它光照条件,幼苗成活率、水分利用和平均净光合速率等指标均达到最优。建议抚育幼苗时应采用适宜的遮荫处理,可选择在中等郁闭度的林下(自然遮荫)或在大田中采用夏季单层遮荫。     

Multivariate product adapted grading of Scots pine sawn timber for an industrial customer,part 1: Method development

ABSTRACT

Rule-based automatic grading (RBAG) of sawn timber is a common type of sorting system used in sawmills, which is intricate to customise for specific customers. This study further develops an automatic grading method to grade sawn timber according to a customer's resulting product quality. A sawmill's automatic sorting system used cameras to scan the 308 planks included in the study. Each plank was split at a planing mill into three boards, each planed, milled, and manually graded as desirable or not. The plank grade was correlated by multivariate partial least squares regression to aggregated variables, created from the sorting system's measurements at the sawmill. Grading models were trained and tested independently using 5-fold cross-validation to evaluate the grading accuracy of the holistic-subjective automatic grading (HSAG), and compared with a re-substitution test. Results showed that using the HSAG method at the sawmill graded on average 74% of planks correctly, while 83% of desirable planks were correctly identified. Results implied that a sawmill sorting station could grade planks according to a customer's product quality grade with similar accuracy to HSAG conforming with manual grading of standardised sorting classes, even when the customer is processing the planks further.