Western Journal of Applied Forestry最新文献_第3页

Field Note: Seed Viability and Female Cone Characteristics of Mature Knobcone Pine Trees 田间笔记:成熟红松种子活力和雌球果特性

Western Journal of Applied Forestry

Pub Date : 2013-01-01 DOI: 10.5849/WJAF.11-046

D. Fry, S. Stephens

引用次数: 4

Density Effects on Giant Sequoia (Sequoiadendron giganteum) Growth Through 22 Years: Implications for Restoration and Plantation Management 22年来密度对巨红杉生长的影响:对恢复和人工林管理的启示

Western Journal of Applied Forestry

Pub Date : 2013-01-01 DOI: 10.5849/WJAF.12-017

R. York, K. O’Hara, J. Battles

vary distinctly between species and growth parameters, providing specific insights for predictions of competitive effects and corresponding management implications. We, therefore, focus on measuring the nature of the development of the density-growth relationships over time, an approach possible in this case because of the frequency and precision of measurements at regular intervals during stand development. Methods Study Site Blodgett Forest Research Station (BFRS) is located on the western slope of the Sierra Nevada mountain range in California (38°52 N; 120°40 W). The study is within BFRS at an elevation of 1,320 m. The climate is Mediterranean with dry, warm summers (14–17° C) and mild winters (0–9° C). Annual precipitation averages 166 cm, most of it coming from rainfall during fall and spring months, while snowfall ( 35% of total precipitation) typically occurs between December and March. Before fire suppression (ca. 1890), the median point fire interval in the area was 9–15 years (Stephens and Collins 2004). The soil developed from andesitic lahar parent material. Soils are productive, with heights of mature codominant trees at BFRS typically reaching 31 m in 50 years. Vegetation at BFRS is dominated by a mixed conifer forest type, composed of variable proportions of five coniferous and one hardwood tree species (Tappeiner 1980). Giant sequoia is not among the five native conifer species present. BFRS is, however, approximately 16 km south of the northernmost native grove. The topography, soils, and climate of the study area are similar to the conditions found in native groves, although total precipitation at BFRS tends to be greater than in the southern Sierra Nevada where the majority of native groves occur. As within native groves, giant sequoia grows well in the study area, outgrowing all associated species through at least year 7 in planted canopy openings (Peracca and O’Hara 2008, York et al. 2004, 2011). In plantation settings throughout the Sierra Nevada, giant sequoias outgrow other conifer species through 3 decades after planting where soil productivity is high (Kitzmiller and Lunak 2012). Where it has been planted in Europe, it also typically outgrows other conifers (Knigge 1992). Study Design and Analysis for Height and Stem Diameter Seedlings were planted in 1989 at nine levels of density ranging from 2.1to 6.1-m hexagonal spacing between seedlings. To ensure that a tree was growing at each planting location, seedlings were initially double-planted, with the less vigorous seedling of the pair removed after 2 years. Treatments were applied across 0.08to 0.2-ha plots, depending on planting density (i.e., wider spacings required larger plots). Competing vegetation was removed periodically to control for any variation in resource availability not due to gradients in giant sequoia density (e.g., West and Osler 1995). Treatments were installed with a randomized block design (Figure 1), with each treatment randomly assigned once with

不同物种和生长参数之间的差异明显，为预测竞争效应和相应的管理含义提供了具体的见解。因此，我们将重点放在测量密度-生长关系随时间发展的性质上，这种方法在这种情况下是可能的，因为在林分发育期间定期测量的频率和精度。Blodgett森林研究站(BFRS)位于美国加利福尼亚州内华达山脉西坡(38°52 N;120°40 W)。该研究位于海拔1320米的BFRS范围内。气候属地中海气候，夏季干燥温暖(14-17°C)，冬季温和(0-9°C)。年平均降水量166厘米，大部分来自秋季和春季的降雨，而降雪(占总降水量的35%)通常发生在12月至3月之间。在灭火之前(约1890年)，该地区的火灾间隔中位数为9-15年(Stephens and Collins 2004)。土壤由安山岩泥凝岩母质发育而成。土壤肥沃，50年内，BFRS共优势成熟树木的高度通常达到31米。BFRS的植被以混合针叶林类型为主，由5种针叶林和1种硬木树种的不同比例组成(Tappeiner 1980)。巨红杉不在现存的五种本土针叶树中。然而，BFRS位于最北端的原生树林以南约16公里处。研究区域的地形、土壤和气候与原生树林的条件相似，尽管BFRS的总降水量往往大于大多数原生树林所在的内华达山脉南部。在原生树林中，巨红杉在研究区域生长良好，至少在第7年长于所有相关树种(Peracca and O 'Hara 2008, York et al. 2004, 2011)。在整个内华达山脉的种植园环境中，在土壤生产力高的地方种植后30年内，巨红杉的生长速度超过了其他针叶树物种(Kitzmiller和Lunak 2012)。在欧洲种植它的地方，它也通常比其他针叶树长得长(Knigge 1992)。1989年，以2.1 ~ 6.1 m的六角形苗间距为9个密度水平，进行了幼苗高度和茎粗的研究设计与分析。为了确保树木在每个种植地点都能生长，幼苗最初被双重种植，两年后将两株中较弱的幼苗移走。根据种植密度(即更宽的间距需要更大的地块)，在0.08至0.2公顷的地块上施用处理。定期移除竞争植被，以控制资源可用性的任何变化，而不是由于巨红杉密度的梯度(例如，West和Osler, 1995年)。处理采用随机区组设计(图1)，每个处理在三个相邻区组中随机分配一次(即每个密度水平有n 3个地块重复)。报告了所有树木在第4、10、16和22个生长期的高度和胸径(1.37 m)测量结果。为了进行分析，沿着处理区域边缘的树木(即“保护树”)被移除，以避免处理之间的相互作用。22年后，任何一侧有死亡或失踪邻居的树木也被从分析中删除(32个种植地点有死亡或失踪的树木)。最终的数据集由2303棵树组成。第七年的研究结果由Heald和Barrett(1999)提出。在这里，对最近的测量(第22年)进行了密度效应的详细分析，并使用6年间隔的所有直径和高度测量来重建密度相关竞争效应随时间的趋势。测量结果以图为实验单位，密度为连续变量(9个密度水平27个总样本单位，每个重复n 3次)。分析高度和直径增长的第一步是用一个合适的方程来拟合22年的测量结果，这个方程最好地描述了密度和树木大小之间的关系。然后，我们使用选定的22年方程来拟合以前测量年的数据，以重建密度效应是如何发展的。这种方法的缺点是假设密度-树大小的关系随着时间的推移是相似的，因为没有为每个测量周期选择单独的拟合。然而，它的优点是提供了相同的斜率参数随时间的变化，因此可以量化密度-尺寸关系的趋势。跟踪斜率的变化使我们能够描绘出随着时间的推移，对给定增长参数的竞争影响的变化性质。对于不同密度水平，以每棵树之间平均分配的水平生长空间(m)作为预测变量。生长空间是通过将每个处理区域的总空间除以该区域内以六边形间距种植的树木数量来计算的。每个处理的生长空间的边界都被定义为延伸到周围树木的茎外，到邻近树木的一半。因此，生长空间在这里被简单地定义为种植时每棵幼苗所分割的水平空间的大小，它与树间的线性距离相关，与树密度成反比。从这一点开始，我们使用术语生长空间来表示茎密度，但请注意，生长空间与密度成反比。处理梯度最小为3.7 m/茎(2702茎/ha)，最大为28.4 m/茎(353茎/ha)。我们使用22年的测量从一组真实的候选模型(sensu Johnson和Omland 2004)中选择最佳模型来描述生长空间对平均单株树木生长的影响，包括高度和茎粗。然后，我们使用选定的模型来拟合前几年的测量结果，比较模型的斜率参数和相应的年份之间的95%置信区间，以跟踪竞争效应随时间的变化。候选模型必须是简单的(如图1所示)。随机街区设计的俯视图，来自加利福尼亚州西部Blodgett森林的巨型红杉密度研究。j:。对。28(1) 2013 31几个参数)合理的生长空间大小关系的量化，每个参数都代表了工作中的单独生物机制。候选集包括四个关系。第一个是一个简单的线性方程，反映了生长空间和树大小之间的可加关系(即，更多的空间等于更多的生长，而不会减少或增加回报):树的大小a b*生长空间，其中a是y截距，b是线性系数(即斜率)。这种关系的管理应用是在最宽的间距下单株生长最大化。第二个模型是对数线性拟合，反映了生长空间对树大小的乘法效应:树大小a b(log*生长空间)当树大小在考虑的生长空间范围内单调增加时，就会发生对数线性拟合。生长在最宽的间距处最大，但与线性拟合不同，树木大小的回报随着最宽的间距而减少。第三个模型是二次拟合，反映了生长空间对树大小的最终负面影响:树大小a b*生长空间c*生长空间，其中c为二次系数。当生长空间的增加对树的大小产生最终的负面影响时，就会出现二次拟合。例如，这种情况会发生在树木因邻近遮阳而长高的情况下(Gilbert et al. 2001)。最后一个模型是Michaelis-Menten拟合，这是一条反映饱和效应的渐近曲线:树的大小d*生长空间/ e生长空间，其中d是曲线的渐近线(预测的最大树大小)，e是树的大小为最大值的一半的生长空间。这种关系意味着一个最大生长空间，在这个空间中，进一步的增长不会导致树的大小增加或减少。值得注意的是，这些数学关系，当以图形形式表示并用于对管理作出推论时，受到数据的限制。例如，如果选择二次型，我们显然不希望树的大小趋向于零。我们也不会期望这种线性关系无限期地持续下去。虽然当相关性变化时，这些曲线之间的差异可能很微妙，但这个特定数据集的高精度使我们能够区分它们。使用Akaike的信息标准权重(AICw)和小样本校正(Sugiura 1978)对最佳模型进行排序和选择。AIC权重是原始AIC值的似然转换，因此，在比较每个模型的执行情况时，它比原始值更有意义。例如，AICw为0.80，意味着与其他候选模型和给定的数据相比，该模型有80%的可能性是最佳模型(Burnham and Anderson 2002)。虽然原始AIC值通常被解释为最低值是最佳模型，但AIC权重恰恰相反。我们还报告了证据比，即最佳模型的AICw与其他模型之间的比率。证据比本质上衡量的是最好的模型有多好。枝径、枝密度和茎体积的测量与分析枝径和枝密度数据仅在第16年后收集(时间安排与进行人工修剪的逻辑年龄一致)。最接近1的

{"title":"Density Effects on Giant Sequoia (Sequoiadendron giganteum) Growth Through 22 Years: Implications for Restoration and Plantation Management","authors":"R. York, K. O’Hara, J. Battles","doi":"10.5849/WJAF.12-017","DOIUrl":"https://doi.org/10.5849/WJAF.12-017","url":null,"abstract":"vary distinctly between species and growth parameters, providing specific insights for predictions of competitive effects and corresponding management implications. We, therefore, focus on measuring the nature of the development of the density-growth relationships over time, an approach possible in this case because of the frequency and precision of measurements at regular intervals during stand development. Methods Study Site Blodgett Forest Research Station (BFRS) is located on the western slope of the Sierra Nevada mountain range in California (38°52 N; 120°40 W). The study is within BFRS at an elevation of 1,320 m. The climate is Mediterranean with dry, warm summers (14–17° C) and mild winters (0–9° C). Annual precipitation averages 166 cm, most of it coming from rainfall during fall and spring months, while snowfall ( 35% of total precipitation) typically occurs between December and March. Before fire suppression (ca. 1890), the median point fire interval in the area was 9–15 years (Stephens and Collins 2004). The soil developed from andesitic lahar parent material. Soils are productive, with heights of mature codominant trees at BFRS typically reaching 31 m in 50 years. Vegetation at BFRS is dominated by a mixed conifer forest type, composed of variable proportions of five coniferous and one hardwood tree species (Tappeiner 1980). Giant sequoia is not among the five native conifer species present. BFRS is, however, approximately 16 km south of the northernmost native grove. The topography, soils, and climate of the study area are similar to the conditions found in native groves, although total precipitation at BFRS tends to be greater than in the southern Sierra Nevada where the majority of native groves occur. As within native groves, giant sequoia grows well in the study area, outgrowing all associated species through at least year 7 in planted canopy openings (Peracca and O’Hara 2008, York et al. 2004, 2011). In plantation settings throughout the Sierra Nevada, giant sequoias outgrow other conifer species through 3 decades after planting where soil productivity is high (Kitzmiller and Lunak 2012). Where it has been planted in Europe, it also typically outgrows other conifers (Knigge 1992). Study Design and Analysis for Height and Stem Diameter Seedlings were planted in 1989 at nine levels of density ranging from 2.1to 6.1-m hexagonal spacing between seedlings. To ensure that a tree was growing at each planting location, seedlings were initially double-planted, with the less vigorous seedling of the pair removed after 2 years. Treatments were applied across 0.08to 0.2-ha plots, depending on planting density (i.e., wider spacings required larger plots). Competing vegetation was removed periodically to control for any variation in resource availability not due to gradients in giant sequoia density (e.g., West and Osler 1995). Treatments were installed with a randomized block design (Figure 1), with each treatment randomly assigned once with","PeriodicalId":51220,"journal":{"name":"Western Journal of Applied Forestry","volume":"28 1","pages":"30-36"},"PeriodicalIF":0.0,"publicationDate":"2013-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.5849/WJAF.12-017","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70979629","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 26

Comparing Aerial Detection and Photo Interpretation for Conducting Forest Health Surveys 比较航空探测和照片解译在森林健康调查中的应用

Western Journal of Applied Forestry

Pub Date : 2013-01-01 DOI: 10.5849/WJAF.12-010

Justin C. Backsen, B. Howell

引用次数: 15

Stand Density Index Estimates Leaf Area Index in Uneven-Aged Ponderosa Pine Stands 林分密度指数估算非均匀年龄黄松林分叶面积指数

Western Journal of Applied Forestry

Pub Date : 2013-01-01 DOI: 10.5849/WJAF.12-004

Seth A. Ex, F. Smith

引用次数: 4

Simulating the Effects of Forest Management on Stream Shade in Central Idaho 模拟爱达荷州中部森林管理对溪流遮荫的影响

Western Journal of Applied Forestry

Pub Date : 2013-01-01 DOI: 10.5849/WJAF.11-037

M. Teply, Dale J. McGreer

引用次数: 2

A density management diagram for even-aged Sierra Nevada mixed-conifer stands 内华达山脉混合针叶林的密度管理图

Western Journal of Applied Forestry

Pub Date : 2012-10-01 DOI: 10.5849/WJAF.11-036

J. Long, J. Shaw

We have developed a density management diagram (DMD) for even-aged mixed-conifer stands in the Sierra Nevada Mountains using forest inventory and analysis (FIA) data. Analysis plots were drawn from FIA plots in California, southern Oregon, and western Nevada which included those conifer species associated with the mixed-conifer forest type. A total of 204 plots met the selection criteria for analysis, which were for even-agedness and species composition. Even-agedness was characterized by a ratio between two calculations of stand density index. Species composition included admixtures of the species characterizing the Sierra Nevada mixed-conifer type with up to 80% of stand basal area contributed by ponderosa and Jeffrey pines. The DMD is unbiased with respect to species composition and therefore should be broadly applicable to the mixed-conifer type. The DMD is intended for use in even-aged stands, but may be used for uneven-aged management where a large-group selection system is used. Examples of density management regimes are illustrated, and guidelines for use are provided.

我们利用森林清查和分析(FIA)数据，为内华达山脉的均匀龄混合针叶林开发了密度管理图(DMD)。分析样地取自加利福尼亚州、俄勒冈州南部和内华达州西部的FIA样地，其中包括与混合针叶林类型相关的针叶林种。共有204个样地符合平均年龄和物种组成的选择标准。林分密度指数的两个计算值之间的比值表征了均匀老化。物种组成包括内华达山脉混合针叶林类型的物种混合物，黄松和Jeffrey松树占林分基底面积的80%。DMD在物种组成方面是无偏的，因此应该广泛适用于混合针叶树类型。DMD旨在用于平均年龄的林分，但也可用于使用大群选择系统的非平均年龄管理。举例说明了密度管理制度，并提供了使用指南。

引用次数: 18

Growth of Giant Sequoia Compared to Ponderosa Pine and Other Mixed-Conifers in California Plantations 加州人工林中巨红杉与黄松及其他混种针叶树的生长比较

Western Journal of Applied Forestry

Pub Date : 2012-10-01 DOI: 10.5849/WJAF.11-029

Jay J. Kitzmiller, G. Lunak

Giant sequoia (Sequoiadendron giganteum, SEGI) is a Sierra Nevada conifer famous for its supreme size, longevity, decay resistance, and visual appeal. A restricted natural range endangers SEGI to catastrophic wildfire and adverse climate change. Conservation aims to protect and restore extant native groves and to create new groves in promising forest environments. SEGI was compared to the best local conifer, usually ponderosa pine (PIPO), planted on 107 productive sites along western slopes of the Sierra Nevada and southern Cascades. SEGI had greater or similar ht and dbh as PIPO in more than 90% of the plantations. Best development and growth superiority of SEGI occurred in the southern latitudes (< 38.6° lat.), on high quality sites, and middle slopes with southwest aspects at low stand densities. SEGI increased in dbh superiority over PIPO linearly with stand age. On the southern latitude high quality sites, SEGI averaged 2.6 m taller and 22 cm larger in dbh than PIPO at age 50. SEGI incurred greater loss in dbh (compared to PIPO) from higher stand densities on southeastern aspects and high sites. Site elevation did not affect species comparisons. Warmer temperatures and higher precipitation differentially favored dbh of SEGI.

巨红杉(Sequoiadendron giganteum, SEGI)是一种内华达山脉的针叶树，以其超大的尺寸，长寿，抗腐性和视觉吸引力而闻名。有限的自然范围使SEGI面临灾难性的野火和不利的气候变化。保育的目的是保护和恢复现存的原生树林，并在有希望的森林环境中创造新的树林。将SEGI与种植在内华达山脉西部斜坡和卡斯卡德南部107个生产地点的最佳当地针叶树，通常是黄松(PIPO)进行比较。在90%以上的人工林中，SEGI的ht和dbh大于或相似于PIPO。南纬(< 38.6°)、高质立地和低林分密度、西南向的中坡上SEGI发育和生长优势最好。SEGI对PIPO的胸径优势随着林龄呈线性增加。南纬高质量样地50岁时SEGI比PIPO高2.6 m，平均胸径大22 cm。东南向和高立地林分密度越大，SEGI的胸径损失越大(与PIPO相比)。地点海拔对物种比较没有影响。气温升高和降水增多对SEGI的dbh有不同的影响。

{"title":"Growth of Giant Sequoia Compared to Ponderosa Pine and Other Mixed-Conifers in California Plantations","authors":"Jay J. Kitzmiller, G. Lunak","doi":"10.5849/WJAF.11-029","DOIUrl":"https://doi.org/10.5849/WJAF.11-029","url":null,"abstract":"Giant sequoia (Sequoiadendron giganteum, SEGI) is a Sierra Nevada conifer famous for its supreme size, longevity, decay resistance, and visual appeal. A restricted natural range endangers SEGI to catastrophic wildfire and adverse climate change. Conservation aims to protect and restore extant native groves and to create new groves in promising forest environments. SEGI was compared to the best local conifer, usually ponderosa pine (PIPO), planted on 107 productive sites along western slopes of the Sierra Nevada and southern Cascades. SEGI had greater or similar ht and dbh as PIPO in more than 90% of the plantations. Best development and growth superiority of SEGI occurred in the southern latitudes (< 38.6° lat.), on high quality sites, and middle slopes with southwest aspects at low stand densities. SEGI increased in dbh superiority over PIPO linearly with stand age. On the southern latitude high quality sites, SEGI averaged 2.6 m taller and 22 cm larger in dbh than PIPO at age 50. SEGI incurred greater loss in dbh (compared to PIPO) from higher stand densities on southeastern aspects and high sites. Site elevation did not affect species comparisons. Warmer temperatures and higher precipitation differentially favored dbh of SEGI.","PeriodicalId":51220,"journal":{"name":"Western Journal of Applied Forestry","volume":"13 14 1","pages":"196-204"},"PeriodicalIF":0.0,"publicationDate":"2012-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.5849/WJAF.11-029","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70979241","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 11

Riparian tree growth response to drought and altered streamflow along the dolores river, colorado 沿科罗拉多多洛雷斯河河岸树木生长对干旱和改变的水流的反应

Western Journal of Applied Forestry

Pub Date : 2012-10-01 DOI: 10.5849/WJAF.12-001

Adam P. Coble, T. Kolb

引用次数: 14

Conifer Crown Fuel Modeling: Current Limits and Potential for Improvement 针叶树冠燃料建模:目前的限制和改进的潜力

Western Journal of Applied Forestry

Pub Date : 2012-10-01 DOI: 10.5849/WJAF.11-039

David L. R. Affleck, Christopher R. Keyes, John M. Goodburn

Research from the wildland fire community during the past decade has targeted this area of decision support for advancement (e.g., Scott and Reinhardt 2001, Cruz et al. 2003, Keane et al. 2005). The need for better stand-level estimates of CBH and CBD prompted plot-scale intensive deconstruction of tree crowns of five western species (Reinhardt et al. 2006). That work resulted in the development of correlative relationships (Keane et al. 2005) and presumably better decision support tools (Scott and Reinhardt 2005) for managers assigning values for those parameters in fire and fuels planning software. Based on this and earlier work, crown fuel attributes are now calculated by managers with few exceptions via single-tree allometries applied to standard forest inventory plot data, most typically by using the Fire and Fuels Extension of the Forest Vegetation Simulator (FVS-FFE; Reinhardt and Crookston 2003). Yet, the intensive methodology applied by Reinhardt et al. (2006) did not permit analysis of crown and canopy features for stands of varying structures or treatment histories. Major weaknesses were exposed in employing FVS-FFE’s existing CBD and CBH algorithms in the Black Hills of South Dakota (Keyser and Smith 2010). Keyser and Smith demonstrated clearly that better models of crown fuels that include more accurate representations of vertical structure and that accommodate variations in local site and stand conditions (e.g., density and structure) are needed. Similarly, using Keyser and Smith’s Black Hills data, Cruz and Alexander (2012) found that, whereas the stand-level CBH and canopy fuel load models of Cruz et al. (2003) performed reasonably well, alternative approaches were needed to estimate CBD. Overall, it is apparent that improved models of crown and canopy characteristics are needed. These models would enable managers to more efficiently plan fuels treatments and evaluate their impacts on potential fire behavior at the project level. More recently developed mechanistic models of fire spread, such as the Wildland Urban Interface Fire Dynamics Simulator (WFDS; Mell et al. 2009) and FIRETEC (Linn et al. 2002), also require detailed characterizations of crown fuels. Linn et al. (2005) and Mell et al. (2009) applied these physics-based models of fire spread to stands simulated using geometric models of crown volume (e.g., parabolic and conic forms) and simplified models of crown bulk density; both studies found that simulated fire behavior was sensitive to crown and canopy characteristics. Adopting a more complex model of crown structure capable of describing withinand amongtree heterogeneity, Parsons et al. (2011) clearly demonstrated that the characterization of crown fuels could materially alter the simulated fire behavior in these systems. Looking beyond static models of crown fuels, silvicultural treatment effects on fuel characteristics have been simulated but not observed. In a rare study of temporal changes to crown fuel characteri

在过去十年中，来自野火社区的研究将这一领域的决策支持作为进步的目标(例如，Scott和Reinhardt 2001年，Cruz等人2003年，Keane等人2005年)。为了更好地估算CBH和CBD的林分水平，对西部五种树种的树冠进行了大规模的样地解构(Reinhardt et al. 2006)。这项工作导致了相关关系的发展(Keane et al. 2005)，并且可能是更好的决策支持工具(Scott and Reinhardt 2005)，用于管理人员在火灾和燃料规划软件中为这些参数分配值。基于这一研究和早期的工作，管理者现在通过应用于标准森林清盘图数据的单树异速生长来计算树冠燃料属性，很少有例外，最典型的是使用森林植被模拟器的火灾和燃料扩展(FVS-FFE;Reinhardt and Crookston 2003)。然而，Reinhardt等人(2006)采用的密集方法不允许分析不同结构或处理历史的林分的树冠和冠层特征。在南达科他州布莱克山使用FVS-FFE现有的CBD和CBH算法暴露了主要弱点(Keyser和Smith 2010)。Keyser和Smith清楚地表明，需要更好的冠状燃料模型，包括更准确的垂直结构表示，并适应当地场地和立地条件(例如密度和结构)的变化。同样，Cruz和Alexander(2012)使用Keyser和Smith的黑山数据发现，尽管Cruz等人(2003)的林分水平CBH和冠层燃料负荷模型表现相当好，但需要其他方法来估计CBD。总的来说，很明显需要改进的冠层和冠层特征模型。这些模型将使管理人员能够更有效地规划燃料处理，并在项目层面评估其对潜在火灾行为的影响。最近开发的火灾蔓延机制模型，如Wildland Urban Interface fire Dynamics Simulator (WFDS;Mell et al. 2009)和FIRETEC (Linn et al. 2002)也要求详细描述皇冠燃料。Linn等人(2005)和Mell等人(2009)将这些基于物理的火灾蔓延模型应用于使用树冠体积几何模型(例如抛物线和圆锥形式)和简化的树冠体积密度模型模拟的林分;两项研究都发现，模拟火灾行为对树冠和冠层特征很敏感。帕森斯等人(2011)采用了一种更复杂的树冠结构模型，能够描述树冠内部和树冠之间的异质性，他们清楚地表明，树冠燃料的表征可以在很大程度上改变这些系统中的模拟火灾行为。除了树冠燃料的静态模型之外，还模拟了造林处理对燃料特性的影响，但没有观察到。Scott和Reinhardt(2007)对冠状燃料特性的时间变化进行了一项罕见的研究，他们使用FVS-FFE模拟了各种处理对冠状燃料的影响。然而，我们意识到迄今为止还没有对观察到的冠状燃料特性的实际处理效果进行长期研究。这样一项研究将使建模模拟的验证试验成为可能。树冠燃料状况与树冠火势的一个相关但常被忽视的关系是叶片含水量。叶面含水量(FMC)与冠层基部高度相结合，决定了冠层着火的可能性(van Wagner 1977)。相对于冠层底部高度，其影响较小(Scott 1998b)，但在树冠抗火性方面是一个重要的操作因素，其比例重要性与地表火灾强度呈正相关(Keyes and O’hara 2002)。对许多北美物种FMC的研究已经发表(Agee et al. 2002, Keyes 2006)，在某些情况下报告了季节变化和新旧树叶之间的差异，这对管理人员在火灾模型模拟中分配广义FMC值很有用。然而，造林处理对FMC的影响尚不清楚，因为显然没有对任何北美树种进行过处理反应的研究(Keyes 2006)。有必要确定处理对FMC的影响，以确定FMC是否发生了变化，如果发生了变化，它们是否抵消或加剧了与危险燃料处理相关的皇冠燃料特性(CBD和CBH)的变化。在火和燃料领域之外，由于针叶树冠作为生物能源和碳储量、木材质量的决定因素以及树木和林分生长的驱动因素的重要性，人们对针叶树冠的结构进行了广泛的研究。各种各样的研究已经调查了针叶树冠的结构关系，从全树生物量异速生长到单个冠成分(如叶或活枝)的三维分布。虽然不同的冠成分传统上在不同的领域以不同的分辨率水平进行研究，但最近的工作已经更加关注其他学科的发展，并且越来越关注冠的垂直结构。然而，关于树冠结构内在变化的幅度或林分操纵的影响，仍然有相对较少的信息(但参见，例如，Brix 1981;Garber和Maguire (2005a, 2005b)在20世纪70年代，全树采伐技术的使用增加，加上化石燃料能源价格的上涨，开始了量化树冠生物量关系的广泛努力。在此之前，北美的许多地区已经使用了商品木材或纸浆木材的重量缩放，但对树枝木材和树叶生物量的兴趣相对较少。美国和加拿大的许多针叶树物种很快建立了冠生物量回归方程(例如，Young et al. 1980, treton and Hornbeck 1982, Evert 1985, Standish et al. 1985)。方法各不相同，但产生这些方程的研究的目的与Brown(1978)的研究相似，即从标准森林清查测量中寻求估算单株树木总树冠质量的区域异速。最近，随着对森林碳清查的兴趣日益增长，这类树木生物量研究的许多结果和数据集在旨在开发适用于国家或大陆尺度的碳产量方程的元分析研究中得到了重新审视(参见，例如，Jenkins等人2003年，Wirth等人2004年)。许多现有的树冠生物量方程对树冠燃料建模的效用有限。大多数生物量研究报告了单独的叶片和枝材生物量方程，但在相对较少的情况下，枝材按燃料时滞类别或活/死状态分类。树冠内生物量的空间分布也通常被忽视，尽管现在更密集的采伐方法引起了对某些地区枝材生物量垂直分布信息的需求(例如，Tahvanainen和Forss 2008)。尽管如此，对针叶树生物量异速性状的研究提供了大量关于树冠成分如何随树木属性系统变化的信息。从广义上讲，胸径的差异显然占总冠生物量变化的相当大的比例。同时，利用树高和冠长(或冠比)的附加信息可以大大提高166 WEST的精度。j:。对。27(4) 2012树冠生物量方程(参见，例如，Brown 1978, Evert 1985)。有关林分属性条件作用的信息较少。特别是，很少有研究在考虑了林分密度对树级属性(如冠长)的伴随效应之后，考察林分密度对单个树木叶片或树枝木材生物量的影响。虽然大多数树木生物量研究都集中在表征总冠重上，但已经开发了更详细的针叶树冠表示，用于茎材质量评估。木材等级和产品回收率受树枝大小和寿命的强烈影响，特别是受最大树枝直径和下孔树枝密度的影响。因此，对于许多具有重要商业价值的针叶树种，已经对其枝基面积的垂直分布进行了彻底的研究(例如，Colin and Houllier 1992, Maguire et al. 1994, 1999)。这条研究路线的特色产品是共同预测树枝基部直径分布和沿孔树枝数量作为树的尺寸，如胸径、总高度和树冠长度的函数的方程系统。一些最高分辨率的分支模型已经为美国南部的松树种植园开发出来。例如，Trincado和Burkhart(2009)最近的工作不仅描述了火炬松(Pinus taeda)分支直径的垂

{"title":"Conifer Crown Fuel Modeling: Current Limits and Potential for Improvement","authors":"David L. R. Affleck, Christopher R. Keyes, John M. Goodburn","doi":"10.5849/WJAF.11-039","DOIUrl":"https://doi.org/10.5849/WJAF.11-039","url":null,"abstract":"Research from the wildland fire community during the past decade has targeted this area of decision support for advancement (e.g., Scott and Reinhardt 2001, Cruz et al. 2003, Keane et al. 2005). The need for better stand-level estimates of CBH and CBD prompted plot-scale intensive deconstruction of tree crowns of five western species (Reinhardt et al. 2006). That work resulted in the development of correlative relationships (Keane et al. 2005) and presumably better decision support tools (Scott and Reinhardt 2005) for managers assigning values for those parameters in fire and fuels planning software. Based on this and earlier work, crown fuel attributes are now calculated by managers with few exceptions via single-tree allometries applied to standard forest inventory plot data, most typically by using the Fire and Fuels Extension of the Forest Vegetation Simulator (FVS-FFE; Reinhardt and Crookston 2003). Yet, the intensive methodology applied by Reinhardt et al. (2006) did not permit analysis of crown and canopy features for stands of varying structures or treatment histories. Major weaknesses were exposed in employing FVS-FFE’s existing CBD and CBH algorithms in the Black Hills of South Dakota (Keyser and Smith 2010). Keyser and Smith demonstrated clearly that better models of crown fuels that include more accurate representations of vertical structure and that accommodate variations in local site and stand conditions (e.g., density and structure) are needed. Similarly, using Keyser and Smith’s Black Hills data, Cruz and Alexander (2012) found that, whereas the stand-level CBH and canopy fuel load models of Cruz et al. (2003) performed reasonably well, alternative approaches were needed to estimate CBD. Overall, it is apparent that improved models of crown and canopy characteristics are needed. These models would enable managers to more efficiently plan fuels treatments and evaluate their impacts on potential fire behavior at the project level. More recently developed mechanistic models of fire spread, such as the Wildland Urban Interface Fire Dynamics Simulator (WFDS; Mell et al. 2009) and FIRETEC (Linn et al. 2002), also require detailed characterizations of crown fuels. Linn et al. (2005) and Mell et al. (2009) applied these physics-based models of fire spread to stands simulated using geometric models of crown volume (e.g., parabolic and conic forms) and simplified models of crown bulk density; both studies found that simulated fire behavior was sensitive to crown and canopy characteristics. Adopting a more complex model of crown structure capable of describing withinand amongtree heterogeneity, Parsons et al. (2011) clearly demonstrated that the characterization of crown fuels could materially alter the simulated fire behavior in these systems. Looking beyond static models of crown fuels, silvicultural treatment effects on fuel characteristics have been simulated but not observed. In a rare study of temporal changes to crown fuel characteri","PeriodicalId":51220,"journal":{"name":"Western Journal of Applied Forestry","volume":"27 1","pages":"165-169"},"PeriodicalIF":0.0,"publicationDate":"2012-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.5849/WJAF.11-039","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70979770","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 21

Effectiveness of Vehicle Washing and Roadside Sanitation in Decreasing Spread Potential of Port-Orford-Cedar Root Disease 车辆清洗与道路卫生对降低柏根病传播潜力的效果

Western Journal of Applied Forestry

Pub Date : 2012-10-01 DOI: 10.5849/WJAF.11-011

D. J. Goheen, K. Mallams, F. Betlejewski, E. Hansen

Two techniques widely recommended for managing Port-Orford-cedar root disease (caused by the introduced pathogen Phytophthora lateralis) are vehicle washing and roadside sanitation. However, their effectiveness has never been tested using a sample-based approach. Vehicle washing effectiveness was evaluated using Port-Orford-cedar seedling baits and a double-washing method. Washing with water can significantly reduce the amount of inoculum adhering to vehicles and boots. Effectiveness of roadside sanitation, the creation of zones along roads with few or no living Port-Orford-cedar hosts, was monitored using seedling baits for up to 12 years along ten infested roadsides that received operational treatments and for 8 years along four that did not. Sanitation treatments greatly reduced the amount of inoculum over time. Inoculum decline became most substantial in years 4 to 12 after treatment, suggesting that this treatment would be most useful in long-term strategies on roads used for many activities rather than in the short-term. Implementation monitoring of 17 roads that were sanitized by contract crews demonstrated that contractors were very thorough in removing all Port-Orford-cedars that met contract specifications. Vehicle washing and sanitation treatments reduce the likelihood of P. lateralis spread and are appropriate for use with other techniques in disease management strategies.

广泛推荐的两种管理Port-Orford-cedar根病(由引入的病原菌疫霉引起)的技术是车辆清洗和路边卫生。然而，它们的有效性从未使用基于样本的方法进行过测试。采用Port-Orford-cedar幼苗诱饵和双重清洗法对车辆清洗效果进行了评价。用水清洗可以显著减少附着在车辆和靴子上的接种菌数量。路边卫生设施的有效性，即沿着很少或没有活的波特福德雪松寄主的道路建立区域，在10个受感染的路边进行了长达12年的监测，在4个没有进行手术治疗的路边进行了8年的监测。随着时间的推移，卫生处理大大减少了接种量。接种量的下降在治疗后的第4年至第12年最为显著，这表明这种治疗对于用于许多活动的道路的长期策略最为有用，而不是短期策略。合同工作人员对17条道路进行了实施监测，结果表明，承包商非常彻底地清除了所有符合合同规定的波特福德雪松。车辆清洗和卫生处理减少了侧边疟原虫传播的可能性，适合与疾病管理策略中的其他技术一起使用。

{"title":"Effectiveness of Vehicle Washing and Roadside Sanitation in Decreasing Spread Potential of Port-Orford-Cedar Root Disease","authors":"D. J. Goheen, K. Mallams, F. Betlejewski, E. Hansen","doi":"10.5849/WJAF.11-011","DOIUrl":"https://doi.org/10.5849/WJAF.11-011","url":null,"abstract":"Two techniques widely recommended for managing Port-Orford-cedar root disease (caused by the introduced pathogen Phytophthora lateralis) are vehicle washing and roadside sanitation. However, their effectiveness has never been tested using a sample-based approach. Vehicle washing effectiveness was evaluated using Port-Orford-cedar seedling baits and a double-washing method. Washing with water can significantly reduce the amount of inoculum adhering to vehicles and boots. Effectiveness of roadside sanitation, the creation of zones along roads with few or no living Port-Orford-cedar hosts, was monitored using seedling baits for up to 12 years along ten infested roadsides that received operational treatments and for 8 years along four that did not. Sanitation treatments greatly reduced the amount of inoculum over time. Inoculum decline became most substantial in years 4 to 12 after treatment, suggesting that this treatment would be most useful in long-term strategies on roads used for many activities rather than in the short-term. Implementation monitoring of 17 roads that were sanitized by contract crews demonstrated that contractors were very thorough in removing all Port-Orford-cedars that met contract specifications. Vehicle washing and sanitation treatments reduce the likelihood of P. lateralis spread and are appropriate for use with other techniques in disease management strategies.","PeriodicalId":51220,"journal":{"name":"Western Journal of Applied Forestry","volume":"27 1","pages":"170-175"},"PeriodicalIF":0.0,"publicationDate":"2012-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.5849/WJAF.11-011","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70979031","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 10