The Houses That Matsutake Built<Superscript>1</Superscript>

The Houses That Matsutake Built. In the mountains of northwest Yunnan, China, a valuable mushroom, matsutake or song rong (Tricholoma matsutake) was commodified in the 1980s. Since that time, it has been exported in large quantities to Japan. The sale of matsutake now contributes more to the income of Shangri-la County (Diqing Autonomous Tibetan Prefecture) than any other crop, including timber and livestock. During the 1980s and 1990s, villagers in this remote region used their mushroom earnings to build spacious, beautiful new houses in the traditional local (Kham) style, and in some cases to buy motor vehicles or open businesses. In villages with access to productive matsutake habitat, virtually every household was able to build a new house; entire villages were transformed. During the 1990s, several villages developed locally based management regimes to enhance production and to address the problems and conflicts that arose from the harvest of such a valuable product. More recently, government agencies and NGOs have played a highly visible role in promoting “sustainable” harvest policies. The implications of their involvement are briefly examined and the future of matsutake harvest in Yunnan is discussed.     

Simulated performance of multi-year harvest regulation cycles for wild turkeys

Wild turkeys (Meleagris gallopavo) are a prolific species and valuable game animal throughout the United States. Stochastic simulations are commonly used to inform harvest management, and we used simulation to test performance of fall harvest management that included 1-, 3-, and 5-year cycles of population assessment and updating of harvest targets, respectively. To assess robustness of our conclusions, we replicated analyses across 18 combinations of model parameters that included population productivity (3 levels), sex-specific vulnerability to fall harvest (3 levels), and magnitude of spring harvest (2 levels). Performance of multi-year cycles, measured using abundance of males and annual harvest, depended on the context of model parameters that interacted to determine responses of populations to harvest. One- and 3-year cycles had similar performance so long as female harvests were less than or equal to male harvests. However, when harvest of females was greater than males, or when 5-year regulation cycles were implemented, there was greater risk due to nonlinear population responses to increased harvest. For example, nonlinearity resulted in thresholds where declines to abundance and harvest could occur with small increases to harvest rates, and thus the sustainability of fall harvests was less robust for multi-year cycles with time-lagged assessment and decision making. Moreover, the harvest rate resulting in threshold responses depended on model parameters and often occurred within the range of harvest rates recommended by earlier modeling studies (7–15%). Our results imply that multi-year cycles can be a viable approach to harvest management. Monitoring that provides information on sex-specific harvest is recommended, however, to determine if nonlinear population responses should be anticipated. Ideally, information on population-specific vital rates would also be available to allow managers to avoid harvest rates near thresholds that are expected to result in population declines. © The Wildlife Society, 2019     

Source areas of Blue-winged Teal harvested in Ontario and Prairie Canada based on stable isotopes: implications for sustainable management

Determining the source areas of harvested individuals is important for effective conservation and management of migratory game birds. Banding has provided much information about source areas, but obtaining samples of marked individuals representative of all potential breeding areas is difficult for most species. To add to previous knowledge of harvest derivation based on banding data and to assist with regulatory decisions, we used stable hydrogen isotope (δ²H) techniques to estimate natal and molt source areas of Blue-winged Teal (Spatula discors) harvested in southern Canada in 2014 and 2017. We found that most birds harvested in southern Saskatchewan, southern Manitoba, northern Ontario, and southern Ontario likely originated in the prairie and boreal plains regions of Canada and the United States, which is the core production area for the species. Based on feather δ²H values, some birds harvested in Ontario may have also originated in Ontario. Our results differ from those of a long-term analysis of band recovery data that revealed that most Blue-winged Teal harvested in Ontario originated in the eastern part of the province and areas along the lower Great Lakes and southwestern Quebec. We found that nearly all birds harvested in Ontario in our study likely originated from areas north and west of the province. Together, banding and stable isotopes likely provide the best information available on source areas of harvested birds for regulatory decision making.     

基于富营养化水体修复的凤眼莲放养及采收条件研究

为实现富营养化水体的修复,对影响凤眼莲〔Eichhornia crassipes(Mart.)Sloms〕高产高效的放养及采收条件(包括初始放养日期、采收标准和采收比例)进行了研究,并对凤眼莲的生长曲线以及N、P和K的积累量进行了分析。实验结果表明:在总氮、总磷和钾含量分别为3.41~7.18、0.05~0.27和2.24~5.18 mg.L-1的水体中,在生长前期由于产生分蘖和植株个体生长,凤眼莲生物量快速增加;当植株生长至一定高度,生物量增幅减小;通过这一生长过程,凤眼莲的最高生物量可达28.28 kg.m-2。初始放养日期对凤眼莲的生长曲线和生物量均有明显影响,随初始放养日期的推迟生物量逐渐增大,在4月10日、4月17日、4月24日、5月1日和5月8日放养的凤眼莲经过63 d的放养,生物量均明显增加,其中,5月8日放养的凤眼莲总生物量最高,达到24.36 kg.m-2。采收标准和采收比例对凤眼莲的采收频率和累计采收量以及N、P和K积累量具有显著影响。按照10~15、15~20、20~25、25 kg.m-2以上及最高生物量的采收标准以及1/2和2/3的采收比例进行采收,凤眼莲的累计采收量均高于一次性采收(对照),且与其生物量呈抛物线型关系,但采收频率则与生物量成反比;采取不同的采收标准及采收比例,凤眼莲的干物质含量及N、P和K含量及总量均有一定的差异,但除干物质含量外,N、P和K含量及总量均明显高于一次性采收;总体上,采用20~25 kg.m-2的采收标准及2/3采收比例,凤眼莲的累计采收量最高、采收频率较少,对N、P和K的积累量最大。综合比较结果显示:在南京地区凤眼莲可于4月初开始放养,4月至5月分蘖,6月以后正常生长,并可按照20~25 kg.m-2的采收标准和2/3的采收比例进行采收。     

Effects of secondary tuber harvest on populations of devil's claw (Harpagophytum procumbens) in the Kalahari savannas of South Africa

Devil's claw ( Harpagophytum procumbens ) is an internationally traded species that is harvested for its secondary tubers. Root extracts are used to treat arthritis and other inflammatory diseases. This study examined population structure, density, growth, mortality, and seed and fruit production in harvested and unharvested populations in the Kalahari savannas of South Africa over 4 years. Plant density and population structure differed significantly between overgrazed and grass-dominated areas, suggesting that the differences may be due to competition for water and nutrients. Experimental removal of secondary tubers (harvest) was not a significant factor for mortality in any of the harvested size classes. Harvest also did not affect growth, although plants in the 3–4 cm size class grew more in both the harvested and unharvested populations. Fruit production was variable; fruits matured only after sufficient rains. Under the conditions of this study, the species appears to be resilient to harvest, with both harvested and unharvested plants surviving. After harvest, both groups recovered and grew (on average) at the same rate. Because of the spatially variable habitat and the plasticity of the plants themselves, a large number of plants over a wide area are required to better understand the species' life history.     

择伐对吉林蛟河阔叶红松林群落结构及动态的影响

科学的森林经营能够优化林分结构,是调控森林生产力和生物多样性的有效手段。择伐作为森林经营的重要方式之一,其对森林结构以及群落动态的影响一直未有定论,因此迫切需要利用更加全面的数据对择伐及伐后林分特征的变化进行长期监测。根据森林大样地建立规范,2010年在吉林蛟河建立了42hm~2阔叶红松林动态监测样地,2011年冬季截取部分面积进行择伐经营,以经营样地为研究对象,运用数值变量描述采伐活动并分析择伐前后群落结构的变化;同时结合2015年的二次调查数据,以立地条件基本一致的对照样地为参照,比较林分水平和物种水平上死亡率、更新率的差异,并利用线性混合效应模型探究择伐活动对个体径向生长的影响。研究结果显示:经营样地的择伐强度为5.4%,受采伐干扰影响较大的物种主要包括色木槭、白牛槭、裂叶榆、胡桃楸、千金榆、水曲柳以及紫椴,采伐主要集中于林冠层树种,亚林层和灌木层个体很少涉及。择伐前后物种组成、径级结构等并未发生明显改变。5年间,经营样地和对照样地的林分密度都降低,对比对照样地,经营样地的死亡率较低,但其更新状况并未优于对照样地。从胸高断面积来看,经营样地整体的年平均生长量高于对照样地,表明择伐导致的稀疏对个体生长和存活起到了一定的促进作用。将采伐强度纳入线性混合效应模型中分析发现,胸径始终是影响个体生长的最重要因素,其次是树木个体之间的非对称竞争;采伐所涉及到的7个主要树种的年平均生长量均高于对照样地,但仅有紫椴的径向生长表现出对采伐干扰的显著响应。综合来看,低强度择伐对群落结构和动态的影响较小,不同物种的径向生长对择伐的响应存在一定差异。     

An assessment of the effect of harvest time and harvest method on biomass loss for Miscanthus × giganteus

This study examines the amount of biomass loss occurring in Miscanthus × giganteus crop at harvest. The study assesses loss incurred as a direct result of the harvest systems employed to collect the material along with examining how the time of harvest effects the amount of loss occurring over the spring harvest window. Pre harvest losses of 4.8–5.1% were measured prior to harvest. There was no significant difference between pre harvest loss and post harvest loss when a self‐propelled forage harvester fitted with a maize harvesting header was used to harvest the crop. The use of a conditioner mower and baler significantly increased crop losses to 9.4–14.1%. This demonstrates that correct selection of the harvest system can significantly increase biomass recovery. Additional losses were measured at headlands when the mower/baler system was used, but headland losses will not occur when self‐propelled forage harvesters are utilized. Losses were significantly greater in the area beside the swath after the baler pass when compared to prior to baling. This study has shown that correct selection of harvest systems can significantly increase biomass recovery, with no significant difference in pre harvest loss or harvest loss occurring as a result of cutting the M. × giganteus crop at different dates during the harvest window (March 1st, March 25th, April 21st).     

Density-Dependent Harvest Modeling for the Eastern Wild Turkey

Abstract Many current wild turkey (Meleagris gallopavo) harvest models assume density-independent population dynamics. We developed an alternative model incorporating both nonlinear density-dependence and stochastic density-independent effects on wild turkey populations. We examined model sensitivity to parameter changes in 5% increments and determined mean spring and fall harvests and their variability in the short term (3 yr) and long term (10 yr) from proportional harvesting under these conditions. In the long term, population growth rates were most sensitive to poult:female ratios and the form of density dependence. The nonlinear density-dependent effect produced a population that maximized yield at 40% carrying capacity. The model indicated that a spring or fall proportional harvest could be maximized for fall harvest rates between 0% and 13% of the population, assuming a 15% spring male harvest and 5% spring illegal female kill. Combined spring and fall harvests could be maximized at a 9% fall harvest, under the same assumptions. Variability in population growth and harvest rates increased uncertainty in spring and fall harvests and the probability of overharvesting annual yield, with growth rate variation having the strongest effect. Model simulations suggested fall harvest rates should be conservative (≤9%) for most management strategies.     

Effects of water stress on N2 fixation and grain yield of Phaseolus vulgaris L.

Most dry bean production in Mexico is under non-irrigated conditions in the semi-arid highlands. One of the most limiting factors is insufficient moisture during the reproductive stage and sometimes during the vegetative stage. The objective of this experiment was to study the effect of drought on nodulation, N₂ fixation and grain yield of beans. The cultivars evaluated were: Flor de Mayo Bajio, Bayocel, Bat-477 and Honduras-35. The treatments were water stress treatments during vegetative or reproductive stage and a control of minimal stress. To measure N₂ fixation, ¹⁵N-labelled fertilizer was used. Data for soil moisture, nodule number and nodule dry weight, as well as, straw and grain yield and total N were taken. The results indicated that water stress during vegetative stage depressed nodulation temporarily, but after watering regularly plants not only recovered completely but were nodulated better than the control. Water stress during the reproductive stage depressed nodulation and after watering there was no recovery. Grain yield was not affected by water stress during vegetative stage but it was reduced when water stress was imposed during the reproductive stage. The percentage of N derived from fixation varied among cultivars but was not affected by water stress treatment. The highest N₂ fixation occurred in Bayocel and Bat-477 and the lowest in Honduras-35 and F.M. Bajio, although the amounts were not as low as in some other reports.     

Regulation of leaf senescence, grain-filling and yield of rice by kinetin and abscisic acid

Senescence of rice ( Oryza sativa L. cv. Jaya) leaves was regulated with kinetin and abscisic acid (ABA) sprays at the reproductive stage. The effect of such sprays on grain-filling and yield was analyzed. Spraying 100-day-old plants with kinetin solution (100 μg ml^-1) significantly delayed senescence as indicated by higher total chlorophyll and protein levels in the three uppermost leaves compared with the controls. In contrast, spraying with ABA (15 μg ml^-1) significantly promoted foliar senescence. The number of spikelets per panicle, number of panicles, percentage filled grains, panicle weight and grain yield per plant and the mobilization and harvest indices were significantly increased by kinetin treatment, while ABA decreased most of them. The possibility of increased grain-filling and thus, yield due to delayed foliar senescence by kinetin treatment and decreased grain-filling due to hastening of senescence by ABA is discussed.     

油菜(Brassica napus L)收获指数的变异

本文首次采用田间试验的方法对国内油菜收获指数的变异进行了研究．结果表明不同油菜品种的收获指数存在变异,其变异规律大致是：１）中熟品种的收获指数高于早熟品种及晚熟品种;２）中长角果的品种较长角品种具有更高的收获指数;３）高产的新品种具有较高的收获指数;４）油菜粒壳比,角杆比及千粒重与收获指数呈正相关,杆重与收获指数呈负相关．     

Small mammals in new farm woodlands

A number of recently planted farm woodlands, along with adjacent agricultural land and hedgerows were surveyed using live traps to compare their importance for small mammals. Small mammal numbers were far higher in newly planted woodlands than in both hedgerows and agricultural land. Seven species were trapped in farm woods compared with five in hedgerows and two in agricultural land. The most frequently trapped species in the establishing woodlands was the harvest mouse Micromys minutus, followed by the wood mouse Apodemus sylvaticus. The potential importance of newly planted farm woodlands for small mammals is discussed.     

Factors contributing to carbon fluxes from bioenergy harvests in the U.S. Northeast: an analysis using field data

With growing interest in wood bioenergy there is uncertainty over greenhouse gas emissions associated with offsetting fossil fuels. Although quantifying postharvest carbon (C) fluxes will require accurate data, relatively few studies have evaluated these using field data from actual bioenergy harvests. We assessed C reductions and net fluxes immediately postharvest from whole‐tree harvests (WTH), bioenergy harvests without WTH, and nonbioenergy harvests at 35 sites across the northeastern United States. We compared the aboveground forest C in harvested with paired unharvested sites, and analyzed the C transferred to wood products and C emissions from energy generation from harvested sites, including indirect emissions from harvesting, transporting, and processing. All harvests reduced live tree C; however, only bioenergy harvests using WTH significantly reduced C stored in snags (P < 0.01). On average, WTH sites also decreased downed coarse woody debris C while the other harvest types showed increases, although these results were not statistically significant. Bioenergy harvests using WTH generated fewer wood products and resulted in more emissions released from bioenergy than the other two types of harvests, which resulted in a greater net flux of C (P < 0.01). A Classification and Regression Tree analysis determined that it was not the type of harvest or amount of bioenergy generated, but rather the type of skidding machinery and specifics of silvicultural treatment that had the largest impact on net C flux. Although additional research is needed to determine the impact of bioenergy harvesting over multiple rotations and at landscape scales, we conclude that operational factors often associated with WTH may result in an overall intensification of C fluxes. The intensification of bioenergy harvests, and subsequent C emissions, that result from these operational factors could be reduced if operators select smaller equipment and leave a portion of tree tops on site.     

栽培黄山药薯蓣皂甙元含量年度变化与适宜采挖期研究

本文主要研究了栽培６ａ的黄山药（Ｄｉｖｓｃｏｒｅａ　ｐａｎｔｈａｉｃａ）薯蓣皂甙元含量变化规律和原因,并结合根茎产量、薯蓣皂甙元产量和农业栽培产值等的变化趋势,提出了黄山药栽培后的适宜采挖年限,对生产有重要指导意义。     

不同采收期紫玉盘中抗癌活性的初步研究

对不同采收期紫玉盘植物提取物,采用SRB法观察其对人口腔上皮癌细胞株(KB)生长的影响进行抗癌活性检测,结果发现抗癌活性物质随采收期的不同其活性具有显著差异,10月份采收的紫玉盘植物提取物体外抗癌活性最强。     

A generalized purification step for viral particles using mannitol flocculation

Vaccine manufacturing has conventionally been performed by the developed world using traditional unit operations like filtration and chromatography. There is currently a shift in the manufacturing of vaccines to the less developed world, requiring unit operations that reduce costs, increase recovery, and are amenable to continuous manufacturing. This work demonstrates that mannitol can be used as a flocculant for an enveloped and nonenveloped virus and can purify the virus from protein contaminants after microfiltration. The recovery of the virus ranges from 58 to 96% depending on virus, the filter pore size, and the starting concentration of the virus. Protein removal of 80% was achieved for the small nonenveloped virus using a 0.1 µm filter because proteins were not flocculated with the virus and flowed through the filter. It is hypothesized that mannitol dehydrates the viral surface by controlling the water structure surrounding the virus. Without the ability to become compact, as occurs with proteins, the virus aggregates in the presence of osmolytes and proteins do not. Osmolyte flocculation is a scalable process using high flux microfilters. It has been applied to both an enveloped and nonenveloped virus, making this process friendly to a variety of vaccine and gene therapy products. © 2018 American Institute of Chemical Engineers Biotechnol. Prog., 34:1027–1035, 2018     

杂种小麦开花后生物产量及其组分的动态变化

试验以化杀杂种CH－1和不育系杂种VH－2及其亲本为材料,比较研究了杂种小麦开花后生物产量及其组分的动态变化,结果表明：（1）杂种小麦开花后的营养体于重量大,籽粒的增长速率高,增量大,收获指数高,生物产量具有较强的杂种优势。杂种的粒重超双亲平均值（MP）9．5％－18．7％,超对照（CK）15．8％;（2）不同器官的干重变化有别。CH－1与其双亲平均值（MP1）和对照（CK）比,中上部器官倒1－3节茎鞘叶中的光合产物输出的多,失重大,对籽粒的贡献大,而中下部器官倒4节下茎鞘叶中的光合产物输出的少,失重小,物质积累的多,不育系杂种VH－2营养体干重的变化规律同CH－1,但器官失重少,与其双亲平均值（MP2）和CK相比,虽然生物产量高,但器官干重于减少量低,收获指数小,究其原因主要是不育系杂种结实率低（88％－94％）,器官中光合产物输出少,积累多,使库源关系不协调所致;（3）营养体干重与籽粒重呈现显著正相关关系（r=0.8728^**),而杂种的粒重优势恰是体现在营养体干重的优势上,因此,通过增加营养重量,进而增加粒重,提高产量,是协调和提高杂种小麦生物产量和收获指数的关键所在。