美国加州的鲜食葡萄生产

美国加州的鲜食葡萄生产＠赵胜建￥河北省农林科学院昌黎果树研究所美国加州的鲜食葡萄生产赵胜建（河北省农林科学院昌黎果树研究所０６６６００美国加州是世界著名的鲜食葡萄产区，占全美葡萄面积的９０％。据１９９３年统计，加州鲜食葡萄面积约５万ｈｍ２，年产量６２万ｔ，...     

美国加州地区生菜生产与关键技术

生菜即叶用莴苣,营养丰富,风味独特,通常分为结球与散叶两种类型,尤其是结球生菜在国际市场十分畅销,也是我国近年来的重要出口创汇蔬菜之一.加州是美国第三大州,面积411,013 km2(平方公里);地形地貌多种,气候条件多样,是美国重要的蔬菜生产地.全美2000年主要蔬菜种植(收获)面积848,256 hm2(公顷),总产值9,325,199(1,000$);其中加州为361,635hm2(公顷),占全美43%,总产值4,937,978(1,000$),占全美53%.本文对美国加州地区生菜生产作一介绍.     

美国加州青花菜生产及其关键技术

青花菜又名西兰花、绿菜花,其营养丰富,具有食疗功效,国际市场十分畅销,也是我国近年来重要的出口创汇蔬菜。加利福尼亚州是美国第三大州,面积411013km~2;地形地貌多种,沿海多山,海岸山脉海拔600～2000m,太平洋沿岸温度一般不超过32℃,也不低于0℃;加州气候条件多样,是美国重要的蔬菜生产地。2000年美国主要蔬菜种植(收获)面积848256hm~2,总产值932519.9万美元;其中加州为361635hm~2,占全美的43％,总产值493797.8万美元,占53％。现对美国加州青花菜生产作一介绍。     

美国加州扁桃的生产与贸易现状

1生产概况1.1栽培地域、面积和产量加州扁桃集中在中央谷地的萨克拉门托和圣华金地区。谷地南部占84.6%,主产县有Kern20.3%、Stanislaus16.9%、Fresno16%、Merced13.4%、Madera9.8%和SanJoaquin5.6%等;谷地北部占15.4%,主产县为Butte6%、Colusa3.9%和Glenn3.6%等。加州扁桃栽培面积一直呈稳步增加趋势,2001年以前10年中,平均年增长5022公顷,现在栽培面积达24.1万公顷(其中挂果树面积21.3公顷,未挂果树面积2.8公顷),2001年总产量37.41万吨,平均每公顷产量1.76吨。在国际上,加州扁桃的产量遥遥领先于扁桃主产国希腊、意大利、西班牙和土…     

美国加州杏的育种与生产

2001年2月8—28日笔者赴美国进行杏、李新品种引进和生产考察。在美期间,先后参观了加州、北达哥达州、新泽西州,参观了3个国家州立大学、2个国家资源圃、2个果脯加工厂、1个杏仁加工厂、1个加州最大的私入苗圃。通过考察了解到,加州是美国杏的主要产区,下面把加州杏的育种和生产情况介绍如下。     

美国加州脐橙产量大幅上升

据美国海外农业统计局2002年9月12日公布的数字，2002/2003年度美国加利福尼亚州(加州)脐橙产量估计达150万t，比上一年度(130万t)提高15．4％。今年，加州脐橙着果率远远高于去年，是1992年以来着果率最高的一年，但果形普遍较小。美国出口甜橙主要就是产于加州的脐橙。2001／2002年市场年度(2001年9月至2002年6月)，美国共出口甜橙447367t，同比下降了12％。加拿大、韩国、日本、香港和中国大陆是美国甜橙最主要的出口市场，占出口总量的87％。     

美国加州鲜食葡萄生产技术考察报告

1994年9月应美国加州维塞利亚果品公司之邀，到美国加州葡萄集中产区进行了鲜食葡萄品种和栽培技术考察，现将加州主要鲜食葡萄品种及生产状况介绍如下：一、加州主要鲜食葡萄品种据美国加州维塞利亚果品公司和加州鲜食葡萄委员会1993年统计资料表明，美国加州1990年有葡萄园28万公顷，占全美国葡萄栽培面积的85%，葡萄产值在加州占整个农业生产的第三位。因此，葡萄生产对加州的经济起着举足轻重的作用。加州鲜食葡萄主要是无核品种，它们是制干和鲜食兼用品种，在无核品种中，排在第一位的是青提(汤姆森无核和森田尼无核)、火焰无核，再次…     

美国加州杏的生产

笔者于 2 0 0 1年 2月 8日至 2 8日赴美进行引种和实地考察 ,先后考察了加州、北达科他州、新泽西州 3个州立大学、2个国家资源圃、2个果脯加工厂、1个杏仁加工厂、1个加州最大的私人苗圃 ,对美国的杏生产有了基本了解。加州位于美国西部 ,西临太平洋 ,年降雨量约 5 0 0mm左右 ,主要降水集中在 1 1～ 3月份 ,生长季气候干燥 ,适合各种水果生长。 1 999年杏结果树面积为 1万hm2 ,产量 1 1 .1 7万t。主要推广品种为海莱那、帕特森、金甜、罗巴塔。海莱那是美国农业部培育并推广的品种 ,果实大 ,果皮黄色或橙黄色 ,无红晕 ,果肉硬 ,风味甜、汁…     

2009年美国加州水果产量有降有升

据美国农业部今年8月公布的统计数据,2009年美国加利福尼亚州（以下简称加州）苹果产量预计为16.5万t,同比减少8%;种植面积预计为7695hm^2,单位面积产量预计为21．43t／hm^2。该州苹果已于7月中旬开始采收，由于气候条件有利，病虫害少，果实品质优。     

美国加州西梅产业化发展现状分析

在查阅大量资料和实地调研的基础上,从美国加州西梅的栽培历史、栽培现状、栽培品种、果园管理、采收加工等方面进行阐述,分析了美国加州西梅产业化发展中存在的问题,以期为我国果树产业化发展提供借鉴。     

美国加州葡萄栽培概况

由中国科协和中国农学会组织的"中国葡萄与葡萄酒技术考察团"一行5人,于1999年10月19～29日对美国葡萄主产区加利福尼亚州进行考察.先后考察了加州福润斯诺大学的葡萄、葡萄酒研究中心及其农业实验园,加州大学戴维斯分校Fresno农业实验站,北加州那帕地区众多葡萄园和葡萄酒厂,加州SAN MALD葡萄干公司和加州农业科技咨询服务公司等教学、科研、生产、推广等部门.并应邀参加了1999年度美国葡萄博览会.     

美国加州葡萄品种和产业发展分析

介绍了美国加州葡萄产业的生产现状,包括酿酒葡萄、制干葡萄、鲜食葡萄的品种结构及其种植面积,分析美国加州葡萄产业发展变化及存在的问题,并对中国葡萄产业发展提出建议。     

美国果品生产概况

美国是果品生产大国之一，1998年各类果树结果面积162.52万hm^2，干鲜果商品总产量31616.3kt，产值119.31亿美元。进口各类果品5761.8kt，果汁30577．6万L，出口各类果品2335.7kt，果汁9001.18万L。近年来，美国果品产量，进出口贸易量均有所上升，果树种植农场呈现数量减少，规模扩大趋势。     

Simulating fire frequency and urban growth in southern California coastal shrublands,USA

Fire is an important natural disturbance in the Mediterranean-climate coastal shrublands of southern California. However, anthropogenic ignitions have increased fire frequency to the point that it threatens the persistence of some shrub species and favors the expansion of exotic annual grasses. Because human settlement is a primary driver of increased ignitions, we integrated a landscape model of disturbance and succession (LANDIS) with an urban growth model (UGM) to simulate the combined effects of urban development and high fire frequency on the distribution of coastal shrublands. We tested whether urban development would contribute to an expansion of the wildland-urban interface (WUI) and/or change in average fire return intervals and compared the relative impacts of direct habitat loss and altered fire regimes on functional vegetation types. We also evaluated two methods of integrating the simulation models. The development pattern predicted by the UGM was predominantly aggregated, which minimized the expansion of the WUI and increase in fire frequency, suggesting that fire risk may be higher at intermediate levels of urbanization due to the spatial arrangement of ignition sources and fuel. The comparison of model coupling methods illustrated how cumulative effects of repeated fires may occur gradually as urban development expands across the landscape. Coastal sage scrub species and resprouting chaparral were more susceptible to direct habitat loss, but increased fire frequency was more of a concern to obligate seeder species that germinate from a persistent seed bank. Simulating different scenarios of fire frequency and urban growth within one modeling framework can help managers locate areas of highest risk and determine which vegetation types are most vulnerable to direct habitat loss, altered fire regimes, or both.     

A municipal forest report card: Results for California,USA

This study integrates two existing computer programs, the Pest Vulnerability Matrix and i-Tree Streets, into a decision-support tool for assessing municipal forest stability and recommending strategies to mitigate risk of loss. A report card concept was developed to communicate levels of performance in terms that managers and the public easily understand. Grades were assigned to four aspects of a stable and resilient municipal forest: Species Dominance, Age Structure, Pest Threat and Potential Asset Loss. The data pool of 29 California municipal forest inventories contained information on 836,943 trees. Letter grades (A–F) were assigned to the four criteria and each city received customized recommendations for improving its grades. Three inventories received final grades of As, 18 received Bs, 6 Cs and 2 Ds. Twelve inventories received their highest grade for Species Dominance. Thirteen inventories received their lowest grade for Age Structure, largely because juvenile trees were underrepresented. Pest Threat received the lowest grade in 11 inventories and reduce Pest Threat was the top priority recommendation in 18 inventories. Four multi-host pests posed the greatest risk: Granulate ambrosia beetle, Asian longhorned beetle, Armillaria root rot and red palm weevil. Sycamore/plane was the most vulnerable taxon, followed by oaks, ash and eucalyptus. Eliminating or limiting the use of highly vulnerable tree species was recommended in nearly every city to reduce Pest Threat and improve Species Dominance. Increased planting of vacant sites with species not vulnerable to the most abundant and severe pests was a frequent recommendation for improving Age Structure. Another common recommendation to improve Age Structure was planned removal and replacement of overabundant mature and senescent taxa such as pear, eucalyptus, jacaranda and carrotwood.     

Change in spatial characteristics of forest openings in the Klamath Mountains of northwestern California,USA

Change in the spatial characteristics of forest openings was investigated in three forested watersheds in north-western Siskiyou County, California totalling approximately 24,600 hectares. Watersheds with minimal human disturbance were chosen for study. However, fire suppression has been pervasive throughout. Characteristics of forest openings (area, perimeter, distance between neighboring openings) were measured on aerial photographs taken 41 years apart. An index of regional form was determined for the landscape. Shape complexity for each opening was calculated using two indices based upon fractals. Significant differences were found using the Kolmogorov-Smirnov two-sample test between the perimeters, areas, distance from sample point to nearest opening, and distance between neighboring openings. The perimeters and areas became smaller, and the distances from the sample point to the nearest opening and between neighboring openings became greater over the 41 years between aerial photo sets. The estimated area occupied by openings decreased from 25.8 % to 15.6 % of the study area. No significant difference was found in the shape of the openings except as the shape indices were influenced by changes in size of the openings.This article was written and prepared by U.S. Government employees on official time, and it is therefore in the public domain and not subject to copyright.     

Early forest dynamics in stand-replacing fire patches in the northern Sierra Nevada, California, USA

There is considerable concern over the occurrence of stand-replacing fire in forest types historically associated with low- to moderate-severity fire. The concern is largely over whether contemporary levels of stand-replacing fire are outside the historical range of variability, and what natural forest recovery is in these forest types following stand-replacing fire. In this study we quantified shrub characteristics and tree regeneration patterns in stand-replacing patches for five fires in the northern Sierra Nevada. These fires occurred between 1999 and 2008, and our field measurements were conducted in 2010. We analyzed tree regeneration patterns at two scales: patch level, in which field observations and spatial data were aggregated for a given stand-replacing patch, and plot level. Although tree regeneration densities varied considerably across sampled fires, over 50 % of the patches and approximately 80 % all plots had no tree regeneration. The percentage of patches, and to a greater extent plots, without pine regeneration was even higher, 72 and 87 %, respectively. Hardwood regeneration was present on a higher proportion of plots than either the pine or non-pine conifer groups. Shrub cover was generally high, with approximately 60 % of both patches and individual plots exceeding 60 % cover. Patch characteristics (size, perimeter-to-area ratio, distance-to-edge) appeared to have little effect on observed tree regeneration patterns. Conifer regeneration was higher in areas with post-fire management activities (salvage harvesting, planting). Our results indicate that the natural return of pine/mixed-conifer forests is uncertain in many areas affected by stand-replacing fire.     

A comparison of municipal forest benefits and costs in Modesto and Santa Monica,California, USA

This paper presents a comparison of the structure, function, and value of street and park tree populations in two California cities. Trees provided net annual benefits valued at $2.2 million in Modesto and $805,732 in Santa Monica. Benefit-cost ratios were 1.85:1 and 1.52:1 in Modesto and Santa Monica, respectively. Residents received $1.85 and $1.52 in annual benefits for every $1 invested in management. Aesthetic and other benefits accounted for 50% to 80% of total annual benefits, while expenditures for pruning accounted for about 50% of total annual costs. Although these results were similar, benefits and costs were distributed quite differently in each city. Variations in tree sizes and growth rates, foliation characteristics, prices, residential property values, and climate were chiefly responsible for different benefits and costs calculated on a per tree basis.     

核桃坚果呼吸特性研究

１、坚果含水量是影响呼吸速率的主要因了，呼吸速度与坚果含水量呈指数型相关，含水量８％以上下时，呼吸速率较低，变化较小。２、呼吸速率与环境温度呈抛物线型相关，最高值出现在３３℃。３．不同时期采收的坚果，其呼吸速率有明显差异，与出仁率及种仁脂类含量呈显著正相关。４．不同种及品种的坚果，呼吸速率有明显差异，与坚果缝合线紧密度呈显著负相关。     

Historical change in coastal sage scrub in southern California,USA in relation to fire frequency and air pollution

Invasions resulting in the transformation of one ecosystem to another are an increasingly widespread phenomenon. While it is clear that these conversions, particularly between grassland and shrubland systems, have severe consequences, it is often less clear which factors are associated with these conversions. We resampled plots from the 1930s (Weislander VTMs) to test whether two widely assumed factors, changes in fire frequency and nitrogen deposition, are associated with the conversion of coastal sage scrublands to exotic grasslands in southern California. Over the 76-year period, coastal sage scrub cover declined by 49%, being replaced predominantly by exotic grassland species. Grassland encroachment was positively correlated with increased fire frequency and, in areas with low fire frequencies, air pollution (percent fossil carbon as indicated by ∂¹⁴C, likely correlated with nitrogen deposition). We conclude that increases in fire frequency and air pollution over the last several decades in southern California may have facilitated the conversion of coastal sage shrubland to exotic grassland systems.