Phanerozoic trends in the global diversity of marine invertebrates

It has previously been thought that there was a steep Cretaceous and Cenozoic radiation of marine invertebrates. This pattern can be replicated with a new data set of fossil occurrences representing 3.5 million specimens, but only when older analytical protocols are used. Moreover, analyses that employ sampling standardization and more robust counting methods show a modest rise in diversity with no clear trend after the mid-Cretaceous. Globally, locally, and at both high and low latitudes, diversity was less than twice as high in the Neogene as in the mid-Paleozoic. The ratio of global to local richness has changed little, and a latitudinal diversity gradient was present in the early Paleozoic.     

Biological bulldozers and the evolution of marine benthic communities

During the Phanerozoic, the diversity of immobile suspension feeders living on the surface of soft substrata (ISOSS) declined significantly. Immobile taxa on hard surfaces and mobile taxa diversified. Extinction rates of ISOSS were significantly greater than in other benthos. These changes in the structure of benthic communities are attributed to increased biological disturbance of the sediment (bioturbation) by diversifying deposit feeders.     

Statistical independence of escalatory ecological trends in Phanerozoic marine invertebrates

Ecological interactions, such as predation and bioturbation, are thought to be fundamental determinants of macroevolutionary trends. A data set containing global occurrences of Phanerozoic fossils of benthic marine invertebrates shows escalatory trends in the relative frequency of ecological groups, such as carnivores and noncarnivorous infaunal or mobile organisms. Associations between these trends are either statistically insignificant or interpretable as preservational effects. Thus, there is no evidence that escalation drives macroecological trends at global and million-year time scales. We also find that taxonomic richness and occurrence data are cross-correlated, which justifies the traditional use of one as a proxy of the other.     

Carbon dioxide fixation in marine invertebrates: a survey of major phyla

Fourteen species of marine invertebrates representing 12 phyla were kept in sea water containing NaHC(14)O(2) for 1 hour. All of them fixed CO(2) into acids of the Krebs citric acid cycle. In most species the major portion of the radioactivity recovered after chromatography was in succinic, fumaric, and malic acids. The findings favor the hypothesis that both CO(2) fixation and the citric acid cycle are virtually universal among marine invertebrates.     

基于大型底栖无脊椎动物生物完整性指数的苏州市水体生态健康评价

为促进城市水体的管理和保护,针对苏州市的23个河道断面开展大型底栖无脊椎动物群落调查。在此基础上通过对备选指标的分布范围、判别能力和相关性分析筛选出适宜城市水体生态健康评价的核心指标。再利用比值法计算各核心指标值并累加求和得到各样点的大型底栖无脊椎动物生物完整性指数值(Benthic macroinvertebrate index of biotic integrity, BIBI)。结果显示：苏州市城区和参照点共发现大型无脊椎底栖动物22种,隶属于3门6纲9目14科。经过指标筛选,得出适宜评价苏州的BIBI指数由以下6个指标组成,分别是总分类单元数、节肢动物分类单元数、Shannon-Wiener多样性指数、广布种百分比、昆虫纲个体百分比、耐污类群个体百分比。经计算BIBI的最佳期望值为4.01,即BIBI值≥4.01为健康,3.01～4.01为良好,2.01～3.01为一般,1.01～2.01为较差,<1.01为极差(区间范围为左闭右开,且BIBI≥0)。根据BIBI结果,苏州市各断面水体生态健康程度参差不齐,处于一般和良好的位点多于健康的,不同季节各点的健康状况是不同的。通...     

Comment on "Statistical independence of escalatory ecological trends in Phanerozoic marine invertebrates"

Madin et al. (Reports, 12 May 2006, p. 897) reported that escalation has not been an important cause of biological change throughout the history of life. However, they evaluated the escalation hypothesis with inappropriate data. First, global-scale data integrate heterogeneous signals that obscure the economic context of life. Second, diversity data cannot yield information about selection and adaptation.     

Application of carbon isotope stratigraphy to late miocene shallow marine sediments, new zealand

A distinct (0.5 per mil) carbon-13/carbon-12 isotopic shift in the light direction has been identified in a shallow marine sedimentary sequence of Late Miocene age at Blind River, New Zealand, and correlated with a similar shift in Late Miocene Deep Sea Drilling Project sequences throughout the Indo-Pacific. A dated piston core provides an age for the shift of 6.2 +/- 0.1 million years. Correlations based on the carbon isotopic change require a revision of the previously established magnetostratigraphy at Blind River. The carbon shift at Blind River occurs between 6.2 and 6.3 +/- 0.1 million years before present. A new chronology provides an age for the evolutionary first appearance datum of Globorotalia conomiozea at 6.1 +/- 0.1 million years, the beginning of a distinct latest Miocene cooling event associated with the Kapitean stage at 6.2 +/- 0.1 million years, and the beginning of a distinct shallowing of water depths at 6.1 +/- 0.1 million years. The Miocene-Pliocene boundary as recognized in New Zealand is now dated at 5.3 +/- 0.1 million years. Extension of carbon isotope stratigraphy to other shallow Late Miocene sequences should provide an important datum for international correlation of Late Miocene shallow and deep marine sequences.     

A review of recent sensing technologies to detect invertebrates on crops

Precision agriculture needs integrated pest management (IPM), for which detection and identification of target invertebrate species is a prerequisite. Researchers have been developing various technologies to detect pests more efficiently and accurately. However, these existing sensing technologies still have limitations for effective infield applications. This review paper aims to explore the relative technologies and find a sensing method that has potential to detect and identify common invertebrates on crops, such as butterflies, locusts, snails and slugs. It was found that there are two main research branches for invertebrate detection and identification: acoustic sensing and machine vision system (MVS). Acoustic sensing is suitable for detecting and identifying pests in soil, stored grains and wood, while usually acoustic sensors need to be attached to samples for inspection, which causes difficulties for efficient infield applications. MVS has the potential to provide a more effective and flexible way to detect and identify invertebrates on crops. In recent work with MVS, the technologies of invertebrate identification have been intensively studied, however, infield detection is relatively weak. This review points out the current research gaps and then discusses the potential research directions.     

祁连山冷龙岭北麓冰川缘地文冠果引种栽培

在祁连山冷龙岭北麓冰川缘地——中牧甘肃山丹马场海拔高度不同的5个试验地(海拔分别为2 560、2 900、2 800、2 500、2 480 m,分别记作spot i,i=0,…,4))引种文冠果.结果表明:1～3年生文冠果播种苗平均苗高由高到低顺序:spot 0＞spot 3＞spot 4＞spot 2＞spot 1,其中spot 1播种苗、插根苗和移植苗连年生长量为零,spot 2苗木连年生长量部分为零.5个试验点的播种苗、插根苗、移植苗地下部分越冬成活率均达到100％.苗木平均枯梢率由大到小依次为spot 1＞spot 2＞spot 4＞spot 0＞spot 3.其中移植苗的枯梢较播种苗轻.在试验地发现文冠果苗木有黄化病和立枯病.spot 3、spot 0、spot 4所在地较适合文冠果的栽培,4年生播种苗在样地3只有1株结果,5年生时无开花及结果的情况.     

Institutional obstacles to expansion of world food production

It was argued that over the near-to-medium term-roughly to the mid-1980's-there is enough potential for growth in existing Green Revolution technology and in technical capacity of farmers that institutions affecting these two sources of increased food production probably will not be seriously constraining. The principal bottlenecks likely will be found among those institutions affecting farmers' incentives to innovate. There is impressive evidence that when other conditions for innovation are favorable the supply of marketing services, for both inputs and outputs, is quite elastic. This seems to include the supply of funds from rural saving and informal credit sources, although the evidence is less clear in this respect. The situation concerning price relations and availability of inputs appears mixed. If national income growth targets are achieved, then the growth in total demand for food in the LDC's should be fast enough to support incentive prices for farmers. This advantage could be lost, however, if governments adopt policies to suppress food prices to keep down the cost of living. The price of fertilizers is expected to fall from the high levels of 1974, the amount of the fall depending in good measure on the success of the LDC's in increasing fertilizer production. Historically, their efforts to expand capacity have been relatively inefficient. Moreover, many countries still lack adequate capacity to produce the HYV's and pesticides. Even with good progress in expanding domestic production of inputs, imports will continue to be an important source of supply. Maintenance of present high prices of petroleum products could be a major obstacle to financing these imports on the necessary scale because of the drain it would place on available foreign exchange. I conclude, on balance, that prices and availability of fertilizers, pesticides, and seeds could have important negative effects on farmers' incentives to adopt Green Revolution technology. Rigidities in water management institutions may be even more limiting, for reasons noted in the previous section. The role of existing land tenure institutions is not clear. The tentative conclusion, however, is that over the near-to-medium term the maintenance will not be a major obstacle to further spread of the Green Revolution. Over the longer term, it could become more seriously limiting. The reason is that continued expansion of food production will eventually require the invention and adoption of new technologies and a higher level of technical and managerial skill than most farmers in the LDC's now possess. To do this will require substantial investments in domestic research and extension institutions and in rural education. In countries where a small class of large landowners wield substantial political power, these investments may not occur on the necessary scale because the large farmers have their own means of acquiring the technology and little perceived interest in supporting the upgrading of the skills of small farmers. This review of institutional obstacles to expansion of food production in the LDC's must end on a tentative note. The review does suggest some observations about the process of institutional change, however. There is impressive evidence of strong latent potential in the private sector of the LDC's for mobilizing the resources and effort needed for agricultural progress when the private economic rewards for doing so are high. Under these circumstances, needed changes in the institutions required to mobilize the resources and direct the effort seem relatively easy to achieve. Institutional resistance is stronger in situations where influential interests perceive change as a threat or where there is no direct personal economic reward to change, as in the typical public institution. The latter point is particularly important because the performance of public institutions is critical. Development of new technology, the fundamental condition for continued longterm growth, is basically a public responsibility because the gains from adoption usually cannot be sufficiently captured by private institutions to justify their assuming the cost. Although private firms often have incentives to impart technical knowledge to farmers as a way of widening the market for their products, the broadening and strengthening of the institutional structures concerned with both the general and technical education of farmers is a public responsibility. This is true also of the development of large irrigation systems, both because of the scale of the needed investments and the potential for social conflict in water management. The lack of a well-defined mechanism that would link responses of public institutions to the large social payoffs to increased public investment in irrigation, new technology, and technical abilities of farmers may prove in the long run to be the most important single obstacle to adequate growth of food production in the LDC's.     

2005年晚稻后期稻飞虱暴发与抗药性原因分析

2005年,全国稻作区晚稻大范围暴发稻飞虱危害,广西宾阳县农作物病虫测报站灯下累计第七代稻飞虱成虫量平均21741头,与上年同期的264头、最高发生年份的735头、8年累计的208.6头相比,分别高出21477头、21006头、21532.4头。短翅型成虫:第七代798头,与上年同期的7头、最高年份10头、8年累计4.6头相比,分别高出791只、788只、793.4只。暴发原因除气候、品种因素外,主因是十几年来一直使用以吡虫啉、噻嗪酮为主药防治稻飞虱,产生高抗药性所致。进行稻飞虱对吡虫啉(irn idacloprid)、噻嗪酮(buprofez in)药效检测,防治效果在30%~50%,抗药性敏感比1994年增加202倍。     

海洋生物活性物质研究简述

海洋生物已成为天然药物的重要来源之一,从各类海洋生物中可提取分离到具有各种药用活性的化合物,具有开发成新药的潜力。该文对海洋生物活性物质主要种类、研究方法和具体应用进行了简要阐述,同时对海洋生物活性物质的研究方向及前景进行了展望。     

番茄抗晚疫病材料筛选初报

番茄晚疫病俗称“黑炭元”、“过火风”、“黑杆病”，由致病疫霉[Phytophthora infestans(Mont)De Bary]侵染所致。它是一种毁灭性的世界性蔬菜病害，发生频繁且易暴发成灾。在我国南北各地均有发生，尤其在潮湿多雨的南方地区和保护地番茄上发生严重，通常年份减产10％～30％，严重可达80％，甚至绝产。1990～1994年云南昆明5年共爆发3次，每次发病率都达100％。     

番茄对番茄晚疫病抗性遗传分析

试验利用04957(感),04968(感),L3708(抗)和Wva700(抗)4个抗感不同的番茄品种,按Griffing(Ⅰ)完全双列杂交方法配置组合,接种番茄晚疫病,调查发病情况进行分析。结果发现:①不同品种、不同组合间抗病性存在极显著差异;②供试品种间一般配合力和特殊配合力存在极显著差异,Wva700,L3708具有较高的一般配合力效应,二者在配制抗性组合时是较为优良的杂交亲本。Wva700×04957,Wva700×04968组合特殊配合力最高,有进一步研究利用的价值;③抗性遗传中加性效应是主要的,同时存在部分显性,存在细胞质效应;④广义遗传力为90.64%,狭义遗传力为81.48%,均较高,说明亲代对后代的影响作用较大,抗性基因可以通过基因累加的方式在后代中表现出来,宜早代选择。     

两种海洋寡糖对植物病原真菌的抑制作用

在马铃薯葡萄糖琼脂(PDA)培养基上,采用生长速率法研究了两种海洋寡糖(壳寡糖Ⅰ、卡拉胶寡糖)对水稻稻瘟菌Pyricularia oryzae、棉花黄萎菌Verticillium dahliae、小麦赤霉菌Fusarium graminearum和番茄灰霉菌Botrytis cinerea的体外抑菌作用。结果表明,聚合度为2~20的壳寡糖Ⅰ对供试的4种植物病原真菌均有一定的抑制作用,抑制强度随壳寡糖Ⅰ浓度的升高而增强,壳寡糖Ⅰ可明显抑制番茄灰霉菌菌丝的生长(EC50=680 mg/L)和孢子的萌发(EC50=162 mg/L);而聚合度低的壳寡糖Ⅱ(聚合度为2~10)对番茄灰霉菌菌丝的生长抑制作用较低;卡拉胶寡糖对3种植物病原真菌菌丝的生长不仅没有抑制作用,反而对水稻稻瘟菌和番茄灰霉菌菌丝的生长有明显促进作用。     

保持金边虎尾兰金边不消失的繁殖方法

金边虎尾兰的金边属于嵌合体彩斑，叶插繁殖易使其金边消失。根据相关文献和实践经验，介绍了保持金边虎尾兰金边不消失的4种繁殖方法，其中根状茎扦插是一种新的繁殖方法。     

柴达木盆地南缘浅层地温对气候变化的响应

利用1961～2019 年柴达木盆地南缘气温、降水及浅层(0cm、10cm、20cm)地温的数据,用数理统计方法分析了气温、降水及浅层地温变化特征,并分析了浅层地温对气温、降水变化的响应。结果表明：1961～2019 年柴达木盆地南缘年平均气温呈升高趋势,升高倾向率为0.4℃/10a;年降水量呈增加趋势,增加倾向率为8.0mm/10a。0cm、10cm、20cm年平均地温均呈增加趋势,变化趋势大体趋于一致,增加倾向率分别为0.43℃/10a 、0.32℃/10a、0.33℃/10a;各浅层地温四季均呈现上升趋势,其中冬季增温趋势较小,春、夏、秋季增温较显著,但随深度不同增温幅度各有差异;各浅层地温每年3月上旬至8月下旬平均地温随深度增加而降低,9月中旬至翌年2月下旬平均地温随深度的增加而升高,各层地温月平均最大值均出现在7月份,最小值出现在1月份。各浅层平均地温与年平均气温、年降水量均呈正相关关系,年平均气温升高1℃, 0cm、10cm、20cm地温分别增加0.98℃、0.74℃、0.75℃;年降水量增加100mm,0cm、10cm、20cm地温分别增加0.89℃、0.67℃、0.77℃,年平均气温对地温的影响较年降水量影响明显。     

DEA理论及其在我国海洋渔业中的应用

阐述了DEA法理论，并将其应用于我国的海洋渔业，分析表明，在我国远洋渔业中，目前存在的主要问题是：船数多但船体不够大，这是提高洋船队捕捞能力的主要，也是远洋渔业效率不高的根本原因，其次，我国远洋捕捞船队的“能力利用度”呈现两极分化的特征，1999年以辽宁，江苏，福建，山东和广东为最高，其余各相关省市都有可能在不增加投入的前提下，通过效率的提高而增加捕捞产量。在帆张网作业中的DEA分析得出结果：一个投入因子若普遍被高估（或低估）相同的比例，应不会影响捕捞能力。因此得出结论：运用DEA法可以对不变投入，可变投入与最终的产出进行综合分析，以确定在多重投入情形下的最大产量；DEA法既能处理大量的数据，也能解决较少数据的情况，其在海洋渔业方面应用的结果是令人满意的。     

DEA理论及其在我国海洋渔业中的应用

阐述了DEA法理论，并将其应用于我国的海洋渔业，分析表明，在我国远洋渔业中，目前存在的主要问题是：船数多但船体不够大，这是提高洋船队捕捞能力的主要，也是远洋渔业效率不高的根本原因，其次，我国远洋捕捞船队的“能力利用度”呈现两极分化的特征，1999年以辽宁，江苏，福建，山东和广东为最高，其余各相关省市都有可能在不增加投入的前提下，通过效率的提高而增加捕捞产量。在帆张网作业中的DEA分析得出结果：一个投入因子若普遍被高估（或低估）相同的比例，应不会影响捕捞能力。因此得出结论：运用DEA法可以对不变投入，可变投入与最终的产出进行综合分析，以确定在多重投入情形下的最大产量；DEA法既能处理大量的数据，也能解决较少数据的情况，其在海洋渔业方面应用的结果是令人满意的。     

准噶尔盆地南缘弃耕地调查对退耕还林的思考

以准噶尔盆地南缘梧桐窝子地区的10块弃耕地为研究对象.通过对弃耕地耕作历史及复生植被的调查,以"时空互代"的思路横向比较不同弃耕地上的植被.发现当周边生境接近似时,相似的历史耕作活动能够塑造出相似的弃耕地植被.最后一次耕种,特别是最后一次耕种的耕种面状况是影响当地弃耕地演替路径的重要因素.耕种时耕作面起伏度大,浇灌易造成局部积水,有利于幼苗早期发育需过湿生境才能完成生活周期的旱生植物定居.以弃耕后复生的柽柳数量为依据,比较当地退耕还林实施办法,探讨新的退耕还林途径.