A minimal model of the variability of marine ecosystems

In marine ecology, population abundance time series often reveal patterns, such as decadal pseudo-cycles, on scales that make them difficult to mathematically characterize by means of conventional models based on functional responses. We propose here a simple non-deterministic model based on three strong ecological constraints, without any use of functional responses or external factors: (i) mass balance constraints between flows and biomass, (ii) a satiation constraint relating inflows and biomass and (iii) an inertia principle restricting the variation of populations of a given species according to its lifespan. This model reproduces in a robust manner observed patterns of variability and can be used to question the relevance of other modelling approaches of ecosystem dynamics with regard to determinism, constraints and stochasticity. Referring to a non-deterministic model without any functional relationships and environmental or anthropogenic forcing can help in avoiding misleading advice based on the belief that we can explain the causes of observed patterns, which may simply result from basic structural constraints within which the ecosystem functions.     

千岛湖风景区林相改造初探

针对千岛湖森林资源现状及存在的问题,从有利于发展旅游事业出发,提出了千岛湖风景区林相改造的主要模式。     

水稻根系建成对高产形成的模拟模型与调控决策研究──Ⅰ 水稻根系形态建成参数与产量形成关系的初步研究

为建立水稻根系的模拟,对水稻根系形态建成参数与产量形成及地上部器官建成之间的关系进行了研究,结果表明齐穗期的上位根干重密度和上位根长密度与每蔸穗数、每蔸有效穗数及籽粒产量之间关系密切,根系参数与地上部叶干重、叶面积指数呈正相关,并建立了上位根重密度及根长密度与产量之间的回归方程。     

DETERMINATION ABOUT THE NORTHWESTERN AREA LIMIT OF PINUS KORAIENSIS AND THE GEOGRAPHIC OCCURRENCE OF PINUS SIBIRICA

By investigation,studying and discussion for 9 years,the determination that it shouldbe Pinus sibirica growing in the Mohe county,Daxing'anling Mountains area,China,ratherthan pinus koraiensis there,is made to correct a false argument in some works from 1950s’till nowthat Pinus koraiensis area limit reach Daxing'anling Mountain.The results are as follows:(1)Thespecies so called as Pinus koraiensis found in northwest of Daxing'anling.Mountain is PinusSibirica indeed;There are no natural distribution of Pinus Koraiensis in Daxing'anling Mountain.Its northwest area limit only reach Shengshan,Aihui county;(3)There is about 500km of space be-tween the area limits of Pinus koraiensis and that of Pinus sibirica,no mixed growing area.Accord-ing to above,a sketch map is made to describe different area limit of the two species at Daxing'anl-ing Mountain and nearby.     

我国半散放麋鹿生境植被及采食植物种类的研究

1985—1986年在北京麋鹿苑,1987—1990年在江苏大丰麋鹿保护区研究了半散放糜鹿Elaphurus davidianus生境植被,系统记录了糜鹿采食植物共263种,隶属于49科164属。其中,北京麋鹿苑采食植物39科86属118种;大丰糜鹿保护区采食植物42科133属194种及变种。植被及采食种类情况表明,两地麋鹿饲料植物多样性较好,鹿群规模在迅速增长。但几年来,两地生境植被不同程度恶化显著,主要因放养范围小、鹿群规模相应过大。而植物区系组成简单、群落发育年轻、植被演替迅速也是植被恶化原因。扩大放养范围、改善栖息条件已属迫切任务。     

林木种子发芽率的软X射线检验研究

本文应用Hy—35型软X—射线仪对杉木、柳杉等15个树种种子进行摄影并进行定位发芽试验。根据各树种种子的X光片成像特征将种子划分为若干等级,将X光片上判读的百分率与定位发芽所得的发芽率进行统计分析,找出估测各树种种子发芽率的X光片判读等级。     

Genetics of Resistance to Phytophthora capsici in the Pepper Line 'SCM-334'

In order to establish a genetic model of the resistance to Phytophthora capsici in Capsicum annuum genotype ‘SCM-334’, two experiments were conducted which included ‘SCM-334’, as well as, the susceptible line ‘Morrón INIA 224’ and their Fl, F2, F3 and BC1 generations. We also tried to introgress a recessive gene, hypothetically responsible for resistance to P. capsici, from ‘SCM-334’ into ‘Morrón INIA 224’. Inoculations were made, when plants had 4—6 leaves, by irrigating the culture substrate with a zoospore suspension of P. capsici isolate ‘Bl’. The χ² test was applied to segregating generations to determine how many genes were involved in resistance. The hypothesis which explained the obtained segregations best, although not completely, was one that assumes 3 genes in ‘SCM-334’;, with at least 3 alleles in the heterozygous condition or 4 at any position, present in any genotype in order to be resistant. The influence of the isolate's aggressiveness and the inoculation method on the results are discussed.     

DPC效应的定向、定量诱导及其在棉花丰产栽培中的应用

根据1980—1982三年的试验,提出了 DPC 对棉花生育的效应应分为基本效应和复合效应两类。主要的基本效应是抑制营养器官的生长;增加叶绿素含量,调整光合产物分配的方向与数量。提出了定量定位诱导基本效应的原则和经验参数,也提出了诱导复合效应的原则,以及从塑造理想株型、生育进程和田间结构,获得较佳的棉铃时空分布以夺得丰产的原理。结合我国棉花生产特点,提出了 DPC 的使用要领。正确使用 DPC,皮棉产量平均可增加12.5%左右。     

Bird species abundance–occupancy patterns and sensitivity to forest fragmentation: Implications for conservation in the Brazilian Atlantic forest

Developing a predictive theory for species responses to habitat fragmentation is a large, complex challenge in conservation biology, and meeting this challenge likely requires tailoring predictions to specific habitats and taxa. We evaluate the effects of fragmentation on forest birds living in three distinct forest ecosystems found in Brazilian Atlantic forest: seasonal semi-deciduous forest (SF), mixed rain forest (MF), and dense rain forest (DF). We test the hypotheses that (1) bird species most prevalent in SF (relative to other habitat types) will be least vulnerable to population declines in fragmented SF, and (2) species with stronger affiliations with DF or MF will be relatively more sensitive to fragmentation in SF. Using an exploratory statistical technique called “Rank Occupancy–Abundance Profiles (ROAPs),” we compared distribution and abundance of birds among large “continuous” areas of each forest type, then compared abundances in continuous SF forests with patterns of abundance in small fragments of SF, where edge effects could play a marked role in population dynamics. Overall, 39 species showed substantially lower local abundance, occupancy, or both in SF fragments versus continuous SF. As predicted, a higher proportion of bird species associated with DF appeared sensitive to fragmentation in SF; by contrast, species most abundant in SF and MF were similarly abundant in fragmented SF. Our study demonstrates how quantifying distribution and abundance in diverse habitats may enhance managers’ ability to incorporate species-specific responses to human disturbances in their conservation plans, and points out ways that even small reserves may have significant conservation value.     

Guidelines for zoo and aquarium veterinary medical programs and veterinary hospitals

These guidelines for veterinary medical care and veterinary hospitals are written to conform with the requirements of the Animal Welfare Act, which states that programs of disease prevention and parasite control, euthanasia, and adequate veterinary care shall be established and maintained under the supervision of a veterinarian. Ideally the zoo and aquarium should be providing the best possible veterinary medical care for the animals in their collections. Many of these animals are rare and endangered and the institutions should endeavor both to provide for the long term health and well being of these animals and to advance the field of non-domestic animal medicine. It is hoped that this publication will aid in this process.