The very etymology of Ecology, from the greek 'Qikos', 'the household', implies that ecologists should devote some attention to the 'house' or habitat of the population or community they are studying. However, as Charles Elton (1966) has so forcibly pointed out, 'definition of habitats, or rather lack of it, is one of the chief blind spots in Zoology'. Elton himself has provided us with a qualitative classification of habitats, while another past President, Alex Watt (1947) highlighted the dynamic nature of habitats by his phrase, 'pattern and process'. Elton referred to the need to quantify habitat characteristics. In this Address I will attempt some quantification;however, you will all be aware that in doing this I will not be able to emulate those former Presidents who have been able to provide a definitative synthesis of a field or of their own studies, my offering can be but a small beginning, an indication of the type of characteristics we should quantify. In considering ecosystem patterns and environment R. M. May (1974) writes 'it is to be emphasized that although patterns may underlie the rich and varied tapestry of the natural world, there is no single simple pattern. Theories must be pluralistic'. Indeed, the complexity of the subject is daunting and in any attempt to formulate some type of general framework, one is continually beset with exceptions. In stressing the need for a framework I am echoing a plea of my predecessor Amyan Macfadyen (1975) who cited K. E. F. Watt's (1971) vivid image 'if we do not develop a strong theoretical core that will bring all parts of ecology back together we shall all be washed out to sea in an immense tide of unrelated information'. In some ways I think we may see ourselves at a similar point to the inorganic chemist before the development of the periodic table; then he could not predict, for example, how soluble a particular sulphate would be, or what was the likelihood of a particular reaction occurring. Each fact had to be discovered for itself and each must be remembered in isolation. It is noteworthy that from Dobereiner's early efforts in 1816 it took more than fifty years before Mendeleeff ormulated his Periodic Law (1869) and even after this there were various attempts at rearrangement. Another parallel may be drawn with astronomy before the development of the Hertzsprung-Russell diagram that relates the evolution and the properties of stars. Again in our own subject biology, the situation is somewhat analagous to that before the formulation of the Linnean system of classification; but now from this system of classification, we are able to organize our knowledge of, for example, the functional morphology of organisms and we can even make assumptions, with a high probability

Habitat, the template for ecological strategies?

The use of recommender systems is an emerging trend today, when user behavior information is abundant. There are many large datasets available for analysis because many businesses are interested in future user opinions. Sophisticated algorithms that predict such opinions can simplify decision-making, improve customer satisfaction, and increase sales. However, modern datasets contain millions of records, which represent only a small fraction of all possible data. Furthermore, much of the information in such sparse datasets may be considered irrelevant for making individual recommendations. As a result, there is a demand for a way to make personalized suggestions from large amounts of noisy data.
Current recommender systems are usually all-in-one applications that provide one type of recommendation. Their inflexible architectures prevent detailed examination of recommendation accuracy and its causes. We introduce a novel architecture model that supports scalable, distributed suggestions from multiple independent nodes. Our model consists of two components, the input matrix generation algorithm and multiple platform-independent combination algorithms. A dedicated input generation component provides the necessary data for combination algorithms, reduces their size, and eliminates redundant data processing. Likewise, simple combination algorithms can produce recommendations from the same input, so we can more easily distinguish between the benefits of a particular combination algorithm and the quality of the data it receives. Such flexible architecture is more conducive for a comprehensive examination of our system.
We believe that a user's future opinion may be inferred from a small amount of data, provided that this data is most relevant. We propose a novel algorithm that generates a more optimal recommender input. Unlike existing approaches, our method sorts the relevant data twice. Doing this is slower, but the quality of the resulting input is considerably better. Furthermore, the modular nature of our approach may improve its performance, especially in the cloud computing context. We implement and validate our proposed model via mathematical modeling, by appealing to statistical theories, and through extensive experiments, data analysis, and empirical studies.
Our empirical study examines the effectiveness of accuracy improvement techniques for collaborative filtering recommender systems. We evaluate our proposed architecture model on the Netflix dataset, a popular (over 130,000 solutions), large (over 100,000,000 records), and extremely sparse (1.1%) collection of movie ratings. The results show that combination algorithm tuning has little effect on recommendation accuracy. However, all algorithms produce better results when supplied with a more relevant input. Our input generation algorithm is the reason for a considerable accuracy improvement.

/pdf/a-distributed-architecture-centric-approach-to-computing-31zmh6iinx.pdf

A distributed, architecture-centric approach to computing accurate recommendations from very large and sparse datasets

Summary
‘How are plants adapted to the low temperatures and other stresses of arctic and alpine environments ?’ At present it is not possible to answer this question completely. Much work remains to be done, particularly on low-temperature metabolism, frost resistance, and the environmental cues and requirements for flowering, dormancy, regrowth, and germination. However, in brief, we can say that plants are adapted to these severe environments by employing combinations of the following general characteristics:

1. Life form: perennial herb, prostrate shrub, or lichen. Perennial herbs have greatest part of biomass underground.

2. Seed dormancy: generally controlled by environment; seeds can remain dormant for long periods of time at low temperatures since they require temperatures well above freezing for germination.

3. Seedling establishment: rare and very slow; it is often several years before a seedling is safely established.

4. Chlorophyll content: in both alpine and arctic ecosystems not greatly different on a land-area basis from that in temperate herbaceous communities. Within a single species there is more chlorophyll in leaves of arctic populations than in those of alpine populations.

5. Photosynthesis and respiration:

(a) These are at high rates for only a few weeks when temperatures and light are favourable.

(b) Optimum photosynthesis rates are at lower temperatures than for ordinary plants; rates are both genetically and environmentally controlled with phenotypic plasticity very marked.

(c) Dark respiration is higher at all temperatures than for ordinary plants; rate is both genetically and environmentally controlled, with phenotypic plasticity very pronounced, i.e. low-temperature environment increases the rate at all temperatures.

(d) Alpine plants have higher light-saturation values in photosynthesis than do arctic or lowland plants; light saturation closely tied to temperature.

(e) There is some evidence that alpine plants can carry on photosynthesis at lower carbon dioxide concentrations than can other plants.

(f) Annual productivity is low, but daily productivity during growing season can be as high as that of most temperate herbaceous vegetation. Productivity can be increased by temperature, nutrients, or water.

6. Drought resistance: most drought stress in winter in exposed sites is due to frozen soils and dry winds. It is met by decreased water potentials, higher concentrations of soluble carbohydrates, and closed stomates. Little drought resistance in snowbank plants. Alpine plants adapted to summer drought stress can carry on photosynthesis at low water potentials; alpine or arctic plants of moist sites cannot do this.

7. Breaking of dormancy: controlled by mean temperatures near or above 0° C., and in some cases by photoperiod also.

8. Growth: very rapid even at low positive temperatures. Respiration greatly exceeds photosynthesis in early re-growth of perennials. Internal photosynthesis may occur in hollow stems of larger plants during early growth. Nitrogen and phosphorus often limiting in cold soil.

9. Food storage: characteristic of all alpine and arctic plants except annuals. Carbohydrates mostly stored underground in herbaceous perennials. Lipids in old leaves and stems of prostrate evergreen shrubs. Depleted in early growth, and usually restored after flowering.

10. Winter survival: survival and frost resistance are excellent after hardening. Cold resistance closely tied to content of soluble carbohydrates, particularly raffinose.

11. Flowering: flower buds are pre-formed the year before. Complete development and anthesis dependent upon temperature of the flowering year and also, in some cases, upon photoperiod.

12. Pollination: mostly insect-pollinated in alpine regions and even in Arctic, but to a lesser extent. Wind-pollination increasingly more important with increasing latitude. Diptera more important than bees in the Arctic and in the highest mountains.

13. Seed production: opportunistic, and dependent upon temperature during flowering period and latter half of growing season.

14. Vegetative reproduction: by rhizomes, bulbils, or layering. More common and important in Arctic than in alpine areas.

15. Onset of dormancy: triggered by photoperiod, low temperatures, and drought. Dormant plant extremely resistant to low temperatures.

The ecology of arctic and alpine plants

The literature on the response of insect species to the changing environments experienced along altitudinal gradients is diverse and widely dispersed. There is a growing awareness that such responses may serve as analogues for climate warming effects occurring at a particular fixed altitude or latitude over time. This review seeks, therefore, to synthesise information on the responses of insects and allied groups to increasing altitude and provide a platform for future research. It focuses on those functional aspects of insect biology that show positive or negative reaction to altitudinal changes but avoids emphasising adaptation to high altitude per se. Reactions can be direct, with insect characteristics or performance responding to changing environmental parameters, or they can be indirect and mediated through the insect's interaction with other organisms. These organisms include the host plant in the case of herbivorous insects, and also competitor species, specific parasitoids, predators and pathogens. The manner in which these various factors individually and collectively influence the morphology, behaviour, ecophysiology, growth and development, survival, reproduction, and spatial distribution of insect species is considered in detail. Resultant patterns in the abundance of individual species populations and of community species richness are examined. Attempts are made throughout to provide mechanistic explanations of trends and to place each topic, where appropriate, into the broader theoretical context by appropriate reference to key literature. The paper concludes by considering how montane insect species will respond to climate warming.

Terrestrial insects along elevation gradients: species and community responses to altitude

Why Bamboos Wait So Long to Flower

Ecology of Plant Galls

Ecology and Biogeography of High Altitude Insects

Chapters' Contents.- I. Introduction.- II. Physical Features.- 1. The Peninsula.- 1.1. The Peninsular Plateau.- 1.2. The Peninsular Foreland.- 1.3. The Coastal Regions.- A. The Western Littoral Region.- B. The Eastern Littoral Region.- 1.4. Ceylon.- 2. The Extra-Peninsular Area.- 2.1. The Ranges of the Himalaya.- 2.2. The Geographical and Biogeographical Divisions of the Himalaya.- 3. The Indo-Gangetic Plains.- 4. The Soil.- 5. The Drainage.- 5.1. The Peninsular Rivers.- 5.2. The Extra-Peninsular Rivers.- 5.3. Changes in the course and evolution of the Drainage Patterns of the Extra-Peninsular Rivers.- 6. Natural Regions.- References.- III. Geology.- 1. General Structure.- 1.1. The Peninsular Area.- 1.2. The Extra-Peninsular Area.- A. The Himalayan Arc.- B. The Burmese Arc.- C. The Baluchistan Arc.- 2. Pre-Cambrian Eras.- 2.1. Kerala.- 2.2. Madras.- 2.3. Mysore.- 2.4. Rajasthan.- 2.5. Southern Bihar and Orissa.- 2.6. The Eastern Ghats.- 2.7. Assam.- 2.8. Cuddapah Basin.- 2.9. The Himalayan Area.- 3. The Palaeozoic Era.- 3.1. Lower Palaeozoic.- 3.2. Devonian System.- 3.3. Carboniferous System.- 3.4. The Gondwana Group.- 3.5. The Permian System.- 4. The Mesozoic Era.- 4.1. Triassic System.- 4.2. Jurassic System.- 4.3. Cretaceous System.- 4.4. Deccan Trap.- 5. The Tertiary Era.- 5.1. Eocene System.- 5.2. Oligocene and Lower Miocene.- 5.3. Middle Miocene to Lower Pleistocene.- 6. Pleistocene and Recent.- References.- IV. Weather and Climatic patterns.- 1. Introduction.- 2. Normal Seasonal and Annual Rainfall.- 3. The Indian Monsoon.- 3.1. The Dates of Establishment of the Monsoon.- 3.2. The Behaviour of the Southwest Monsoon during 1875-1950.- 3.3. Rainfall week by week during the year.- 3.4. Contemporary relationships of the Monsoon rainfall in fifteen divisions.- 3.5. Regional peculiarities of distribution of rainfall.- 4. Other important Weather Phenomena that bring rainfall.- 4.1. The Eastern Depression.- 4.2. The Western Depressions.- 4.3. Cyclonic Storms.- 4.4. Thunderstorms and Hailstorms.- 5. Cold and Heat Waves.- 6. Microclimatology.- 6.1. Solar and Terrestrial Radiation.- 6.2. The Ground as Active Surface.- 6.3. The Diurnal temperature range.- 6.4. Shimmering layer above ground.- 6.5. Invisible condensation at soil surface.- 6.6. Thermal balance on a clear day.- 6.7. Microclimate of the open and some typical crop-fields.- A. Some typical microclimates and their diurnal range.- B. Effect of plant communities on wind velocity.- C. Effect of environment on the evaporating power of air layers near the ground.- References.- V. Limiting factors.- 1. Present-day Climate and its relation to the Himalaya.- 1.1. The monsoon-dominated Seasons.- 1.2. The mechanism of the Indian Monsoon.- 2. The Relation between the Himalayan uplift and the biogeographical composition of India.- 3. The Relation between Distributional Patterns and Man.- 3.1. Destruction of habitats.- 3.2. Extermination of Fauna.- 4. Conclusion.- References.- VI. The Flora.- 1. General characters of the Flora.- 2. The Major Floristic groups.- 2.1. Exotic naturalized plants.- 2.2. Tropical Asiatic Elements.- 2.3. The Temperate zone Elements.- 2.4. The Steppes Elements.- 2.5. The Mediterranean Elements.- 2.6. The Tropical African and Madagascan Elements.- 2.7. Pleistocene Relicts.- 3. The Major Ecological groups.- 3.1. Tropical forests.- 3.2. Montane subtropical and Temperate Forests.- 3.3. Alpine Forests.- 3.4. Littoral Forests.- 4. Phytogeographical Divisions.- References.- VII. Vegetation and Phytogeography of the Western Ghats.- 1. Introduction.- 2. History of botanical studies in the Western Ghats.- 3. Phytogeographical regions and Vegetation.- 3.1. The Western Ghats from the R. Tapti to Goa.- 3.2. The Western Ghats from the R. Kalinadi to Coorg.- 3.3. The Nilgiri.- 3.4. The Anamalai, Cardamom and Palni Hills.- 4. The Endemic Flora of the Western Ghats.- 5. Acknowledgments.- References.- VIII. The Vegetation and Phytogeography of the Eastern Ghats.- 1. Introduction.- 2. The Northern Sal Division.- 3. The Deccan Division.- 4. The Southern Division.- References.- IX. The Vegetation and Phytogeography of Assam-Burma.- 1. Introduction.- 2. Vegetation of Assam.- 2.1. The Tropical Vegetation.- 2.2. The Temperate Vegetation.- 2.3. The Alpine Vegetation.- 2.4. Some other Interesting Elements of the Assam Flora.- 3. Phytogeographical Affinities of Assam.- 4. Burma.- References.- X. Vegetation and Phytogeography of the Himalaya.- 1. Introduction.- 2. The Northwest Himalaya.- 2.1. Kashmir.- 2.2. Himachal Pradesh.- 3. The Western Himalaya.- 4. The Central Himalaya.- 5. The Eastern Himalaya.- 5.1. Sikkim.- 5.2. Bhutan.- 5.3. Assam and the North-East Frontier Agency.- 6. Phytogeographical Affinities.- References.- XI. The tribal man in India: A study in the Ecology of the primitive communities.- 1. Introduction.- 2. Tribal Society.- 3. Tribal Villages.- 4. Tribal family and Marriage Types.- 5. Tribal Demography.- 6. Regional Distribution of Tribal populations.- 7. Tribal Government.- 8. Interrelations with others.- 9. Cultural-Ecological Adaptations and Changes.- 9.1. Hunters, Fishers and Gatherers.- 9.2. Shifting cultivators.- 9.3. Peasants, Artisans and Castes.- 9.4. Transhumant herders and Terrace Cultivators.- 9.5. Nomadic Groups.- References.- XII. Some examples of recent Faunal Impoverishment and Regression.- 1. Introduction.- 2. Some Vanishing species of Reptiles.- 3. Some Vanishing species of Birds.- 4. Some Vanishing Mammals.- 5. Impoverishment and Regression.- 6. Major Factors determining Faunal Impoverishment and Regression.- References.- XIII. The Ecology of Vertebrates of the Indian Desert.- 1. Introduction.- 2. The Indian Desert.- 3. Fishes.- 4. Amphibians.- 5. Reptiles.- 5.1. Ecological Distribution.- 5.2. Food.- 5.3. Breeding.- 5.4. Zoogeography.- 6. Birds.- 7. Mammals.- 7.1. Ecological Distribution.- 7.2. Food.- 7.3. Reproduction.- 7.4. Population characteristics.- 8. The Vanishing Desert Wildlife.- 9. Behavioural and Physiological Adaptations to the Xeric Environment.- 10. Zoogeography.- References.- XIV. Ecology and Biogeography of the Termites of India.- 1. Introduction.- 2. Some Aspects of the Ecology of Termites in India.- 2.1. Termites and Soil.- 2.2. Termites and Living Plants.- 2.3. Relation between Atmospheric temperature and humidity and Termites.- 2.4. Gravity response and Vertical distribution of Termites.- 2.5. Populations of Termite Colonies.- 2.6. Inquilinism.- 2.7. Termites and Fungi.- 2.8. Natural Enemies of Termites.- 2.9. Termitophile Associates.- 3. Limiting Factors in Distribution of Termites.- 4. Distribution of some important Termites from India.- 4.1. Kalotermitidae.- 4.2. Termopsidae.- 4.3. Hodotermitidae.- 4.4. Rhinotermitidae.- 4.5. Termitidae.- 4.6. Indotermitidae.- References.- XV. The Biogeography of Indian Butterflies.- 1. Introduction.- 2. The faunal centres of Indian butterfly genera.- 3. The Derivation of the Indian butterfly fauna in relation to Continental Drift.- 4. The faunal elements of Indian butterfly species and their relation to the generic centres.- 5. Conclusion.- References.- XVI. Some aspects of the Ecology and Geography of Diptera.- 1. Introduction.- 2. Major Ecological Types.- 2.1. The monsoon Communities.- 2.2. The winter Communities.- 2.3. The Humid-tropical Elements.- 2.4. The Dry Tropical deciduous Forest Communities.- 2.5. The Temperate zone Communities.- 2.6. The Synanthropous Communities.- 3. Nematocera.- 4. Brachycera.- 5. Conclusion.- References.- XVII. Ecology and Distribution of fresh-water Fishes, Amphibia and Reptiles.- 1. Introduction.- 2. Fish.- 2.1. Distributional Patterns of the primary fresh-water fishes.- 3. Amphibia.- 4. Chelonia.- 5. Lacertilia.- 6. Serpentes.- 7. Crocodilia.- 8. Summary.- References.- XVIII. Mammals of Assam and the Mammal-Geography of India.- 1. Introduction.- 2. The major Ecological Associations.- 3. The Faunal composition.- 4. Faunal Resemblance.- 5. Faunal Interchanges.- 6. Species Dispersal.- 6.1. Nature of Invasions.- 7. Criticism of the Satpura Hypothesis.- 8. Mainstreams of the Faunal Flow.- References.- XIX. Biogeography of the Peninsula.- 1. Introduction.- 2. The Character Fauna.- 3. The Gondwana Faunal Derivatives.- 3.1. The Peninsular Endemics.- 3.2. The Madagascan Elements.- 4. The Younger Intrusive Elements.- 4.1. The Indo-Chinese Faunal Derivatives.- 4.2. The Malayan Elements.- 5. The Palaearctic Elements.- 6. Distributional Patterns.- 7. Faunal subdivisions.- 8. The Laccadive and Maladive Islands.- 9. Seychelles Islands.- References.- XX. Biogeography of the Eastern Borderlands.- 1. Ecology.- 2. The Character Fauna.- 2.1. Endemics.- 2.2. The Indo-Chinese and Malayan Elements.- 2.3. Other Component Elements.- 3. Distributional Patterns.- 4. The Andaman and Nicobar Islands.- References.- XXI. Biogeography of the Himalaya.- 1. Introduction.- 2. Fauna of the Forest Zones.- 2.1. The Himalayan Forest east of the R. Sutlej.- 2.2. The Himalayan Forest west of the R. Sutlej.- 3. Fauna above the Forestline.- References.- XXII. Biogeography of the Western Borderlands.- 1. Introduction.- 2. General Ecology.- 3. Character Fauna and Biogeographical Affinities.- References.- XXIII. Biogeography of the Indo-Gangetic Plain.- 1. Introduction.- 1.1. The Indus Plains.- 1.2. The Gangetic Plains.- 1.3. The Upper Gangetic Plain.- 1.4. The Middle Gangetic Plain.- 1.5. Bengal.- 2. Ecology.- 3. Character Fauna and Distributional Patterns.- References.- XXIV. Biogeographical Evolution in India.- 1. Introduction.- 2. The origins of the Flora and Fauna.- 3. The origins of the Distributional Patterns.- References.

M. S. Mani

Papers

Ecology of Plant Galls

Ecology and Biogeography of High Altitude Insects

Ecology and Biogeography in India

Introduction to high altitude entomology

Ecology of Plant Galls