Annual desert plant species of unrelated taxa in the Negev Desert of Israel have developed complementary sets of adaptations and survival strategies as ecological equivalents with physiological, morphological and anatomical resemblances, in the various stages of their life cycles. After 40 years of research in hot deserts Yitzchak Gutterman provides a comprehensive treatise of such adaptations and strategies. In doing so he covers the following topics: post-maturation primary seed dormancy, which prevents germination of maturing seeds before the summer; seed dispersal mechanisms with escape or protection strategies; cautious or opportunistic germination strategies; seedling drought tolerance. The day-length is an important factor in regulating flowering as well as the phenotypic plasticity of seed germination which is also affected by maternal factors.

Inhalt

1 The Desert Biome, Survival Adaptations and Strategies of Annual Plant Species.- 1.1 Introduction.- 1.1.1 The Environment in Deserts and Arid Zones.- 1.1.2 Deserts with Winter or Summer Rain.- 1.1.3 Classification of Semi-Arid and Arid Zones According to the Amounts of Rain and Vegetation Zones.- 1.1.4 Annuals in Deserts and Survival Adaptations Throughout the Stages of Their Life Cycles.- 1.2 Plant Adaptation and Survival Strategies.- 1.3 The Negev Desert.- 1.3.1 Rain Amounts and Distribution.- 1.3.2 Amounts of Runoff Water After an Intense Rainfall Affected by Soil Crust, Stones and Slope Gradient.- 1.3.3 Biotic Activity, Diggings, Distribution of Runoff Water and Plant Succession.- 1.3.4 Temperatures in Winter or Summer.- 1.3.5 Temperatures, Relative Humidity and Rain Efficiency for Seed Germination.- 1.3.6 Day Length, Date of Seed Germination, Plant Development, Flowering and Plant Life Span.- 1.3.7 Dew During Winter or Summer Affecting Plant Adaptation.- 1.3.8 The Annual Environmental Factors and Life Cycle of Annual Plants.- 1.3.9 Seed Collectors.- 1.4 Conclusion.- 2 Flowering Strategies.- 2.1 Introduction.- 2.2 Flowering Adaptations and Strategies of Perennial Plants.- 2.3 Flowering Adaptations and Strategies of Selected Annual Plants.- 2.3.1 One-Seasonal Winter Annuals.- 2.3.1.1 Facultative Long-Day Response for Flowering (FLD).- 2.3.1.2 The Day Length Independent Response for Flowering (DIF).- 2.3.1.3 Intermediates.- 2.3.1.4 Single-Season Summer Annuals.- 2.3.2 Bi-seasonal Plants.- 2.3.2.1 Long-day (LD) Response for Flowering.- 2.3.2.2 Flowering Under Short Days and High Temperatures.- 2.4 Conclusion.- 3 Strategies of Phenotypic Plasticity of Germination During Seed Development and Maturation.- 3.1 Introduction.- 3.2 Environmental Factors Affecting Phenotypic Germination Plasticity.- 3.2.1 Seed Maturation Dates in a Natural Environment Affecting Germination.- 3.2.2 Day Length During Plant Development and Seed Maturation.- 3.2.2.1 Long or Short Days Affecting Seed Coat Permeability to Water.- 3.2.2.2 Day Length and Plant Age Affect Seed Plasticity of Germination.- 3.2.2.3 Short-Term and Long-Term Seed Banks.- 3.2.2.4 Quantitative Short-Day Effect.- 3.2.2.5 Quantitative Long-Day Effect.- 3.2.2.6 Day Length Effect on Short-Term and Long-Term Seed Banks.- 3.2.2.7 Day Length Affects Seed Germination of Plant Species with Soft Fruit.- 3.2.2.8 The Ecological Importance of the Critical Time During Seed Maturation at Which Day Length Affects Seed Germination.- 3.2.3 Influences of Light Quality During Seed Maturation on Seed Germination.- 3.2.4 Water Stress During Seed Maturation Affecting Seed Germination.- 3.2.5 Water and Temperature Stresses.- 3.2.6 Temperatures During Maturation Affecting Seed Germination.- 3.2.7 Plant Age, Seed Size and Germination Plasticity.- 3.3 Seed Position on the Mother Plant During Seed Development and Maturation Affecting Seed Germination.- 3.3.1 Seed Position in the Capsules, Pods and Fruit.- 3.3.2 The Effect of Position of Capsules or Pods in the Plant Canopy on Seed Germination.- 3.3.2.1 Central or Peripheral Capsules.- 3.3.3 Position of Pods in the Upper and Lower Part of the Inflorescence.- 3.3.4 Position of the Fruits, Dimorphism and Germinability.- 3.3.5 Position, Heteromorphism and Germination.- 3.3.6 Seed Position in Inflorescences That Are Also Dispersal Units.- 3.3.6.1 Position and Heteroblasty in Pteranthus dichotomus.- 3.3.6.2 The Heteroblasty of the Caryopses of Synaptospermic, Lignified Dispersal Units.- 3.3.6.3 The Influences of the Order of the Caryopses on Germination Percentage, Plant Development, Flowering and the Number of Tillers and Spikelets.- 3.3.6.4 The Influence of the Order of the Caryopses on the Size and Germination of the Caryopses of the Following Generation.- 3.3.7 Position in Burr - a Synaptospermic Dispersal Unit.- 3.3.8 Position of Achenes in the Capitulum Whorls Affecting the Time Distribution of Dispersal and Germination (serotinas).- 3.3.9 Position Effect on Seed Germinability and Seedling Survival of Female and Hermaphrodite Flowers in Inflorescences.- 3.3.10 Position of Achenes in Umbels Affecting Germinability.- 3.3.11 Position of Aerial and Subterranean Inflorescences Affecting Dispersability and Germinability.- 3.4 Desiccation Tolerance of Maturing Seeds.- 3.5 Conclusion.- 4 Strategies of Phenotypic Plasticity of Germination: Dormancy After Seed Maturation.- 4.1 Introduction.- 4.2 Post Maturation Environmental Influences on Dry Seed Primary Dormancy (After-Ripening).- 4.2.1 Hordeum spontaneum.- 4.2.2 Schismus arabicus.- 4.2.3 Stipa capensis.- 4.2.4 Ammochloa palaestina.- 4.2.5 Plantago coronopus.- 4.2.6 Spergularia diandra.- 4.3 Periods of Storage of Dry Seeds at High Temperatures Affecting Primary Dormancy in Seeds of Different Plant Species.- 4.3.1 Short Periods of Dry Seed Storage at High Temperatures Increases Germination.- 4.3.2 Long Periods of Dry Seed Storage at High Temperatures.- 4.3.2.1 Portulaca oleracea.- 4.3.2.2 Hirschfeldia incana.- 4.3.3 "Bet Hedging" Germination.- 4.3.3.1 Asteriscus hierochunticus.- 4.3.3.2 Mesembryanthemum nodiflorum.- 4.4 Post Maturation Phenotypic Germination Plasticity of Hard Seeds.- 4.4.1 Day Length During Seed Maturation Affecting Hard Seeds.- 4.4.2 Temperature Amplitude During Summer Affecting Hard Seeds.- 4.4.3 Gradual or Sudden Increase of Relative Humidity Affecting Hard Seeds.- 4.4.4 Low Relative Humidity Affecting Seed Germination.- 4.5 Post-Maturation Supra-optimal Temperatures Affecting Germination of Wet Seeds, and Thermodormancy.- 4.5.1 Lactuca serriola.- 4.5.2 Lactuca sativa.- 4.5.3 Cheiridopsis.- 4.6 Conclusion.- 5 Seed Dispersal Adaptations and Strategies.- 5.1 Seed Consumption, Plant Adaptations and Strategies of Seed Dispersal.- 5.2 One-Season Winter Annuals and Seed Dispersal Seasons.- 5.2.1 Dispersal of Lignified, Synaptospermic, Multi-Seeded Dispersal Units at the End of the Season with Rains.- 5.2.2 Entangled Lignified Dispersal Units.- 5.2.3 Dry Unopened, Lignified Pod as a Dispersal Unit.- 5.2.3.1 Multi-Seeded Dispersal Unit.- 5.2.3.2 Single-Seeded Lignified Sections of a Pod.- 5.2.4 Lignified Aerial Seed Banks with Delayed Seed Dispersal by Rain (Serotinous and Hygriescence).- 5.2.4.1 Dispersal by Rain of Aerial Protected Non-mucilaginous Seeds that 'Escape' into the Soil Seed Bank.- 5.2.4.2 Aerial Lignified Seed Banks with Mucilaginous Seeds, Seed Dispersal by Rain During the Season or Seasons Following Maturation.- 5.2.4.3 Shooting of Seeds to a Distance from the Mother Plant Triggered by Rain or Flood Water.- 5.2.4.4 Seeds Released by Rain and Dispersed by Wind.- 5.2.5 Subterranean Lignified, Protected Seed Banks, Germination in Situ.- 5.2.6 Escape Dispersal Adaptations and Strategies of Tiny Seeds.- 5.2.6.1 Tiny, Dust-Like Seeds.- 5.2.6.2 Dispersal by Wind of Small Seeds with Pappus or Corolla.- 5.2.6.3 Dispersal by Wind and Boring Hydrochastic Mechanisms.- 5.2.6.4 Dispersal by Wind of Mucilaginous Seeds During the Dry Season.- 5.2.6.5 Dispersal by Wind of Polymorphic Mucilaginous and Non-mucilaginous Achenes.- 5.2.6.6 Delayed Seed Dispersal …