DOCSLIB.ORG

Punam Jaiswal PG-IV XEROPHYTES(Morphology).Pdf

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Punam Jaiswal PG-IV XEROPHYTES(Morphology).Pdf Environmental Biology Prof.(Dr.) Punam Jeswal Head M.Sc semester IV Botany Department XEROPHYTES A xerophyte (Gr. Xeros, dry; phyton, plant) is a plant which is able to survive in an environment with low availability of water or moisture, such as desert, ice or snow covered region. Xerophytes defined as "plants of dry habitats". Xerophytes are plants adopted in order to survive or grow in dry habitats (xeric condition) where the availability of water is very less. Daubenmire (1959) defined xerophytes as "plants which grow on substrate that usually become depleted of water to a depth of at least two decimeters during normal growth season". Xerophytes are plants of relatively dry habitats - dry in soil and most often also climatically. Xerophytes plants live in condition of water scarcity i.e. in xeric condition (habitat). Xeric habitats are of two types - 1) Physically dry habitat :- Water retaining capacity of the soil very low and climate is dry. Water cannot retained like desert or rock surface. 2) Physiologically dry :- Water is present in excess, but not in absorbable conditions or the plants cannot absorb it. e.g. high salt water, high acidic water and high cold water, water in snow form. Adaptation Strategies of Xerophytes :- Xerophytes adopt various features according to their climate, geography and requirements. Xerophytes plants aim at the following adaptation strategies :- 1) Absorb more water from the surrounding. 2) Retain water in their organs. 3) Reduce the water loss by transpiration to minimise. 4) Reduce utilisation of water ( Prevent high consumption of water) Types Of Xerophytes On the basis of morphology, physiology and life cycle patterns, xerophytes are classified into three categories :- 1) Ephemeral Annuals ( Drought Evaders or Drought Escapers) * They are also called as 'drought evaders' or 'drought escapers' common in arid zones. * They are annuals, which complete their life cycles within a very short period. * They actually avoid and not withstand dry seasons, and thus escape dryness in external and internal environments. * They survive critical dry periods as seeds or propagules. With the onset of rainfall, the plant seeds germinate, quickly grow to maturity, flower, and set seed, i.e., the entire life cycle is completed before the soil dries out again. * They are usually shorts sized plants in which the flowering and fruiting occur before the next unfavourable season. * The principal morphological adaptation of ephemeral are their small size and large shoot in relation to root system. * Most of these plants are small, roundish, dense shrubs represented by species of Papilionaceae, some inconspicuous Compositae, and some grasses * Examples - Solanum xanthocarpum, Argemone mexicana, Cassia tora etc. 2) Succulents Xerophytes ( Drought Enduring Xerophytes) - * These plants suffer from dryness in their external environment only. Their succulent, fleshy organs (stems, leaves, roots) serve as water storage organs which accumulate large amount of water during the brief raining reason. * In some xerophytic plants, stem becomes succulent which are called the 'fleshy Xerophytes' as in Opuntia and Euphorbia. * Those succulent xerophytes in which leaves become fleshy; are also known as malacohyllous xerophytes', such as Aloe, Bryophyllum, Agava, Yucca etc. 3) Non- Succulent Perennial ( Drought Resisting Plants) * These are drought resistant plants and called as the true xerophytes. * They possess a number of morphological, anatomical and physiological characteristics, which enable them to withstand critical dry condition. Thus they suffer from dryness both in their internal as well as external environments. * They exhibit rapid root growth and form an extensive root systems to maximize water supply from the soil. The leaf size is greatly reduced and in many xerophytic grasses, leaves roll on to reduce the leaf surface for restricting loss of water due to transpiration. Some of the examples are Calotropis procera, Acacia nelotica Casuarina, Nerium, Saccharum, Pinus and Salvadora. ECOLOGICAL ADAPTATIONS IN XEROPHYTES The environmental adaptation or chief characteristics features exhibits by xerophytes to escape drought or to endure recurrent drought can be either morphological , anatomical or physiological . These features are more or less common to all xerophytes which enables them to survive under the prevailing xeric conditions Morphological Features (Adaptation) Xerophytes exhibits a number of special features in their morphological organs. Root :- Xerophytes develop under water deficient condition and in order to secure water, the root system in xerophytes are well developed and show following characteristics :- * Root system is well developed. Profusely branched . It is very extensive and more elaborate then shoot system in true xerophytes. * Roots of perennial xerophytes reach greater depth to absorb water but some xerophytes have shallow root system especially when water is available in the surface layers * Roots are long, tap roots, with extensive branching spread over wide areas. * Root hairs and root caps are very well developed. Stems :- * Stems are mostly stunted, woody , dry, hard, ridged and covered with thick bark. * In some xerophytes as Saccharum, stem becomes underground, whereas in Opuntia it becomes fleshy, green, leaf-like covered with spines. In Euphorbia also it becomes fleshy and green. * Stems are covered with dense hairs ( Calotropis), coated with wax (Opuntia) or silica (Equisetum). * Stem in some xerophytes are modified into thorns ( Ulex). * Succulent and bulbous xerophytes can store water in their stem. e.g. Cactus and some species of Euphorbia. * In succulent xerophytes the stems are modified into structures like phylloclades, cladophylls or cladodes. a) Phylloclades - Stem modified into flattened leaf like organs (Opuntia) b) Cladophylls - Branches developed in the axil of scale leaves, become metamorphosed to leaf-like structure ( Ruscus) c) Cladophyll - Many axillary branches become modified into small needle like green structures which look exactly like leaves (Asparagus). Fig :- Stem and Leaf Modified Structures ( Phylloclade, Cladode, Cladophyll and phyllode). Leaves :- Usually leaves of xerophytes are reduced or modified to various kinds of structure to minimise transpiration. * Leaves are usually absent in many xerophytes or they fall very early (caducous). * In majority of the xerophytes the leaves are modified into spines or scales as in Casuarina, Asparagus . Lamina may be long narrow or needle-like as in Pinus or divided into many leaflets as in Acacia. * Foliage leaves, wherever present, may become thick, fleshy and succulent, or tough and leathery in texture. * Leaf may modified into phyllode (Leaf petiole or rachis modified or flattened into leaf like organ) in some plant e.g. Acacia. * leaves of some xerophytes posses reduced leaf blades or pinnate and have very ` dense network of veins. * In some xerophytes especially those growing in high wind blowing area, the under surface of the leaves are covered with thick hairs which protect the stomatal guard cells and check the transpiration. These xerophytes are known as trichophyllous. * Leaf surfaces are shiny glazed to reflect light and heat, e.g. Calotropis. * In some monocots as Ammophila, Poa, and Agropyron, leaves become folded and rolled in such a manner that the sunken stomata become hidden and thus the rate of transpiration is considerably minimised. * In some of them as Euphorbia, Acacia nelotica and Capparis anphylla, stipules become modified into spines. * In some xerophytes, leaves are stiff and hard (sclerophyllous) e.g. Banksia. A) b) Fig :- A) Non-succulent Perenials Xerophytes B) Succulent Xerophytes. .
Load more

Recommended publications
  • The Synergistic Effects of Sodium and Potassium on the Xerophyte
    Plant Physiology and Biochemistry xxx (xxxx) xxx–xxx Contents lists available at ScienceDirect Plant Physiology and Biochemistry journal homepage: www.elsevier.com/locate/plaphy Research article The synergistic effects of sodium and potassium on the xerophyte Apocynum venetum in response to drought stress ∗ Yan-Nong Cuia,1, Zeng-Run Xiaa,b,1, Qing Maa, Wen-Ying Wanga, Wei-Wei Chaia, Suo-Min Wanga, a State Key Laboratory of Grassland Agro-ecosystems, College of Pastoral Agriculture Science and Technology, Lanzhou University, Lanzhou 730000, PR China b Ankang R&D Center of Se-enriched Products, Key Laboratory of Se-enriched Products Development and Quality Control, Ministry of Agriculture, Ankang, Shaanxi, 725000, PR China ARTICLE INFO ABSTRACT Keywords: Apocynum venetum is an eco-economic plant species with high adaptability to saline and arid environments. Our Apocynum venetum previous work has found that A. venetum could absorb large amount of Na+ and maintain high K+ level under Potassium efficiency saline conditions. To investigate whether K+ and Na+ could simultaneously enhance drought resistance in A. Osmotic stress venetum, seedlings were exposed to osmotic stress (−0.2 MPa) in the presence or absence of additional 25 mM Sodium NaCl under low (0.01 mM) and normal (2.5 mM) K+ supplying conditions, respectively. The results showed that Osmotic adjustment A. venetum should be considered as a typical K+-efficient species since its growth was unimpaired and possessed Photosynthesis a strong K+ uptake and prominent K+ utilization efficiency under K+ deficiency condition. Leaf K+ con- centration remained stable or was even significantly increased under osmotic stress in the presence or absence of NaCl, compared with that under control condition, regardless of whether the K+ supply was sufficient or not, and the contribution of K+ to leaf osmotic potential consistently exceeded 37%, indicating K+ is the uppermost contributor to osmotic adjustment of A.
    [Show full text]
  • (2) How Plants Manage Water Deficit and Why It Matters
    Plant-Water Relations (2) How plants manage water deficit and why it matters Photo credits: Mel Oliver; William M. Ciesla, Forest Health Management International; R.L. Croissant Bugwood.org © 2014 American Society of Plant Biologists Outline 1. Water scarcity is a growing problem 2. Desiccation-tolerant plants and xerophytes 3. Plant responses to water deficit Perception and signaling Transcriptional responses Effects on photosynthesis Effects on growth and development 4. Towards water-optimized and drought-tolerant agriculture Optimizing irrigation Monitoring water stress 5. Breeding for drought-tolerance Classical approaches Candidate gene approaches © 2014 American Society of Plant Biologists Key definitions and concepts Desiccation: Extreme water loss, equilibration to the water potential of the air which is generally low Desiccation tolerance: The ability to withstand and recover from desiccation Dehydration: The process of water loss from a cell or system Water deficit: Sub-optimal water status from the perspective of plant function Drought: Lack of rainfall or water supply leading to water deficit Drought tolerance: The ability to withstand suboptimal water availability through adaptations or acclimations (not the same as desiccation tolerance) Xerophyte: A plant adapted to live in a low-water environment Mesophyte: A plant without specialized adaptions to low-water or high- water environments Adaptation: Long-term evolutionary process by which an organism becomes suited to its environment Acclimation: Short-term physiological process
    [Show full text]
  • Plant Classification and Seeds
    Ashley Pearson – Plant Classification and Seeds ● Green and Gorgeous Oxfordshire ● Cut flowers ● Small amounts of veg still grown and sold locally Different Classification Systems Classification by Life Cycle : Ephemeral (6-8 wks) Annual Biennial Perennial Classification by Ecology: Mesophyte, Xerophyte, Hydrophyte, Halophyte, Cryophyte Raunkiaers Life Form System: based on the resting stage Raunkiaers Life Form System Classification contd. Classification by Plant Growth Patterns Monocots vs. Dicots (NB. only applies to flowering plants - angiosperms) Binomial nomenclature e.g., Beetroot = Beta vulgaris Plantae, Angiosperms, Eudicots, Caryophyllales, Amaranthaceae, Betoideae, Beta, Beta vulgaris After morphological characters, scientists used enzymes and proteins to classify plants and hence to determine how related they were via evolution (phylogeny) Present day we use genetic data (DNA, RNA, mDNA, even chloroplast DNA) to produce phylogenetic trees Plant part modifications ● Brassica genus ● ● Roots (swede, turnips) ● Stems (kohl rabi) ● Leaves (cabbages, Brussels Sprouts-buds) ● Flowers (cauliflower, broccoli) ● Seeds (mustards, oil seed rape) Plant hormones / PGR's / phytohormones ● Chemicals present in very low concentrations that promote and influence the growth, development, and differentiation of cells and tissues. ● NB. differences to animal hormones! (no glands, no nervous system, no circulatory system, no specific mode of action) ● Not all plant cells respond to hormones, but those that do are programmed to respond at specific points in their growth cycle ● Five main classes of PGR's ● Abscisic acid (ABA) ● Role in abscission, winter bud dormancy (dormin) ● ABA-mediated signalling also plays an important part in plant responses to environmental stress and plant pathogens ● ABA is also produced in the roots in response to decreased water potential.
    [Show full text]
  • Characterization of the Transcriptome of the Xerophyte Ammopiptanthus Mongolicus Leaves Under Drought Stress by 454 Pyrosequencing
    RESEARCH ARTICLE Characterization of the Transcriptome of the Xerophyte Ammopiptanthus mongolicus Leaves under Drought Stress by 454 Pyrosequencing Tao Pang1☯, Lili Guo1,2☯, Donghwan Shim3,4☯, Nathaniel Cannon3, Sha Tang1, Jinhuan Chen1, Xinli Xia1*, Weilun Yin1*, John E. Carlson3* 1 National Engineering Laboratory for Tree Breeding, College of Biological Sciences and Technology, Key Laboratory for Silviculture and Conservation, Beijing Forestry University, Beijing, People’s Republic of China, 2 College of Agricultural, Henan University of Science and Technology, Luoyang, People’s Republic of China, 3 The Schatz Center for Tree Molecular Genetics, Department Ecosystem Science and Management, Pennsylvania State University, University Park, Pennsylvania, United States of America, 4 Department of Forest Genetic Resources, Korea Forest Research Institute, Suwon 441–350, Korea ☯ These authors contributed equally to this work. * [email protected] (XX); [email protected] (WY); [email protected] (JEC) OPEN ACCESS Abstract Citation: Pang T, Guo L, Shim D, Cannon N, Tang S, Chen J, et al. (2015) Characterization of the Transcriptome of the Xerophyte Ammopiptanthus Background mongolicus Leaves under Drought Stress by 454 Pyrosequencing. PLoS ONE 10(8): e0136495. Ammopiptanthus mongolicus (Maxim. Ex Kom.) Cheng f., an endangered ancient legume doi:10.1371/journal.pone.0136495 species, endemic to the Gobi desert in north-western China. As the only evergreen broad- Editor: Mukesh Jain, National Institute of Plant leaf shrub in this area, A. mongolicus plays an important role in the region’s ecological-envi- Genome Research, INDIA ronmental stability. Despite the strong potential of A. mongolicus in providing new insights Received: February 17, 2015 on drought tolerance, sequence information on the species in public databases remains Accepted: August 4, 2015 scarce.
    [Show full text]
  • Isotopic Approaches to Quantify Root Water Uptake and Redistribution
    Isotopic approaches to quantify root water uptake and redistribution: a review and comparison of methods Youri Rothfuss1, Mathieu Javaux1,2,3 1Institute of Bio- and Geosciences, IBG-3 Agrosphere, Forschungszentrum Jülich GmbH, Jülich, 52425, Germany 5 2Earth and Life Institute, Environnemental Sciences, Université catholique de Louvain (UCL), Louvain-la-Neuve, 1348, Belgium 3Department of Land, Air and Water Resources, University of California Davis, Davis, California, 95616, USA. Correspondence to: Youri Rothfuss ([email protected]) Abstract. Plant root water uptake (RWU) and release (i.e., hydraulic redistribution – HR, and its particular case hydraulic 10 lift – HL) have been documented for the past five decades from water stable isotopic analysis. By comparing the (hydrogen or oxygen) stable isotopic composition of plant xylem water to those of potential contributive water sources (e.g., water from different soil layers, groundwater, water from recent precipitation or from a nearby stream) studies could determine the relative contributions of these water sources to RWU. Other studies have confirmed the existence of HR and HL from the isotopic analysis of the plant xylem water following a labelling pulse. 15 In this paper, the different methods used for locating / quantifying relative contributions of water sources to RWU (i.e., graphical inference, statistical (e.g., Bayesian) multi-source linear mixing models) are reviewed with emphasis on their respective advantages and drawbacks. The graphical and statistical methods are tested against a physically based analytical RWU model during a series of virtual experiments differing in the depth of the groundwater table, the soil surface water status, and the plant transpiration rate value.
    [Show full text]
  • Glossary of Landscape and Vegetation Ecology for Alaska
    U. S. Department of the Interior BLM-Alaska Technical Report to Bureau of Land Management BLM/AK/TR-84/1 O December' 1984 reprinted October.·2001 Alaska State Office 222 West 7th Avenue, #13 Anchorage, Alaska 99513 Glossary of Landscape and Vegetation Ecology for Alaska Herman W. Gabriel and Stephen S. Talbot The Authors HERMAN w. GABRIEL is an ecologist with the USDI Bureau of Land Management, Alaska State Office in Anchorage, Alaskao He holds a B.S. degree from Virginia Polytechnic Institute and a Ph.D from the University of Montanao From 1956 to 1961 he was a forest inventory specialist with the USDA Forest Service, Intermountain Regiono In 1966-67 he served as an inventory expert with UN-FAO in Ecuador. Dra Gabriel moved to Alaska in 1971 where his interest in the description and classification of vegetation has continued. STEPHEN Sa TALBOT was, when work began on this glossary, an ecologist with the USDI Bureau of Land Management, Alaska State Office. He holds a B.A. degree from Bates College, an M.Ao from the University of Massachusetts, and a Ph.D from the University of Alberta. His experience with northern vegetation includes three years as a research scientist with the Canadian Forestry Service in the Northwest Territories before moving to Alaska in 1978 as a botanist with the U.S. Army Corps of Engineers. or. Talbot is now a general biologist with the USDI Fish and Wildlife Service, Refuge Division, Anchorage, where he is conducting baseline studies of the vegetation of national wildlife refuges. ' . Glossary of Landscape and Vegetation Ecology for Alaska Herman W.
    [Show full text]
  • Isoprenoid Emission in Hygrophyte and Xerophyte European Woody Flora: Ecological and Evolutionary Implications
    Global Ecology and Biogeography, (Global Ecol. Biogeogr.) (2014) 23, 334–345 bs_bs_banner RESEARCH Isoprenoid emission in hygrophyte and PAPER xerophyte European woody flora: ecological and evolutionary implications Francesco Loreto1*, Francesca Bagnoli2, Carlo Calfapietra3,4, Donata Cafasso5, Manuela De Lillis1, Goffredo Filibeck6, Silvia Fineschi2, Gabriele Guidolotti7, Gábor Sramkó8, Jácint Tökölyi9 and Carlo Ricotta10 1Dipartimento di Scienze Bio-Agroalimentari, ABSTRACT Consiglio Nazionale delle Ricerche, Piazzale Aim The relationship between isoprenoid emission and hygrophily was investi- Aldo Moro 7, 00185 Roma, Italy, 2Istituto per la Protezione delle Piante, Consiglio Nazionale gated in woody plants of the Italian flora, which is representative of European delle Ricerche, Via Madonna del Piano 10, diversity. 50019 Sesto Fiorentino (Firenze), Italy, Methods Volatile isoprenoids (isoprene and monoterpenes) were measured, or 3 Istituto di Biologia Agroambientale e data collected from the literature, for 154 species native or endemic to the Medi- Forestale, Consiglio Nazionale delle Ricerche, terranean. The Ellenberg indicator value for moisture (EIVM) was used to describe Via Marconi 3, Porano (Terni), Italy, plant hygrophily. Phylogenetic analysis was carried out at a broader taxonomic scale 4Global Change Research Centre – CzechGlobe, on 128 species, and then refined on strong isoprene emitters (Salix and Populus Belidla 4a, 603 00 Brno, Czech Republic, species) based on isoprene synthase gene sequences (IspS). 5Dipartimento di Biologia, Università degli Studi di Napoli ‘Federico II, Complesso Results Isoprene emitters were significantly more common and isoprene emis- Universitario di Monte S. Angelo, Via Cinthia, sion was higher in hygrophilous EIVM classes, whereas monoterpene emitters were 80126 Napoli, Italy, 6Dipartimento di Scienze more widespread and monoterpene emission was higher in xeric classes.
    [Show full text]
  • 6 Principles of Ecology
    UNIT IX: Plant Ecology Chapter 6 Principles of Ecology Learning Objectives • How soil, climate and other physical features aff ect the fl ora and fauna or vice versa? Th e learner will be able to Th ese questions can be better answered with Understand the interaction between the study of ecology. organisms and their Ecology is essentially a practical science environment. involving experiments, continuous Describe biotic and observations to predict how organisms react abiotic factors that to particular environmental circumstances infl uence the dynamics of and understanding the principles involved in populations. ecology. Describe how organisms adapt themselves to environmental changes. 6.1 Ecology Learn the structure of various fruits and The term “ecology” seeds related to their dispersal mechanism. (oekologie) is derived from two Greek words – oikos (meaning house or dwelling Chapter outline place and logos meaning study) It was first proposed by 6.1 Ecology R. Misra Reiter (1868). However, the 6.2 Ecological factors most widely accepted definition of ecology was 6.3 Ecological adaptations given by Ernest Haeckel (1869). 6.4 Dispersal of seeds and fruits Alexander von Humbolt - Father of Ecology Ecology is a division of biology which deals Eugene P. Odum - Father of morden Ecology with the study of environment in relation to R. Misra - Father of Indian Ecology organisms. It can be studied by considering individual organisms, population, community, biome or biosphere and their environment. 6.1.1 Definitions of ecology While observing
    [Show full text]
  • An English-Spanish Glossary of Terminology Used in Forestry, Range, Wildlife, Fishery, Soils, and Botany
    United States Department of Agriculture Forest Service AN ENGLISH-SPANISH GLOSSARY Rocky Mountain Forest and Range Experiment St ation OF TERMINOLOGY USED IN Fort Collins, FORESTRY, RANGE, WILDLIFE, FISHERY, Colorado 80526 SOILS, AND BOTANY General Technical Report RM.152 GLOSARIO EN INGLESESPANOL DE TERMINOLOGIA USADOS EN FORESTALES, PASTIZALES, FAUNA SILVESTRE, PESQUERIA, SU ELOS, Y BOTANICA ABSTRACT The English-Spanish/Spanish-English equivalent translations of scientific and management terms (jargon) commonly used in the field of natural resource management are presented. The glossary is useful in improving communications and fostering understanding between Spanish- and English-s~eaking Persons. Key Words: Bilingual glossary, animal names, botany, fishery, forestry, range, soils, wildlife ACKNOWLEDGEMENTS This glossary has required considerable time Este glosario ha requerido bastante tiempo in preparation by some people. Special de preparacihn en parte de varias personas. recognition for the successful completion of this ReconocimienCo especiales por acabamiento dichoso work is given to Penny Medina for her assistance de este trabajo se da a Penny Medina por su in translating scientific articies, Diane Prince asistencia en traducir articulos de ciencia, and Josephine Gomez for their part in manuscript Diane Prince y Josephine Gomez por su parte en preparation and editing, the Mexican scientists preparaci6n y compilaci6n del manuscrito, 10s for their reviews, and to David Patton ,for his cientfficos mexicanos por su revistas, y David support, Patton por su apoyo. USDA Forest Service General Technical Report RM.152 January 1988 AN ENGLISH-SPANISH GLOSSARY OF TERMINOLOGY USED IN FORESTRY, RANGE, WILDLIFE, FISHERY, SOILS, AND BOTANY GLOSARIO EN INGLES-ESPAN'OL DE TERMINOLOGIA EJSADOS EN FORESTALES, PASTIZALES, FAUNA SILVESTRE, , PESQUERIA, SUELOS, Y BOTANICA Alvin Leroy Medina, Range Scientist Rocky Mountain Forest and Range Experiment Station1 'Headquarters is in Fort Collins, in cooperation with Colorado State University.
    [Show full text]
  • Plant Adaptations
    BIL 161 – Plant Form and Function Designing a Research Project In almost all terrestrial environments, water is a limiting factor that affects the function of living organisms. All terrestrial organisms, from animals to fungi to plants, and even some unicellular organisms, exhibit various adaptations (or lack thereof) that allow them to inhabit habitats where water may be somewhat or severely limiting to their daily functions and reproduction. Because your research project will focus on plants, here we provide a bit of background that might inspire you. I. Water Conservation: Variation Among Species Plants exhibit tremendous variety of form and function due to natural selection pressures exerted by their environments. They have evolved different morphologies and features due to selective pressures exerted by pollinators, herbivores, climate and other environmental factors. The climate in which a plant evolves has a profound effect on its characteristics affecting water transport. A. ModiFications to Epidermis: Plant “Skin” Plant epidermis is analogous to your own skin. It is the plant body’s first line of defense against pathogens and desiccation. However, its anatomy is quite different from your skin’s. Plant epidermis • is one cell-layer thick (in most species) • consists of cells containing no choroplasts • is covered by a non-cellular, waxy cuticle secreted by the epidermal cells • may contain specialized structures such as • stomates (gas exchange structures bordered by guard cells that open and close the stomate) • trichomes (hairlike projections that can be modified to serve any number of functions) Many adaptations for water conservation in plants can be observed at the level of the epidermis.
    [Show full text]
  • Introduction to Botany. Lecture 16
    Questions and answers Anatomy of leaf Introduction to Botany. Lecture 16 Alexey Shipunov Minot State University October 3rd, 2011 Shipunov BIOL 154.16 Questions and answers Anatomy of leaf Outline 1 Questions and answers 2 Anatomy of leaf Ecological adaptations of leaves Shipunov BIOL 154.16 Questions and answers Anatomy of leaf Outline 1 Questions and answers 2 Anatomy of leaf Ecological adaptations of leaves Shipunov BIOL 154.16 Questions and answers Anatomy of leaf Previous final question: the answer Please draw the entire (not dissected), ovate leaf with acute apex, cordate base, smooth margin and hyphodromous venation. Shipunov BIOL 154.16 Questions and answers Anatomy of leaf Previous final question: the answer Please draw the entire (not dissected), ovate leaf with acute apex, cordate base, smooth margin and hyphodromous venation. Shipunov BIOL 154.16 Questions and answers Anatomy of leaf The remainder: simple and compound leaves Shipunov BIOL 154.16 Questions and answers Ecological adaptations of leaves Anatomy of leaf General leaf anatomy Epidermis with stomata Mesophyll Vascular bundles, or veins Shipunov BIOL 154.16 Questions and answers Ecological adaptations of leaves Anatomy of leaf Lilac (Syringa vulgaris) leaf in cross-section Shipunov BIOL 154.16 Questions and answers Ecological adaptations of leaves Anatomy of leaf Epidermis and stomata Covered with cuticle Include stomata with guard cells and (often) subsidiary cells and trichomes Opening of stomata is a result of exchange of K+, osmosis and uneven cell wall Lower epidermis
    [Show full text]
  • An Investigation of Hydrological Separation
    Water cycling on cultivated land: an investigation of hydrological separation in the vadose zone Thesis Presented in Partial Fulfillment of the Requirements for the Degree Master of Science in the Graduate School of The Ohio State University By Devin Foster Smith Graduate Program in Earth Sciences The Ohio State University 2019 Thesis Committee Anne E. Carey Thomas H. Darrah Michael T. Durand Rattan Lal 1 Copyrighted by Devin Foster Smith 2019 2 Abstract There is a need to improve our understanding of water cycling in the soil-plant- atmosphere-continuum and the degree of hydrological separation in the vadose zone. Stable water isotopes, oxygen-18 and hydrogen-2, are natural tracers that effectively delineate water flow paths. Isotopic fingerprinting methods can be used to track hydrologic flow through a system after the water is extracted from the sample. However, the ecohydrologic community lacks a universally accepted method of water extraction from soils and plants. This study incorporated methods development, field work, and modeling to delineate water flow and determine the degree of hydrological separation in a Crosby silt loam field planted with Zea mays L. (maize) at the Waterman Agricultural and Natural Resources Laboratory on The Ohio State University campus from May to September 2018. Stable water isotopes were used as natural tracers to delineate flow throughout the soil profile. Soil water samples were extracted via cryogenic vacuum distillation and analyzed for δ18O and δD using cavity ring-down spectroscopy. Field results showed vertically dominated flow regimes and low variation in soil water isotopic composition, which indicated limited mixing between precipitation event water and pre- existing soil water.
    [Show full text]