Plant Ecology Lecture Notes PDF

1 First Meeting  ‫مقدمة‬ ‫ ال يوجد كائن حي يمكنه العيش في معزل تام عن باقي‬ ‫الكائنات أو عن ما يحيط به من مكونات بيئية غير حية‪.‬‬ ‫(وبصفة خاصة الكائنات النباتية المنتجة حيث تعتبر‬ ‫مصدرا ً للغذاء والمأوى والكساء والدواء)‬ ‫ يرتبط الكائن الحي مع غيره في غذا...

1 First Meeting  ‫مقدمة‬ ‫ ال يوجد كائن حي يمكنه العيش في معزل تام عن باقي‬ ‫الكائنات أو عن ما يحيط به من مكونات بيئية غير حية‪.‬‬ ‫(وبصفة خاصة الكائنات النباتية المنتجة حيث تعتبر‬ ‫مصدرا ً للغذاء والمأوى والكساء والدواء)‬ ‫ يرتبط الكائن الحي مع غيره في غذائه‪ ،‬تنفسه‪ ،‬مسكنه‪...،‬‬ ‫ كما إن لكل كائن أثره على ما يحيط به من بيئة فأن‬ ‫العمليات الحيوية لكل كائن تـتأثر بما يحيط بها من عوامل‬ ‫وظروف بيئيه‪.‬‬ ‫وكلمة علم البيئة ‪ Ecology‬اشتقت من أصول يونانية‪.‬‬ ‫ ‬ ‫وتتكون من مقطعين األول ‪ Oikos=Eco‬بمعنى‬ ‫ ‬ ‫البيت أو الموئل‪.‬‬ ‫والثاني ‪ science = logos‬بمعني العلم‪.‬‬ ‫ ‬ ‫أول من أستخدمها ووضع لها تعريفا مقبوال في الكتابات‬ ‫ ‬ ‫العلمية هو ‪ Ernist Haeckel‬عام ‪1885‬م‪.‬‬  ‫توزيع الدرجات‬ ‫النهائي‬ ‫أعمال السنة‬ ‫النظري‬ ‫أنشطة‬ ‫العملي‬ ‫النظري‬ ‫ومهام‬ ‫نهائي‬ ‫مشاركات‬ ‫االختبار‬ ‫وواجبات‬ ‫النصفي‬ ‫‪10‬‬ ‫‪35‬‬ ‫‪5‬‬ ‫المجموع = ‪50‬‬ ‫مالحظة‪ :‬موعد اختبار أعمال السنة يحدد من‬ ‫قبل إدارة الكلية‬ ‫مهام ومسؤوليات الطلبة‬ ‫‪ -1‬االلتزام التام بالحضور وعدم‬ ‫‪‬‬ ‫التأخير بحيث لن يتم إدخال الطالبة‬ ‫بعد االستاذ ‪.‬‬ ‫‪ -2 ‬وضع الجوال على الصامت‪.‬‬ ‫‪ -3 ‬المشاركة و المناقشة خالل‬ ‫المحاضرة‬ ‫‪ -4 ‬أداء جميع الواجبات و االختبارات‬  ‫تقسيم الشعبة إلى مجموعات‬ ‫قائد‪/‬ة‬ ‫المجموعة‬ ‫‪6‬‬ ‫‪5‬‬ ‫‪4‬‬ ‫‪3‬‬ ‫‪2‬‬ ‫‪1‬‬  1 CHAPTER The Nature of Ecology © 2016 Pearson Education, Ltd. Adopted by Dr. Sameh Ismail Elements of ECOLOGY Lecture Presentation by NINTH EDITION, GLOBAL EDITION Carla Ann Hass Penn State University Thomas M. Smith Robert Leo Smith  Plant Ecology  Definitions  Ecosystem Example of Ecosystem  Food Chain and food web  Ecological pyramids  Environmental factors (Edaphic, climatic, physiographic and biotic)  Vegetation  Adaptations Chapter 1 The Nature of Ecology  What is Ecology?  Ecology is the study of the interrelationships between organisms and their environment.  What is meant by the term “Spaceship Earth”?  What demands does a growing human population put on the environment?  Figure 1.1 Spaceship Earth or Spacecraft Earth is a world view term usually expressing concern over the use of limited resources available on Earth and encouraging everyone on it to act as a harmonious team working toward the greater worthy. Harmonious :consistent Chapter 1 The Nature of Ecology  Ecology is a science  term means “the study of the household”  how does this relate to “spaceship Earth”?  Ecologistsstudy the interactions between organisms and their environment Section 1.1 Ecology Is the Study of the Relationship between Organisms and Their Environment  What are the components of an organism’s environment?  physical conditions  chemical conditions  other organisms, both the same and different species (Biotic Factors)  “Ecology is the study of all of those complex interrelationships.” (Haeckel). Section 1.2 Organisms Interact with the Environment in the Context of the Ecosystem  Organisms interact with their environment at many levels.  What are some of the physical and chemical conditions in an organism’s environment?  How do organisms interact with other organisms in their environment? Section 1.2 Organisms Interact with the Environment in the Context of the Ecosystem  Physical and chemical conditions include:  temperature  moisture  concentration of gases (O2 and CO2)  light intensity  Interactions with other organisms include:  mating  predator and prey Section 1.2 Organisms Interact with the Environment in the Context of the Ecosystem  What is the environment in which an organism lives?  It is a place simply  a physical location in time and space  can be large or small  can be aquatic or terrestrial  can be stable or transient  Includes physical and chemical conditions and other organisms. Section 1.2 Organisms Interact with the Environment in the Context of the Ecosystem  An ecosystem is a collection of parts that function as a unit  biotic – living components  abiotic – nonliving (physical and chemical) components  A forest is an ecosystem  What are the abiotic components?  What are the biotic components? Section 1.2 Organisms Interact with the Environment in the Context of the Ecosystem  Abiotic – atmosphere, climate, soil, water  Biotic – other organisms in the forest.  Figure 1.2 Example of the components and interactions that define a forest ecosystem.  The abiotic components of the ecosystem, including the:-  (a) climate.(b) soil,  Biotic: (c) Herbivores feed on the canopy, (d) while predators such as this warbler feed upon insects.  (e) The forest canopy intercepts light, modifying its availability for understory plants.  (f) A variety of decomposers, both large and small, feed on dead organic matter on the forest floor, and in doing so, release nutrients to the soil that provide for the growth of plants.  (a) Precipitation (mm) (c) Temperature (°C) 350 35 300 30 250 25 200 20 150 15 100 10 50 5 0 0 J FMA M J J A S O ND (d) (b) (e) (f) Figure 1.2: Example of the components and interactions that define a forest ecosystem. The abiotic components of the ecosystem, including the (a) climate and (b) soil, directly influence the forest trees. (c) Herbivores feed on the canopy, (d) while predators such as this warbler feed upon insects. (e) The forest canopy intercepts light, modifying its availability for understory plants. (f) A variety of decomposers, both large and small, feed on dead organic matter on the forest floor, and in doing so, release nutrients to the soil that provide for the growth of plants. Section 1.3 Ecological Systems Form a Hierarchy  Ecologists study interactions at different levels of organization.  These levels can be arranged in a hierarchy or a pyramid.  All levels involve biotic and abiotic interactions  The biosphere is the highest level of organization Figure 1.3 Step 7 Slide 7 Individual Landscape What characteristics allow How do variations in topography the Echinacea to survive, and soils across the landscape grow, and reproduce in the influence patterns of species environment of the prairie composition and diversity in the grasslands of central North different prairie communities? America? Population Biome Is the population of this species What features of geology and increasing, decreasing, or regional climate determine the remaining relatively constant transition from forest to prairie from year to year? grassland ecosystems in North America? Community How does this species interact with other species of plants Biosphere and animals in the prairie community? What is the role of the grassland biome in the global carbon cycle? Ecosystem How do yearly variations in rainfall influence the productivity of plants in this prairie grassland ecosystem?  Section 1.4 Ecologists Study Pattern and Process at Many Levels  At each level in the ecosystem hierarchy, different patterns and processes emerge.  In order to study these different levels, different approaches may be needed.  What are some of the sub-disciplines in Ecology? Species: different types exist in the different places Section 1.4 Ecologists Study Pattern and Process at Many Levels  The effects of birth and death can be studied at multiple levels:  Individual– birth and death are discrete events and happen only once.  Population– birth and death are continuous  measured as rates, such as births/year  Community– focus shifts to relative abundance of species within the community.  How do interactions among species affect birth and death rates? Section 1.4 Ecologists Study Pattern and Process at Many Levels  Ecosystem – emphasis shifts from species to the flows of energy and nutrients through both biotic and abiotic components of the ecosystem. Includes questions such as:  At what rate are energy and nutrients converted into biomass, including new individuals?  At what rate are energy and nutrients in organisms broken down, including decomposition after death? Section 1.4 Ecologists Study Pattern and Process at Many Levels  Landscape – a patchwork of ecosystems in which spatial patterns are important  How are energy and nutrients exchanged between ecosystems?  Global scale – focus on the distribution of different types of ecosystems or biomes  How do patterns of biological diversity vary in different biomes? Section 1.4 Ecologists Study Pattern and Process at Many Levels  Biosphere – emphasis on the linkages between ecosystems and other components of Earth, such as the atmosphere.  How are nutrients such as carbon exchanged between the atmosphere and terrestrial ecosystems?  Sub-disciplines in ecology are organized based on these different levels.  identifying linkages to other levels is an important goal. Section 1.8 Ecology Has Strong Ties to Other Disciplines  What are some of the physical and chemical (abiotic) parts of the environment?  How do ecologists gain information on these? Section 1.8 Ecology Has Strong Ties to Other Disciplines  Ecologists must draw on information from other sciences  Geology  Hydrology  Meteorology Section 1.8 Ecology Has Strong Ties to Other Disciplines  For example:  plants take up water, influencing soil moisture and surface water flow  plantslose water to the atmosphere, increasing water vapor and influencing precipitation  the geology of an area influences the available water and nutrients that plants need Section 1.8 Ecology Has Strong Ties to Other Disciplines  Today, many ecologists are studying the dominant role that humans are playing in earth’s ecosystems.  What are some impacts that humans are having on the environment?  There are four main areas of impact:  human population growth  biological diversity  sustainability  global climate change Section 1.8 Ecology Has Strong Ties to Other Disciplines  The environmental problems caused by humans are ecological problems  Ecology allows us to understand the causes and identify ways to lessen their impacts  Environmental science provides a broader, interdisciplinary approach that includes social, political and ethical dimensions to these problems. Section 1.9 The Individual Is the Basic Unit of Ecology  What is an individual?  Why is the individual the basic unit of ecology?  The individual organism senses and responds to its environment  The individual reproduces, passing its genetic information to future individuals that will be part of future populations, communities, and ecosystems.  The Niche A niche is the role of a species in their environment. No two species hold the EXACT same niche. Niche : An organism’s habitat + role + tolerance limits to all limiting factors. The niche of a species therefore consists of: Its role in the ecosystem (producer, herbivore, carnivore, decomposer) Tolerance limits (e.g. soil pH, humidity) Requirements for shelter, nesting sites etc, all varying through time.  Aliens  Alien species are a good example of species that occupy more of their niche than in their native habitats  In their native habitats competitors and predators limit their niche