MindMap Gallery Phytogeography
Phytogeography mind map. Phytogeography is a science that studies the distribution patterns of plants. Mainly discusses plant classification, plant life and environment, plant communities, etc.
Edited at 2024-04-10 17:46:27Avatar 3 centers on the Sully family, showcasing the internal rift caused by the sacrifice of their eldest son, and their alliance with other tribes on Pandora against the external conflict of the Ashbringers, who adhere to the philosophy of fire and are allied with humans. It explores the grand themes of family, faith, and survival.
This article discusses the Easter eggs and homages in Zootopia 2 that you may have discovered. The main content includes: character and archetype Easter eggs, cinematic universe crossover Easter eggs, animal ecology and behavior references, symbol and metaphor Easter eggs, social satire and brand allusions, and emotional storylines and sequel foreshadowing.
[Zootopia Character Relationship Chart] The idealistic rabbit police officer Judy and the cynical fox conman Nick form a charmingly contrasting duo, rising from street hustlers to become Zootopia police officers!
Avatar 3 centers on the Sully family, showcasing the internal rift caused by the sacrifice of their eldest son, and their alliance with other tribes on Pandora against the external conflict of the Ashbringers, who adhere to the philosophy of fire and are allied with humans. It explores the grand themes of family, faith, and survival.
This article discusses the Easter eggs and homages in Zootopia 2 that you may have discovered. The main content includes: character and archetype Easter eggs, cinematic universe crossover Easter eggs, animal ecology and behavior references, symbol and metaphor Easter eggs, social satire and brand allusions, and emotional storylines and sequel foreshadowing.
[Zootopia Character Relationship Chart] The idealistic rabbit police officer Judy and the cynical fox conman Nick form a charmingly contrasting duo, rising from street hustlers to become Zootopia police officers!
Phytogeography
Chapter One
1. Principles of plant classification
Species
concept
Species: The basic unit of biological classification, including a number of individuals that originated from a common ancestor and have very similar morphological and biological characteristics.
- Basic Features:
Species are fertile natural groups that are reproductively isolated from other natural groups - making each species an independent evolutionary unit
- Relationship with the environment:
Species can differentiate and form through natural selection in a certain environment, or they may die out when the environment becomes unfavorable to it.
Population:
Individuals within a species are often divided into several groups, each group is distributed in a certain area, called a population
Varieties:
Certain individuals within a species have accumulated certain morphological variations, which are relatively stable and distributed in a certain spatial area. Variants can be divided based on this.
- form:
Although there are morphological variations, they are scattered sporadically.
plant naming
Binomial nomenclature: Founded by Linnaeus. That is, the method of naming plant species by using two Latin words or Latinized words - each plant has only one legal name: scientific name, see "International Rules of Botanical Nomenclature"
Additional rules for plant nomenclature
There are two Latin names for plants. The last names of the two people are connected by et (meaning "and") or "&"
Such as: Metasequoia glyptostroboides Hu & W. C. Cheng
(Hu Xiansu and Zheng Wanjun)
The plant is named by one author but published by another author. The two surnames must be connected with the Latin prefix ex (meaning "from, from"), and the surname of the publisher is placed last.
Such as: Paspalum thunbergii Kunth. ex Steud.
If a taxonomist misnames a genus and is later corrected by someone else, the original name of the species will be retained, only the genus name will be changed, and the original namer will be appended in parentheses after the species epithet.
Such as: Podocarpus macrophyllus (Thunb.) Sweet
Taxus macrophylla Thunb.
To name a subspecies or variety of a plant, add the species and variant to the genus name (when writing, it is required to write the abbreviation of Variety before the variant).
Such as: white lilac——Syringa oblata Lindl. var. alba Rehd.
large group of plants
Prokaryotes (bacteria and cyanobacteria)
Features
single cell organism
No nuclear structure
Has a cell wall, composed of non-cellulosic polysaccharides and amino acid conjugates
Asexual reproduction: cell division
Includes bacteria and cyanobacteria
bacteria
The oldest and smallest
Extremely adaptable
Omnipresent, pervasive
About 1,600 species have been recorded
shape
ball
rod
arc
form
cocci, bacilli, spiral bacteria
energy source
Autotrophic bacteria, heterotrophic bacteria
Aerobic or not
Anaerobic bacteria, aerobic bacteria
cyanobacteria
Contains chlorophyll a, carotene, phycocyanin and other pigments
Eukaryotic algae and fungi, lichens
eukaryotic algae
Unicellular or multicellular, the latter has no roots, stems, or leaves.
Has a nuclear structure
Chloroplasts contain chlorophyll a and other types of pigments, and they live autotrophically
Asexual or sexual reproduction
Contains 9 phyla including green algae, red algae, brown algae, and diatoms, with approximately 27,000 to 40,000 species
Mainly distributed in water (freshwater or seawater)
Fungi,
Except for typical unicellular fungi, most multinucleated unicellular bacteria are composed of mycelium.
≡≡ Hyphae: septate, septate
Has a nuclear structure
The main component of the cell wall is chitin
Typical heterotrophs (parasitic, saprophytic, symbiotic)
Various modes of reproduction - vegetative reproduction, asexual reproduction, sexual reproduction
2850 genera and about 70,000 species
lichen gate
Perennial, a symbiosis between autotrophic cyanobacteria or green algae and heterotrophic fungi
Provide photosynthetic products and absorb nutrients and water
According to the shape, it is divided into leaf-shaped, shell-shaped and branch-shaped
Pioneer plants—very capable of adapting to harsh environments
About 1,700 species
Moss and ferns
Bryophyta
Leaf-like or stem-leaf differentiation
No perfect conductive tissue, no root differentiation - short plants
Autotrophic, capable of photosynthesis
Alternation of generations - sexual reproduction generation + asexual reproduction generation
form gametes form spores
Mostly found in moist environments, possibly in tundra, peat bogs or mountains.
dominant species
Divided into liverworts and mosses
Pteridophyta
Differentiation of roots, stems and leaves
Vascular plants - taller - have greater ability to obtain energy and matter
Autotrophic, capable of photosynthesis
Alternation of generations - sexual reproduction generation + asexual reproduction generation
form gametes form spores
Mostly born in humid and hot and humid environments, with more species and quantities in tropical and subtropical areas.
seed plant
Features
Seed production is beneficial to racial reproduction
The vascular bundles are more developed, and the mechanical organization and conduction organization are more complete.
The sporophyte is well developed and the gametophyte is simplified and is only formed during sexual reproduction.
and always depends on sporophyte growth
Pollen tubes appear, and fertilization can no longer rely on water as a medium
Divided into gymnosperms and angiosperms
Gymnosperms
Woody. Leaves are needle-shaped, scale-shaped, linear, rarely fan-shaped, oval or degenerate into sheath-like leaves
sporophylls aggregate into cones
with naked ovules
Pollen tubes form and fertilization is no longer limited by water
The sporophytes are well-developed, and the branches and stems have well-developed xylem, but they generally only have tracheids and rarely have vessels, and the gametophytes are degenerated.
Angiosperms
with real flowers
Having pistils, forming fruits
Have double fertilization
The sporophyte further develops and differentiates
Divided into monocots and dicots
Features: The entire process of seed reproduction, large and small spores developing into male and female gametes, and gametophyte generation is completed in the sporangium of the sporophyte, which is not susceptible to external damage. The embryo walks out under the protection of the large sac wall and lives independently when it grows up.
2. Ontogeny and phylogeny of plants
ontogeny plant life history
A certain plant starts from a certain stage of its life (such as spores, zygotes, seeds, etc.), goes through a series of morphological and physiological development changes such as germination, growth, differentiation, development, maturity and reproduction, and then appears and starts that developmental stage. Same whole process for the second generation. That is the life history or life cycle of the plant.
Phylogenetic
The historical process of the occurrence, development, evolution and decline of an organism or a group of organisms on the earth.
The relationship between ontogeny and phylogeny
Ontogeny is the premise and basis of phylogeny. Without ontogeny, phylogeny will stop.
Ontogeny is influenced and restricted by phylogeny
Ontogeny and phylogeny are two inseparable processes that drive biological evolution
Plant evolution and the earth's environment
The geological time of the development of the biological world
age of algae
Approximately Late Archaean to Silurian Period of Paleozoic Era
change the composition of the atmosphere
- Fix CO2 in the atmosphere through photosynthesis and release O2
- The ozone layer begins to form
accumulated organic matter
Changing Earth's climate conditions, global cooling creates rich and diverse niches
The cornerstone for the differentiation of animals and plants. Green algae may be the distant ancestors of the 300,000 species of existing higher plants
fern age
Approximately the end of the Silurian Period to the Permian Period
Plants left the sea, producing the first land plants represented by the naked fern
Ferns evolved toward the development of sporophytes, while bryophytes evolved toward the development of gametophytes.
The world’s first coal-forming period
gymnosperm era
At the turn of the Carboniferous and Permian periods, the earth's natural environment changed, and gymnosperms gained advantages in the competition for survival:
- Well-developed root system and vascular bundles
- Leaf cuticle is well developed
- Fertilization no longer depends on the presence of water
The Mesozoic Era is the most prosperous period of gymnosperms and the second coal-forming period in the world.
angiosperm age
The development of angiosperms and the global environment
- At the beginning of the Late Cretaceous, angiosperms exploded
- The most developed and the most diverse
- The morphological diversity of angiosperms is the result of various variations resulting from extensive adaptation to the natural environment
- Co-evolution with the animal kingdom, especially insect animals, is also one of the important reasons for the development of angiosperms.
Chapter two
Section 1 Basic concepts of flora
flora
It refers to the general name of all plant species in a certain area, a certain period, a certain taxonomic group, a certain type of vegetation, etc.
Section 2 Distribution Areas and the Formation of Distribution Areas
species distribution area
A species consists of several plant individuals, and the entire area they occupy constitutes the distribution area of the species
The distribution area of the genus
A collection of distribution areas of each species included
distribution center
If the distribution area of several species is concentrated in the distribution area of a genus, contour lines can be drawn, and the area with the most concentrated distribution is the distribution center of the genus.
Formation and distribution of species
allopatric speciation
Conditions for occurrence:
geographical environment
Populations of a species become isolated due to changes in the geographical environment (such as mountain building) or changes in the population itself (such as migration of the population);
Isolated populations will diverge in genotype and/or phenotype,
The reason is that the isolated population and the original population face different selection pressures, or each undergoes genetic drift, or their respective gene pools undergo mutations.
Over time, the two populations will evolve different characteristics. Even if the geographical barrier later disappears, the two populations will become unable to mate successfully. At this point, the two communities with different genes become different species.
Sympatric speciation
In non-geographically isolated conditions, the emergence of polyploidy can lead to the formation of new species;
The proportion of polyploid species is higher in arid places, alpine mountains, arctic regions and coastal salt environments.
parallel speciation
A certain plant is widely distributed, and part of it enters a new habitat and undergoes changes. Although there is no physical barrier between these individuals and other local populations, gene flow may be interrupted, and new species may gradually form.
Overview of Chinese flora
Characteristics of Chinese flora:
Rich plant species
Ancient in origin, with various taxa in the evolutionary system
Diverse distribution types and complex geographical components
The regional differences in geographical distribution are obvious and interpenetrating.
High degree of endemism
Island flora analysis
Impact of island isolation (distance)
The farther away from the mainland, the smaller the number of species and the greater the proportion of water-seeded plants.
Impact of Island Area Differences
The larger the island, the greater the number of species
Effects of island age
The earlier the island is formed, the longer the isolation time, and the higher the proportion of unique families, genera, and species.
island biogeographic balance theory
1 Equilibrium is a dynamic balance, that is, extinct species are constantly replaced by newly imported species;
2 Large islands can sustain more species than small islands;
3 As the distance between the island and the mainland increases, the number of species at the equilibrium point gradually decreases.
Anthropogenic activities and plant distribution
center of origin of cultivated plants
East Asia Center (China-Japan Center):
The origin of mulberry trees (peach, plum, pear, apple, mulberry, etc.), grain vegetables (millet, buckwheat, barley, cabbage, cucumber, onion, etc.), other plants (jujube, coptis, osmanthus, camellia, etc.);
Southeast Asia Center (Indochina-Indonesia Center):
Origin of banana, orange, betel nut, wood pineapple, bamboo;
India Center:
Rice, eggplant, lemon, mango, pomelo and other origins;
Central Asia Center:
Origin of wheat, peas, broad beans, lentils, Indian hemp, walnuts, carrots, onions, green onions, beets, etc.;
Australian Center:
Origin of eucalyptus, origin of certain cottons, bananas;
Near East Center:
The origin of rye, oats, barley, einkorn wheat, alfalfa, melons, radishes, apples, pears, plums, walnuts, apricots, grapes and other fruit trees;
Mediterranean (coastal) center:
The origin of beets, cabbage, fennel, grapes, etc.; the origin of large-seeded flax, chickpeas, oats, tetraploid wheat, pomegranates, figs, olives, etc.;
Africa Center:
Origin of certain rice, sorghum, coffee, oil palm, date palm, gourd, and barley;
Euro-Siberian Center:
Origin of barley, hops, cabbage, strawberries, wild mint, etc.;
South America Center:
Origin of potatoes, peanuts, tomatoes, pineapples, cocoa, tobacco, Brazilian rubber, cinchona, etc.;
Sino-American Center:
Origin of corn, sweet potato, cassava, beans, sisal, upland cotton, etc.;
North American Center:
The origin of sunflowers, Jerusalem artichokes, sugar maples, chestnuts, persimmons and pecans.
biological invasion
The process in which organisms invade another new environment through natural or artificial means from their original habitat, causing damage and ecological disaster to the ecosystem and human health.
Alien species
Usually refers to the relative concept of a species occurring outside its normal distribution.
Chapter 3 Plant Life and Environment
Section 1
1 The concept of ecological factors
Environmental factors in the environment that have direct or indirect effects on biological growth, development, reproduction, behavior and distribution. All ecological factors constitute the ecological environment of organisms.
3. Restrictive effects of ecological factors
limiting factors:
The survival and reproduction of organisms depend on the comprehensive action of various ecological factors, among which the key factors that limit the survival and reproduction of organisms are called limiting factors.
Liebig's "Law of Minimum Factors"
The growth rate of a plant depends on which nutrient is supplied in the least amount.
Shelford's "Law of Patience"
Any ecological factor is insufficient or excessive in quantity and quality, that is, when it approaches or reaches the tolerance limit of a certain organism, the organism will decline or become unable to survive.
Ecological width (tolerance, tolerance width, ecological value)
Ecological amplitude: The size of the adaptive range of each species to environmental factors is the ecological amplitude, also known as ecological valance.
Habitat:
The ecological environment where specific biological individuals and groups live is called habitat.
Classification of ecological factors
Climatic factors:
Temperature, humidity, light, precipitation, wind, air pressure, lightning, etc.
Soil factors:
Soil structure, soil organic/inorganic matter, physical and chemical properties and soil organisms
Terrain factors:
The ground is undulating, the yin/yang slope of the mountain, etc.
Biological factors:
Includes various interactions between animals, plants and microorganisms
Human factor:
Human activities have a huge impact on living things, manifesting in many aspects, such as pollution.
Section 2 Lighting Conditions
c4c3
Subtopic 1
plant photoperiod
(1) Photoperiodic phenomenon: Plants have lived in an environment with a certain pattern of changes in sunlight length for a long time. With the help of natural selection and evolution, various plants have formed unique ways of responding to changes in sunlight length.
Classification:
Long day plants:
It originates and is distributed in temperate and cold temperate zones. Only when the sunshine exceeds a certain critical value can it bloom.
Short-day plants:
Originated and distributed in the tropics and subtropics, it can bloom only if the sunshine is less than a certain critical value.
Medium sun plants:
Only a few tropical plants fall into this category, flowering when day and night lengths are nearly equal (sugar cane
Japanese neutral plants:
Flowering is not affected by day length (cucumber, tomato)
Section 3 Temperature Conditions
distributed
Distribution of temperature on the earth's surface
Decreases with increasing dimension (average annual temperature is about 0.5°C/degree), dividing the earth's surface into tropical, subtropical, temperate and frigid zones
- Decreases with altitude (about 0.5-0.6℃/100m)
grow
Within a certain temperature range, the growth rate is proportional to the temperature
Temperature and plant water metabolism
- Temperatures that are too low or too high will limit plant roots from absorbing water.
- Temperature affects plant transpiration
Temperature and photosynthesis of plants
- Photosynthesis requires a suitable temperature range
- Three basic point temperatures of photosynthesis: photosynthetic optimum temperature, thermal compensation point (CO2 balance temperature)
Temperature and plant respiration
- Plant respiration requires a suitable temperature range (-10-50 ℃)
- Plants with different geographical origins have large differences in the three basic points of respiratory temperature
(lowest temperature, highest temperature, optimum temperature)
Temperature and plant growth and development
- The growth of various plant organs requires a suitable temperature range
- The plant's own body temperature directly affects its growth and development and various physiological processes
daily temperature cycle
Within a suitable temperature range, periodic changes in day and night temperatures significantly affect plant seed germination, growth, development, morphological composition, and dry matter accumulation. The response of plants to the temperature difference between day and night is called the diurnal cycle.
Plant phenological rhythm (annual temperature cycle)
Plants adapt to rhythmic changes in temperature over a long period of time and form corresponding growth and development patterns.
Phenology:
As the temperature changes, plants will appear in sequence such as seed germination, leaf expansion, flower buds, flower blooms, fruiting, leaf fall, and cessation of growth.
Accumulated temperature
Average daily temperature days
Effective accumulated temperature:
Accumulation of daily mean temperatures above biological zero
Effective accumulated temperature law
Each developmental stage of a plant needs to meet a certain effective accumulated temperature before it can enter the next stage.
Section 4 Moisture Conditions
(1) Plant cells absorb water
Ψc=Ψп Ψm Ψp
Ψc——plant cell water potential
Ψп——osmotic potential (-)
Ψm——matrix potential (-)
Ψp——pressure potential ( )
Classification of ecological categories based on water conditions
Terrestrial
Change water
-The vascular bundle is underdeveloped and is greatly affected by external moisture.
-Can adapt to arid habitats
- Low productivity
Hengshui
xerophytic
Habitat: Arid environment, strong drought tolerance
(1) Less serous plants
Habitat: - Hot and dry grasslands and desert areas
Representative plants: - camel thorn, spiny dianthus, etc.
Adaptable features:
-1. Very little water content in the body
2. Minimize leaf area as much as possible
3. There are a large amount of hydrophilic colloidal substances in cells
4. Well-developed root system
(2) Multiple serous plants
- Cacti, aloe and other dry and hot grasslands and desert areas
- 1. Transformation of parenchyma tissue of roots, stems and leaves
Become a water storage organization
2. Decreased area to volume ratio
middle school student
Habitat: Terrestrial environment with moderate water and moisture conditions
- Most plants are mesophytes
Dampness
Habitat: Humid environment, terrestrial plants with the weakest drought resistance
(1) Shade-growing wet plants
-Habitat: Humid forest understory or humid environment
- Representative plants: epiphytic ferns and epiphytic orchids in tropical rainforests
(2) Sun-growing and hygrophytic plants
-Habitat: An environment with plenty of sunshine and often saturated soil moisture
-Representative plants: rice, etc.
aquatic
sink into water
The whole plant sinks into the water
floating water
The whole plant floats on the water or only the leaves float on the water
emergent
Only the lower part of the plant sinks in the water or the whole plant sinks in the water
. Only the lower part of the plant sinks in the water, and the upper part rises out of the water.
Section 5 Nutritional Conditions
Lots of elements
trace elements
Section 6 Biological Conditions
nutritional relationship
Adaptive groups of plants
- Growth method: changing the position of the growth point; strong regeneration ability
- Morphological characteristics: thorns; hairs; hard cortex
- Chemical means: producing protective chemicals
- Carnivorous plants: feed on animals
Parasitic relationship:
A plant lives in or on the body of another plant, thereby absorbing nutrients and water from the host to maintain life.
Symbiotic relationship:
Nutritional exchange and mutual complementation between heterogeneous plants
mechanical interrelation
chemical interrelationships
Other effects:
Plants often interact with each other by secreting chemicals
Chemical promotion:
Chemical inhibition:
chemical lethality
competitive relationship
pollination relationships
The synergistic symbiotic relationship between plants and pollinating animals results in the distribution of the two being closely linked and often consistent
seed dispersal relationship
There are three ways to spread seeds: attachment, food, and accidental spread. Plants have also evolved corresponding characteristics.
Section 9 Plant Life Forms and Adaptation Strategies
lifestyle
concept:
Plant groups are divided according to their morphological structure and comprehensive adaptive characteristics, which are called "life forms"
-Reflect the comprehensive effects of various ecological factors in the environment
- Different types of plants adapt convergently in the same or similar environments and become the same life form
Life style - the characteristics of ecological adaptation are the basis for classification
Adaptive Characteristics of Renewal Buds
High bud plants (P): giant (>30m), large (16-30m), medium (8-16m), small (2-8m), short (25cm-2m)
- Above ground budding plants (Ch): (< 25cm)
- Ground budding plants (H): Shallow underground budding or semicryptic budding plants
- Cryptobud plants (Cr): Renewal buds hidden in the ground or water
- Annual plants (T): When the environment is harsh, the plants die, leaving only the seeds to continue life.
Life style spectrum:
Life style spectrum: (life style composition)
Division basis
Leaf type system - morphological characteristics of leaves
-Leaf size: scale leaves, micro leaves, small leaves, medium leaves, large leaves, giant leaves
- Leaf quality: membranous, herbaceous, leathery, thick leathery
- Leaf growth stage: evergreen leaves, summer green leaves, semi-evergreen leaves, winter green leaves
Whittaker system: - Morphological growth characteristics of stems
- Trees: woody plants higher than 3m
- Vine: woody climbing plant or vine
- Shrubs: woody plants below 3m
- Subshrubs or dwarf shrubs: low shrubs less than 25cm
- Epiphytes: The entire plant is above the ground and grows on other plants
- Herbs: perennial above ground woody stem plants
Comprehensive lifestyle system - a classification system that combines two or more classification systems
Ellenberg, Mueller-Dombois Lifestyle Systems:
- Level 1: Nutritional characteristics (autotrophic, heterotrophic, semi-autotrophic)
- Second level: structural characteristics (vascular plants, leafy plants, etc.)
- Level 3: Growth status (self-reliant growth or growth relying on supports)
-Level 4: Bud characteristics and plant life habits
"Chinese Vegetation" Lifestyle System
- Level 1: Stem morphological growth characteristics
- Level 2: Leaf and branch characteristics
life history
concept
Plants start from a certain stage of their life (such as spores, zygotes, seeds, etc.) and go through a series of morphological and physiological development changes such as germination, growth, differentiation, development, maturity and reproduction, and then reappear at the same developmental stage as when they started. The whole process of the second generation. That is the life history or life cycle of the plant.
type
first year
Breed once a year, using a big bang strategy
Early reproductive period, large seed production, adapt to harsh environment with dormant seeds
The competition in height is weak, and the microenvironment suitable for seed germination and growth is often unstable, so the survival rate is low.
perennial herbs
Use multiple breeding strategies
Occupy growing space for a long time
New branches must be regrown every year and light conditions must be re-fighted.
Trees and arbor-like plants
Almost all adopt multiple breeding strategies
Strong competitiveness for nutritional space and long life duration
Relatively less resources and energy are allocated to reproductive growth, and reproduction occurs later
reproductive strategies
rSelect plants
Life is short, development is rapid, individual size is small, reproduction is early, seeds are abundant, and the energy consumed for reproduction is high
Adapt to unstable and changeable environments and win with high reproductive rate
annual weeds
K Select Plants
Life span is longer than one year, growth is slow, individual size is large, competitiveness is strong, reproduction is late, reproduction occurs multiple times, and the energy consumed for reproduction is low
Adapt to stable habitats and win with high efficiency and stability
like perennial trees
Plant resource allocation strategies
Competitive type: Type C, adapted to low stress + low disturbance habitat
Use main resources and energy for growth
Equivalent to K selection species
Stress type: S type, adapted to high stress + low disturbance habitat
Use major resources and energy to maintain survival
Between r-selected species and K-selected species
Weed type: R type, adapted to low stress + strong interference habitat
Dedicate major resources and energy to reproduction
Equivalent to r selection species
Chapter 4 Plant Community
Section 1 The appearance and structure of plant communities
plant community definition
In a specific space or specific habitat, it has a certain composition of plant species and spatial structure, the influence and interaction between various plants and between plants and the environment, has a certain appearance and structure, including morphological structure and nutritional structure, and has A collection of plants with specific functions.
Spatial structure of plant communities and plant environment
vertical structure
Stratification of plant communities
The stratification of terrestrial communities is related to the use of light, and the community level is mainly determined by the growth and life forms of plants.
As the light intensity gradually decreases, it develops into the canopy layer, underwood layer, shrub layer, herb layer and ground cover layer.
Stratification of aquatic communities
Related to factors such as sunlight, temperature, dissolved oxygen, etc.
The stratification phenomenon of forest communities is closely related to light intensity. The light intensity in a community always gradually weakens as the height decreases.
horizontal structure
Refers to the distribution of the community
condition or level
pattern,
Leaf area index =
total leaf area
Ground projected area
ply
time pattern
Section 2 Type composition of plant communities
community area
Usually, the method of gradually expanding the sample plot area is used, and the species-area curve chart can be drawn based on the obtained data. The area shown at the turning point of the curve is called the minimum area of the community, that is, the minimum space that contains most species of the community.
Species diversity measure—diversity index
Simpson Diversity Index
D=1-∑Pi2
The proportion of individuals belonging to species i among all individuals
Simpson's diversity index = the probability that two randomly sampled individuals belong to different species
Shannon-Wiener Index
H′=-∑Pilog2Pi
The proportion of individuals belonging to species i among all individuals
The greater the number of species, the more even the distribution of various individuals, and the higher the index, indicating better community diversity.
population dynamics
It shows a "J" shape when the environmental conditions are good, and an "S" shape when the environmental conditions are unfavorable. "J"-shaped growth can be regarded as an incomplete "S"-shaped growth, that is, environmental restrictions occur suddenly, and before that, population growth is unrestricted.
community member type
Dominant species:
It has obvious control over the structure of the community and the formation of the community environment.
Plants for crafting. They usually have a large number of individuals and large projection coverage
Large, high biomass, larger volume, stronger living ability, that is, dominance
Larger species.
Companion species:
It is a common species in the community. It exists together with the dominant species but does not play a major role. It relies on the conditions provided by dominant species. If dominant species are excluded, they will be lost in the habitat, such as epiphytes, parasites, obligate shade plants, etc.
Section 3 Plant community functions
Plant community biomass and productivity
Primary production:
Green plants in the ecosystem absorb and fix solar energy through photosynthesis, and synthesize and transform inorganic substances into complex organic substances. The amount of organic matter synthesized by green plants through photosynthesis is called primary production, also known as primary production.
Net primary production:
During the primary production process, part of the fixed energy of the plant is consumed by the plant's own respiration, and the rest can be used for the growth and reproduction of the plant, which is part of the production volume.
Distribution characteristics
Land has greater primary production than water.
Primary production on land gradually decreases with increasing latitude
Primary production in the ocean gradually decreases from estuaries to continental shelves and ocean areas.
Section 4 Dynamics of plant communities
fluctuations in plant communities
fluctuation:
It is limited to short-term reversible changes within the community and does not produce community replacement. The direction of change from year to year is often different, and directional replacement of new species generally does not occur.
Features:
The relative stability of community flora components, the uncertainty of changes in community quantitative characteristics and the reversibility of changes
reason:
Fluctuations and changes in environmental conditions; activity cycles of organisms themselves; interference from human activities
plant community succession
succession
It is the process in which one plant community is replaced by another plant community in a certain area. It is one of the most important features of community dynamics.
progress succession
The succession of the community shows that the community passes through a series of stages from the pioneer community to the mesophytic climax community. This succession process along sequential stages toward the climax community is called progressive succession.
retrograde succession
Occurring after man-made destruction or natural disaster interference factors, the original stable and complex communities disappear and are replaced by communities with simple structures and low stability. The ability to utilize and transform the environment is relatively weakened, and even retreats to bare land.
Specific examples
Lakes become forests
Naked bottom stage
Submerged aquatic plant stage
floating leaf root stage
Emergent and marsh plant stages
forest community stage
The difference between succession and fluctuation
Succession is a process in which one community replaces another community, and it is a process of continuous change in one direction; while fluctuation is a short-term reversible change, and its direction of change from year to year is often different, and directional replacement of new species generally does not occur.
climax of succession
unit capstone theory
In the same climate zone, there can only be one climax community, and the characteristics of this climax community are completely determined by the local climate, so it is also called the climate climax. Within any given climate zone, all successional series will eventually converge toward a climax community (given enough time), and this area will eventually be covered by a single plant community.
theory of plural culmination
There are multiple climax communities in any area, and they are all controlled and determined by certain environmental conditions, such as soil moisture, soil nutritional properties, topography, and animal activities. Some people call these communities respectively the topographic pole, the soil pole and the animal pole.
top pattern theory
Natural communities are determined by many environmental factors, including soil, organisms, fire, wind and other factors in addition to climate. In the gradually changing environmental gradient, the top community types also change continuously and gradually, and it is difficult to completely separate them from each other.
vegetation map
Thematic maps that mainly reflect plant communities
Chapter 6: World vegetation distribution patterns and vegetation divisions
ecotone
The climate usually changes gradually between zonal vegetation, and the two adjacent types of vegetation each occupy a favorable habitat, forming a transition zone in which the spatial distribution is mosaic, but the advantages (area) are transformed into each other, which is especially called the zonal community ecotone.
Vertical distribution pattern of mountainous vegetation in China
1.Moist type
Humid cold temperate mountain vertical zone
humid temperate mountain vertical zone
Humid warm temperate mountain vegetation vertical zone
Humid subtropical mountain vegetation vertical zone
Humid Northern Tropical Mountain Disposal Zone
2. Drought type:
Forest-steppe and steppe-mountain vertical zones
Desert steppe zone (semi-arid) mountain vegetation vertical zone
Temperate desert (arid) mountain vegetation vertical zone
Warm temperate desert (extreme desert) mountain vegetation vertical zone