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.

Species are fertile natural groups that are reproductively isolated from other natural groups - making each species an independent evolutionary unit

Species can differentiate and form through natural selection in a certain environment, or they may die out when the environment becomes unfavorable to it.

Individuals within a species are often divided into several groups, each group is distributed in a certain area, called a population

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.

Although there are morphological variations, they are scattered sporadically.

There are two Latin names for plants. The last names of the two people are connected by et (meaning "and") or "&"

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.

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.

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).

Features

Includes bacteria and cyanobacteria

eukaryotic algae

Fungi,

lichen gate

Bryophyta

Pteridophyta

Features

Divided into gymnosperms and angiosperms

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.

- Fix CO2 in the atmosphere through photosynthesis and release O2

- The ozone layer begins to form

- Well-developed root system and vascular bundles

- Leaf cuticle is well developed

- Fertilization no longer depends on the presence of water

Conditions for occurrence:

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.

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.

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

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.);

Origin of banana, orange, betel nut, wood pineapple, bamboo;

Rice, eggplant, lemon, mango, pomelo and other origins;

Origin of wheat, peas, broad beans, lentils, Indian hemp, walnuts, carrots, onions, green onions, beets, etc.;

Origin of eucalyptus, origin of certain cottons, bananas;

The origin of rye, oats, barley, einkorn wheat, alfalfa, melons, radishes, apples, pears, plums, walnuts, apricots, grapes and other fruit trees;

The origin of beets, cabbage, fennel, grapes, etc.; the origin of large-seeded flax, chickpeas, oats, tetraploid wheat, pomegranates, figs, olives, etc.;

Origin of certain rice, sorghum, coffee, oil palm, date palm, gourd, and barley;

Origin of barley, hops, cabbage, strawberries, wild mint, etc.;

Origin of potatoes, peanuts, tomatoes, pineapples, cocoa, tobacco, Brazilian rubber, cinchona, etc.;

Origin of corn, sweet potato, cassava, beans, sisal, upland cotton, etc.;

The origin of sunflowers, Jerusalem artichokes, sugar maples, chestnuts, persimmons and pecans.

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.

The growth rate of a plant depends on which nutrient is supplied in the least amount.

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.

Long day plants:

Short-day plants:

Medium sun plants:

Japanese neutral plants:

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)

- Temperatures that are too low or too high will limit plant roots from absorbing water.

- Temperature affects plant transpiration

- Photosynthesis requires a suitable temperature range

- Three basic point temperatures of photosynthesis: photosynthetic optimum temperature, thermal compensation point (CO2 balance temperature)

- 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)

- 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

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.

Each developmental stage of a plant needs to meet a certain effective accumulated temperature before it can enter the next stage.

Change water

Hengshui

sink into water

floating water

emergent

A plant lives in or on the body of another plant, thereby absorbing nutrients and water from the host to maintain life.

Nutritional exchange and mutual complementation between heterogeneous plants

Other effects:

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

Adaptive Characteristics of Renewal Buds

Life style spectrum:

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.

first year

perennial herbs

Trees and arbor-like plants

rSelect plants

K Select Plants

Use main resources and energy for growth

Equivalent to K selection species

Use major resources and energy to maintain survival

Between r-selected species and K-selected species

Dedicate major resources and energy to reproduction

Equivalent to r selection species

Stratification of plant communities

Refers to the distribution of the community

condition or level

pattern,

Leaf area index =

D=1-∑Pi2

Simpson's diversity index = the probability that two randomly sampled individuals belong to different species

H′=-∑Pilog2Pi

The greater the number of species, the more even the distribution of various individuals, and the higher the index, indicating better community diversity.

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.

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.

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.

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.

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.

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.

The relative stability of community flora components, the uncertainty of changes in community quantitative characteristics and the reversibility of changes

Fluctuations and changes in environmental conditions; activity cycles of organisms themselves; interference from human activities

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

retrograde succession

Specific examples

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.

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.

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.