The greatest variety of species is typical. According to the number of species that make up this biocenosis, biocenoses rich and poor in species are distinguished

Teacher of chemistry, biology, ecology

GBOU secondary school No. 402.

BIOGECENOSIS

GRADE 10

The learning objectives of the lesson:

deepen knowledge about biogeocenosis;

to acquaint students with the properties of biogeocenosis;

Developing objectives of the lesson:

to develop in students the ability to highlight the main, essential in the educational material, to compare, generalize and systematize, to establish cause-and-effect relationships;

promote the development of volitional and emotional qualities of the individual;

pay special attention to the development of interest in the subject and speech of students.

Educational objectives of the lesson: contribute to the formation of worldview ideas:

the materiality of the world;

continuity of the process of cognition.

Form of the educational process: cool lesson.

Lesson type: learning lesson.

Lesson structure:

Org. moment

1 min.

Update

2 minutes.

Goal setting

1 min.

Learning new material

25min

reflection

10 minutes

Homework

1 min.

Equipment:

Board;

Projector;

A computer;

Handout;

Way of providing information: Textual, structural-logical, information-technological.

Teaching method: partial search

Technology: Person-oriented.

During the classes.

Stage.

The activities of the teacher.

Student activities.

Organizing time.

Greetings.

Gets the kids ready for the lesson.

Getting ready for the lesson.

Actualization.

What is a biocenosis?

How to translate the prefix "GEO"

Let's connect the prefix "GEO" and the concept of BIOCENOSIS.

Continue the phrase.

They answer questions.

Goal setting.

Today in the lesson we will analyze the concept of BIOGEOCENOSIS.

Write down the topic of the lesson: BIOGECENS.

Learning new material.

In biology, three concepts that are close in meaning are used:

1. Biogeocenosis- a system of a community of living organisms (biota) and its biotic environment on a limited area of ​​the earth's surface with homogeneous conditions (biotope)
2. Biogeocenosis- biocenosis, which is considered in interaction with abiotic factors that affect it and, in turn, change under its influence. Biocenosis is synonymous with community; the concept of ecosystem is also close to it.
3. Ecosystem- a group of organisms of different species, interconnected by the circulation of substances.

Every biogeocenosis is an ecosystem, but not every ecosystem is a biogeocenosis - Justify this phrase.

To characterize biogeocenosis, two close concepts are used: biotope and ecotope (factors of inanimate nature: climate, soil).Define these terms.

Properties of biogeocenosis

1. natural, historically established system
2. a system capable of self-regulation and maintaining its composition at a certain constant level
3. characteristic circulation of substances
4. open system for energy input and output, the main source of which is the Sun

The main indicators of biogeocenosis

1. Species composition - the number of species living in a biogeocenosis.
2. Species diversity - the number of species living in a biogeocenosis per unit area or volume.

In most cases, the species composition and species diversity do not quantitatively coincide, and the species diversity directly depends on the area under study.

Why?

3. Biomass - the number of organisms of biogeocenosis, expressed in units of mass. Most often, biomass is divided into:
a. producer biomass
b. consumer biomass
in. decomposer biomass

Define: Who are producers, decomposers and consumers.

4. sufficiency of living space, that is, such a volume or area that provides one organism with all the resources it needs.
5. richness of species composition. The richer it is, the more stable the food chain and, consequently, the circulation of substances.
6. Variety of species interactions that also maintain the strength of trophic relationships.
7. environment-forming properties of species, that is, the participation of species in the synthesis or oxidation of substances.
8.direction of anthropogenic impact

Make a conclusion on the properties of biogeocenosis.

The joint life of organisms in a biogeocenosis is regulated by five types of biogeocenotic relationships:

Define each type of biogeocenosis and give examples.

Give examples with justifications for each concept.

Justify the phrase

Define the terms:

Biotope - this is the territory occupied by biogeocenosis.

Ecotop - this is a biotope that is affected by organisms from other biogeocenoses.

Write down in a notebook.

Discuss the material with the teacher and ask questions.

They answer the question.

Answer the question:

Producers - organisms, capabletoa photo- orchemosynthesisandbeinginfood. chainsfirstlink, creatororganic. in- infrominorganic, t. e. allautotrophicorganisms. Consumers - organisms, beingintrophicchainsconsumersorganicsubstances. Reducers - organisms, decomposingdeadorganicsubstanceandtransforminghisininorganic, employeefoodothersorganisms.

Summarize the properties of biogeocenosis:

Thus, the mechanisms ensure the existence of unchanging biogeocenoses, which are called stable. A stable biogeocenosis that has existed for a long time is called climax. There are few stable biogeocenoses in nature, more often there are stable - changing biogeocenoses, but capable, thanks to self-regulation, to return to their original, initial position.

Listen and write down the material in a notebook.

Give definitions and give examples.

Reflection.

Let's summarize today's lesson:

Do a test job:

1. Autotrophic organisms include

B) tinder fungus

B) blood-sucking insects

D) red algae

2. The stability and integrity of the biogeocenosis does not depend on

A) geological changes in the Earth's crust

B) diversity of species composition

C) seasonal climate changes

D) the flow of energy and matter

3. Self-regulation in biogeocenosis is manifested in the fact that

A) species multiply rapidly

B) the number of individuals changes

C) some species are not completely destroyed by others

D) the number of populations of individual species is increasing

4. A reservoir is considered a biogeocenosis, since the species living in it

A) located in the same tier

B) food chains are formed

C) belong to the same kingdom

D) not related

5. The adaptability of plants to cohabitation in the biogeocenosis of the forest is manifested in

A) increased competition between species

B) tiered arrangement

B) increase in leaf surface

D) modification of root systems

Test work is discussed and correct answers are given.

Solve test work.

Perform a self-check.

Homework

Steam….., Vopr…. Page…..

Do a test job:

1. A meadow is a more sustainable ecosystem than a wheat field, as it

A) there are producers

B) more fertile soil

C) there are more species

D) there are no predators

2. An example of a biogeocenosis is a set

A) plants grown in a botanical garden

B) oak trees and shrubs

C) all organisms that live in the swamp

D) birds and mammals of the spruce forest

3. The greatest diversity of populations and animal species is characteristic of biocenosis

A) oak trees

B) pine forest

B) an orchard

D) tundra

4. The continuous movement of carbon, nitrogen and other elements in biogeocenoses is carried out largely due to

A) the action of abiotic factors

B) the vital activity of organisms

B) the action of climatic factors

D) volcanic activity

5. The ecosystem becomes more resilient when

A) increasing species diversity

B) the presence of a variety of food chains

B) a closed circulation of substances

D) violation of the circulation of substances.

Write down in a notebook.

114. The greatest diversity of plant and animal species is characteristic of biocenosis

1. tundra;

3. Rainforest +

4. forest-steppe

115. Productivity of ecosystems (in terms of formation of dry matter biomass) from the equator to the poles:

1. decreases +

2. remains unchanged;

3. increases;

4. first decreases and then increases again

5. first increases and then decreases

116. A large ecological group of aquatic organisms that have the ability to move regardless of water currents:

2. plankton

3. nekton +

4. neuston

5. periphyton

117. A large ecological group of aquatic organisms localized at the bottom

1. plankton

2. periphyton

3. neuston

4. benthos +

118. A large ecological group of aquatic organisms that live freely in the water column and passively move in it

1. plankton +

2. periphyton

3. neuston

119. Large ecological group of aquatic organisms attached to aquatic plants

1. plankton

2. periphyton +

3. neuston

120. The ecological group of aquatic organisms living near the surface of the water, on the verge of the aquatic and air environment:

1. plankton

2. periphyton

3. neuston +

121. Freshwater ecosystems that form in stagnant water bodies

1. wetlands

2. lotic

3. lake

4. tape +

5. eutrophic

122. Freshwater ecosystems formed in flowing waters

1. wetlands

2. lotic +

3. lake

4. tape

5. eutrophic

123. The main edificator of communities in the tundra are

1. lichens +

3. shrubs

5. dwarf trees

124. Species that determine the structure and nature of communities in biocenoses, playing an environment-forming role

1. dominants

2. edifiers +

3. subdominants

4. Assectators

5. violets

125. For simple biocenoses of the tundra, under certain conditions,

1. outbreaks of mass reproduction of certain species +

2. very small fluctuations in the number of individual species

3. outbreaks of mass reproduction of individual species are never observed

4. gradual rises in the number of species

5. gradual decline in the number of species

126. The main condition for the sustainability of ecosystems is

1. the presence of formed fertile soil

2. closed ecosystem

3. the presence of large herbivores

4. constant circulation of substances and the influx of energy +

5. high level of biodiversity

127. The scientist who proposed the term biogeocenosis

1. V.N. Sukachev +

2. V.I. Vernadsky

3. Dokuchaev

5. Ch. Darwin

128. The set of environmental factors affecting the composition and structure of biocenoses

1. phytocenosis

2. edaphotop

3. climate top

4. landscape

5. biotope +

129. The concept characterizing the position of a species in the biocenosis, expressed in the features of geographical localization, relation to environmental factors and functional role

1. ecological niche +

2. life form

3. dominance system

4. adaptation

5. life strategy

130. Similar morpho-ecological groups of different types of living organisms, with varying degrees of kinship, expressing the type of adaptation to similar environmental conditions, which occurs as a result of convergent adaptation:

1. ecological niche

2. life form +

3. dominance system

4. adaptation

5. life strategy

131. The resilience of an ecosystem with increasing complexity tends to:

1. varies depending on the nature of the relationship of organisms

2. does not change

3. increases +

4. decreases

5. does not depend on the degree of difficulty

132. The significance of swamps lies in the fact that these ecosystems are capable of ...

1. regulate the temperature regime of ecotopes

2. give a crop of mushrooms

3. to harvest cranberries and lingonberries

4. regulate the water regime of the territory +

5. produce peat

133. The most complex tropical rainforest ecosystems are characterized by:

1. high level of diversity and low abundance of species +

2. high level of diversity and high abundance of species

3. low diversity and low species abundance

4. low diversity and high species abundance

5. high level of diversity and changing abundance of species

134. The highest rate of processing of dead organic matter by decomposers is observed in ecosystems:

2. Tropical rainforests +

3. boreal coniferous forests

5. savannas

135. The abundance of large ungulate phytophages is characteristic of ecosystems

2. Tropical rainforest

3. boreal coniferous forests

5. savannas +

136. The totality of all connections of a species with the environment, which ensure the existence and reproduction of individuals of a given species in nature, are:

1. biocenosis +

3. edaphotop

4. climatetop

5. competitive environment

137. At the level of consumers, the flows of living organic matter transferred to different groups of consumers follow the chains:

1. savings

2. decomposition

3. transformation

4. Eating +

5. synthesis

138. At the consumer level, the flows of dead organic matter transferred to different consumer groups follow the chains:

1. savings

2. expansions +

3. transformation

4. eating

5. synthesis

139. When transferring organic matter to different groups of consumers-consumers, it is divided into two streams:

1. accumulation and decomposition

2. expansions and transformations

3. transformation and synthesis

4. eating away and decomposition +

5. synthesis and accumulation

140. A more complete use of resources at each trophic level of the biocenosis is ensured by:

1. increase in the number of individual species

2. increase in the number of species +

3. increase in the number of all species

4. cyclical changes in numbers

5. increase in predation

141. The amount of biomass and associated energy, at each transition from one trophic level to another, is about:

142. As you ascend the trophic levels, the total biomass, production, energy and number of individuals change:

1. progressively increase

2. increases during the transition from producers to consumers, and then decreases

3. the direction to decrease or increase changes cyclically depending on external factors

4. progressively decrease +

5. remain constant

143. The most important mechanism for maintaining the integrity and functional stability of biocenoses is:

the abundance and diversity of species composition +

increased competition

interaction of all kinds at all levels

reduced competition and species composition

constancy of species composition and reduced competition

144. The sequence of trophic relationships, the end result of which is the mineralization of organic matter:

eating chains

transformation chains

decomposition chains +

mineralization chains

decomposer chains

145. The sequence of trophic links during which the synthesis and transformation of organic matter occurs:

1. Eating chains +

2. chain transformation

3. decomposition chains

4. chains of mineralization

5. circuit synthesis

146. The elementary structural and functional unit of the biosphere is:

biogeocenosis +

phytocenosis

communities of living organisms

147. Areas of the world's oceans, the high productivity of which is due to ascending flows of water from the bottom to the surface

sargasso

rift

convention areas

upwelling +

148. Areas of the world ocean, the high productivity of which is due to the presence of fields of floating brown algae:

1. sargasso +

2. rift

3. conventional areas

4. upwelling

5. reef

149. Areas of high biological diversity in the oceans, localized around hot springs on faults in the oceanic crust and based on primary production supplied by chemotrophic organisms:

sargasso

abyssal rift

offshore

upwelling

reef +

150. Bottom concentrations of biodiversity at great depths of the ocean owe their existence to life

algae

coral polyps

molluscs and echinoderms

chemotrophic bacteria +

151. The factor that determines the geographic distribution in the oceans of areas of thickening of living matter and high productivity around coral reefs is:

1. temperature not less than 20 o +

2. depth no more than 50 m

3. water transparency

4. water salinity

152. Areas of high productivity in the world's oceans, in the communities of which there are no photosynthetic organisms:

sargassum thickenings

abyssal rift +

shelf concentrations

upwelling clusters

reef concentrations

153. The most productive fishing areas of the world's oceans, providing about 20% of the world's fishery, are the areas:

upwelling +

abyssal rift

offshore

sargasso fields

coral reefs

154. The ecological region of the ocean coast, located above the water level at high tide, but exposed to ocean waters during storms and surges:

2. littoral

3. abyssal

4. supralittoral +

5. sublittoral

155. The ecological region of the ocean floor, located in the zone between the water levels at the highest tide and the lowest tide:

A) bathyal

B) littoral +

C) abyssal

D) supralittoral

E) sublittoral

156. The ecological region of the ocean floor, located in the zone from the water level at the lowest ebb to a depth of 200 m:

A) abyssal

B) littoral

C) bathyal

D) supralittoral

E) sublittoral +

157. The ecological area of ​​the ocean floor, located on the continental slopes at depths of 200-2000 m:

A) bathyal +

B) littoral

C) abyssal

D) supralittoral

E) sublittoral

158. Ecological area of ​​the ocean floor at depths exceeding 2000 m:

A) bathyal

B) littoral

C) abyssal +

D) supralittoral

E) sublittoral

159. Ecological groups of marine organisms - nekton, plankton, neuston and pleuston are typical for communities:

A) littoral

B) bathyali

C) abyssals

D) pelagials +

E) sublittoral

160. A community that includes phytocenosis, zoocenosis and microbiocenosis, having certain spatial boundaries, appearance and structure:

A) biocenosis +

E) biogeocenosis

161. The basis of most terrestrial biocenoses, which determine their appearance, structure and certain boundaries, is:

A) zoocenosis

C) edaphotop

D) microbiocenosis

E) phytocenosis +

162. The primary habitat of living organisms, formed by a combination of soil and climatic factors:

A) biotope

B) ecotope +

C) edaphotop

D) climatetop

163. Secondary habitat formed as a result of the active impact of living organisms on the primary habitat:

A) biotope +

C) edaphotop

D) climatetop

164. In the steppe biocenoses, soil formation is dominated by the following processes:

A) mineralization

B) nitrification

C) humification +

D) denitrification

E) ammonification

165. The key factor in the formation of steppe biogeocenoses, which determines the features of the circulation of biogenic elements, is:

A) temperature

B) the level of solar radiation

C) the seasonality of precipitation

D) soil moisture +

E) temperature contrast

166. Among the life forms of plants of steppe biogeocenoses, the most characteristic are:

A) shrubs

B) dwarf shrubs

C) ephemera

D) turf grasses +

E) rhizomatous cereals

167. For the vertical structure of the animal population of the steppe ecosystems, the following is most characteristic:

A) above-ground tier

B) tree layer

C) underground tier

D) tree-shrub layer

E) abundance of burrows +

168. The colonial way of life of various species and groups of rodents is most typical in ecosystems:

A) boreal forests

C) deciduous forests

E) tropical rain forests

169. In the vertical structure of steppe biocenoses there is no:

A) tree layer +

B) tree-shrub layer

C) shrub layer

D) underground tier

E) herbaceous layer

170. In the steppe ecosystems, among the phytophage animals, the following group is practically not represented:

A) frugivorous +

B) seed-eating

C) green-eating

D) rhizophages

E) seed-eating and rhizophagous

171. Steppe ecosystems are geographically localized:

A) in the tropics

B) at high latitudes

C) in the subtropical climate

D) in the inland regions of temperate latitudes +

E) in the mountains

172. The soil cover of steppe biogeocenoses is formed:

A) brown soils

B) serozems

C) podzolic soils

D) chernozems

E) chernozems and chestnut soils +

173. The change of several aspects during the growing season is a pronounced feature of phytocenoses:

A) steppes +

B) tropical rainforests

D) boreal forests

E) deserts

174. Types of edificators among vertebrates in steppe ecosystems are:

A) ungulate mammals

B) carnivorous mammals

C) reptiles

D) amphibians

E) rodents +

175. An important group of vertebrates that contribute to maintaining the stability of steppe phytocenoses are:

B) rodents

C) ungulates +

D) carnivorous mammals

E) insectivorous mammals

176. Of the terrestrial vertebrates in the steppe ecosystems, the worst represented are:

A) reptiles

B) amphibians +

C) mammals

E) carnivorous mammals

177. In the steppe ecosystems of Asia, with an increase in aridity in the direction from north to south in phytocenoses, the importance of life forms increases:

A) semi-shrubs +

B) turf grasses

C) shrubs

D) rhizomatous cereals

E) forbs

178. In accordance with the increase in the moisture gradient from south to north, changes in the phytocenoses of the Asian steppes are expressed

A) in a decrease in species richness and an increase in the value of ephemers and ephemeroids

B) in increasing the value of subshrubs

C) in reducing the value of densely tufted cereals

D) in an increase in species richness and the number of herb species +

E) in increasing the species diversity of rhizomatous grasses and dwarf shrubs

179. The characteristic life forms of plants of tropical rainforests, which have received great development here, are:

A) epiphytes and lianas +

B) dwarf shrubs

C) perennial grasses

D) bushes

E) trees

180. Fruit-eating and insect-eating consumer species prevail in ecosystems:

A) boreal forests

B) deciduous forests

C) tropical rain forests +

E) subtropical forests

181. Termites are the leading group of saprophogi in ecosystems:

A) boreal forests

B) deserts

C) tropical rain forests

D) savannah +

E) subtropical forests

182. Amphibians living mainly in the tree layer are typical for ecosystems:

A) boreal forests

B) deciduous forests

C) subtropical forests

183. Lianas and epiphytes - specific life forms of plants, the most common and characteristic:

A) boreal forests

B) in deciduous forests

C) tropical rainforests +

D) in the savannas

E) in subtropical forests

184. In the ecosystems of tropical rainforests among animals, according to the nature of trophic relationships, the following prevail:

A) frugivorous and insectivorous +

B) seed-eating

C) herbivores

D) rhizophagi

185. Birds that feed on nectar and are effective pollinators of flowering plants are typical for ecosystems:

A) gallery forests

B) deciduous forests

C) subtropical forests

E) tropical rain forests +

186. Complex polydominant communities of plants and animals characterize ecosystems:

B) deciduous forests

C) subtropical forests

E) boreal forests

187. The absence of a clearly expressed layering of phytocenoses and, at the same time, the high complexity of their structure characterizes ecosystems:

A) gallery forests

B) deciduous forests

C) subtropical forests

E) tropical rain forests +

188. Large mammals occupy a very small place among phytophages in ecosystems:

A) boreal forests

B) deciduous forests

C) subtropical forests

E) tropical rain forests +

189. The dynamics of the number of animals, characterized by smooth changes without sharp peaks and declines, distinguishes ecosystems:

A) tropical rainforests +

C) deserts

E) deciduous forests

190. Tree layer communities absolutely dominate among all taxonomic groups of animals in ecosystems:

A) gallery forests

B) deciduous forests

C) subtropical forests

E) tropical rain forests +

191. Phytocenoses of tropical rainforests lack this layer:

A) shrubby +

B) herbaceous plants

C) epiphytes

E) trees

192. Tree layer life forms represent more than 50% of mammal species living in ecosystems

A) boreal forests

B) deciduous forests

C) subtropical forests

E) tropical rain forests +

193. The number of tree species significantly exceeds the number of grass species in phytocenoses of ecosystems:

A) boreal forests

B) tropical rainforests +

C) subtropical forests

E) deciduous forests

194. Efficient direct return of biogenic elements into cycles ensures high productivity of ecosystems:

A) boreal forests

B) deciduous forests

C) subtropical forests

E) tropical rain forests +

195. The main factors that make tropical rainforest ecosystems possible are:

A) rich soils and high rainfall

B) rich soils and high temperatures

C) constancy of temperatures and evenly distributed rainfall +

D) high temperatures and high rainfall

E) rich soils and constant temperatures

196. Low temperatures and a short growing season are the main limiting factors in ecosystems:

A) boreal forests

B) tundra +

D) deciduous forests

E) deserts

197. Snow is the most important edaphic factor affecting the functioning of ecosystems:

A) boreal forests

B) deciduous forests

C) deserts

198. The main edificators of plant communities in the tundra are:

B) shrubs

C) dwarf trees

E) lichens +

199. Tundra phytocenoses have a very simple structure, in which only a few tiers are distinguished:

200. The main phytophages in tundra ecosystems are

A) large ungulates

B) voles and lemmings +

E) insects

201. High productivity of primary production of tundra phytocenoses is ensured by:

A) rich soils

B) optimal temperature conditions

C) a wide variety of producers

D) long summer photoperiods +

E) abundance of moisture

202. Low diversity and high animal populations are a characteristic feature of ecosystems:

A) boreal forests

B) deciduous forests

C) subtropical forests

203. The simplest structure of the fauna of terrestrial vertebrates, including only terrestrial life forms, is characteristic of ecosystems

A) boreal forests

B) deciduous forests

C) tundra +

204. In terms of biomass among animals-saprophages of the soil-litter layer in the tundra, the first place is occupied by

A) earthworms +

B) nematodes

D) springtails

E) larvae of typulid mosquitoes

205. Among vertebrates, the greatest diversity in the tundra is reached by:

A) mammals

B) reptiles

C) freshwater fish

D) amphibians

206. The most common adaptation of vertebrates, which allowed them to adapt to living in extreme conditions of the tundra:

A) hibernation

B) seasonal migrations +

C) food storage

D) life under the snow

E) hibernation and food storage

207. Boreal coniferous forests are geographically localized:

A) in North America

B) in the southern latitudes of South America and Australia

C) in the northern latitudes of North America, Eurasia and the southern latitudes of South America and Australia

D) in the northern latitudes of North America and Eurasia +

E) in the northern latitudes of Eurasia

208. The moisture balance (ratio of precipitation and evaporation) in boreal coniferous forests over most of the territory is characterized by:

A) excess precipitation +

B) balance

C) excess evaporation

D) long-term fluctuations

E) cyclic changes

209. The main edificators in phytocenoses of boreal coniferous forests are:

A) small-leaved species

C) lichens

D) conifers +

E) herbaceous layer

210. The monodominant structure of phytocenoses is characteristic of ecosystems:

A) coniferous boreal forests +

B) deciduous forests

C) subtropical forests

D) gallery scaffolding

211. For the vertical structure of phytocenoses of boreal coniferous forests, the most characteristic number of layers is:

212. In the ecosystems of boreal coniferous forests among vertebrates, edificator species include:

A) hibernating

B) migratory

C) coniferous storage seeds +

E) ungulates

213. The animal population of boreal coniferous forests has a vertical structure, the number of tiers in which is equal to:

214. Features of the lotic ecosystem include:

A) Presence of flow, high oxygen content, active exchange between

water and land. +

B) Weak exchange between water and land, the presence of a current.

D) Predominance of detrital food chains.

E) No water flow, high oxygen content.

215. The presence of soil-bedding, ground, shrub and tree layers of the animal population is typical for ecosystems:

A) subtropical forests

B) deciduous forests

C) subtropical forests

D) gallery scaffolding

E) coniferous boreal forests +

216. The least productive ecosystems are located:

A) in the savannas

B) in the tundra;

C) in coniferous forests;

D) in deserts; +

E) in the steppes;

217. The successive change of biocenoses with a gradual directed change in environmental conditions is called:

A) adaptation

B) evolution +

C) succession

D) dynamic

E) trending

218. Biome distributed in the Arctic zone of the Earth:

A) savannah;

D) forest-steppe;

E) tundra. +

219. Relationships between organisms, through which the transformation of matter and energy occurs in ecosystems:

A) trophic web;

B) food web;

C) trophic chain; +

D) trophic level;

E) trophic branch.

220. Autotrophic organisms include:

A) consumers;

B) producers; +

C) decomposers;

E) predators.

221. Water bodies with an average level of primary production:

A) oligotrophic;

B) dystrophic

C) polysaprobic;

D) eutrophic;

E) mesotrophic; +

222. Pedobionts that make up most of the biomass of soil fauna:

A) springtails;

B) nematodes;

D) earthworms; +

E) insect larvae

223. Biocenoses on agricultural land:

A) agrocenosis; +

B) agro-wall

C) agrophytocenosis;

D) agrobiogeocenosis

E) agroecosystem.

224. All relationships in the biocenosis are carried out at the level of:

B) communities

C) individuals;

D) families, packs, colonies

E) populations. +

225. The most important factor in the transition from tropical rain forests to semi-evergreen tropical forests is:

A) lowering the temperature

B) seasonal rhythm of precipitation +

C) decrease in the amount of precipitation

D) decrease in air humidity

E) reduction of solar radiation

226. The appearance of seasonal rhythms of life processes in all animal species during the transition from tropical rainforests to semi-evergreen tropical forests is due to:

A) lowering the temperature

B) a decrease in solar radiation

C) a decrease in the amount of precipitation

D) decrease in air humidity

E) seasonal rhythm of precipitation +

227. Communities characterized by the presence of a closed grass cover with a varying share of shrubs and trees, the seasonality of which is associated with the frequency of precipitation:

A) prairies;

B) semi-evergreen forests;

C) mangroves;

D) savannas; +

E) forest-steppe

228. Large phytophages from the orders of artiodactyls, equids and proboscis are the most widespread and most characteristic group of mammals in ecosystems:

A) prairies;

B) semi-evergreen forests;

C) mangroves;

D) savannas; +

E) forest-steppe

229. The largest accumulations of large phytophages, the biomass of which reaches the maximum values ​​for modern ecosystems up to 50 kg per 1 ha, are found:

A) on the prairies;

B) in semi-evergreen forests;

C) in savannas; +

D) in the Asian steppes

E) in the forest-steppe

230. Forest communities of the littoral zone of the tropical belt, characterized among animal organisms by a mixture of terrestrial and marine forms adapted to long-term or temporary life on land:

A) gallery scaffolding;

B) semi-evergreen forests;

C) mangroves; +

D) floodplain forests;

E) tropical rainforests

231. Types of biogeocenoses localized in the temperate, subtropical and tropical zones, the appearance, structure, dynamics and productivity of which are controlled by a sharp predominance of evaporation over precipitation:

A) prairies;

B) deserts; +

D) savannas;

E) forest-steppe

232. Life forms of plants, in which the mass of roots significantly exceeds the mass of shoots, are characteristic of ecosystems:

A) prairies;

B) tundra;

C) steppes;

D) savannas;

E) deserts. +

233. Adaptations, expressed in the presence of a period of rest (hibernation) in seasons of the year unfavorable for active life, the development of underground layers, migrations, specific physiological processes, are characteristic of animals living in ecosystems:

B) tundra;

C) deserts; +

D) savannas;

E) forest-steppe

234. The ecosystems with the lowest primary production and biomass reserves are:

B) tundra;

C) deserts; +

D) savannas;

E) forest-steppe

235. Hydrothermal regime with non-coincidence of warm and humid periods in time (wet cool winters and dry hot summers) is the most striking feature of ecosystems:

B) deciduous forests;

C) deserts;

D) savannas;

E) subtropical hardwood forests +

236. Forest communities in areas with a large amount of evenly distributed precipitation, moderate temperatures and pronounced seasonal changes:

A) boreal coniferous forests;

B) deciduous forests; +

C) semi-evergreen forests;;

E) forest-steppe

237. An ecosystem in which the seasonality of the cycles of development of plants and animals is determined not by temperature, but by rain:

A) deciduous forests;

C) deserts;

D) savannas; +

C) subtropical hardwood forests

238. Forest communities with the most pronounced vertical structure, consisting of four tiers - tree, shrub, grass (or grass-shrub) and moss (moss-lichen):

A) boreal coniferous forests;

B) deciduous forests; +

C) semi-evergreen forests;;

D) subtropical hardwood forests;

E) gallery forests;

Biocenoses differ in the species diversity of their constituent organisms.

The species structure of a biocenosis is understood as the diversity of species in it and the ratio of their abundance or biomass.

Species structure.

STRUCTURE OF BIOCENOSIS.

A biotope is a place of existence, or a habitat for a biocenosis, and a biocenosis can be considered as a historically established complex of living organisms, characteristic of a particular biotope.

A biotope is a piece of territory with more or less homogeneous conditions, occupied by one or another community of living organisms (biocenosis).

In other words,

The section of ecology that studies the patterns of composition of communities and the joint life of organisms in them is called synecology (biocenology).

Synecology arose relatively recently - at the beginning of the twentieth century.

The structure of a biocenosis is the ratio of various groups of organisms that differ in their systematic position; according to the place occupied by them in space; according to the role that they play in the community, or according to another sign that is essential for understanding the patterns of functioning of this biocenosis.

Distinguish species, spatial and ecological structure of the biocenosis.

Each specific biocenosis is characterized by a strictly defined species composition (structure).

In those biotopes where environmental conditions are close to optimal for life, extremely species-rich communities arise ( for example, biocenoses of tropical forests or coral reefs).

The biocenoses of the tundra or desert are extremely poor in species. This is due to the fact that only a few of the species can adapt to such unfavorable environmental conditions as a lack of heat or lack of moisture.

The ratio between the conditions of existence and the number of species in the biocenosis is determined by the following principles:

1. The principle of diversity: the more diverse the conditions of existence within the biotope, the more species in a given biocenosis.

2. The principle of rejecting conditions: the more the conditions of existence within the biotope deviate from the norm (optimum), the poorer the biocenosis becomes in species and the more numerous each species.

3. The principle of smooth change of environment: the more smoothly the environmental conditions in the biotope change and the longer it remains unchanged, the richer the biocenosis in species and the more balanced and stable it is.

The practical significance of this principle is that the more and faster the transformation of nature and biotopes occurs, the more difficult it is for species to have time to adapt to this transformation, and therefore the species diversity of biocenoses becomes less

The pattern of change in species diversity is also known (Wallace's rule): species diversity decreases as one moves from south to north ( those. from the tropics to the high latitudes).

For example:

• in humid tropical forests, there are up to 200 species of tree species per 1 hectare;

· pine forest biocenosis in the temperate zone can include a maximum of 10 tree species per 1 ha;

· in the north of the taiga region, there are 2-5 species per 1 ha.

The species diversity of biocenoses also depends on the duration of their existence and the history of each biocenosis.

• young, emerging communities, as a rule, have a smaller set of species than long-established, mature ones;
• biocenoses created by man (gardens, orchards, fields, etc.) are usually poorer in species compared to similar natural biocenoses (forest, meadow, steppe)

In each community, a group of the main, most numerous species can be distinguished.

Species that prevail in the biocenosis in terms of numbers are called dominant or dominant.

Dominant species occupy a leading, dominant position in the biocenosis.

So, for example, the appearance of a forest or steppe biocenosis is represented by one or more dominant plant species:

in an oak forest it is an oak, in a pine forest it is a pine, in a feather-grass-fescue steppe it is a feather grass and a fescue..

Usually terrestrial biocenoses are named according to the dominant species:

* larch forest, coniferous forest (pine, spruce, fir), sphagnum bog (sphagnum moss), feather grass-fescue steppe (feather grass and fescue).

Species living at the expense of dominants are called predominants.

For example, in an oak forest, these are various insects, birds, mouse-like rodents feeding on oak.

Among the dominant species are edificators are those species that, by their vital activity, create the conditions for the life of the entire community to the greatest extent.

Consider the edificatory role of spruce and pine.

Spruce in the taiga zone forms dense, heavily darkened forests. Under its canopy, only plants adapted to conditions of strong shading, high humidity, high acidity of soils, etc. can live. According to these factors, a specific animal population is formed in spruce forests.

Consequently, spruce in this case acts as a powerful edificator, which determines a certain species composition of the biocenosis.

In pine forests, pine is the edificator. But compared to spruce, it is a weaker edificator, since the pine forest is relatively light and sparse. Its species composition of plants and animals is much richer and more diverse than in the spruce forest. In pine forests there are even plants that can live outside the forest.

Edificator species are found in almost any biocenosis:

* on sphagnum bogs - these are sphagnum mosses;

* in steppe biocenoses, feather grass serves as a powerful edificator.

In some cases, animals can also be edificators:

* in the territories occupied by marmot colonies, it is their activity that mainly determines the nature of the landscape, the microclimate and the conditions for the growth of grasses.

However, the role of edificators in certain biocenoses is not absolute and depends on many factors:

* Thus, when a spruce forest is thinned out, spruce may lose the functions of a powerful edifier, since this leads to lightening of the forest and other species that reduce the edificatory value of spruce are introduced into it;

* in a pine forest located on sphagnum bogs, pine also loses its edificatory value, as sphagnum mosses acquire it.

In addition to a relatively small number of dominant species, a biocenosis usually includes many small and even rare forms (secondary species), which create its species richness, increase the diversity of biocenotic relationships and serve as a reserve for replenishment and replacement of dominants, i.e. give stability to the biocenosis and ensure its functioning in different conditions.

Based on the relationship of species in populations, biocenoses are divided into complex and simple.

Complex biocenoses are called biocenoses, consisting of a large number of populations of different species of plants, animals and microorganisms, interconnected by various food and spatial relationships.

Complex biocenoses are the most resistant to adverse effects. The disappearance of any species does not significantly affect the organization of such biocenoses, since, if necessary, another species can replace the disappeared one.

In exceptionally complex biocenoses of tropical forests, outbreaks of mass reproduction of individual species are never observed.

For simple tundra or desert biocenoses are characterized by a sharp increase or decrease in the number of animals that have a significant impact on the vegetation cover.

This is explained by the fact that in the simplified biocenosis there are not enough species that, if necessary, could replace the main species and act, for example, as food for predators.