1 GEN 1030 Introduction to Environmental Studies Aliya

1 GEN 1030 Introduction to Environmental Studies Aliya Nurtaeva, Ph.D., C.Sc. Dept of General Education, KIMEP University Office # 507, [email protected]

2 Lecture 3: A. Species Populations, Interactions & Communities. B. Bioms & Biodiversity. Chapters 3, 5. Outline Who Lives Where, and Why? Species Interactions Population Dynamics Community Properties Communities in Transition Bioms & Biodiversity

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8 1: Who Lives Where, and Why? Generalists vs. Specialists 2 basic strategies for surviving - in a broad range of environmental conditions: "generalists“. - in a narrow set of environmental conditions: "specialists."

9 LIMITING FACTORS The geographical range of a species is not always limited by the presence of barriers that prevent its spread. It is often limited by a particular factor in the environment that limits it ability to survive, grow or reproduce – These are Limiting Factors

10 Abiotic Factors Temperature, Pressure, Wind, Moisture, Salinity Light availability /day length pH, C02, O2, availability of N, P, K, Ca. Biotic Factors Competition, Predation Diseases, Parasitism Food availability, Pollinators Species density Limiting factors include ABIOTIC (physical) factors and BIOTIC factors

11 Tolerance Limits Each environmental factor (temperature, humidity, food supply, etc.) has both minimum and maximum levels beyond which a species cannot survive or is unable to reproduce: lower & upper limits of tolerance. Tolerance range is the range between these 2 limits.

12 Abundance and Distribution of Species Liebig’s Law of Minimum: the environmental factor in the shortest supply is the critical one in species distribution. LIEBIG’s BUCKET Cactus: 1) dry environment 2) critical factor = T (not freezing)

13 define range and abundance of a species. Populations can only live in those areas where the favourable parts of the environmental gradients overlap Interaction of several factors, rather than a single factor, determines species distribution. “biodiversity hotspot” Abiotic and biotic factors

14 Adaptation and Natural Selection Adaptation - physical or behavioral trait that helps a plant or animal survive in its habitat. Two types of adaptation: Acclimation - changes in an individual organism due to non-permanent physiological modifications Evolution - gradual changes in a species due to changes in genetic material and competition Natural selection - according to Darwin's theory, the organisms best adapted to their environment tend to survive and while less adapted tend to be eliminated. Theory of evolution - developed by Charles Darwin and Alfred Wallace.

15 Habitat - the place or set of environmental conditions in which a particular organism lives Ecological niche - the role played by a species in a biological community Niche defines: - way of obtaining food; - relationships w /other species - services to the community. Habitat & Ecological Niche

16 Competition for the resources causes Resource Partitioning Law of Competitive Exclusion: No two species will occupy the same niche and compete for the same resources in the same habitat for very long.

17 2. Species Interactions Most obvious are Predation and Competition - antagonistic relationships

18 Symbiosis: coexistence of 2 species. 3 types of symbiosis: Commensalism - one member benefits, while the other is neither benefited nor harmed Mutualism - both members of the partnership benefit; Parasitism - a form of predation where one species benefits and the other is harmed ADD FIG. 3.18 A-C

19 Defensive Mechanisms Poison arrow frog: strong neurotoxin in its skin.

20 Batesian Mimicry

21 3. Population Dynamics Exponential growth - the unrestricted increase in a population (also called the biotic potential of a population) - J-curve Carrying capacity - the maximum number of individuals of any species that can be supported by a particular ecosystem on a sustainable basis

22 3. Population Dynamics Exponential growth - the unrestricted increase in a population (also called the biotic potential of a population) - J-curve Carrying capacity - the maximum number of individuals of any species that can be supported by a particular ecosystem on a sustainable basis

23 Population Oscillations

24 Growth to a Stable Population ADD FIG. 3.22

25 4. Community Properties Primary productivity - a community's rate of biomass production, or the conversion of solar energy into chemical energy stored in living (or once-living organisms) Net primary productivity - primary productivity minus the energy lost in respiration Productivity depends on light, temperature, moisture, and nutrient availability. Environmental resistance - factors that tend to reduce population growth rates: may depend or not on pop density

26 Abundance and Diversity Abundance - the number of individuals of a species in an area Diversity - the number of different species in an area A useful measure of the variety of ecological niches or genetic variation in a community Decreases as we go from the equator towards the poles Abundance and diversity depend on total resource availability in an ecosystem.

27 Properties of Ecosystems Stability (or homeostasis) - a dynamic equilibrium among the physical and biological factors in an ecosystem Resiliency - ability to recover from disturbance 3 types of stability or resiliency in ecosystems: Constancy - lack of fluctuations Inertia - resistance to perturbations Renewal - ability to repair damage after disturbance

28 Communities in Transition Ecological succession - the process by which organisms occupy a site and gradually change environmental conditions by creating soil, shelter, shade, increasing humidity Primary succession - occurs when a community begins to develop on a site previously unoccupied by living organisms Secondary succession - occurs when an existing community is disrupted and a new one subsequently develops at the site

29 Primary Succession on Land Primary Succession

30 Exotic & Invasive Species Sometimes communities can be completely altered by the introduction of exotic species. Exotic species – not native to the area often introduced by humans. Invasive species – cause damage to ecosystem Successful exotics tend to be prolific, opportunistic species, such as goats, cats, and pigs. Invasion of exotic species: a pressing hazard for biological communities in the coming century.

31 Invasive Species &Community Change

32 B: Biomes Biomes Broadly defined life zones Environments with similar climates, topographies, soil conditions, and biological communities Biome distribution mainly dependent on temperature and precipitation

33 ADD FIG. 5.1 Main factors of biomes: T and precipitation

34 Biomes of the World

36 Biomass production by major world ecosystems. ADD FIG. 3.29

37 B2: Biodiversity Genetic diversity - variety of different versions of the same genes within a species Species diversity - number of different kinds of organisms within an ecosystem Ecological diversity - complexity of a biological community (number of niches, trophic levels, etc.) ~1.8 mln types of species in the world Biodiversity - the variety of living things 3 types essential:

38 Biodiversity Hotspots Most of the world's biodiversity concentrations are near the equator (tropical rainforests, coral reefs).

39 How do we benefit from biodiversity? Food Drugs and medicines Ecological benefits Aesthetic and cultural benefits Mangosteen – tasty fruits

40 What Threatens Biodiversity? Extinction - the elimination of a species Natural process - one species lost every 10 years Process been accelerated by human impacts on populations and ecosystems We are currently losing thousands of species a year

41 Human-Caused Biodiversity Loss Habitat destruction Poaching /Hunting / Fishing Commercial products and live specimens Predator and pest control Exotic species introduction Diseases Pollution Genetic assimilation

42 Saiga antelopes in Kazakhstan 1993 – 1.3 млн species Cold winter 1993: saigas moved to South Techno-catastrophe in 1995: thousands died 2004 - ~20 thousand SAIGA: male horns in oriental medicine 1999 – ban on shooting 2008 - ~60 thousand

43 Protecting Biodiversity Hunting and fishing laws Legislation: “On protected territories” National Reserves, National Parks Recovery plans Private land and critical habitat International wildlife treaties RED BOOK in Kazakhstan, Russia (IUCN Red List): 1st category: critically endangered 2 category: endangered 3 – vulnerable IUCN – International Union of Conservation of Nature

44 IUCN Red List 2007 data: % of species, listed as RED - critically endangered, BROWN - endangered, YELLOW - vulnerable

45 QUESTIONS ? ASK ME…