Biodiversita / Biodiversity
A. Some 1 413 000 species have been described by scientists; most of these are either insects or plants (Wilson,
1992). B. Estimated species number in taxa with over 100 000 species expected (vertebrates given for comparison);
number of described species indicated by grey part of bars …. Number of undescribed species may reach 10 million,
or even 30-150 million (Hammond, 1992) - see next page (slide)
- viz další stránka
insects
other animals
viruses
bacteria
fungi
algaeprotists
Biodiversita / Biodiversity
undescribed
species
described
species
number of species in millions
viruses
bacteria
nematodes
crustaceans
prostists
algae
vertebrates
molluscs
fungi
arachnids
plants
insects
/ million
Precision of estimate
very bad
bad
medium
very bad
very bad
good
medium
medium
good
medium
Biodiversita / Biodiversity
genetická a fenetická
diversita (úroveň jedince
a populace)
genetic and phenetic
diversity (level of the
individual and population)
úroveň společenstva
community diversity
diversita ekosystémů
(diversita krajiny –
zahrnující vícero
biotopů)
ecosystem diversity
(-landscape diversity –
encompasing various
habitats)
Biodiversita / Biodiversity
Viz další snímek
See next slide
Které společenstvo je rozmanitější? Druhová diversita!
Which community is more diverse? Species diversity!
Biodiversita / Biodiversity
Shannonův (Shannon-Wienerův) index diversity (a příslušná vyrovnanost = H’/H’max)
The Shannon (-Wiener) Index of Diversity (and the associated Evenness = H’/H’max)
Které společenstvo je rozmanitější? Druhová diversita!
Which community is more diverse? Species diversity!
Biodiversita / Biodiversity
compositional
diversity
structural
diversity
functional
diversity
Biodiversita / Biodiversity
Funkční biodiversita / Functional Biodiversity
Příklad / Example: ekologické skupiny žížal / ecological groups of earthworms
epigeické endogeické anektické
Schéma rozmístění a tvaru chodeb ekologických skupin žížal
jak je definoval Bouché.
Effect of earthworm populations and soil erosion: annual surface erosion
/ annual run off)
Struktura společenstva žížal na aktivní pastvině a přilehlém vlhkém
tropickém lese na aluviálním inceptisolu v Puerto Ricu.
Biodiversita / Biodiversity
Početnost jedinců (abundance) u zjištěných druhů členovců
Ekologický význam Význam pro
ochranu druhů
Nízká ochranářská hodnota? Ekologická redundantnost?
Biodiversita / Biodiversity
Keystone species as wolves, bats, fig trees, infectious species make up for a small
proportion of biomass of a natural community but have a big effect on its organisation
and survival.
Keystone species (e.g. wolfs, bats,
fig trees, infectious organisms)
Dominant species (e.g. forest trees, high game,
grasses, brown algae)
Rare species (e.g. butterflies,
mosses, wild plants)
Common species with little
effect (e.g. understorey trees,
shrubs, economically unimportant
grasses)
Proportional biomass of species
Overalleffectofspecies
Biodiversita / Biodiversity
Increase of species diversity in the middle stages of succession
pionier early medium stage
climax
/ time
/diversity
Biodiversita / Biodiversity
Schematic representation of the impact of r- and K-selection on the population dynamics
(Lepš & Spitzer, 1988)
K – carrying capacity of the environment
N – number of individuals
K-strategy
r-strategy
K-selectionr-selection
density-dependent
mortality
environment
rather stable
environment
unstable
catastrophy-dependent
mortality
Biodiversita / Biodiversity (see next slide)
více ovlivněna populační
hustotou
méně ovlivněna populační
hustotou
mortalita
tendence k pomalému
vývoji, k nízkému rmax, k
pozdní a opakované
reprodukci (iteroparii), k
vysoké tělesné hmotnosti,
ke vysokověkosti
tendence k rychlému
vývoji, k vysokému rmax, k
časné a jednorázové
reprodukci (semelparii), k
nízké tělesné hmotnosti, ke
krátkověkosti
životní cyklus
vyššínižšíkonkurenceschopnost
většinou intensivnějšírůzně silná, často slabávnitro- a mezidruhová
konkurence
relativně konstantní v čase,
blíže k nosné kapacitě
prostředí
proměnlivější v čase,
většinou daleko pod
nosnou kapacitou prostředí
velikost populace
přibližně konstantní a/nebo
lépe předvídatelné
proměnlivější a/nebo hůře
předvídatelné
relevantní abiotické faktory
K-selekce/strategier-selekce/strategie
Vlastnosti r- a K-stratégů a jejich prostředí:
Biodiversita / Biodiversity (English)
Traits of r- and K-strategists and their environment:
r-selection/strategy K-selection/strategy
relevant abiotic factors more variable or less approximately constant
predictable and/or more predictable
population size more variable over close to constant over time,
time, mostly far below closer to carrying capacity
the carrying capacity
intra- and interspecific competion of various strenght, usually more intensive
often week
competitevness lower higher
life cycle tendency towards faster tendency towards slow
development, often development, low rmax,
unrepeated reproduction late and repeated
(semelparity), low body reproduction (iteroparity),
mass, short life span high body mass, long life
span
mortality less influenced by more influenced by
population density population density
Biodiversita / Biodiversity
Biodiversita / Biodiversity
importance of stressdecisive
low
importance of
competition
low
high
low
decisive
importance of
disturbance
A scheme simulating the relationships
between the ability of vegetation to
resist competition, stress and
disturbance (GRIME, 1981).
A – The sides of the triangle correspond
to the relative importance of competition
(left side), disturbance (right side) and
stress (base). The basic life strategies
of plants (C, R, S) and transitional
strategies (C-S, C-R, C-S-R, S-R) are
placed within these coordinates.
B – Assumed range of life strategies
found in a – annuals, b - biannuals,
c - perennial herbs and ferns, d –
lichens, f – mosses (all according to
field data from N England)
C – Assumed course of succession:
a – in an environment with high (S1),
average (S2) and low (S2) potential
productivity;
b – in an environment with rising or
falling potential productivity.
The amount of biomass in each stage
of succession is indicated by the size
of the circles. The representation of
species and life forms in the
individual succession stages
corresponds with schemes A and B.
C – competition / konkurence
S – stress / stres
R – ruderal / ruderální
Biodiversita / Biodiversity
Total number of species on the study site
Totalnumberofspeciespertaxonomicgroup
Vhodnost různých taxonomických skupin hmyzu jako indikátorů celkového druhového
bohatství (jako míry biodiversity) / Suitability of various taxonomic groups of insects
to server as an indicator of species richness (as a measure of biodiversity)
Biodiversita / Biodiversity
Biodiversita / Biodiversity
Biodiversita / Biodiversity
Biodiversita / Biodiversity
The extinction rate in birds and mammals shown in 50 year steps since 1600.
The y-axis shows for these steps the percentage of extinct species from the total
number of known species. From 1800 tp 1950 the rate of extinction increased, while
it seems that it decreased somewhat since then (Smith et al., 1993).
birds
mammals
Biodiversita / Biodiversity
Blue whale
Fin whale
Sei whale
The decline in the abundance of Antarctic baleen whales under the influence of human harvesting.
Biodiversita / Biodiversity
Recorded extinctions of species from 1600 to 1995
Number of extinct species
Average
species number Percentage of
extinct species
Mainland Island Ocean Total
Mammals
Birds
Reptiles
Amphibians
Fishes
Invertebrates
Vascular plants
Biodiversita / Biodiversity
area 1
area 2
area 3
alpha
(average number of
species per mountain)
gama
(total number of
species in the area)
beta
(gama/beta)
Biodiversity indices for three areas,
each containing three mountains.
Each letter represents the population
of one species. Some species occur
on a single mountain only, other on
two or three. The alpha-, beta- and
gama-diversity are shown for each
area. If funds were available to protect
one of these areas only, area 2 should
be selected as it contains the highest
total diversity (here: species number).
However, if only a single mountain
were to be protected, a mountain
from area 1 should be selected as
this area contains the highest alpha-diversity
(local), i.e. the highest number
of species per mountain.
Any of the mountains in area 3 hosts
a more specialised assemblage than
any mountain in the other areas, as
shown by beta-diversity. Generally
area 3 would have a lower conservation
priority.
Biodiversita / Biodiversity
Co jsou "vzácné" druhy ? / What are “rare” species?
Rozšíření / Distribution
• Druhy s malým areálem / Species with a small area of distribution
• Druhy omezené na malý počet izolovaných stanovišť (přinejmenším v regionálním kontextu)
/ Species limited to a small number of insolated habitats (at least in the regional context)
Vazba na určité prostředí / Association with a specific habitat
• Druhy s výskytem na jednom nebo málo typech stanovišť (přinejmenším v regionálním kontextu)
/ Species ocurring only in one or few types of habitat (at least in the regional context)
Abundance (početnost jedinců, velikost populací) /(number of individuals, population size)
• Druhy, které mají pouze malé populace / Species with small populations only
Neznalost biologie, ekologických nároků druhu - domnělá vzácnost ! / Insufficient
knowledge of the biology, ecological requirements of species – apparent rarity
• Chybná hlášení (historická) výskytu / Erroneous records of occurrence (in the past)
• Nevhodná metodika sběru/pozorování/inventarizace / Inadequate methodology of collecting/
observation/making species inventories
Biodiversita / Biodiversity
Zastoupení katogorií vzácnosti při vyhodnocení 160 druhů rostlin na Britiských ostrovech
(na základě geografického rozšíření, vazby na stanoviště, velikosti jednotlivých populací) /
Representation of categories of rarity when evaluating 160 plant species on the British Isles
(based on geographic distribution, association with habitat, size of individual populations):
3 spp.6 spp.pouze malé populace
/ only small populations
14 spp.71 spp.existují velké populace
/ a large population exists
výrazná vazba na typ stanoviště
strong association with habitat type
0 spp.2 spp.pouze malé populace
/ only small populations
6 spp.58 spp.existují velké populace
/ a large population exists
malá vazba na typ stanoviště
weak association with habitat type
malý / smallvelký / large
areál
distribution area
velikost populace
population size