GRADIENT:Himalayan elevation gradient NICHE: temperature niches Richness Endemics Life forms

GRADIENT: Himalayan elevation gradient

NICHE: temperature niches

Richness

Endemics

Life forms

But first: do communities exist?

A short answer after a long debate: No.

Compositional variation in nature tends to be gradual.

How can we analyse species composition?

Pinus Tsuga

Site 1 3 10

Site 2 5 1

Site 3 0 2

Site 4 4 8

Site 5 3 5

....... .... ....

Within some defined environment or area we sample a number of plots and register the species present

The temperature niche

Habitat is where plant live, e.g. in oak forest, on open slopes, at

rhododendron trees, etc

Distribution range is where on a geogrphical one may find the

target species

Elevation gradient variation in temperature and correlated variables e.g. soil

MontaneMontaneConiferouConiferou

ssForestForest

DeciduousDeciduousForestForest

AlpineAlpineTundraTundra

Temperated ForestTemperated Forest Northern Coniferous Northern Coniferous ForestForest

Arctic TundraArctic Tundra

lowlow

highhigh

Elevation

Elevation

elevation

Me

an

an

nu

al T

em

pe

ratu

re

0 1000 2000 3000 4000

51

01

52

02

5

elevation

Me

an

an

nu

al T

em

pe

ratu

re

0 1000 2000 3000 4000

51

01

52

02

5

Laps rate = 0.55 oC pr 100 elevation-meter

ELEVATION GRADIENT SPCECIES OCCURE AND DISAPEAR

Low-land spMid elevation

High-land sp

M ASL

ELEVATIONE RANGEELEVATION CONVERTED TO

TEMPERATURE

EXAMPLES:RHODODENDRON IN THE HIMALAYAS

Milke Danda

1000 masl Elevation range of Rh. Arboreum 3600 masl

Concepts: realized and potential niche

Realized climate niche = the average climate conditions where the species are growing in nature

Potential climate niche = the climate conditions where the (fundamental) species are able to grow without

interference from other organisms

temperature

abundance

Elevation gradient in temperature lapse rate= decrease 0.5 degrees Celsius each 100 elevation meter

MontaneMontaneConiferouConiferou

ssForestForest


AlpineAlpineTundraTundra

Subtropical ForestSubtropical Forest NorthernNorthern Arctic TundraArctic Tundra

lowlow

highhigh

Elevation

Elevation

elevationM

ean

annu

al T

empe

ratu

re

0 1000 2000 3000 4000

510

1520

25

species 100 200 300 400 500 …. 6000

sp1 0 0 1 1 0 0

sp2 1 1 1 1 1 0

sp3 0 0 0 1 1 0

sp n-1 0 0 0 0 1 0

sp n 0 0 0 0 0 0

sum of spp 1 1 2 3 3 0

INTERPOLATION : ASSUMING ALL SPECIES ARE PRESNET IN ALL 100M INTERVALS BETWEEN LOWER AND UPPER ELEVATION LIMIT

This gives total number of specie in all different elevation bands from 100 m to 6000 m a.s.l.

INTERPOLATION : ASSUMING ALL SPECIES ARE PRESNET IN ALL 100M INTERVALS BETWEEN LOWER AND UPPER ELEVATION LIMIT

This gives total number of species in all different elevation bands from 100 m to 6000 m a.s.l.

This can be done for different life forms, such as ferns,trees or total number of endemics and total number of species

Tree species richness patterns

• Unimodal relationship between tree species richness and elevation.

• Maximum tree species found between 900 and 1000 m.

Elevation

Sp

ecie

s r

ich

ne

ss

0 1000 2000 3000 4000

05

01

00

15

02

00

Elevation

Spe

cies

ric

hnes

s

Mountain BiomesMountain Biomes

“Islands” = isolation= speciation, polyploidy => endemics

“Islands” = isolation= speciation, polyploidy => endemics

Internpolated species richness in the Himalayas

eleva

spp

no

0 1000 2000 3000 4000 5000 6000

02

00

40

06

00

80

01

00

01

20

0

Interpolated species richness in the Himalayas

eleva

spp

no

0 1000 2000 3000 4000 5000 6000

02

00

40

06

00

80

01

00

01

20

0

Plateau

MASL

1500 200 m asl

Is Gamma diversity able to predict the pattern of

Alpha diversity along an elevation range?

Ole R. Vetaas, M. Panthi, & K. Shrestha, IE Maaren

Centre for Development Studies, University of Bergen, Nygaardsgt. 5, N-5015 Bergen, NORWAY.

Central Department of Botany, Tribhuvan University, P.B. 5927 Kathmandu, Nepal.

Elevation Gradient

ConiferousConiferousForestForest


Ice & rockIce & rockAlpineAlpine

TundraTundra

TROPICAL TROPICAL FORESTFOREST

EVERGREENEVERGREENOAK-RHODODENDRON-ForestOAK-RHODODENDRON-Forest

MontaneMontaneBETULABETULA

&…… &……

elevation gradient




TundraTundra




&…… &……

2000 m asl

4000 m asl

elevation gradient




TundraTundra




&…… &……

Rh. arboreum spp. arboreum

Rh. arboreum spp. cinnamomeum

elevation gradient




TundraTundra




&…… &……

Area: Manag 3200 – 4000 maslSampling: 5 plots (10m x10m) in each 100m elevation on N- and S- aspects of the valley

elevation gradient




TundraTundra




&…… &……

BETULA

Dry inner valleys

ANNAPURNA RANGE

MONSOON

Dry south-exposed slopes

Alpine shrub at 3800+ masl

Diversity concepts

• Two of late R.H. Whittakers diversity concepts

• Alpha diversity number of species in community, i.e. # species per area

• (point-alpha)

• Gamma diversity not well-defined concept, high alpha and high beta produce high gamma.

• Gamma diversity?

• Lomolino defined Gamma diversity as total number of species in certain elevations zone in a mountain range.

• Similar to the concept of Species pool, which is indicating the potential number of species that could be found in a given area.


eleva

sppn

o

0 1000 2000 3000 4000 5000 6000

020

040

060

080

010

0012

00

MASL

We used data on elevation ranges in the Enumeration of flowering plants in Nepal (Hara et al., 1978;Hara & Williams,1979; Hara et al., 1982) to describe the pattern of species richness along the elevation gradient.

GAMMA diversity~ species pool


eleva

spp

no

0 1000 2000 3000 4000 5000 6000

02

00

40

06

00

80

01

00

01

20

0

Plateau

MASL

LOCATION OF THE PLOTS

Alpha diversity number of species per 100 square metre

• Species richness was recorded from

350 10m x 10m plots: 2000 - 4000 m asl

Average species richness (alpha diversity)

for each 100 m elevation zone

Sources: Vetaas, Maaren, KB Shrestah, M Panthi, and

Ohasi H. (The Flora of eastern Himalaya)

Species pool for each 100m elevation interval = Gamma diversity

Elevation

Tota

l nu

mb

er

of

spe

cie

s a

t e

ach

10

0m

ele

vatio

n r

an

ge

2000 2500 3000 3500 4000

95

01

00

01

05

011

00

115

01

20

0

Average alpha diversity in 100 square metre plots for each 100m elevation interval

Elevation

Me

an

nu

mb

er

of

spe

cie

s p

r 1

00

m-2

2000 2500 3000 3500 4000

10

20

30

40

41% Deviance explained

38% Deviance explained

Gamma diversity at each 100m elevation range

Alp

ha

div

ers

ity a

t e

ach

10

0m

ele

vatio

n r

an

ge

950 1000 1050 1100 1150 1200

10

20

30

40

Gamma diversity at each 100m elevation range

Alp

ha

div

ers

ity a

t e

ach

10

0m

ele

vatio

n r

an

ge

10.5 11.0 11.5 12.0 12.5 13.0

2.5

3.0

3.5

• There is a significant drop in richness from the evergreen oak forest and deciduous forest at 2500 m asl to the marginal boreal zone with dominance of coniferous trees.

• This appear both in gamma level and alpha level

• Thus the gamma level can predict the alpha level, at least the pattern of change

The plateau ?

• Gamma diversity also indicate a plateau

• This is found in alpha level

• But

• Tree species gamma does not predict this

• Herbaceous species gamma does!

Tree species richness patterns

• Unimodal relationship between tree species richness and elevation.

• Maximum tree species found between 900 and 1000 m.

• No plateau in

3000 – 4000 m asl.

Dispersal of herbaceous species

Elevation

Sp

ecie

s r

ich

ne

ss

0 1000 2000 3000 4000

05

01

00

15

02

00

Elevation

Spe

cies

ric

hnes

s

Elevation

Tota

l nu

mb

er

of

he

rba

ceo

us

spe

cie

s a

t e

ach

10

0m

ele

vatio

n r

an

ge

2000 2500 3000 3500 4000

95

01

00

01

05

011

00

115

01

20

0

Herbaceous gamma explain 22 % of the deviance in total Alpha

Herbaceous Gamma diversity at each 100m elevation range

Me

an

alp

ha

div

ers

ity a

t e

ach

10

0m

ele

vatio

n r

an

ge

950 1000 1050

10

20

30

40

What cause these patterns?

• Drop in richness

• Increased change in temperature

Laps rate break!

Temperature decreases at a fasterrate above 3000 m

U-valley with glaciers

elevation

Me

an

an

nu

al T

em

pe

ratu

re

0 1000 2000 3000 4000

51

01

52

02

5

9 of 12 points are colder than laps rate estimate

Dry south-exposed slopes

PLATEAUGeology : U-valleyDomestic animals seed dispersal

CONCLUSIONS

• Gamma diversity estimates are useful to detect pattern and deduce hypothesis that can be tested by field sampling

• Example here:• The drop in richness form evergreen forest to

‘boreal’ sub-alpine coniferous forest• Plateau in richness in the coniferous dominated

U-valley of the arid central Himalayas.

GRADIENT:Himalayan elevation gradient NICHE: temperature niches Richness Endemics Life forms

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