Photo credit: NASA

Propagation of global stressors

at the algae-consumer interface:

From short- to

long-term scales of observations

Manuel Villar-Argaiz, JM Medina-Sánchez, FJ Bullejos, G Herrera, C Duran, S

Rosillo and P Carrillo

University of Granada, Spain

Global Change and the World's Mountains, Perth 2010

(Urabe & Sterner 1996, PNAS)

One of the most marked nutrient imbalances in food webs is observed between

plants and herbivores (Brett & Goldman 1997, Science)

Nutrients (P, N, Fe…)

Photo: Agencia EFE

“Extremely simple” biological communities

(Medina-Sánchez et al., L&O 2004)

High Mountain Lakes = Global change labs

3482 m

Snowline depends on altitude and latitude

Löfter H. 1969. High altitude lakes in Mt. Everest region. Verh.Int.Ver.Theor.Lim. 17: 373-385

Photo: NASA

Mediterranean High Mountain lakes Low latitude and High altitude

HIGH UV IRRADIANCE

Photo: NASA

Mediterranean High Mountain lakes Proximity Major dust sources

HIGH ATMOSPHERIC

AEROSOL INPUTS

Mediterranean High Mountain lakes Proximity Major dust sources

HIGH ATMOSPHERIC

AEROSOL INPUTS

Photo: NASA

Mixodiaptomus laciniatus (~100% biomass) (Carney & Elser, 1990; Villar-Argaiz et al., 2001; Nuwer et al., 2008)

…integrating different scales….

MID-TERM

Population dynamics

Growth (growth rate)

Nutrition (asimilaton carbon AEC)

LONG-TERM

Population dynamics

Observational

Studies Experimental

Studies

Abiotic/biotic Monitoring

Growth (growth rate)

Experimental

Studies

+ UVR ― UVR (plexiglass)

(2700 L)

20 30

40 60

Control 20 30

40 60

Control

2 X 5 factorial

design

(Carrillo et al., GCB 2008; Bullejos et al., L&O 2010 in press)

+ UVR - UVR

Food quantity (same quality distinct quantity )

+ UVR – UVR 60 60

No dilution

100 %

– U

VR

+ U

VR

50 % 25 % 12.5 %

Dilution 0.2 μm filtered water

– U

VR

– U

VR

– U

VR

+ U

VR

+ U

VR

+ U

VR

Food quality (same quantity distinct quality)

+ U

VR

+ U

VR

+ U

VR

+ U

VR

+ U

VR

– U

VR

– U

VR

– U

VR

– U

VR

– U

VR

Dilution (0.2 μm) to Food Concentration of Treatment Control

20

– UVR + UVR

Control Control 20 30 30 40 40 60 60

Herbivore consumer growth rate

• Copepod & Daphnid growth rate

• Rotifer growth rate

t = 12 d

t = 5 d

t = 13 d

Somatic GR

Intrinsic GR

g = ln(Mt) - ln(M0) / t

r = [ln(N13) - ln(N0) / t

Villar-Argaiz et al. In Review

Nu

trie

nts

Nutr

ien

ts X

UV

R

NUTRIENTS

NUTRIENTS

and UVR

Villar-Argaiz et al. In Review

Effects on zooplankton growth of UVR (1), Nutrients (2) and their interaction

Population dynamics

Experimental

Studies

(Bullejos et al., L&O 2010 in press)

(Bullejos et al., L&O 2010 in press)

STRONG P-ENRICHMENT

and UVR (at inter. P levels)

constrained zooplankton

control

control

20

20

30

30

40

40

50

50

20 20

30

30

40

40

50

50 P-ENRICHMENT increased

algae, whereas UVR

slightly constrained algae

Population dynamics

Observational

Studies

Abiotic/biotic Monitoring

http://jwocky.gsfc.nasa.gov/

Data Product: AEROSOL INDEX

OZONE

REFLECTIVITY

UV - IRRADIANCE

ITCZ (InterTropical Convergence Zone)

PRECIPITATION National and International

Environmental Agencies

Villar-Argaiz et al. In Review

Abiotic

characterization

Villar-Argaiz et al. In Review

Deposition

event AI =0.5

Large

deposition

event AI > 5

Photo credit: R. Morales

Abiotic

characterization

Population Dynamics

Villar-Argaiz et al. In Review

Villar-Argaiz et al. In Review

(Bullejos et al., L&O 2010 in press)

Phytoplankton

Zooplankton

Low-Moderate

atmospheric

inputs

Strong

atmospheric

inputs

Eutrophication High grazing

herbivores

(Daphnia)

Strong UVR role

No UVR role

Acknowledgment

> National Park of Sierra Nevada for permission and

help to study high mountain lakes.

> Finantial support: I+D Projects, MMA-National Parks

> Colleagues and students who helped with the sampling

Thanks !

Manuel Villar-

Argaiz

mvillar@ugr.es