Ecosystem processes and heterogeneity
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Ecosystem processes and heterogeneity. Landscape Ecology. Today. Global NPP Lake position Moose impacts. Questions/Comments. Ecosystem processes. What do we mean? Energy Matter Carbon Nutrients. Spatial Heterogeneity in ecosystem process .

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Today
Today

  • Global NPP

  • Lake position

  • Moose impacts



Ecosystem processes
Ecosystem processes

  • What do we mean?

    • Energy

    • Matter

      • Carbon

      • Nutrients


Spatial heterogeneity in ecosystem process
Spatial Heterogeneity in ecosystem process

  • What can cause ecosystem processes to vary spatially?

    • Temperature

    • Moisture

    • Topography





Paradox
Paradox…

  • How do the factors that drive NPP differ between marine and terrestrial ecosystems?

  • the basic processes of plant photosynthesis are the same for terrestrial and marine/aquatic plants

  • the key factors must be the physical and chemical properties of the environments in which plant growth occurs,

  • or the carbon allocation and life history dynamics of the plants themselves.


Marine npp
Marine NPP

  • “Marine NPP was a major driver of the preindustrial cultures and economies of civilizations in the higher latitudes, and is still a major driver of the global fishing industry”

  • Driven by:

    • Nutrients – upwelling

    • Geology


Terrestrial npp
Terrestrial NPP

  • “The most remarkable feature of the terrestrial NPP distribution is that it is the opposite of the pattern of marine NPP”

  • Driven by:

    • Climate?

    • Why not nutrients?


Nutrients in tropics
Nutrients in Tropics

  • Are the tropics a good place for agriculture?

  • The basic processes of soil weathering have several inevitable consequences that result in a decline in soil fertility, and thus in the resources available to support plant growth and NPP over time as soils age.

  • All of these processes occur most rapidly in the tropics.




Conclusions
Conclusions with the availability of mineral nutrients in the oceans and the adjacent continents, while the productivity of the plants growing in the soil on those continents is inversely correlated with nutrient availability?”

  • In fact, the highest short-term rates of NPP (eNPP) apparently occur in temperate and boreal forests.

  • These patterns of forest productivity are consistent with the global distribution of soil fertility

  • as well as the productivity of certain types of crops

  • and the standardized economic value of agricultural production


Why is might our current paradigm about npp wrong
Why is might our current paradigm about NPP wrong? with the availability of mineral nutrients in the oceans and the adjacent continents, while the productivity of the plants growing in the soil on those continents is inversely correlated with nutrient availability?”

  • Hard to measure NPP

  • Satellites measure green leaves, not necessarily carbon that goes into wood.


Landscape position and lakes
Landscape Position and Lakes with the availability of mineral nutrients in the oceans and the adjacent continents, while the productivity of the plants growing in the soil on those continents is inversely correlated with nutrient availability?”

  • What factors influence the ecosystem functions of a lake?

    • Geology

    • Size/Depth

    • Climate

    • Terrestrial inputs

  • What about the spatial arrangement of lakes can influence functions?

    • Geology

    • Climate

    • Hydrologic connectivity


What type of ecosystem properties could be influenced
What type of ecosystem properties could be influenced? with the availability of mineral nutrients in the oceans and the adjacent continents, while the productivity of the plants growing in the soil on those continents is inversely correlated with nutrient availability?”


How to test
How to test? with the availability of mineral nutrients in the oceans and the adjacent continents, while the productivity of the plants growing in the soil on those continents is inversely correlated with nutrient availability?”

  • Observational study..


Conclusion
Conclusion with the availability of mineral nutrients in the oceans and the adjacent continents, while the productivity of the plants growing in the soil on those continents is inversely correlated with nutrient availability?”

  • Many factors change with position

    • Ionic composition

    • Biota

    • Size

    • Primary Production


Species and ecosystem function
Species and ecosystem function with the availability of mineral nutrients in the oceans and the adjacent continents, while the productivity of the plants growing in the soil on those continents is inversely correlated with nutrient availability?”

  • How do species influence ecosystem function?


Effects of Moose Browsing on Vegetation and Litter of the Boreal Forest, Isle Royale,Michigan – McInnis et al. Spatial patterns in the moose-forest-soil ecosystem on Isle Royale, Michigan USA – J. Pastor et al.


Background
Background Boreal Forest, Isle Royale,Michigan – McInnis et al.

  • Landscape heterogeneity affects population dynamics and movement.

  • Animals can alter ecosystem function due to their behavior.

    • Ecosystem engineer?

  • Large herbivores could have large impacts:

    • Large home ranges.

    • Eat a lot.

      • But only what is tasty.


Background cont
Background cont. Boreal Forest, Isle Royale,Michigan – McInnis et al.

  • With selective feeding, herbivores can affect species composition, nutrient cycling, etc.

    • Obvious on a local scale.

  • Can herbivores alter ecosystem function at the scale of their home range, or of a valley?


Effects of moose browsing on vegetation and litter of the boreal forest isle royale michigan
Effects of Moose Browsing on Vegetation and Litter of the Boreal Forest, Isle Royale,Michigan

  • Observations:

    • Herbivores change the structure, biomass, production, and species composition of vegetation in heavily browsed or grazed areas

  • Questions:

  • Results:


Effects of moose browsing on vegetation and litter of the boreal forest isle royale michigan1
Effects of Moose Browsing on Vegetation and Litter of the Boreal Forest, Isle Royale,Michigan

  • Observations:

  • Questions:

    • What are the effects of browsing upon the biomass and production of trees, shrubs, and herbs?

    • Does browsing alter species composition of the vegetation?

    • Do changes in species composition affect the quality and quantity of litterfall in browsed areas?

  • Results:




Effects of moose browsing on vegetation and litter of the boreal forest isle royale michigan2
Effects of Moose Browsing on Vegetation and Litter of the Boreal Forest, Isle Royale,Michigan

  • Observations:

  • Questions:

    • What are the effects of browsing upon the biomass and production of trees, shrubs, and herbs?

    • Does browsing alter species composition of the vegetation?

    • Do changes in species composition affect the quality and quantity of litterfall in browsed areas?

  • Results:

    • Higher biomass, alters species composition, …


Spatial patterns in the moose forest soil ecosystem on isle royale michigan usa j pastor et al
Spatial patterns in the moose-forest-soil ecosystem on Isle Royale, Michigan USA – J. Pastor et al.

  • Observations:

  • Hypotheses:

  • Results:


Spatial patterns in the moose forest soil ecosystem on isle royale michigan usa j pastor et al1
Spatial patterns in the moose-forest-soil ecosystem on Isle Royale, Michigan USA – J. Pastor et al.

  • Observations:

    • Moose preferentially forage on aspen and avoid conifers.

  • Hypotheses:

    • If moose browsing causes a shift in dominance from hardwoods to conifers across adjacent areas, we should expect corresponding changes in soil nutrient availability over the landscape.

  • Results:


What was the study about
What was the study about? Royale, Michigan USA – J. Pastor et al.

  • Examine the large-scale landscape distribution of moose browsing intensity in relation to plant community composition and size structure, as well as soil nitrogen availability.

    • Do moose control plant community composition and soil nitrogen at large scales?


What did they measure
What did they measure? Royale, Michigan USA – J. Pastor et al.

  • Available browse.

  • Annual consumption by moose.

  • Soil nitrogen availability.


They tested three models
They tested three models Royale, Michigan USA – J. Pastor et al.

  • Random

  • Short-range autocorrelation

  • Higher order of regularly arranged patterns


What would these models look like
What would these models look like? Royale, Michigan USA – J. Pastor et al.

  • Random

    • No autocorrelation – constant variance

  • Short-range autocorrelation

    • Low-variance at short distances

  • Higher order of regularly arranged patterns

    • Low-variance at short distance and low-variances at large distances as well.


Spatial patterns in the moose forest soil ecosystem on isle royale michigan usa j pastor et al2
Spatial patterns in the moose-forest-soil ecosystem on Isle Royale, Michigan USA – J. Pastor et al.

  • Observations:

    • Moose preferentially forage on aspen and avoid conifers.

  • Hypotheses:

    • If moose browsing causes a shift in dominance from hardwoods to conifers across adjacent areas, we should expect corresponding changes in soil nutrient availability over the landscape.

  • Results:


What did pastor conclude
What did Pastor conclude? Royale, Michigan USA – J. Pastor et al.

  • Tested hypothesis…

    • Moose causing patterns.

  • Alternative hypotheses?

    • Slope

    • Aspect

    • Fire

    • Bedrock

    • Geology

    • Beavers

  • No differences in nitrogen availability or consumption due to slope or aspect.

    • Spatial patterns not caused by topographic relief.

    • Nor other factors.


What did pastor conclude1
What did Pastor conclude? Royale, Michigan USA – J. Pastor et al.

  • Conclusion:

    • Patterns are a result of dynamic interactions between moose foraging and plant communities.

    • Uncommonly strong impact for a large mammal.

    • This patterns has occurred in less than 50 generations.


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