Ecosystem Functional Type

In 1992, Soriano and Paruelo{{cite journal|author=Soriano|author2=Paruelo|name-list-style=amp|title=Biozones: vegetation units defined by functional characters identifiable with the aid of satellite sensor images |journal=Global Ecology and Biogeography Letters|date=1992|volume=2|issue=3|pages=82–89|doi=10.2307/2997510|jstor=2997510}} proposed the concept of Biozones to identify vegetation units that share ecosystem functional characteristics using time-series of satellite images of spectral vegetation indices. Biozones were later renamed to EFTs by Paruelo et al. (2001), using an equivalent definition and methodology.{{cite book|last1=Shugart|first1=H.H.|chapter=Plant and ecosystem functional types |title=Plant functional types: their relevance to ecosystem properties and global change |editor=T.M. Smith |editor2=H.H. Shugart |editor3=F.I. Woodward)|publisher=Cambridge University Press|date=1997|pages=20–45}} was one of the first authors that used the term EFT as "aggregated components of ecosystems whose interactions with one another and with the environment produce differences in patterns of ecosystem structure and dynamics". Walker (1997){{cite book|last1=Walker|first1=B.H.|chapter=Functional types in non-equilibrium ecosystems |title=Plant functional types: their relevance to ecosystem properties and global change |editor=T.M. Smith |editor2=H.H. Shugart |editor3=F.I. Woodward|publisher=Cambridge University Press|date=1997|pages=91–103}} proposed the use of a similar term, vegetation functional types, for groups of PFTs in sets that constitute the different states of vegetation succession in non-equilibrium ecosystems. The same term was applied by Scholes et al.{{cite book|last1=Scholes|chapter=Plant functional types in African savannas and grasslands |title=Plant functional types: their relevance to ecosystem properties and global change |editor=T.M. Smith, H.H. Shugart and F.I. Woodward|publisher=Cambridge University Press|date=1997|pages=255–268|display-authors=etal}} in a wider sense for those areas having similar ecological attributes, such as PFTs composition, structure, phenology, biomass or productivity. Several studies have applied hierarchy and patch dynamic theories{{cite book|last1=Aber|title=Group report: hydrological and biogeochemical processes in complex landscapes — what is the role of temporal and spatial ecosystem dynamics?Integrating hydrology, ecosystem dynamics and biogeochemistry in complex landscapes|date=1999|editor=J.D. Tenhunen|editor2=P. Kabat|location=John Wiley & Sons, Berlin|pages=335–356|display-authors=etal}}{{cite book|author=Reynolds|author2=Wu|name-list-style=amp|title=Do landscape structural and functional units exist? Integrating hydrology, ecosystem dynamics and biogeochemistry in complex landscapes|date=1999|editor=J.D. Tenhunen|editor2=P. Kabat|publisher=John Wiley & Sons |place=Berlin |pages=273–296}}{{cite book|author=Wu|author2=David|name-list-style=amp|title=Linking land-use change with ecosystem processes: a hierarchical patch dynamic model. Integrated land use and environmental models|date=2003|editor=S. Guhathakurta|location=Springer, Berlin|pages=99–119}} for the definition of ecosystem and landscape functional types at different spatial scales, by scaling-up emergent structural and functional properties from patches to regions. Valentini et al.{{cite book|last1=Valentini|title=Ecological controls on land–surface atmospheric interactions. Integrating hydrology, ecosystem dynamics and biogeochemistry in complex landscapes|date=1999|editor=J.D. Tenhunen|editor2=P. Kabat|publisher=John Wiley & Sons |place=Berlin |pages=105–116|display-authors=etal}} defined land functional units by focusing on patches of the land surface that are able to exchange mass and energy with the atmosphere and show a coordinated and specific response to environmental factors.

Paruelo et al. (2001) and Alcaraz-Segura et al. (2006, 2013){{cite journal|last1=Alcaraz-Segura|title=Environmental and Human Controls of Ecosystem Functional Diversity in Temperate South America|journal=Remote Sensing|date=2013|volume=5|issue=1|pages=127–154|display-authors=etal|doi=10.3390/rs5010127|bibcode=2013RemS....5..127A|doi-access=free|hdl=10835/7381|hdl-access=free}} refined the EFT concept and proposed a remote-sensing based methodology to derive them. Since then, several authors have implemented the idea under the same or similar approaches using NOAA-AVHRR, MODIS and Landsat archives.{{cite journal|author=Azzali|author2=Meneti|name-list-style=amp|title=Mapping isogrowth zones on continental scale using temporal Fourier analysis of AVHRR-NDVI data|journal=International Journal of Applied Earth Observation and Geoinformation|date=1999|volume=1|issue=1|pages=9–20|doi=10.1016/s0303-2434(99)85023-5|bibcode=1999IJAEO...1....9A}}{{cite journal|last1=Karlsen|title=Satellite‐based mapping of the growing season and bioclimatic zones in Fennoscandia|journal=Global Ecology and Biogeography|date=2006|volume=15|issue=4|pages=416–430|display-authors=etal|doi=10.1111/j.1466-822x.2006.00234.x}}{{cite journal|last1=Duro|title=Development of a large area biodiversity monitoring system driven by remote sensing.|journal=Progress in Physical Geography|date=2007|volume=31|issue=3|pages=235–260|display-authors=etal|doi=10.1177/0309133307079054|s2cid=129809993 }}{{cite journal|last1=Fernández|title=Ecosystem functioning of protected and altered Mediterranean environments: A remote sensing classification in Doñana, Spain.|journal=Remote Sensing of Environment|date=2010|volume=114 |issue=1|pages=211–220|display-authors=etal|doi=10.1016/j.rse.2009.09.001|bibcode=2010RSEnv.114..211F|hdl=10261/50225|hdl-access=free}}{{cite journal|last1=Geerken|title=An algorithm to classify and monitor seasonal variations in vegetation phonologies and their inter-annual change|journal=ISPRS Journal of Photogrammetry and Remote Sensing|date=2009|volume=64|issue=4|pages=422–431|doi=10.1016/j.isprsjprs.2009.03.001|bibcode=2009JPRS...64..422G}}{{cite journal|last1=Ivits|title=Global Biogeographical Pattern of Ecosystem Functional Types Derived From Earth Observation Data.|journal=Remote Sensing|date=2013|volume=5 |issue=7|pages=3305–3330|display-authors=etal|doi=10.3390/rs5073305|bibcode=2013RemS....5.3305I|doi-access=free}}{{cite journal|last1=Pérez-Hoyos|title=Identification of Ecosystem Functional Types from Coarse Resolution Imagery Using a Self-Organizing Map Approach: A Case Study for Spain|journal=Remote Sensing|date=2015|volume=6 |issue=11|pages=11391–11419|display-authors=etal|doi=10.3390/rs61111391|doi-access=free}}{{cite journal|author=Wang|author2=Huang|name-list-style=amp|title=Identification and analysis of ecosystem functional types in the west of Songnen Plain|journal=Journal of Applied Remote Sensing|date=2015|volume=9 |issue=1|pages=096096|doi=10.1117/1.jrs.9.096096|s2cid=123090366 }} In brief, all these approaches use the seasonal dynamics of spectral indices related to key functional aspects of ecosystems such as primary production, water exchange, heat exchange and radiative balance.

The functional classification of EFTs developed by Paruelo et al. (2001) and Alcaraz-Segura et al. (2006, 2013) uses time series of spectral vegetation indexes to capture the carbon gains dynamics, the most integrative indicator of ecosystem functioning. To build EFTs, these authors derive three descriptors or metrics from the seasonal dynamics (annual curve) of spectral vegetation indexes (VI) that capture most of the variance in the time series (Fig.2): File:AnualDynamics EVI 3vars.png

• Annual mean of VI (VI_Mean): estimator of annual primary production, one of the most essential and integrative descriptors of ecosystem functioning.
• Intra-annual coefficient of variation of VI (VI_sCV): descriptor of seasonality or differences in carbon gains between the growing and non growing seasons.
• Date of maximum VI value (VI_DMAX): phenological indicator of when in the year does the growing season take place.{{cite journal|last1=Pettorelli|title=Using the satellite-derived NDVI to assess ecological responses to environmental change.|journal=Trends in Ecology and Evolution|date=2005|volume=20|issue=9|pages=503–510|display-authors=etal|doi=10.1016/j.tree.2005.05.011|pmid=16701427}}{{cite journal|last1=Alcaraz-Segura|title=Baseline characterization of major Iberian vegetation types based on the NDVI dynamics.|journal=Plant Ecology|date=2009|volume=202|pages=13–29|display-authors=etal|doi=10.1007/s11258-008-9555-2|s2cid=38077489 }}

The range of values of each VI metric is divided into four intervals, giving the potential number of 4x4x4=64 EFTs. Each EFT is assigned a code of two letters and a number (three characters). The first letter of the code (capital) corresponds to the VI_Mean level, ranging from A to D for low to high (increasing) VI_Mean or productivity. The second letter (small) shows the seasonal CV, ranging from a to d for high (decreasing) to low VI_sCV or seasonality. The numbers refer to DMAX or phenology and indicate the season of maximum VI (1–4: spring, summer, autumn and winter).

• To characterize the spatial and temporal heterogeneity of ecosystem functioning at the local and regional scales.
• To describe the biogeographical patterns of functional diversity at the ecosystem level.
• To assess the functional diversity at the ecosystem level by determining the EFTs richness and equity in the landscape.{{cite book|last1=Cazorla|first1=B.|title=Ecología y conservación de la diversidad funcional de ecosistemas en la transición mediterráneo-desierto-tropical de la Península de Baja California|date=2015|location=Universidad de Granada|page=http://hdl.handle.net/10481/38511|display-authors=etal}}
• To evaluate the environmental and human controls of ecosystem functional diversity.
• To identify priorities for Biodiversity Conservation.{{cite journal|last1=Cabello|title=Funcionamiento ecosistémico y evaluación de prioridades geográficas en conservación|journal=Ecosistemas|date=2008|volume=17 |issue=3|pages=53–63|display-authors=etal}}
• To assess the representativeness of protected area networks to capture the functional diversity at the ecosystem level.{{cite journal|last1=Cabello|title=Ecosystem services assessment of national park networks for functional diversity and carbon conservation strategies using remote sensing|editor=Di Bella|editor2=Alcaraz-Segura|journal=Earth Observation of Ecosystem Services|date=2013|pages=179–200|display-authors=etal}}
• To quantify and monitor the level of provision of intermediate support ecosystem services.{{cite book|last1=Paruelo|title=El seguimiento del nivel de provisión de los servicios ecosistémicos. Valoración de Servicios Ecosistémicos. Conceptos, herramientas y aplicaciones para el ordenamiento territorial.|date=2011|publisher=Ediciones INTA|location=Buenos Aires, Argentina|pages=141–162|display-authors=etal}}{{cite journal|last1=Volante|title=Ecosystem functional changes associated with land clearing in NW Argentina.|journal=Agriculture, Ecosystems & Environment|date=2012|volume=154|pages=12–22|display-authors=etal|doi=10.1016/j.agee.2011.08.012|hdl=11336/81528|hdl-access=free}}
• To assess the effects of land-use changes on ecosystem functioning.{{cite book|author=Oki|title=Land Cover and Land Use Changes and Their Impacts on Hydroclimate, Ecosystems and Society. In: Asrar GR, Hurrell JW, Climate Science for Serving Society|date=2013|publisher=Springer Science+Business Media|location=Dordrecht|pages=185–203|display-authors=etal}}{{cite journal|author=Lee|title=The Impact of Ecosystem Functional Type Changes on the La Plata Basin Climate|journal=Advances in Atmospheric Sciences|date=2013|volume=30 |issue=5|pages=1387–1405|display-authors=etal|doi=10.1007/s00376-012-2149-x|bibcode=2013AdAtS..30.1387L|s2cid=123806117 }}
• To improve weather forecast models by introducing the effects of inter-annual changes in ecosystem biophysical properties into land-surface and general circulation atmospheric models.{{cite journal|last1=Lee|title=Effect of implementing ecosystem functional type data in a mesoscale climate model|journal=Advances in Atmospheric Sciences|date=2013|volume=30 |issue=5|pages=1373–1386|display-authors=etal|doi=10.1007/s00376-012-2143-3|bibcode=2013AdAtS..30.1373L|s2cid=120485640 }}{{cite journal|last1=Müller|title=Regional model simulations of the 2008 drought in southern South America using a consistent set of land surface properties|journal=Journal of Climate|date=2014|volume=27 |issue=17|pages=6754–6778|display-authors=etal|doi=10.1175/jcli-d-13-00463.1|bibcode=2014JCli...27.6754M|hdl=11336/92811|s2cid=129315993 |hdl-access=free}}

• Functional classifications provide a useful framework for understanding the large-scale ecological changes.
• Environmental changes are particularly noticeable at the ecosystem level.{{cite journal|last1=Vitousek|s2cid=66138238|title=Beyond global warming: ecology and global change.|journal=Ecology|date=1994|volume=75 |issue=7|pages=1861–1876|doi=10.2307/1941591|jstor=1941591}}
• Ecosystem functional attributes, such as the exchange of energy and matter of an ecosystem, have shorter time response to environmental changes than structural or compositional attributes, such as species composition or vegetation physiognomy.{{cite journal|author=Milchunas|author2=Lauenroth|name-list-style=amp|title=Inertia in plant community structure: State changes after cessation of nutrient enrichment stress|journal=Ecology Applied|date=1995|volume=5|pages=1195–2005}}
• Ecosystem functioning can be more easily monitored than structural attributes by using remote sensing at different spatial scales, over large extents, and utilizing a common protocol in space and time.
• Functional attributes allow the qualitative and quantitative evaluation of ecosystem services.{{cite journal|last1=Costanza|title=The value of New Jersey's ecosystem services and natural capital|date=2006|display-authors=etal}}

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Category:Ecology

Category:Ecosystems