Dear Giovanni,

I agree with you. It is crucial to choose the most important ESs and focus on them. What do you think which ESs are really essential?

Dear Andràs, thanks for your question. I think that, in a nutshell, the overall delivery of ESs is a complex dynamic feature of social-ecological systems and should not be treated as a summatory of different ESs. Thus, supporting services like net primary production (NPP) as provided by remote sensing techniques (through e.g., NDVI) in a dynamic and spatially explicit way, underpin most of ESs allowing a proper dynamic, systemic, and synoptic approach to study all the provisioning cascade of resulting ESs that can shift in concert with NPP. Indeed, NPP results the real engine as it is the energetic foundation of the overall system functioning. This helps gauge synergies, trade-offs, and synchronies and asynchronies of resulting ESs and relative time lags. Therefore, differently from what is currently done, ES assessments should be conducted based on the dynamical features of SELs otherwise all ES estimates would turn very inaccurate and unreliable strongly affecting subsequent accounting and payments for ESs and their practical application and acceptance in the real world.

Yes, I agree with Prof.Giovanni!, All ecosystems may not bear the same importance for the sustainable development.

Dear Giovanni,

Thanks for your explications.

I have no experiences in this field but how efficient and reliable can be remote sensing in measuring NPP?

Dear Andràs, there is a huge literature on this matter. Let's say that remote sensing (integrating leaf area index -LAI) and other ancillary data is now a well established tool (e.g., Ruimmy et al. 1994; Asner et al., 2003; Liu et al., 1997) for estimating NPP all over the world at different scales. For instance, to give an idea of the accuracy of NPP in Canada is estimated to be 60% for single pixels and 75% for 3×3 pixel areas (9 km9) (Liu et al., 1997), however this accuracy by now with new platforms and integrated techniques has been largely increased. E.g., the total annual NPP in Quebec is estimated to be 0.24 Gt C in 1993, which is about 0.3–0.4% of the global NPP (Liu et al., 1997). Riu and Qi-jiang (2001) estimated NPP in China. Cramer et al. (1999) performed global estimates of NPP The broad global pattern of NPP and the relationship of annual NPP to the major climatic variables coincided in most areas allowing predictive models to be made. About efficiency, remote sensing is the only tool allowing global and synoptic analyses to be made across different scales. Thus, for instance, the goal of the MOD17 MODIS project is to provide continuous estimates of Gross/Net Primary Production (GPP/NPP) across Earth’s entire vegetated land surface. MOD17 GPP/NPP outputs are useful for natural resource and land management, global carbon cycle analysis, ecosystem status assessment, and environmental change monitoring. MOD17 is part of the NASA Earth Observation System (EOS) program and is the first satellite-driven dataset to monitor vegetation productivity on a global scale. Uncertainty in the estimates is going to be reduced through the advancement of remote sensors (e.g., hyperspectral) and the calibration procedures through training fields at local scale. Clearly measuring NPP at the very local scale would be much more accurate. But who could do this more efficiently at the global scale and instantaneously?

I believe that the proper approach to ecosystem service assessment is a top down approach addressing their delivery assessment in a dynamic and spatially explicit way, and thus allowing the proper study of all the provisioning cascade of the resulting web of ESs that depends on NPP and can shift in concert with NPP. Indeed, NPP results the real engine of all socio-ecological systems as it is the energetic foundation of the overall system functioning. This helps their proper assessment and to gauge synergies, trade-offs, and synchronies and asynchronies of resulting ESs and relative time lags.

For clarity, give concrete examples of NPP. 'Chlorophyll' or 'plankton' that support many other more complex life components in (aquatic) systems will depend on clean, daily consumed, water that constitute all living beings or Earth.

Thanks Marcel, from WIKIPEDIA: Primary production is the synthesis of organic compounds from atmospheric or aqueous carbon dioxide. It principally occurs through the process of photosynthesis, which uses light as its source of energy, but it also occurs through chemosynthesis, which uses the oxidation or reduction of chemical compounds as its source of energy. Almost all life on earth is directly or indirectly reliant on primary production. The organisms responsible for primary production are known as primary producers or autotrophs, and form the base of the food chain. In terrestrial ecoregions, these are mainly plants, while in aquatic ecoregions algae are primarily responsible. Primary production is distinguished as either net or gross, the former accounting for losses to processes such as cellular respiration, the latter not.

Dear G.,

Very clear explanation! If I remember well, and as you know, satellite pictures can give a global surface image of NPP and it's dynamics. What aspects of NPP cannot be capture by satellite pictures?

Cheers

Dear Giovanni,

Many thanks for your thorough explication. However, I think in order to attain a higher degree of accuracy one should do periodically assessment of NPP at local scale in order to calibrate remote sensing data.

I think one of the most important gains of NPP assessment by satellites may be to calculate the trend showing the change and tendency of global and particular NPP.

Now, I have only a wish to use efficiently and successfully these NPP data. I am afraid the temporal tendency of NPP data cannot be too hopeful.

Dear M and A.., just to have a quick glance at the information that can be extracted , for instance, this kind of data have shown that recent climatic changes have enhanced plant growth in northern mid-latitudes and high latitudes, as shown by Nemani et al., (2003) in Science. Terrestrial net primary production (NPP) is sensitive to a number of controls, including aspects of climate, topography, soils, plant and microbial characteristics, disturbance, and anthropogenic impacts (Field et al., 1995). The CASA (Carnegie, Stanford, Ames Approach) model introduced by Potter et al. (1993) and expanded subsequently uses a combination of ecological principles, satellite data, and surface data to predict terrestrial NPP on a monthly time step. Training fields at the ground are normally used to calibrate satellite data. At the moment we can go down to a spatial resolution of less than 250 m and with a frequency of less than a week to get reliable data. This is the main tool gauging climate change impacts on vegetation cover in terrestrial environments all over the world, and in oceans too. New recent satellite platforms will allow a much better spatial and temporal resolution and a much better accuracy.

This is the calibration curve between observed and estimated NPP that is normally used. As you can see the CASA model predicts rather well what is measured at the local scale in many parts of the world.

I agree with Giovanni if you use remote sensing data to assess the ecosystem services. You can make that assessment by RS software like ERDAS IMAGINE, ER MAPPER etc by calculating Vegetation Indices or NPPs as already mentioned. Another way using ARC GIS as a software by locating the ecosystems and giving them importance values. By having different outputs from ARC GIS maps you can make judgement based on the classified images. However, who doesn't have an educational background on remote sensing or at least in computer science with some geographic knowledge, then probably would be a bit hard to follow the computation of the RS techniques.

My suggestion for your case is to go inside the Biodiversity concept. Specifically, Biodiversity Economics. There are four main levels of Biodiversity, such as, Genes, Species, Ecosystems and its Functioning. It depends on the author for their definitions of Biodiversity stages. There is a concept called Total Economic Value (TEV) by including Use, Non Use Values etc, by considering their importance and by computing the values of biodiversity.

There are alternative Perspectives on Biodiversity Values.

Some valuation concepts are as Producer's Surplus, Marshalian Surplus, Hicksian Surplus.

Willingness to pay (WTP) for the preservation and Willingness to Accept (WTA) for the damages are other approaches.

Contigent Valuation (CV) Techniques could be used for that purpose.

Comparative Biological Value Index (CBVI) is a type of biotic richness approach.

There are many ways adapted from the environmental attitudes towards the value orientations.

Definitely not all ecosystems services have the same importance for their overall delivery. If you are interested in computation, I do suggest to compute TEV values based on the ecosystem stages according to the Biodiversity Economics approach.

With best regards.