1. Producers
• Estimating biomass with satellite imagery: The Canadian Forest service has developed a method for estimating the biomass of black spruces using high-resolution imagery instead of aerial photos. This method uses the shadows portrayed by trees to estimate the total biomass per hectare.
• A probable problem that might arise from this method is that it only works with very tall tree specimens (over 20 meters in height) and might not take into account smaller individuals also; it might confuse different tree species and give wrong data at the end. But, it might help after further tuning, in the estimation of biomass in boreal areas where no species inventory is available.
• Estimating biomass density based on existing volume data: This method uses pre-existing data from a certain forest area to make an estimate of the aboveground biomass density of the place. After the information is recollected, it is substituted in a formula.
o Many limitations arise from this method. First of all, the totality of the trees in the area need to be taken in account in the existing data for it to be valuable and the records need to be recent. Since most of the forest inventories only take into account commercial tree species, the validity of the biomass given can be refuted. But, these estimations provide a quick way of doing these calculations especially if those doing the investigation lack enough capital to do a thorough investigation.
2. Consumers
• Estimate of worldwide fish biomass using two approaches: Two scientists from the University of British Columbia have examined global ocean plant production and its efficiency as it moves through the food chain, and at the same time tallied global fish catches since 1950 and calculated how much fish there must have been in the oceans to support fisheries. This has let to a fish biomass range from 0.8 to 2.0 billon tons.
o Each method has a series of problems. The second method uses commercial information that might or might not be factual. Also it uses the speculation that there are only enough fishes to support fisheries while there can be more.
Bibliography:
- Beaudoin, André. "Estimating biomass with satellite imagery." 29 January 2009. Natural Resources Canada. 24 August 2010.
- Brown, Sandra. "Estimating Biomass and Biomass Change of Tropical Forests: a Prime." 1997. FAO. 24 August 2010 <http://www.fao.org/docrep/w4095e/w4095e00.htm>.
- University of British Columbia. "Researcher gives first-ever estimate of worldwide fish biomass and impact on climate change." 19 January 2009. Physorg. 24 August 2010 <http://www.physorg.com/news151251277.html>.
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