Question

Talk About Terrestrial Ecosystems
(Next Week Anatomy)

Answer 1

i guess nowadays terretrail ecosytem is getting depleted isntd? a compare to ocean ecosystem

Answer 2

Phenology is the subdiscipline of ecology which deals with temporal changes in biologic events. Much of phenology focuses on relating temporal changes in ecosystems with changes in climate - but at least as far as terrestrial ecosystems go, one big challenge is relating global climate data to problems in local terrestrial ecosystems. The two data sets are just not on a scale suitable for comparison.

In the last couple years, phenologists have started using "remote sensing" and "near remote sensing" - that is, images from satellites and planes, respectively - to gather data on "greenness" on a global scale. This is a wonderful technique: the algorithms for processing the data are well developed and the results are robust, accurate and reliable - but some practitioners in this field with whom I have spoken have expressed their reservations about having to rely on national security satellites to gather data and who then use the same algorithms for purposes they might not believe in. This is serious stuff: about eight weeks ago, I was kicked off a phenology team when they got into using remotely sensed data because my request for security clearance was not approved. Not sure how I feel about that. :/

Phenology is computationally interesting because it does not just concern correlating temporal changes in ecosystems with climate changes - it also involves using long term ecologic data to construct, parametrize and quality control check long term climate data. One dataset, on dates of cherry tree blossoming, in Japan goes back to the year 880 AD and has been used to reliably reconstruct regional climate models going back that far.