In the activity in today’s Biodiversity Change session, each of our five tutorial groups were given the same dataset from the Niwot Ridge Long-term Ecological Research site and asked to summarize the biodiversity trends and potential drivers of change.
We wanted to know if you give five different collaborative groups of scientists the same data will they come up with the same findings and interpretations. And the answer was… we spotted many of the same trends, but our interpretations were sometimes quite different (see summaries below)! Sure this was a speed science activity, as we had to do our analyses in 45 min or less, but I think this might have held true even if we had been given more time.
There are many different papers coming out of the Niwot LTER site that attribute the different trends in vegetation change being observed there to a variety of factors, so even the experts have different interpretations of pretty much the same data!
Summaries of our different findings
Species richness: Sites A1+B1 richness is increasing overall
Driver: Temperature and may be suppressed by another factor before the mid-1990s
- Nutrient Availability?
Species richness: D1 richness is decreasing
Driver: Temperature because extinction rates are greater than recruitment rates – species have nowhere to go
- Migration between sites (species composition change with temperature)
- Community Assemblages
Species richness: Change is different between subsites
Driver: NO3 deposition?, No strong evidence for temperature as a driver
Species richness: Goes up, down and stays the same at different subsites
Driver: No trend in temperature over the long-term, temperature goes down from 2006 to 2014, Deposition data is variable and seems to track climate, but the change at the alpine site D1 could be due to pocket gopher herbivory and burrowing!
Species richness: No clear trends
Driver: Nitrogen deposition – NH4 is increasing, NO3 is decreasing, climate?
Species richness: Different trends for different plots – increase is greater for B1 > A1 > C1(negative) > D1 (negative)
Driver: General warming trend, increasing NH4 but decreasing NO3, glacier melt, tree cover change, and human disturbance might also be factors
By Isla and all five groups