Species richness is 10.6% higher inside protected areas compared to areas outside. This result has been recently published by researches, under the leadership of Claudia Gray from University of Sussex (UK). Check out, what else has been found!
Are protected areas successful?
One of the essential strategies for the conservation of habitat and species is to create protected areas. Parties to the Convention on Biological Diversity committed to increase the protected terrestrial area from 15.4% to at least 17% in by 2020. A recent assessment
of progress suggests that the coverage target will be completed.
Due to the human pressures in Latin American, African and Asian protected areas, other studies have found declines in animal and plant abundance. Therefore, there is a doubt over the success of protected areas in terms of their quality, not quantity.
Researchers, under the leadership of Dr Claudia Gray from University of Sussex (UK), assessed the effect of protection on species and assemblages using PREDICTS (Projecting Responses of Ecological Diversity In Changing Terrestrial Systems) database. This database contains data on species’ presence or abundance at sampled sites. Next, scientists calculated 4 biodiversity measures based on sampled abundances and occurrences at each site (henceforth ‘within-sample’ biodiversity measures) inside and outside of protected areas.
In other words, team of Dr Gray analyzed data from 156 studies, including 13,669 species of vertebrates, invertebrates and plants, that had sites both inside (n=1,939 sites) and outside (n=4,592 sites) 359 terrestrial protected areas around the globe.
Researchers found that globally, species richness is 10.6% higher and abundance 14.5% higher in samples taken inside protected areas compared with samples taken outside.
In addition, it was concluded that the positive effects of protection were mostly attributable to differences in land use between protected and unprotected sites. Neverheless, scientists showed that even within some human-dominated land uses, species richness and abundance are higher in protected sites.
Jörn Scharlemann, an ecologist at the University of Sussex in England and one of the authors of the study said:
“The most exciting and important finding is that protected areas actually do work.”
My first small own research
When I was reading this interesitng study, I recalled my small experiment that I conducted, together with my friends, during Euroforester Master Program. The Euroforester Master Program was based in Sweden, but in the course called “Broadleaves -Ecology, Conservation and Silviculture” we had an opportunity to visit Bialowieza National Park, located on the eastern boarder of Poland. In our small research, were checking tree species diversity, by using Simpson index and Jaccard’s similarity index.
First we started in managed part of Bialowieza National Park. We were selecting sample plots and we were counting tree species. Sample plots had 10 meters radius and one sample plot covered 314 squared meters. In managed and natural forest we had 10 sample plots in total (5 sample plots in each part). After counting trees we did phytosociology relevés (or plots) to notice the changes in herb layer in these two stands. Herb inventory was mainly our additional goal. We divided forest structure on three layers:
- Regeneration (<0,5 m),
- Second layer (> 0,5m and supressed trees),
- First layer (dominant trees).
I have to mention that the plots selection was totally random and was not biased by our subjective choice. We were walking 50 steps from middle of every sample plot in completely randomly selected direction. The location of the sample plots, in the protected area, and not protected area, presented is below.
Hypothesis of small research
Our hypothesis was mainly formulated on our ecology knowledge that biodiversity in managed stand should be lower than in natural one. The most important points which we wanted to prove were:
1)Simpson’s diversity index should be higher in natural than in managed forest
2)Jaccard’s similarity index between natural and managed forest should be relatively low
3) The visible differences in herb layer should occur
In the table below, we can see that Jaccard’s index was quite similar in every layer what means that these two stands had a lot of in common. Species composition did not differ so much and it was mainly caused by closeness of stands and species migration. In the table there is also very easy trend to observe that Simpson’s index in every layer is higher in natural stand than in managed forest. It means that biodiversity was higher in natural stand. In the field it was hard to observe because Simpson’s index takes into account number of species and their abundance.
Although this was very small research project (we had only few hours to conduct it in the field) during my Master studies, I and my team were very proud of it. We won even a prize among all studens, for the best conducted research project, what was very nice for us.
I found the research very inspiring, and I think that in all forestry schools around the globe, practical experiments that teach students how research should look like, should be introduced. Thanks to such research projects, students are able to learn a lot of about research, its preparation, challenges, and practical solutions how to face different problems.
And finally, practical research experiments are a bit like cooking, in terms of creativity improvement 🙂
Source: Gray, C. L. et al. Local biodiversity is higher inside than outside terrestrial protected areas worldwide. Nat. Commun. 7:12306 doi: 10.1038/ncomms12306 (2016).
Main photo: Forest in Bieszczady National Park. Credit: Rafal Chudy