One hundred years of population ecology: Successes, failures and the road ahead

Abstract

Population ecology is the most mature of the three subdisciplines of ecology partly because it has a solid mathematical foundation and partly because it can address the primary questions of distribution and abundance with experimental protocols. Yet there is much left to do to integrate our population knowledge into community and ecosystem ecology to help address the global issues of food security and the conservation of biodiversity. Many different approaches are now being developed to bring about this integration and much more research will be necessary to decide which if any will be most useful in achieving our goals of explaining the changes we see in the distribution and abundance of animals and plants. Food web ecology would appear to be the best approach at present because it uses the detailed information of the population ecology of particular species in combination with data on consumer-resource interactions to apply to the applied problems of biodiversity conservation, food security, pest management and disease prevention. If we can use our understanding of population ecology to address the practical problems of our time in a creative way, we will benefit both the human population and the Earth's biodiversity. Much remains to be done.

Successive sheep grazing reduces population density of Brandt’s voles in steppe grassland by altering food resources: a large manipulative experiment

“…However, due to the limited data of 4 years, we are not able to draw reliable conclusions about the effects of climate on vole populations in the long term. Long-term experiments are needed to reveal the temporal effects of climate on vole populations in our enclosures (Evans et al 2015;Krebs 2015).…”

Monitoring boreal avian populations: how can we estimate trends and trajectories from noisy data?

“…Extending the spatial and temporal coverage of bird population monitoring schemes in the boreal forest will take decades of effort and a long-term commitment of resources. Long-term monitoring programs can take many decades before delivering reliable population trends (Gerrodette 1987, Hatch 2003, and the lack of commitment to maintaining long-term monitoring programs until they pay off has particularly hampered conservation efforts (Krebs 2015). Given the vagaries of time and changes in organizational priorities, monitoring programs that are built through collaborative efforts among government agencies, academia, and nongovernmental organizations are therefore more likely to survive.…”

The shape of density dependence and the relationship between population growth, intraspecific competition and equilibrium population density

“…Population regulation and density dependence of population growth are at the core of fundamental but also controversial research in ecology (see e.g., Turchin, 1999;Henle et al, 2004;Sibly et al, 2005;Herrando-Prez et al, 2012;Krebs, 2015;Saether et al, 2016). Density dependence of population growth is often captured by the logistic growth model and its more complex extensions, such as the θ-logistic model .…”