Recent articles that caught my eye

Please see below links for articles that I enjoyed recently:

A global plan for nature conservation

Waiting can be an optimal conservation strategy, even in a crisis discipline

Shifting patterns of oil palm driven deforestation in Indonesia and implications for zero-deforestation commitments

Sixteen years of change in the global terrestrial human footprint and implications for biodiversity conservation

Impact factors in Environmental Economics, Conservation and interdisciplinary environmental journals.

It is again that time of the year and the impact factors of journals are released by Thompson Reuters. I have compiled some of the journals related to environmental economics, then journals related to conservation and environmental areas and finally multidisciplinary journals. I have also estimated the number of articles per year given the impact factor and total citations. Here is how the environmental economics journals look:

Name Total cites Publications Impact factor
J ENVIRON MANAGE 11,875 3725 3.2
ECOL ECON 11,775 4678 2.5
FOOD POLICY 2,031 871 2.3
AM J AGR ECON 4,680 3434 1.4
AGR ECON-BLACKWELL 1,500 1382 1.1
AUST J AGR RESOUR EC 502 471 1.1
NAT RESOUR MODEL 309 295 1.0
J AGR ECON 925 950 1.0
CAN J AGR ECON 391 553 0.7
J AGR RESOUR ECON 570 1316 0.4

The Journal of Environmental Economics and Management has leapt first. I think overtaking Ecological Economics. At any rate, both are leading the group closely. The reason is the environmental/ecological side they present. This gives them an edge as it is well known that purely environmental or ecological journals have higher impact factors as they represent larger scientific communities. Nonetheless I find interesting that JEEM is leading given the more analytical nature of their publications, that tend to get penalized when it comes to citations.

The rest of the ranking makes sense with the AJAE leading the agricultural economics journals departing from the impact factor of 1 they tend to have.

Regarding numbers of publications Ecol Econs (sorry couldn’t get JEEM) and AJAE are carrying the bulk of them. It is thus laudable that they are leading despite of this.

This potpourri of conservation and environmental interdisciplinary journals looks like this:

Name Total cites Publications Impact factor
FRONT ECOL ENVIRON 5,362 637 8.41
GLOBAL ENVIRON CHANG 6,195 1033 6.00
CONSERV LETT 1,176 234 5.03
CONSERV BIOL 17,277 3999 4.32
ENVIRON RES LETT 3,525 862 4.09
BIOL CONSERV 19,784 4902 4.04
AGR ECOSYST ENVIRON 12,307 3842 3.20
AMBIO 4,738 1594 2.97
CURR OPIN ENV SUST 1,020 370 2.76
ANIM CONSERV 2,221 880 2.52
ENVIRON CONSERV 2,539 1094 2.32
ECOHEALTH 1,088 480 2.27
BIODIVERS CONSERV 7,589 3675 2.07
ORYX 1,814 948 1.91


Frontiers is expected to lead, nice papers and the extra citation edge that give opinion and review papers. Interesting how high appears Global Env Change, I think this reflects the increasing concern in the hot topics that are covered by the journal. Conservation letters appears to lead the conservation pack.

Just for the sake of comparison the multidisciplinary category appears like this:

Name Total cites Publications Impact factor
NATURE 590,324 13939 42.35
SCIENCE 537,035 17061 31.48
P NATL ACAD SCI USA 565,934 57695 9.81
J R SOC INTERFACE 6,525 1692 3.86
PLOS ONE 226,708 64151 3.53

It seems that Nature has left behind Science. PNAS continues steady and this is great given the super large volume of publications. I am a bit sad that Interface has dropped a bit in its impact factor. They do a great job at publishing interdisciplinary mathematical and life sciences papers. Perhaps they are penalized by their technicality. PLOS One resists with a high impact factor and again this is amazing given the 64k articles published.

At the end of the day impact factors are just a game and it is interesting to look at them. Nonetheless a good agricultural economics journal containing the best papers in its field will continue to have an impact factor of around one. This just shows how little relevance impact factors would have to this community.

Anyway, let me know your thoughts, I was just throwing some hypotheses to the trends observed.

My favorite paper of the week… are actually two: “Interactive effects among ecosystem services and management practices on crop production: Pollination in coffee agroforestry systems” and “Ten principles for a landscape approach to reconciling agriculture, conservation, and other competing land uses”.

Both papers come from a very interesting special feature in PNAS: “Agricultural
Innovation To Protect The Environment”. All the papers in the feature are worth
reading and it was hard to choose only one paper so I decided to choose two.


The first one is:

Boreux, V., Kushalappa, C.G., Vaast, P., Ghazoul, J. (2013) Interactive effects among ecosystem services and management practices on crop production: Pollination in coffee agroforestry systems. Proceedings of the National Academy of Sciences. link.


The paper by Boreux et al. is very interesting as it highlights the complexities between bees and the pollination services provided to coffee in India. Aspects related to management of the crop are commonly ignored when trying to enhance pollination services. Instead, most of the focus revolves around enhancing natural habitats surrounding the crop. Surprisingly, management factors such as irrigation, that lead to a synchronization of flowering might increase bee visits and hence pollination services. Counter-intuitively, more habitat might decrease pollination services.

This paper is a great example of how complex the mechanisms determining the flow of ecosystem services provided by agro ecosystems are. I think it is a good call for integrating management in the potential solutions to maximize ecosystem services provision.

The second paper:

Sayer, J., Sunderland, T., Ghazoul, J., Pfund, J.-L., Sheil, D., Meijaard, E., Venter, M., Boedhihartono, A.K., Day, M., Garcia, C., van Oosten, C., Buck, L.E. (2013) Ten principles for a landscape approach to reconciling agriculture, conservation, and other competing land uses. Proceedings of the National Academy of Sciences 110, 8349-8356. link.

gives a comprehensive perspective on the necessary principles for a landscape approach to natural resources management — and approach that reconciles conservation and agricultural production. The paper represents a synthesis of current research and theories combined with a broad survey of practitioners. Ten principles are suggested to foster such reconciliation. It is remarkable how, for a landscape approach to work, very different and somehow disconnected disciplines are necessary. The principles range from and understanding of the system with multiples interconnected scales, its resilience and nonlinearities to multifunctionality concepts from the EU CAP or institutional commons management concepts/ property rights in line with E. Ostrom’s line of work.

I see this paper as both a roadmap for the approaches needed for the reconciliation of biodiversity conservation and food production and as a thought-provoking piece that invokes a management of resources from a multiple adaptive fashion that includes all the actors involved and the complexity of the system.

Anyway, it is hard for me to make justice to the special feature, I recommend going there and reading them directly.

My favourite paper of the week is: “A complex system perspective on the emergence and spread of infectious diseases: Integrating economic and ecological aspects”

Ceddia, M.G., Bardsley, N.O., Goodwin, R., Holloway, G.J., Nocella, G., Stasi, A. (2013) A complex system perspective on the emergence and spread of infectious diseases: Integrating economic and ecological aspects. Ecological Economics 90, 124-131.  Link.

I particularly enjoyed reading the paper by Ceddia et al (2013) this week in Ecological Economics.

More often than not we tend to forget that the emergence of infectious diseases responds to macroeconomic drivers such as trade and economic growth – that generate destruction of habitats leading to new disease emergence – and that the spread and how impactful they are respond to microeconomic drivers such as the decisions of individuals.

Ceddia et al. explain nicely the complex nature of the system and the multiple causality relationships at different levels. I agree that there is much to be done in the integration of economic and psychological concepts into epidemic models of spread and emergence.

A very interesting paper to read to remind us that disease emergence is not only an epidemiological/genetic process.

(We are about to publish a somewhat related paper in Emerging Themes for Epidemiology for those interested in human behaviour modelling in pandemics link).


My favourity paper of the week is: “Agricultural intensification in Brazil and its effects on land-use patterns: an analysis of the 1975–2006 period”

Barretto, A.G., Berndes, G., Sparovek, G., Wirsenius, S. (2013) Agricultural intensification in Brazil and its effects on land use patterns: An analysis of the 1975‐2006 period. Global Change Biology. Abstract.

I guess my choice of this paper is somewhat affected by the fact that our PNAS paper on agricultural intensification in DRC was published also this week and I think that Barretto et al study is a very good piece of empirical evidence to our modelling approach.

The important question: “does agricultural intensification spare land for conservation?”. Remains controversial. Empirical spatially explicit studies such as that published this week in Global Change Biology by Barretto et al. shed light in this area.

One of their main results is that there are two types of dynamics depending whether it is an “agriculturally consolidated” area or agriculture at the forest frontier. Agricultural intensification in the consolidated area will lead to land sparing BUT in the forest frontier it will lead to crop expansion and presumably deforestation.

The reason behind the dynamics in consolidated areas is that land is scarce and producers need to intensify without the opportunity of expansion. This is not the case in the forest frontier.

Finally, they show that forest land conversion can be countered with adequate policies that protect forests as shown in the Atlantic Forest biome.

Overall a very good paper highly recommended.

My favourite paper of the week is… “Socioeconomic and political trade-offs in biodiversity conservation: a case study of the Cerrado Biodiversity Hotspot, Brazil”

Frederico V. Faleiro and Rafael D. Loyola (2013) Socioeconomic and political trade-offs in biodiversity conservation: a case study of the Cerrado Biodiversity Hotspot, Brazil. Diversity and distributions. 1-11. article.


I really enjoyed reading this article this week. Very often we see spatial conservation papers that base their recommendations only on ecological reasons. This is great but may not agree with political will—whose inclusion in this paper is rather innovative—or the opportunity costs of having other land uses in certain areas. This article is a great example of how spatial conservation priorities change when other criteria are incorporated and, interestingly, how it is possible to find areas where conservation can match political will and avoid conflict with other land uses.

The methods are well-balanced between sophisticated ecological niche models of 100 over species and trade-off analyses in a multi-criteria framework using the Zonation software.

The result is that the resulting protected area network is very different to the one that would be obtained using biodiversity considerations alone.

Overall a paper worth reading and pondering about.

My favourite paper of the week is… “The global distribution and burden of dengue”

Samir Bhatt, Peter W. Gething, Oliver J. Brady, Jane P. Messina, Andrew W. Farlow, Catherine L. Moyes, John M. Drake, John S. Brownstein, Anne G. Hoen, Osman Sankoh, Monica F. Myers, Dylan B. George, Thomas Jaenisch, G. R. William Wint, Cameron P. Simmons, Thomas W. Scott, Jeremy J. Farrar & Simon I. Hay (2013) The global distribution and burden of dengue. Nature 496: 504-507. article.

I chose this paper mainly for two reasons: (1) having global maps of dengue incidence represents a tremendous help for all those working on dengue research and policy makers, it also helps to open our eyes to how serious the problem is (~3 times more infections than those estimated by WHO!); (2) the beauty of the methods that are required to produce global estimates of such an elusive disease when it comes to reporting.

I enjoyed the integration of dengue reporting in the boosted regression tree with spatial covariates like vegetation, urban areas and accessibility. But the most interesting bit is how the spatial distribution is combined with multiple cohort datasets to, using MCMC, create a global map of dengue burden.

This is a great advancement for dengue disease burden estimation that paves the way for an update of economic burden of dengue worldwide. This may suppose the definite push for new technologies for dengue control (e.g. RIDL, Wolbachia) which are waiting for the last policy nod.

As a negative note, if any, is that I could not find the estimated global maps available as shapefiles or raster files in the supplementary information of the publication. I hope these are made available upon request to the authors? Having the files available in the Nature website would be a great help to many of us, I really hope journals implement a stronger policy for straight data sharing.

Anyway, this is a terrific paper and my favourite one for the week. I highly recommend reading it (even the supplementary information!).


Agricultural intensification escalates future conservation costs

Phelps J, Carrasco LR, Webb EL, Koh LP, Pascual U (2013) Agricultural intensification escalates future conservation costs. Proceedings
of the National Academy of Sciences. doi:10.1073/pnas.1220070110



The supposition that agricultural intensification results in land sparing for conservation has become central to policy formulations across the tropics. However, underlying assumptions remain uncertain and have been little explored in the context of conservation incentive schemes such as policies for Reducing Emissions from Deforestation and forest Degradation, conservation, sustainable management, and enhancement of carbon stocks (REDD+). Incipient REDD+ forest carbon policies in a number of countries propose agricultural intensification measures to replace extensive “slash-and-burn” farming systems. These may result in conservation in some contexts, but will also increase future agricultural land rents as productivity increases, creating new incentives for agricultural expansion and deforestation. While robust governance can help to ensure land sparing, we propose that conservation incentives will also have to increase over time, tracking future agricultural land rents, which might lead to runaway conservation                              costs. We present a conceptual framework that depicts these relationships, supported by an illustrative model of the intensification of key crops in the Democratic Republic of Congo, a leading REDD+ country. A von Thünen land rent model is combined with geographic information systems mapping to demonstrate how agricultural intensification could influence future conservation costs. Once postintensification agricultural land rents are considered, the cost of reducing forest sector emissions could significantly exceed current and projected carbon credit prices. Our analysis highlights the importance of considering escalating conservation costs from agricultural intensification when designing conservation initiatives.


Swidden, slash and burn, land use change, payment for ecosystem services, biodiversity


Who should pay for global health, and how much?

Our article was published in PLOS Medicine (Carrasco, Coker, Cook). We devise a new way to identify the expected contributions to global health from each country in the world. We propose a global health cost-effectiveness threshold coupled to a DALY (disability-adjusted life year) credit market.

The idea is simple, high or middle-income countries or health projects in these countries that allocate resources to not very cost-effective projects need to buy DALY credits from highly cost-effective projects in low income countries to carry on with their projects.

For instance, if we want to adopt a very costly vaccine in Singapore, we would need to contribute a little bit to very cost-effective children immunization vaccines in Sub-Saharan Africa. Given how cheap is to avert DALYs in low-income countries compared to high income countries, we would only need to contribute an equivalent to ~0.1–0.5% of the costs of the project. We believe that this system could help to prevent the tragedy of the commons in global health by promoting a massive scale-up of global health donations to low-income countries.

The paper pdf and supporting information is open can be found here.


Maternal health in Afghanistan.

Source: Merlin, Wikipedia.


Carrasco LR, Coker R, Cook AR (2013) Who Should Pay for
Global Health, and How Much? Plos Medicine 10: e1001392. doi:10.1371/journal.pmed.1001392




  • Mechanisms to establish the expected financial contribution from each country to achieve the health Millennium Development Goals (MDGs) could encourage scaling-up of contributions.
  • Mirroring global carbon permit markets to mitigate climate change, we propose a cap-and-trade system consisting of a global cost-effectiveness criterion and a disability-adjusted life year (DALY) global credit market.
  • Under this system, high-income and middle-income countries should contribute, respectively, 74% and 26% of the additional US$36–US$45 billion annually needed to attain the health MDGs. The change relative to current contributions would vary, with some countries needing to scale-up substantially their expected annual contributions under the proposed market (e.g., US, US$7–US$10 billion; China, US$2–US$3 billion; Japan, US$2 billion; Germany, US$1.5–US$2 billion), while a few already meet or exceed their required contributions (i.e., Norway, the United Arab Emirates, Luxembourg, and the UK).
  • A DALY tradable credit market offers the potential to increase the efficiency of global health investments while promoting international obligations to the pursuit of an agreed global common good.


carbon credits, DALYs, global health, health aid, vaccination.