Monthly Archives: June 2016

Does Forestry Make Money – Part 2

About 2 years ago I wrote a blog asking the simple question of whether the forest industry in British Columbia makes money or whether it is operational only because of subsidies and the failure to recognize that biodiversity and ecosystem services could be valuable. A recent report from the research group in the Fenner School of the Australian National University has put the spotlight on the mountain ash forests of the Central Highlands of Victoria to answer this question for one region of southern Australia. I summarize their findings from their report (Keith et al. 2016) that you can access from the web address given below.

The ANU research group chose the Central Highlands study area because it included areas with controversial land use activities. The study area of 7370 sq km contains a range of landscapes including human settlements, agricultural land, forests, and waterways, and is used for a variety of activities including timber production, agriculture, water supply and recreation. It is also home to a range of species, including the endemic and critically endangered Leadbeater’s Possum. These activities and their use of ecosystems can be either complementary or conflicting. Managing the various activities within the region is therefore complex and requires evaluation of the trade-offs between different land uses and users, an issue common to forestry areas around the world.

The accounting structure (System of Environmental-Economic Accounting) which is used by the United Nations is described in more detail in the report. Both economic and ecological data are needed to produce ecosystem accounts and these sources of data must be integrated to gain an overall picture of the system. This integration of ecosystem services with traditional cash crops is the key to evaluating an area for all of its values to humans. In this particular area the provisioning of water to cities is a key economic benefit provided by this particular area. The following table from their report puts all these accounts together for the Central Highlands of Victoria:

Table 5. Economic information for industries within the study region in 2013-14
Agriculture Native Forestry Water supply Tourism
Area of land used (ha) 96,041a 324,380b 115,149c 737,072d
Sale of products ($m) 474 49 911 485
Industry valued added ($m) 257 9 233 260
Ecosystem services ($m) 121 15 101 42
Sale of products ($ ha-1) 4918 151 7911 659
Industry value added ($ ha-1) 2667 29 2023 353
Ecosystem services ($ ha-1) 1255 46 877 57

a area of agricultural land use
b area of native forest timber production
c area of water catchments
d total area of study region

The key point in this table is that the value-added per ha of forestry is $29 per ha per year. The equivalent value for water is $2033 per ha per year – or 70 times more, and the value added for agriculture is about 90 time more than that of forestry. The value-added value for tourism is $350 per ha per year, about 12 times more than that of forestry. None of this takes into account any potential government subsidies to these industries, and none involves directly the endangered species in the landscape. Three main points emerge from this analysis:

  1. In 2013-14, the most valuable industries in the region were tourism ($260 million), agriculture ($257 million), water supply ($233 million) and forestry ($9 million). This is as measured by the estimated industry value added (the contribution to GDP).
  2. In 2013-14, the most valuable ecosystem services in the region were food provisioning ($121 million), water provisioning ($101 million), cultural and recreation services ($42 million).
  3. At a carbon price of $12.25 per ton (the average price paid by the Commonwealth in 2015), the potential ecosystem service of carbon sequestration ($20 million) was more valuable than the service of timber provisioning ($15 million).

The main implications from the report for this large geographical area are three:

  • The benefits from tourism, agriculture, and water supply are large, while those from forestry are comparatively small. There is a potential for income from carbon sequestration.
  • The activities of tourism, agricultural and water supply industries are complimentary and may be combined with biodiversity conservation and carbon sequestration.
  • Timber harvesting in native forests needs to better account for the occurrence of fires and can be incompatible with species requirements for conservation.

The recent global interest in both climate change and species conservation has pushed this type of analysis to uncover the complementary and conflicting activities of all major global industries. Replacing the conventional GDP of a country or a region with a measure that takes into account the changes in the natural capital including gains and losses is a necessary step for sustainability (Dasgupta 2015, Guerry et al. 2015). This report from Australia shows how this goal of replacing the current GDP calculation with a green GDP can be done in specific areas. Much of biodiversity conservation hinges on these developments.

Dasgupta, P. 2015. Disregarded capitals: what national accounting ignores. Accounting and Business Research 45(4): 447-464. doi: 10.1080/00014788.2015.1033851.

Guerry, A.D., et al. 2015. Natural capital and ecosystem services informing decisions: From promise to practice. Proceedings of the National Academy of Sciences 112(24): 7348-7355. doi: 10.1073/pnas.1503751112.

Keith, H., Vardon, M., Stein, J., Stein, J., and Lindenmayer, D. 2016. Exzperimental Ecosystem Accounts for the Central Highlands of Victoria. Australian National University, Fenner School of Environment and Society. 22 pp. Available from:

On Disease Ecology

One of the sleepers in population dynamics has always been the role of disease in population limitation and population fluctuations. Part of the reason for this is that disease studies need cooperation between skilled ecologists and skilled microbiologists. Another problem is the possibility of infinite regress in looking for disease agents as a cause of population change in natural populations – e.g. if it is not virus X, there are hundreds of other viruses that might be the culprit. In both North America and Europe one focus of concern has been on the hantavirus group (Luis et al. 2010; Mills et al. 2010, Davis et al. 2005, Mills et al. 1999). Hantaviruses come in many different forms and are typically carried by rodent species. Some varieties produce hemorrhagic fever with renal syndrome in Europe, Asia and Africa, but in the Americas the main disease of concern is HPS (hantavirus pulmonary syndrome). It is no surprise that often emerging diseases are studied only because some humans die from them. As of 2016, 690 cases of hantavirus pulmonary syndrome have been recorded in the USA, and 36% of these cases resulted in death. The reverse question of what the disease is doing to the animal population gets rather less attention typically than the human disease problem. The example I want to discuss here is the Sin Nombre virus (SNV) in deer mice (Peromyscus spp.), widespread rodents in North America.

The hantavirus outbreak in the Southwestern USA in the 1990s caused numerous human deaths and produced a number of field studies that showed a patchy pattern of infection among deer mice in Arizona and Colorado (Mills et al. 1999). Male mice were infected more than females and the suggestion was that males fighting for territories were infecting one another directly when population densities were high. The call for long-term studies went out and several studies from 3-5 years were carried out in the late 1990s until the problem of infection in the human population became less of an issue compared with other diseases such as Ebola in other parts of the world. The shift in concern resulted in reduced funding for field studies in North America.

In 1994 Rick Douglass and his research team began long term studies on the Sin Nombre virus in deer mice using 18 live trapping areas of 1 ha each spread across Montana and placed in a variety of habitats (Douglass et al. 2001). Long-term for their study was 15 years, all this at a time when 2-3 year studies were thought to be sufficient to unravel the nexus of infection and transmission. The idea was to complement in Montana similar rodent research in Arizona, New Mexico, and Colorado. The results are fascinating and important because they illustrate the importance of long term research and the understanding of what a well designed field study can produce.

Rightfully many of the hantavirus studies were focused on the human connection, but what I want to emphasize here is the impact of this virus on the rodent populations. Luis et al. (2012) estimated that male Peromyscus had their monthly survival rate reduced from 0.67 to 0.58 if they were seropositive, a 13% reduction, but females showed no effect of hantavirus on survival so that infected and uninfected females survived equally well. Hantavirus does reduce body growth rates of infected male mice. One consequence of these findings should be that the growth rate of Peromyscus populations in Montana should be only slightly affected by hantavirus infections, since it is the female component of the population that drives numbers. There are limitations to these conclusions since juveniles too young to live trap could suffer mortality that at present cannot be measured. The threshold for hantavirus transmission in these Peromyscus populations was about 17 individuals per ha (Luis et al. 2015), implying that hantavirus would disappear in populations smaller than this because it would not transmit. The consequence for us is that human hantavirus infections in North America are much more likely when deer mouse populations are high, and by monitoring deer mice ecologists can broadcast warnings when there are increased possibilities of infection with this lethal disease.

The details about the Sin Nombre hantavirus in North America are well covered in these and other papers. The most important general message from this research has been the need for long term studies to get at what might initially seem to be a simple population problem (Carver et al. 2015). There are a host of other viruses that infect rodent species and many other mammals and birds about which we know very little. The path to understanding the effects of these viruses on the animals they infect and their potential for human transmission will require much detailed work over a longer time period than what is now the funding horizon of our granting agencies. The Montana studies on the Sin Nombre virus required ecologists to trap for 20 years with more than 851,000 trap nights to catch 16,608 deer mice, and collect 10,572 blood samples to assess infections and gain an understanding of this virus disease. The problem too often is that it is easy to find ecologists and virologists keen to cooperate in these studies of disease, but it is not easy to find the long term funding that looks at these ecological problems in the time scale of 10-20 years or more. We need much more long term thinking about ecological problems and the funding to support team efforts on difficult problems that are not soluble in a 3-year time frame.

Carver, S., Mills, J.N., Parmenter, C.A., Parmenter, R.R., Richardson, K.S., Harris, R.L., Douglass, R.J., Kuenzi, A.J., and Luis, A.D. 2015. Toward a mechanistic understanding of environmentally forced zoonotic disease emergence: Sin Nombre hantavirus. BioScience 65(7): 651-666. doi: 10.1093/biosci/biv047.

Davis, S., Calvet, E., and Leirs, H. 2005. Fluctuating rodent populations and risk to humans from rodent-borne zoonoses. Vector-Borne and Zoonotic Diseases 5(4): 305-314.

Douglass, R.J., Wilson, T., Semmens, W.J., Zanto, S.N., Bond, C.W., Van Horn, R.C., and Mills, J.N. 2001. Longitudinal studies of Sin Nombre virus in deer mouse-dominated ecosystems of Montana. American Journal of Tropical Medicine and Hygiene 65(1): 33-41.

Luis, A.D., Douglass, R.J., Hudson, P.J., Mills, J.N., and Bjørnstad, O.N. 2012. Sin Nombre hantavirus decreases survival of male deer mice. Oecologia 169(2): 431-439. doi: 10.1007/s00442-011-2219-2.

Luis, A.D., Douglass, R.J., Mills, J.N., and Bjørnstad, O.N. 2010. The effect of seasonality, density and climate on the population dynamics of Montana deer mice, important reservoir hosts for Sin Nombre hantavirus. Journal of Animal Ecology 79(2): 462-470. doi: 10.1111/j.1365-2656.2009.01646.x.

Luis, A.D., Douglass, R.J., Mills, J.N., and Bjørnstad, O.N. 2015. Environmental fluctuations lead to predictability in Sin Nombre hantavirus outbreaks. Ecology 96(6): 1691-1701. doi: 10.1890/14-1910.1.

Mills, J.N., Amman, B.R., and Glass, G.E. 2010. Ecology of hantaviruses and their hosts in North America. Vector-Borne and Zoonotic Diseases 10(6): 563-574. doi: 10.1089/vbz.2009.0018.

Mills, J.N., Ksiazek, T.G., Peters, C.J., and Childs, J.E. 1999. Long-term studies of hantavirus reservoir populations in the southwestern United States: a synthesis. Emerging Infectious Diseases 5(1): 135-142.