utorak, studenoga 03, 2015

Invasive species

Part of my thesis investigation deals with invasive species in the Galapagos, which is a fascinating subject to me. 


Alien, introduced or exotic species are those that are found outside of their native range or ecosystem, most often being transported by humans deliberately; some of those species may negatively affect the new ecosystem, being then termed as invasive species.

Many of the current invasive species were brought to the Galapagos Islands for agricultural purposes by the colonists. Some of the more common plant examples include rose apple (Syzygium jambos), guava (Psidium guajava), blackberry (Rubus niveus), cuban cedar (Cedrela odorata), citrus (Citrus spp), cuban hemp (Furcraea hexapetala) and red quinine (Cinchona pubescens). Guézou et al. (2010) performed an extensive survey of the inhabited area of Santa Cruz, San Cristobal, Isabela and Floreana islands and recorded 754 alien plant species, whose most common use was ornamental. 


But today the main concern is the introduction and spread of these species from the inhabited areas into the NP; it is estimated that roughly 1,14% of the area of NP is occupied by  invasive plant species (CEPROEC-IAEN & SENPLADES, 2014).


According to my (somewhat simple) calculation of their spread in the next 10 years, the area covered by invasive species will be as shown in the map below.





The projected spread of invasive species on Isabela Island (shown in red and yellow) in the next 10 years.

Bibliography
Gardener, M. R., Trueman, M., Buddenhagen, C., Heleno, R., Jäger, H., Atkinson, R., & Tye, A. (2013). A Pragmatic Approach to the Management of Plant Invasions in Galapagos. In L. C. Foxcroft, P. Pyšek, D. M. Richardson, & P. Genovesi (Eds.), Plant Invasions in Protected Areas (pp. 349–374). Dordrecht: Springer Netherlands. 

Guézou, A., Trueman, M., Buddenhagen, C. E., Chamorro, S., Guerrero, A. M., Pozo, P., & Atkinson, R. (2010). An Extensive Alien Plant Inventory from the Inhabited Areas of Galapagos. PLoS ONE, 5(4), e10276.
 
CEPROEC-IAEN, & SENPLADES. (2014). Diagnóstico y análisis biofísico para evaluación y formulación de escenarios de desarrollo en el Archipiélago de Galápagos (No. Informe Técnico CEPROEC IT2014_01) (p. 402). Quito: IAEN, Senplades.


subota, kolovoza 22, 2015

Mapping ecosystem services

Ecosystem services can be defined as benefits that humans obtain from ecosystems, and are divided into four categories (Millennium Ecosystem Assessment (Program), 2005), as shown below, which can be evaluated globally. Many ecosystem services have been reduced in the recent past, most notably fisheries, water supply and purification, waste treatment, natural hazard protection, regulation of air quality, regulation of regional and local climate, among others.
Ecosystem services. Adapted from (Millennium Ecosystem Assessment (Program), 2005)

For my thesis I decided to work with ecosystem services instead of biodiversity since not enough georeferenced information was available. I found an assessment of the ecosystem services of the ecosystems on Galapagos Islands that have been evaluated by their trend (improved, improving, mixed or deteriorating) and the importance (high, medium high, medium low and low). After giving these descriptive values a numeric value, and assigning that final value to terrestrial ecosystems on Galapagos, I got the following map as a result.


Note that the orange-red area is the highest value ecosystem - the humid zone, the orange area is the second-highest value - the arid zone, while the pale yellow is the lowest value ecosystem - the transitional zone.


References: Millennium Ecosystem Assessment (Program). (2005). Ecosystems and human well-being: synthesis. Washington, DC: Island Press.

utorak, lipnja 16, 2015

Environmental Risk Surface

Environmental Risk Surface is a module of the Protected Areas Tools developed by The Nature Conservancy, which is an extension for ArcMap. I've started using it for my thesis recently and so far so good! I was initially worried about taking on new software for something as important as my thesis, since I have no direct support to guide me, but for the moment I'm satisfied. The User's manual could use more detail, but I managed to get it to work.

The software lets the user spatially connect data on threats (human or natural) and conservation data. In my case, I am looking at geo-referenced human activities, such as garbage disposal, roads, urbanization, etc. After assigning an impact zone for each, relative intensity between all of them is determined and then input into the software. There are several option on the decay type of the impact and how individual impacts overlap, depending on expert opinion.

To make a long story short, this is a sample of the output of the program. Here I'm looking at roads, that have been divided into three categories - primary, secondary and paths on Santa Cruz island on Galapagos.



Each category has a different impact zone, based on its characteristics and expert opinion, which looks like this after the ERS has produced a raster based in the input:


The red zone that around the primary roads indicates strongest impact and it is also most far-reaching. Most roads are secondary so the prevailing colors are yellows and greens, indicating that their impact is smaller. The next image focuses on paths that have the smallest impact zone and intensity, so their buffers are comparatively small.


After obtaining similar rastes for all the human threats I'm considering, I will combine them in one layer, that can be overlain with areas that are important for conservation, thus indicating conservation-important areas that are being threatened by human activities.

The software is available at: http://maps.usm.edu/pat/

subota, travnja 18, 2015

Solid waste in Ecuador

Waste generation and its management are sensitive subjects for most municipalities, and even more so in the developing countries, where problems encompass the growing production of waste, very low consumer consciousness, limited incentives for separation of waste at the source, problems in the recycling chain, disposal management, to name a few.

When it comes to impacts of waste generation and management, they range from air contamination and release of greenhouse gases that contribute to global warming, leachates that contaminate water and soil with chemicals such as heavy metals and organic compounds, and numerous health effects for the waste management workers and local populations.

In Ecuador, the current solid waste generation rate is 0,81 kg/person/day, but there are large differences between regions. According to Soliz Torres (2015), the differences between the highest and lowest producing cantons are extreme and range from 0,1 to 2,21 kg/person/day for 2012.

The great majority of waste disposal sites in the country are waste dumps that use virtually zero management techniques, but they are in a process of being closed permanently and substituted by sanitary landfills that generate fewer health and environmental impacts, a goal that should be accomplished by 2017.

Unfortunately, due to the confidentiality agreement of my work contract, I can’t publish my own work regarding the subject, so instead I present here a map published by Soliz Torres in a very interesting article entitled “Political ecology and critical geography of waste in Ecuador”.





Source: Soilz Torres (2015):  Political ecology and critical geography of waste in Ecuador.  Letras Verdes. Revista Latinoamericana de Estudios Socioambientales N.° 17, marzo 2015, pp. 4-28



srijeda, veljače 25, 2015

Conservation prioritization

The time has come to do some more research on my thesis, which deals with identifying conservation priorities in the Galapagos Islands.

http://www.galapagostours.net/images/galapagos-map.jpg


The field of identifying conservation priorities is known as conservation prioritization, and can be defined as “the process of using spatial analysis of quantitative data to identify locations for conservation investment”[1], which isn’t applied only to protected areas, but can also pertain to management strategies and conservation activities outside them. One of the more important considerations in conservation prioritization is that of comprehensiveness, by which the ideal conservation area should contain the composition, structure and function representative of the biodiversity feature. The complementarity principle should also be considered, since it states that costs should be optimized while ensuring that all biodiversity features receive benefit; furthermore, prioritization should be designed for the long term, with considerations for cost-effectiveness and taking into account threats that biodiversity faces.

The prioritization is a socio-political process, in which the goals are determined by societal considerations, but one in which science is the key provider of technical information and options. Even though mapping of the relevant factors is in itself an important aspect of this process, it should not focus solely on this tool in order to design a successful conservation strategy, but also include stakeholders opinions, development of scenarios, of decision support systems, social marketing, facilitation and conflict resolution, institutional establishment, monitoring and management, to name a few. The scope of the current work, however, only includes the production of the prioritization map due to technical, political and economic restraints.

http://i.telegraph.co.uk/multimedia/archive/01692/galapagos_1692336c.jpg


The identification of conservation goals is the initial phase of the process, followed by identifying the variables (factors or system attributes) to be considered, which is a scientific and technical stage involving the understanding and describing of the dynamic relations that define the ecology of a system. The next phase requires the gathering of information of the previously defined factors, which should principally be spatial information; in the absence of georeferenced data, carefully selected proxies can be used. The final and critical phase is to perform the prioritization analysis itself by means of one of the two basic principles: scoring of factors or complementarity based approach.

A variety of software has been designed with the purpose of aiding in the process of conservation prioritization analysis, such as MARXAN, Zonation, C-Plan, Res-Net, and this current work will use one such tool (Environmental Risk Surface, ERS) in order to determine priority conservation areas in the Galapagos Islands. Literature pertaining to the ERS software is extremely limited, therefore the main basis for this investigation is the work of McPherson et al. (2008) and Lessmann et al. (2014), both assessing human impact on conservation. McPherson et al. use GIS tools to assign weight and distance of influence to several human activities and map its impacts, in order to identify optimal conservation areas in Jamaica. Lessmann et al., on the other hand, use GIS map the distribution of target species, include conservation feasibility costs, in order to identify conservation gaps in Ecuador. Both articles focus on conservation efforts while evaluating and mapping the effect of such human influences as population, roads, tourism, agriculture, mining, and will thus offer guidance in the judgment of their impact.

References
Ferrier, S., & Wintle, B. A. (2009). Quantitative approaches to spatial conservation prioritization : matching the solution to the need. In Spatial Conservation Prioritization. Quantitative Methods and Computational Tools (p. 328). New York: Oxford University Press. 
Knight, A. T., Cowling, R. M., Possingham, H., & Wilson, K. A. (2009). From theory to practice: designing and situating spatial prioritization approaches to better implement conservation action. In Spatial Conservation Prioritization. Quantitative Methods and Computational Tools (p. 328). New York: Oxford University Press.
Lessmann, J., Muñoz, J., & Bonaccorso, E. (2014). Maximizing species conservation in continental Ecuador: a case of systematic conservation planning for biodiverse regions. Ecology and Evolution, n/a–n/a. doi:10.1002/ece3.1102
McPherson, M., Schill, S., Raber, G., John, K., Zenny, N., Thurlow, K., & Sutton, H. (2008). GIS-based Modeling of Environmental Risk Surfaces (ERS) for conservation planning in Jamaica. Journal of Conservation Planning, 4, 60–89.

[1] Wilson, Cabeza, & Klein, C., 2009, pg. 16
I may not have gone where I wanted to go, but I'm sure I ended up where I needed to be.