Modulo estructural

While analysing the various nodes and coding within those nodes, some of the trends in valuation studies were visually evident by viewing the ‘sources’ coded into each node.

A. Trends Visually Observable

Out of 129 Valuation studies, 108 articles were found to be spatial, i.e. having spatial datasets used for analysis or spatial representation of results, while 21 articles were found to have no substantial spatial analysis. 108 articles had spatial datasets; 19 articles used interviews, surveys, questionnaires or group discussions as source of data collection. The spatial studies were double checked by the Node Valuation or Not -- Direct Valuation – Methodology -- Spatial; which also showed 108 spatial method articles, whereas, the Non-Spatial Method node had 21 articles coded into the node. Therefore, it can be said that the keywords used resulted in 83.7% of spatially explicit articles and 16.2% of non-spatial articles.

It was also observed that in the Node ‘Landuse’, forest had the highest number of articles quoted (18). The nodes were reclassified into Terrestrial Land use, Marine or Water

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Land use, and Regional Division. This analysis showed that Marine and Water had the highest number of articles (58), followed by Regional Division having 44 articles, and Terrestrial having 30. This showed that most of the valuation research in the past decade has been focussed on marine, coastal regions, wetlands, mangroves and watersheds.

B. Trend by Study Area

In terms of Study Areas, the analysis showed that valuation studies framed in the context of Chinese landscapes had the highest number of publications over the past decade. A series of value transfer valuation studies were published out of China. These studies were based on equivalent weight factor derived per hectare for estimating the ecosystem services contributions of land use (Zhao et al. 2004, Amut et al. 2006, Hao et al. 2012, Liu et al. 2012). These published articles drew largely on the concepts provided in Costanza’s paper (Costanza et al. 1997) and an equivalent weight factor matrix derived from a survey of more than 200 Chinese scholars (Xia et al. 2003, Xie et al. 2003). A number of review papers had also been published in relation to ecosystem services valuation studies conducted in China (Bao et al. 2007, Zhang et al. 2010, Zhang and Liu 2011, Siew and Döll 2012). These reviews highlighted discrepencies in the separate studies and indicated a need for development in the areas of uncertainty analysis, standardization of methods and advancement of spatially and temporally explicit tools and models. One of the reviews (Zhang et al. 2010) noted that, despite having discrepencies, the studies conducted raised public awareness of the value of ecological and biological resources in China.

The second largest contributor of spatial ecosystem valuation studies was USA with 19 articles followed by Spain with 9. Chart 3.1 shows the number of published articles on spatial valuation based on country names from 2004 to 2014. The chart shows only those countires having more than three published articles.

Chart 3.1: Distribution of number of articles published from 2004 to 2014 specifically on spatial ecosystem services valuation based on study areas presented by country of

origin

This analysis was also carried out on the basis of continents. Asia had the highest number of studies, followed by Europe and then North America. In turn, the highest

0 10 20 30 40 50

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contributor of articles in Asia was China and that of Europe was Spain as shown in Chart 3.2.

Chart 3.2: Distribution of articles on the basis of continents

C. Trend by Methods

A similar analysis was carried out for methods used. Valuation methods were classified into monetary and non-monetary approaches which were further classified into subcategories. Alongside this classification, the studies were divided into spatial and non-spatial categories based on their usage of spatial or non-spatial strategies.

Chart 3.3 shows that the highest number of articles that were spatial in nature were direct market approaches including different market price and cost based approaches. The spatial studies show a higher trend towards benefit transfer approach than the non- spatial ones. In the case of a stated preference approach, contingent valuation was the primary method, contributing almost equally to the spatial and non-spatial studies. The direct market based approach and benefit transfer approach were more prevalent and dominated the spatial valuation studies. Benefit transfer is more dominant in spatial studies than non-spatial studies.

Chart 3.3: Distribution of articles on the basis of monetary approaches and spatial

characteristics 0 5 10 15 20 25 30 35 40 45 50

Asia Europe North

America

Africa Australia South

America

Articles Distribution by Continents

0 10 20 30 40 50 60 Direct Market Revealed Preference Stated Preference Benefit Transfer Others

Articles by Monetary Approaches

Spatial Non-Spatial

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Chart 3.4 shows the number of published articles employing spatial and non-spatial methods in relation to non-monetary valuation approaches. The public preference and expert panel approaches have predominantly been used in the spatially enabled studies.

Chart 3.4: Distribution of number of articles on the basis of non-monetary approaches and spatial characteristics

D. Trend by Tools

Similarly, the trend of studies was analysed in relation to the tools and models used, thus indicating the types of tools more or less common in spatially enabled methods. A large number of studies used GIS tools for analysis purposes, although the published papers often did not provide specific details (software etc) of the tools used and thus here have been included in a general category of ‘GIS Tools’. Several valuation studies used various valuation methodologies, but a specific software or tool was not utilised in the study, thus including it in the ‘None’ category. The None category studies were all non-spatial in nature. Out of 129 direct valuation articles, 69 used some kind of GIS tool, 17 of these used ArcGIS (ESRI) for analysis, and 14 used InVest as a valuation tool. There were 14 non-spatial studies that did not use any software or tools for analysis. In the case of analysing remote sensing data, ENVI (Harris GeoSpatial Solutions) was used the highest number of times, followed by IDRISI (Clark Labs). Chart 3.5 shows the trend of tools being used in the articles during the period of 2004 to 2014.

Chart 3.5: Distribution of articles on the basis of tools used for the period ‘2004 to 2014’

0 1 2 3 Public Preference

Expert Panel Others

Articles by Non-monetary Approaches

Spatial Non-Spatial 0 15 30 45 60 75

GIS tools ArcGIS InVest None ENVI IDRISI

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Figure 3.3 provides a deeper insight into a valuation tool known as InVest that has been widely used in the past decade. InVEST is used as an ecosystem service valuation tool. Initially, the tool was developed by the Natural Capital Project within the ArcGIS platform, but was later released as open source, requiring any GIS based desktop tool to operate and so making it more convenient to use. InVest contains sub-models addressing habitat quality, habitat risk assessment, marine water quality, carbon sequestration, blue carbon, water yield model and others that are diverse and cover various ecosystems, thus enabling it to be used by a larger scientific community.

Figure 3.3: The InVest node linked with 14 articles that used InVest as a valuation tool An analysis of the studies using InVest indicated that out of 14 total articles that used InVest for ecosystem services valuation, 13 were journal articles while one of them was a conference proceeding published in 2011. The studies were published from 2010 to 2014, and showed an increasing trend with time as shown in Chart 3.6. The highest numbers of publication were in journal Acta Ecologica Sinica as shown in Chart 3.8, followed by International Journal of Biodiversity Science, Ecosystem Services and Management and The Science of the Total Environment. Five articles reported study areas in China, two articles each reported study areas Spain and USA as shown in Chart 3.7.

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Chart 3.6: Distribution of InVest articles from 2004 to 2014

Chart 3.7: Distribution of InVest articles on the basis of study area

E. Trend of Publishing Activity

In order to review the overall trend of the publishing activity over the past decade, an analysis was first carried out on the number of articles and their distribution. Chart 3.9 shows that the trend has generally increased from 2004 to 2014 from less than 5 publications per year to more than 35 per year. Of 192 articles published, 174 were journal articles and 13 were conference proceedings. A list of journal titles in ascending order of number of publications was generated along with their impact factor. Table 3.5 shows that the highest publication rate (19) was in the journal Ecological Economics, followed by 17 in Acta Ecologica Sinica (having mainly studies with China as their study area), and 10 in Ecosystem Services. Chart 3.9 indicates the increasing number of articles in journals along with increasing number of cumulative impact factors for those

0 1 2 3 4 5 6 2010 2011 2012 2013 2014

Distribution of Articles

China Spain USA Australia Canada Ghana Japan UK

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articles from 2004 to 2014, which indicates the growing importance of these valuation studies over time.

Chart 3.8: Distribution of InVest articles on the basis of publication type

Table 3.5: Distribution of articles on the basis of journal titles along with their impact factors

Journal Title No of Articles Impact Factor as

per 2014

Ecological Economics 19 2.517

Acta Ecologica Sinica 17 0

Ecosystem Services 10 4.307

Chemistry and Ecology 5 1.047

Ecological Indicators 5 3.23 0 1 2 3 Publication Type

Acta Ecologica Sinica 3

International Journal of Biodiversity Science, Ecosystem Services & Management

2

The Science of the total

environment 2

Agriculture, Ecosystems &

Environment 1

Applied Geography 1

Ecological Indicators 1

Ecosystem Services 1

Global and Planetary

Change 1

Journal of Great Lakes

Research 1

ISWREP 2011 Proceedings 1

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Journal Title No of Articles Impact Factor as

per 2014

Ecology and Society 5 3.31

Ocean & Coastal Management 5 1.769

Annals of the New York Academy of Sciences

4 4.375

Environmental and Resource Economics 4 1.703

International Journal of Biodiversity

Science, Ecosystem Services & Management

4 0.77

Journal of environmental management 4 3.188

Environmental management 3 1.648

Environmental Science & Policy 3 3.514

International Journal of Sustainable Development & World Ecology

3 1.771

Landscape and Urban Planning 3 2.606

PloS one 3 3.53

The Science of the total environment 3 3.163

Charts 3.10 and 3.11 show an analysis of publication activity from 2004 to 2014. Chart 10 shows the distribution of articles on the basis of publication type. Chart 3.11 shows the frequency of words used in articles and illustrates the significance of the words ecosystem, services, value, water, land, use etc. in spatial valuation studies and therefore, can be suggestive keywords for publication purposes.

Chart 3.9: Distribution of spatial ecosystem services valuation articles and their cumulative impact factors from 2004 to 2014

0 10 20 30 40 50 60 70 80 90 100 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014

Distribution of Articles and Cummulative Impact Factors

from 2004 to 2014

No of Papers Cum IF

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Chart 3.10: Distribution of articles on the basis of publication type for the period ‘2004 to 2014’

Chart 3.11: Frequency of words used in all published articles along with their number for the period ‘2004 to 2014’