Global Drivers and Tradeoffs of Three Urban Vegetation Ecosystem Services

<div><p>Our world is increasingly urbanizing which is highlighting that sustainable cities are essential for maintaining human well-being. This research is one of the first attempts to globally synthesize the effects of urbanization on ecosystem services and how these relate to governance, social development and climate. Three urban vegetation ecosystem services (carbon storage, recreation potential and habitat potential) were quantified for a selection of a hundred cities. Estimates of ecosystem services were obtained from the analysis of satellite imagery and the use of well-known carbon and structural habitat models. We found relationships between ecosystem services, social development, climate and governance, however these varied according to the service studied. Recreation potential was positively related to democracy and negatively related to population. Carbon storage was weakly related to temperature and democracy, while habitat potential was negatively related to democracy. We found that cities under 1 million inhabitants tended to have higher levels of recreation potential than larger cities and that democratic countries have higher recreation potential, especially if located in a continental climate. Carbon storage was higher in full democracies, especially in a continental climate, while habitat potential tended to be higher in authoritarian and hybrid regimes. Similar to other regional or city studies we found that the combination of environment conditions, socioeconomics, demographics and politics determines the provision of ecosystem services. Results from this study showed the existence of environmental injustice in the developing world.</p></div

Bayesian models for three ecosystem services.

<p>Values overlapping zero imply a consistent effect of the bio-socio-political factor in the probability of having a positive or negative effect in the provision of ecosystem services. HDI: Human Development Index, DI: Democracy Index, PP: Annual precipitation, MAT: Mean Annual Temperature, HMI: Heat Moisture index.</p

Ordination of the first and second standardized principal component for each ecosystem services and main drivers for 100 cities.

<p>The value of PC1 (Principal Component1) and PC2 (Principal Component 2) for the cities was standardised in order to more clearly show their location in the orthogonal space. The length of the arrow is an indication of the strength of the socio-political-climate variables and the ecosystem service in each PC. HMI: Heat Moisture Index, DI: Democracy Index, HDI: Human Development Index.</p

Socioeconomic, political and climatic characteristics for the 100 cities included in this study.

<p>Socioeconomic, political and climatic characteristics for the 100 cities included in this study.</p

Significant differences (ANOVA) in the provision of ecosystem services using categories from significantly influential urban characteristics.

<p>Values label with the different letter a imply significant differences among categories of analysis for Tukey’s HSD comparison test.</p><p>Significant differences (ANOVA) in the provision of ecosystem services using categories from significantly influential urban characteristics.</p

Spearman correlations between different ecosystem services for all the cities and by categories of population, democracy and climate.

<p>Fisher significant test: *p-value<0.01, **p-value<0.05, ***p-value<0.001.</p><p>Spearman correlations between different ecosystem services for all the cities and by categories of population, democracy and climate.</p

Flower colour difference between species in the field and two invasive species.

<p>Pairwise mean flower colour difference (measured as the Earth Mover’s Distance) was calculated between individual yellow-orange flowers of different species and mean colour of individuals of <i>H</i>. <i>aurantiacum</i> (light bars) and <i>H</i>. <i>praealtum</i> (dark bars). 95% confidence intervals are shown.</p

Leaf and flower colour difference.

<p>Pairwise Euclidean distance in CIE 1976 (L*a*b*) space was calculated and an nMDS generated for a) yellow-orange flowers and b) leaves (the leaf nMDS used data from the two highest quality cameras only: the Nikon D300 and Sony NEX-5n).</p

Variation in leaf colour measured by different cameras.

<p>Leaf colour is shown in <i>a*</i>-<i>b*</i> space for five species calculated from images taken with five different digital cameras.</p