Ecoregion TopSpots: The Conservation Mona Lisas
Ecoregions are geographic regions of the world that indicate the distribution of ecosystems and plant and animal communities. See:
- Funk SM (2020) Ecoregions: Mapping Ecosystems to Protect Biodiversity. In: Encyclopedia of the UN Sustainable Development Goals- Life on Land.
Ecoregion TopSpots are the most important areas for conservation containing the most unique and the most vulnerable ecoregions of the world. We published two papers on the prioritisation of ecoregions:
- Funk SM, Fa JE (2010) Ecoregion Prioritization Suggests an Armoury Not a Silver Bullet for Conservation Planning. PLoS ONE 5(1): e8923
In the face of accelerating species extinctions, map-based prioritization systems are increasingly useful to decide where to pursue conservation action most effectively. However, a number of seemingly inconsistent schemes have emerged, mostly focussing on endemism. Here we use global vertebrate distributions in terrestrial ecoregions to evaluate how continuous and categorical ranking schemes target and accumulate endangered taxa within the IUCN Red List, Alliance for Zero Extinction (AZE), and EDGE of Existence programme. We employed total, endemic and threatened species richness and an estimator for richness-adjusted endemism as metrics in continuous prioritization, and WWF’s Global200 and Conservation International’s (CI) Hotspots in categorical prioritization. Our results demonstrate that all metrics target endangerment more efficiently than by chance, but each selects unique sets of top-ranking ecoregions, which overlap only partially, and include different sets of threatened species. Using the top 100 ecoregions as defined by continuous prioritization metrics, we develop an inclusive map for global vertebrate conservation that incorporates important areas for endemism, richness, and threat. Finally, we assess human footprint and protection levels within these areas to reveal that endemism sites are more impacted but have more protection, in contrast to high richness and threat ones. Given such contrasts, major efforts to protect global biodiversity must involve complementary conservation approaches in areas of unique species as well as those with highest diversity and threat.
- Funk SM, Fa JE (2007) Global endemicity centres for terrestrial vertebrates: an ecoregions approach. Endangered Species Research 3: 31-42
Endemic taxa are those restricted to a specific area, and can be defined as the exclusive biodiversity of a region. Areas with high endemic numbers are irreplaceable, and are of high priority for conservation. We investigated global patterns of endemicity of terrestrial vertebrates (mammals, birds, reptiles and amphibians) by employing data from World Wildlife Fund-US on 26452 species distributions (endemic and non-endemic) within 796 ecoregions. Ecoregions represent global ecosystem and habitat types at a landscape level. We explored the entire dataset by first using a principal components analysis, PCA, to identify which parameters and ordinations (transformations) best characterise the ecoregions. PCA identified the empirical logit transformation of proportional endemicity, not absolute or relative endemicity, as the appropriate variable. We prioritised ecoregions by ranking the empirical logit transformation of proportional endemicity, standardised across animal groups to avoid taxonomic biases. Finally, we analysed how ecoregion characteristics and the degree of isolation correlated with endemicity in all studied groups, by fitting logistic regression models. We argue that using our method, conservationists can better denote areas of importance for protection of endemic biodiversity worldwide.
Outcome
Our innovative high-level investigation has identified a new world map, that will allow conservation organisations to join forces and work together on protecting crucial natural areas of the world.
The map displays the congruence of the 100 highest ranking ecoregions of each prioritisation scheme
- Yellow: endemism only
- Orange: ∂-endemism only
- Turquoise: richness only
- Light, medium or dark purple: two, three or all metrics, respectively
- Smaller islands with Ecoregion TopSpots are marked by circles coloured as above
How did we identify these areas?
Read MoreStep 1. Select ecoregions
We used the World Wildlife Fund-US’ fantastic database of terrestrial regions identified by their ecological characteristics. These are the terrestrial ecoregions. They represent global ecosystem and habitat types at a landscape level. The dataset includes the distributions (endemic and non-endemic) of terrestrial vertebrates (mammals, birds, reptiles and amphibians).
Step 2. Identify parameters that best characterize ecoregions
We explored the entire dataset of ecoregions by first using a principal components analysis, PCA, to identify which parameters and ordinations (transformations) best characterise the ecoregions. PCA identified the empirical logit transformation of proportional endemicity, not absolute or relative endemicity, as the appropriate variable. Because of the mathematical form of the the empirical logit function, we call the empirical logit transformation of proportional endemicity δ-endemism, which constitutes an adjustment of absolute endemism with richness.
This means that a measure of proportional endemicity best characterizes ecoregions, not absolute endemism. These are areas that are of interest to the worldwide conservation community to protect. Published in Endangered Species Research.
Step 3. Identify the conservation value of different approaches
We prioritised ecoregions by ranking them according four different metrics, which were standardised across animal groups to avoid taxonomic biases. The four metrics are:
- number of threatened species (based on the IUCN Red List of Threatened Species),
- number of endemic species,
- δ-endemism, and
- species richness.
We then identified how the ecoregions, ranked according these four metrics, target threatened species, identified by the IUCN’s Red List, the Alliance for Zero Extinction (AZE) species, ZSL’s EDGE of Existence programme, WWF’s Global200 andConservation International’s (CI) Hotspots. Our results demonstrate that all metrics target endangerment more efficiently than by chance, but each selects unique sets of top-ranking ecoregions, which overlap only partially, and include different sets of threatened species.
There is not one “silver bullet” as a single way of maximising conservation impact with the limited resources available. However, the new map identifies how an “armoury of weapons” can be targeted to combat extinction. Published in PlosOne.
The top 100 ecoregions for each of the four metrics highlight the most important ecoregions for species endemism (absolute and δ), richness and threat (Top100). Together the Top100 of each metric identify 243 different ecoregions.
- 9 ecoregions are in the top 100 for all four metrics. These are highly important for endemism, richness, δ-endemism and threat.
- 98 TopSpots have two or three overlapping metrics.
- 136 ecoregions are unique for any of the four metrics.
The Top100 ecoregions for each of the four metrics identify ecoregions not covered by the Global 200 Ecoregions or Biodiversity Hotspots.
- 88 are not within Global 200 Ecoregions, and
- 75 are not within Biodiversity Hotspots.
Step 4. Identify the most endangered species in the most endangered places: Ecoregion TopSpots
Using the Top100 ecoregions as defined by continuous prioritization metrics, we develop an inclusive map for global vertebrate conservation that incorporates tose areas mots important for conservation:
- the most unique ecoregions: these are the ecoregions with the highest level of δ-endemism
- the most threatened ecoregions: these are the ecoregions with the highest number of threatened species.
The top-ranking ecoregions are this most important for conservation or most in need for protection. We call these ecoregions the Ecoregion TopSpots for conservation.
Together the Top100 of the two metrics identify 181 different ecoregions.
- 19 ecoregions are in the Top100 for both metrics. These are highly important for δ-endemism and threat,
- 81 ecoregions are unique for δ-endemism, and
- 81 ecoregions are unique for δthreat.
- 61 are not within Global 200 Ecoregions, and
- 32 are not within Biodiversity Hotspots.
The most important areas are:
- Islands including the Galápagos Islands, which helped Charles Darwin to develop the theory of evolution, and Juan Fernandes Island in Chile.
- Highlands including the Tropical Andes in South America.