Overview of Obo

This report contains biodiversity, species and environmental information about Obo and Sao Tome e Principe. It starts with a simple overview of Obo, including links to external databases such as WDPA, Ramsar, BirdLife International, World Heritage, UNESCO and Google Earth. Then it summarises our protected area indicators, including species irreplaceability, habitat irreplaceability and pressure on the park. The species found with in the park (according to various species databases) are summarised and their IUCN categories, with links to detailed species information that can be found in this report. The long term environmental trends and environmental seasonality information are provided for the park, and this is followed by country level information.

The map to the right shows: Sao Tome e Principe with Obo in purple; protected areas in our study in green and; all other protected areas in grey. Move your mouse over the image to see the park clearly.

Information on this protected area is provided by The World Database on Protected Areas which is held at the UNEP-World Conservation Monitoring Centre (UNEP-WCMC) and is managed in partnership with IUCN - The World Conservation Union. It is continually updated, so if you can help with this process please email protectedareas@unep-wcmc.org - quoting the name, country and/or site code of any site that you have improved information for.

Overview of the irreplaceability and pressure indicators

This section describes the indicators that were developed to characterise the PA in terms of threats and pressures to species and their habitats.

We have generated species irreplaceability indicators for three taxa, Mammals, Birds and Amphibians. This was done by counting how many protected areas a species occurs in (n), and adding 1/n to the SI index of each of those protected areas. We also characterise the habitat of each of our studied PAs in Africa based on climate, terrain, land cover and human population, to create an indicator of habitat irreplaceability such that the more irreplaceable a PA habitat is, the higher the ranking in any potential prioritisation scheme. Finally, we have computed two pressure indicators that aim to quantify the threat to species within the PA - by (i) estimating the population pressure in the surrounding area and (ii) quantifying the amount of agriculture found in the immediate vicinity of the protected area.

These indicators are represented in a series of graphs and tables which give an overview of the irreplaceability of the PA and the pressures on the PA, relative to the average values for the country and ecoregion.

The radar plot - to the right - shows all six of the PA indicators for this park in red along with the country averages which are grey. Each indicator has been scaled from 0 (lowest) to 100 (highest) to allow easy comparison.

Below is a tabular summary of the ranking of this PA with respect to other PAs in the same country and same ecoregion. If the PA is in the top five for this indicator, it is highlighted in red.

Indicators for species irreplaceability (SI)

Firstly, in order to provide a general overview of the spatial distribution of species richness, endemism, and threat over the whole continent, a 1km resolution map was calculated using the geographical distributions of all species for the three different taxa.

Secondly, a species irreplaceability (SI) index was calculated for each protected area, with respect to all the species of a given taxon. This was done by counting how many protected areas a species occurs in (n), and adding 1/n to the SI index of each of those protected areas. The same procedure was carried out for all species in a given taxon.

Indicator for PA habitat irreplaceability (HI)

This component of the method aims to characterise the habitat of each of the PAs in Africa that have an area of at least 1,000 hectares. Typically a protected area contains a specific habitat that can be characterised by climate, terrain, land cover and human population. With such a characterisation, it is possible to identify similar areas within the same biome. Naturally some areas will be more similar to the PA habitat than others, and for some PAs there may be large areas of similar habitat and yet others PA habitats may be unique.

Here, we have identified and ranked PAs based on their habitat similarity, and we have created an indicator of the habitat irreplaceability (HI) of the PA. The more irreplaceable a PA habitat is, the higher the ranking in any potential prioritisation scheme. The habitat similarity is computed using the Mahalanobis distance metric.

Indicators for pressure on the park (PP and AP)

This component of the method aims to quantify the level of threat to the PA - and by proxy the threat to species within the PA - by (i) estimating the population pressure in the surrounding area and (ii) quantifying the amount of agriculture found in the immediate vicinity of the protected area.

The premise for the population pressure (PP) index is that high population density within and around the PA implies: (i) High pressure for land use conversion (conversion to agricultural use) in the buffer zone around the PA and within the PA itself. (ii) Higher levels of fishing and hunting in and around the PA. (iii) Higher risk of small scale deforestation (thinning) for timber and fuel. (iv) Higher risk of intentional burning and clearing.

Not all these factors may be applicable to a single PA, but if one or more of these risk are present then we suggest that population pressure is a reasonable indicator of these factors.

For the agricultural pressure (AP) index, we assume that the greater the extent of agricultural land that is found immediately next to the boundary of the PA, then the more pressure there is likely to be on land cover conversion within the boundary of the PA. This is considered a threat to the habitat and consequently the species found within a protected area.

Species data and IUCN categories

This section lists the species from our three studued taxa that are potentially associated with this PA. The first table summarises the number of species per taxa per IUCN Red List category. The second table explains the IUCN Red List Categories and Criteria which are intended to be an easily and widely understood system for classifying species at high risk of global extinction. This is followed by up to three tables, one for each class (Mammals, Birds, Amphibians). Each table shows the IUCN category which links to the species distribution map, the number of areas in our study where each species is found, and links more detailed species information in the IUCN Red List database and associated species databases.

Large and medium mammals

Mammal species considered threatened by IUCN that occur within this Protected Area,
based on overlaps with habitat and range maps from the African Mammals Databank¹

Mammal species considered threatened by IUCN that occur within this Protected Area,
based on overlaps with habitat and range maps from the African Mammals Databank¹

IUCN	English name	Scientific name	Family	Number of studied PAs where species is found	IUCN Red List database2
VUSpecies extent map	African manatee	Trichechus senegalensis	Trichechidae	93	22104

This list only contains mammal species considered threatened at the global level by IUCN that occur within this Protected Area,based on overlaps with habitat and range maps from the African Mammals Databank. The data bank models the Area of Occupancy of 281 species, belonging to 28 families, over the whole African continent excluding Madagascar. It does NOT contain the rhinos for preserving the confidentiality of their distribution, nor the elephant since there is a more detailed database by the Elephant Specialist Group of the Species Survival Commission SSC/IUCN.

1. African Mammals Databank (1999) IEA (Institute of Applied Ecology), Italy: http://www.gisbau.uniroma1.it/amd.php
2. IUCN (2006) 2006 IUCN Red List of Threatened Species: http://www.iucnredlist.org

Amphibians

Amphibian species considered threatened by IUCN that occur within this Protected Area,
based on overlaps with range maps from the Global Amphibian Assessment¹

Amphibian species considered threatened by IUCN that occur within this Protected Area,
based on overlaps with range maps from the Global Amphibian Assessment¹

IUCN	English name	Scientific name	Family	Number of studied PAs where species is found	IUCN Red List database2	Global Amphibian Assessment species factsheet1
ENSpecies extent map	Newton's Grassland Frog	Ptychadena newtoni	Ranidae	1	58514	58514
ENSpecies extent map	Sao Tome Giant Treefrog	Hyperolius thomensis	Hyperoliidae	1	56289	56289
LCSpecies extent map	Sao Tome Caecilian	Schistometopum thomense	Caeciliidae	1	59592	59592
LCSpecies extent map	Moller?s Gulf Frog	Hyperolius molleri	Hyperoliidae	1	56288	56288
LCSpecies extent map	Peters' River Frog	Phrynobatrachus dispar	Ranidae	1	58107	58107

This lists only contains amphibian species from the Global Amphibian Assessment (GAA), which is the first-ever comprehensive assessment of the conservation status of the world's 5,743 known species of frogs, toads, salamanders, and caecilians.

1. IUCN, Conservation International, and NatureServe (2006) IUCN Global Amphibian Assessment: http://www.globalamphibians.org
2. IUCN (2006) 2006 IUCN Red List of Threatened Species: http://www.iucnredlist.org

Long term trends in phenology and climate

This first graph shows the start, peak and end of all detected growing seasons in the PA for 1983 to 2002. The data can be used to "assess deviations in the vegetation calendar, as an indicator of interannual variation of vegetation status, to forecast the development of climate driven diseases, and to support long term analysis in terms of land cover change - such as a change in vegetation type associated with permanent change in the vegetation calendar." (Phenology Product Sheet) The growing season data will be updated soon to include information from 2002 to the present day.

The second graph shows the long term averages for monthly rainfall and temperature ranges for the PA. This information helps to interpret the phenology data above. This data is taken from 1km resolution interpolated climate surfaces, and so it should be taken as a general overview of the climate in the PA and surrounding region.

Environmental seasonality

These two graphs show the same environmental data in different ways. The first graph shows the dekadal (10 day composites) values for rainfall, small water body presence, a water index (NDWI), a vegetation index (NDVI) and active fires for the past 10 years, where data were available. This graph clearly shows any variation in the environmental factors from year to year and any long term trends.

The second graph, shows how the environmental factors for this year and last year compare to the long term average. For each factor, we have plotted the dekadal values for the previous year (2007) and we update the graph every 10 days as data for this year (2008) becomes available. The dark gray line on each graph is the average for each dekad based on the available timeseries, and the light grey areas indicate the 95% confidence limits around this average. From these graphs we can see if there are any differences between this year and last year, how this compares to the average, and whether the differences are significantly different from the average.

Fire activity

Fires are central in the ecology of African tropical savannas and are commonly used as a tool for managing the tree-grass balance in protected areas. Because of their impacts on the habitats, fires are also used for conservation purposes. We monitor fire seasonality considering the number of fire events per unit area over a 10-day period (decade). This information is important to understand the level of protection in the PAs and in their surrounding zone. The density of fires observed inside and outside a PA is used as an indicator of the PA's ecological peculiarity.

The graph below reports the number of active fires detected in the PA and the 25km buffer zone. The period shown starts at the beginning of the dry season until present, information is updated as soon as satellite data become available. Active fire data come from the NASA funded Fire Information for Resource Management System (FIRMS).

NEW! More information on fire activity!

© European Communities 2008 | Last updated on December 14, 2009.