Malika Virah-Sawmy

How does spatial heterogeneity influence resilience to climatic changes? Ecological dynamics in southeast Madagascar.

Conceptual models suggest a link between spatial heterogeneity, diversity, and resilience, but few empirical studies exist to demonstrate such an ecological relationship. In this study, we investigated the nature of spatial heterogeneity and resilience of two forest fragments from Madagascars highly endangered littoral forest, and two nearby sites in the surrounding ericoid grassland. This ecosystem has been subjected to a number of large environmental disturbances over the last 6000 years, including a late Holocene sea-level rise of 1–3 m above the present level, pronounced drought events, and natural and anthropogenic fires. The aims were to determine the driving mechanisms for heterogeneity and to compare the impact of large environmental disturbances among the four sites. Overall, our results indicate that, contrary to previous assumptions of continuous forest cover, the ecosystem was already spatially heterogeneous prior to the arrival of humans. Differences in groundwater, nutrients, and fires main...

Protected areas for conservation and poverty alleviation: experiences from Madagascar

Protected areas for conservation and poverty alleviation: experiences from Madagascar Charlie J. Gardner*, Martin E. Nicoll, Tsibara Mbohoahy, Kirsten L. L. Oleson, Anitry N. Ratsifandrihamanana, Joelisoa Ratsirarson, Lily-Arison Ren e de Roland, Malika Virah-Sawmy, Bienvenue Zafindrasilivonona and Zoe G. Davies WWF Madagascar and Western Indian Ocean Programme Office, BP738, Antananarivo 101, Madagascar; Durrell Institute of Conservation and Ecology (DICE), School of Anthropology and Conservation, University of Kent, Canterbury, Kent CT2 7NR, UK; D epartement de Biologie, Facult e des Sciences, Universit e de Toliara, Toliara 601, BP 185, Toliara, Madagascar; Blue Ventures Conservation, Level 2 Annex, Omnibus Business Centre, 39-41 North Road, N7 9DP London, UK; ESSA-D epartement Eaux et Forets, Universit e d’Antananarivo, BP 175 Antananarivo, Madagascar; and The Peregrine Fund, BP 4113 Antananarivo, Madagascar

Business and professional networks: scope and outcomes in Oxfordshire

This paper examines the relationship between formal networks, such as business and occupationally based professional networks, and place in determining network patterns and types in regional economic development. It distinguishes between ‘network-rich’ and ‘network-poor’ regions and considers why and how formal networks operate as a service and a resource to participants and as components of regional business infrastructures. Formal networks in the Oxfordshire to Cambridge Arc in the UK are used to illustrate these points.

'Tales of Symphonia': extinction dynamics in response to past climate change in Madagascan rainforests.

Madagascars rainforests are among the most biodiverse in the world. Understanding the population dynamics of important species within these forests in response to past climatic variability provides valuable insight into current and future species composition. Here, we use a population-level approach to analyse palaeoecological records over the last 5300 years to understand how populations of Symphonia cf. verrucosa became locally extinct in some rainforest fragments along the southeast coast of Madagascar in response to rapid climate change, yet persisted in others. Our results indicate that regional (climate) variability contributed to synchronous decline of S. cf. verrucosa populations in these forests. Superimposed on regional fluctuations were local processes that could have contributed or mitigated extinction. Specifically, in the forest with low soil nutrients, population model predictions indicated that there was coexistence between S. cf. verrucosa and Erica spp., but in the nutrient-rich forest, interspecific effects between Symphonia and Erica spp. may have pushed Symphonia to extinction at the peak of climatic change. We also demonstrate that Symphonia is a good indicator of a threshold event, exhibiting erratic fluctuations prior to and long after the critical climatic point has passed.

New evidence of megafaunal bone damage indicates late colonization of Madagascar

The estimated period in which human colonization of Madagascar began has expanded recently to 5000–1000 y B.P., six times its range in 1990, prompting revised thinking about early migration sources, routes, maritime capability and environmental changes. Cited evidence of colonization age includes anthropogenic palaeoecological data 2500–2000 y B.P., megafaunal butchery marks 4200–1900 y B.P. and OSL dating to 4400 y B.P. of the Lakaton’i Anja occupation site. Using large samples of newly-excavated bone from sites in which megafaunal butchery was earlier dated >2000 y B.P. we find no butchery marks until ~1200 y B.P., with associated sedimentary and palynological data of initial human impact about the same time. Close analysis of the Lakaton’i Anja chronology suggests the site dates <1500 y B.P. Diverse evidence from bone damage, palaeoecology, genomic and linguistic history, archaeology, introduced biota and seafaring capability indicate initial human colonization of Madagascar 1350–1100 y B.P.

Migration and Interaction between Madagascar and Eastern Africa, 500 BCE–1000 CE: An Archaeological Perspective

The debate on the peopling of Madagascar has long been dominated by historical linguistics and the observed similarities between Malagasy and Austronesian languages. It is clear from the linguistic evidence that there have been several periods of human contact with, or migration to, Madagascar—and that these also brought different domesticates to the island (Allibert 1998, 2007; Beaujard 2011a,b; Boivin et al. 2013). Genetics is currently the main tool being used to understand the peopling of Madagascar (Hurles et al. 2005; Tofanelli et al. 2009; Murray et al. 2012; Pierron et al. 2014). However, despite recent advances in the field of genetic studies we still know very little about either the first colonisation on Madagascar or about the contacts between the populations of Madagascar, the Austronesian influence zone, and the African mainland. Moreover, Verin and Wright (1999) have warned that inferences from linguistic and genetic studies can be misleading, and that there is often a disjuncture between language and human biology on the one hand and material culture and identity on the other.

Holocene book review: Extinct Madagascar – Picturing the Island’s Past

Large faunal species disappeared from Madagascar at a time when humans were certainly present on the island. A deduction, though not a parsimonious one, purported by many scholars is to attribute these extinctions to the hands of man, whether as a primary or contributory factor (e.g. Burney et al., 2003; Martin, 1984). By contrast, in Extinct Madagascar, Steven M Goodman and William L Jungers explore in greater depth than the current literature presently offers the recent past of these animals through specific case studies presented by sites and by species. Each site is splendidly illustrated by the artist Velizar Simeonovski in arresting artworks, depicting how some of these animals may have lived or gone extinct based on available palaeontological evidence. These plates allow the reader a pictorial (though still speculative) glance of the past. In one of my favourite plates, a colony of elephant birds are nesting along the gentle coastal escarpment of Cap Ste Marie in southern Madagascar, where exceptionally high concentrations of egg debris have been found. Such high concentrations of egg debris for a large ratite species are surprising. Goodman and Jungers speculate that this could indicate an ancestral communal breeding system found in certain living ratites. But intriguingly, what could have caused the extinction of such a large breeding colony? Goodman and Jungers use the published literature about the deposits to suggest that the extinction occurred as recent as 750 yr BP but with little evidence to date of extensive human hunting of these birds in this region. Perhaps the most provocative (or misleading) plate is a view of a hunter–gatherer settlement at Taolambiby in southwest Madagascar. While some people are butchering and roasting a suite of large extinct lemur species, others from a hunting party are bringing additional preys. The depiction, according to Goodman and Jungers, is based on the deposit of bones analysed from a palaeontological site at Taolambiby, where 40% of bones of the large extinct sloth-like lemur Palaeopropithecus and 33% of the large lemur Pachylemur show signs of butchering. Bones bearing evidence of butchery, in the form of cut-marks, have been commonly perceived as demonstrable human modification of faunal compositions. However, all of the claimed modified bones come from the palaeontological site at Taolambiby, and none of them are associated with any other evidence of contemporaneous human occupation. Goodman and Jungers argue that the lack of archaeological artefacts probably indicates that these huntergatherers did not live in permanent settlements or that the settlements have yet to be found. It is regrettable, according to the authors, that only a single radiocarbon date from the above mentioned species is available and dated to 2345 yr BP. According to the authors, the present evidence is not sufficient to purport the hypothesis of human-driven extinction at Taolambiby, and one can only wonder whether Simeonovski’s plate at Taolambiby is not rather misleading. It has long been assumed that Madagascar’s highlands, a geographic area that represents a large proportion of the island, were once completely forested; this assumption is mainly based on the apparent poverty of species and endemism in the grasslands relative to the forested parts of Madagascar (e.g. Lowry et al., 1997). However, over the past years, researchers have proposed that grasslands are probably native to Madagascar, given the presence of endemic grasses, endemic shade-intolerant trees and endemic vertebrate and invertebrate grassland specialists (Bond et al., 2008; Goodman and Benstead, 2005). But whether the highland landscape was mostly ‘grassland’, or a ‘savannah with some woody component’, or ‘open wooded forest with some grassland component’, is still open for debate. In Extinct Madagascar, Goodman and Jungers examine the palaeontological sites in the highlands at Ampoza, close to the Isalo Massif, to illustrate that the highland was probably more of a mosaic vegetation. The fossil record from Ampoza gives two important clues to the more forested nature of the highlands: first, bones of the extant Indri, Indri indri, have been recovered. This lemur is known today only from the eastern humid formations. It is therefore very probable that pockets of humid forest were continuous with open woodland, which would have provided the means for strictly forest dwelling animals to disperse in the highlands. The second clue is the abundance of bones of the extinct Palaeopropithecus, which implies that the habitat at Ampoza would have been a closed forest as this sloth-lemur is considered as one of the most specialised suspensory mammals on Earth. Given that the bones have been dated between 2950 and 1830 BP, it implies not only the loss of those animals from the highlands but profound ecological changes in the highland landscape. Extinct Madagascar provides superb information on a large number of palaeontological sites, contextualising the ecological uniqueness of each site. By examining such a large number of palaeontological sites individually, Goodman and Jungers bring us closer to the words of the late Robert Dewar (1997): ‘it seems less and less appropriate to expect a single, uniform cause for the extinctions will be ever found’. As the authors themselves described, the ‘jury is still out’ on determining a clearer picture of extinction processes. The material presented should certainly provide more ‘meat’ to pursue research on the elusive nature of past extinction processes in Madagascar, especially if the past is to be Holocene book reviews 572728 HOL0010.1177/0959683615572728The HoloceneHolocene book reviews book-review2015