A sense of direction: spatial boundaries in a cognitive, cultural, and deep time perspective.

This brief note points toward new potentials that lie at the interface between research on landscape archaeology and cognitive science. Recent advances in the cognitive and neural sciences have sharpened our understanding of spatial cognition, by providing new explanations for how the brain reduces the dimensionality of complex topography and geography for effective navigation. This research suggests that space is represented in grid-like structures in the brain, and that grid-like forms are a basic ingredient of spatial processing. At the same time, recent archaeological research shows that the organization of larger-scale space into linear forms, and in particular grid-like landscapes, is a relatively recent social invention, which suggests that these forms are historically and culturally contingent. Taken together, this research raises the question of how the dimensionality-reducing function of grid-like processing in the brain is related to higher-level conceptual and imaginative processing of space needed to plan and negotiate large-scale landscape structures. This brief note motivates this question and argues for further exploration of the relationships between biological, cognitive, and cultural processes related to space and its conceptualization between these fields of research.

New land tenure fences are still cropping up in the Greater Mara.

Expanding and intensifying anthropogenic land use is one of the greatest drivers of changes of biodiversity loss and political inequality worldwide. In the Greater Mara, Kenya, a trend of private land enclosure is currently happening, led by smallholders wishing to protect and uphold their land titles. Here we expand on previous work by Løvschal et al. quantifying the rapid, large-scale development of fencing infrastructure that began in 1985 but has increased by 170% from 2010 onwards. We provide fine-scale analysis of the spatial and temporal trends in fencing using high-resolution Sentinel-2 imagery. The formally unprotected regions have distinctly more fences than the rest of the Mara, one experiencing a 740% increase in fenced land in four years. Conservancies have an effect in stemming fencing but fences crop up within and along conservancy boundaries. We estimate the actual geographical coverage of the fences in the Mara to be 130,277 ha (19% of the total region) using an error margin of 8%, derived by calibrating our satellite mapping with ground-truth data. The study suggests the need for revising community-based eco-conservation efforts and pursuing a richer understanding of the socio-political and historical dynamics underlying this phenomenon.

Landscape Dynamics (landDX) an open-access spatial-temporal database for the Kenya-Tanzania borderlands.

The savannas of the Kenya-Tanzania borderland cover >100,000 km2 and is one of the most important regions globally for biodiversity conservation, particularly large mammals. The region also supports >1 million pastoralists and their livestock. In these systems, resources for both large mammals and pastoralists are highly variable in space and time and thus require connected landscapes. However, ongoing fragmentation of (semi-)natural vegetation by smallholder fencing and expansion of agriculture threatens this social-ecological system. Spatial data on fences and agricultural expansion are localized and dispersed among data owners and databases. Here, we synthesized data from several research groups and conservation NGOs and present the first release of the Landscape Dynamics (landDX) spatial-temporal database, covering ~30,000 km2 of southern Kenya. The data includes 31,000 livestock enclosures, nearly 40,000 kilometres of fencing, and 1,500 km2 of agricultural land. We provide caveats and interpretation of the different methodologies used. These data are useful to answer fundamental ecological questions, to quantify the rate of change of ecosystem function and wildlife populations, for conservation and livestock management, and for local and governmental spatial planning.

Mapping the ecological resilience of Atlantic postglacial heathlands.

Anthropogenic heathlands are semi-natural ecosystems with a unique cultural and biodiversity value, considered worthy of preservation across most of the world. Their rate of loss, however, is alarming. Currently, we know little about the heathlands' actual span of resilience affordances and their association with abiotic and anthropogenic factors, including how much additional intervention they need to persist. Consequently, we are missing out on vital knowledge for conservation, management and the historical persistence of heathlands.This paper develops a method to assess the ecological resilience affordances of Atlantic postglacial heaths in the absence of human management. We use 12 existing cases of heathland succession to establish a four-step resilience grade for each site, which we regress onto a series of explaining factors and use it in predicting heath resilience across postglacial Atlantic Northern Europe.We find that temperature, humidity, elevation and sandiness have a positive correlation with high heathland resilience. Our predictive mapping shows an uneven distribution of ecological heath resilience across Atlantic Northern Europe within an area of 1,000 × 1,200 km of 5 × 5 km resolution.Historic heathland distributions far exceed areas that afford high heath resilience, suggesting that heath distribution and persistence depend on both abiotic and anthropogenic factors. Policy implications: The map predicting the ecological resilience of Atlantic postglacial heaths can be used by managers working towards heath preservation and restoration to prioritize conservation efforts and to plan management practices across Atlantic Northern Europe. Together with the predictive model, it provides an important initial screening tool to assess heathland resilience in the absence of management as well as the impact of atmospheric nitrogen. The results are equally relevant for scholars who are interested in humans' role in increasing and decreasing ecosystem resilience. Our predictive method can be applied in other regions across the world by adding regionally specific variables.

Direct evidence of a large Northern European Roman period martial event and postbattle corpse manipulation.

New archaeological excavations at Alken Enge, Jutland, Denmark, have revealed a comprehensive assemblage of disarticulated human remains within a 75-ha wetland area. A minimum of 82 individuals have been uncovered. Based on the distribution, the total population is estimated to be greater than 380 individuals, exclusively male and predominantly adult. The chronological radiocarbon evidence of the human bones indicates that they belong to a single, large event in the early first century AD. The bones show a high frequency of unhealed trauma from sharp-edged weapons, which, together with finds of military equipment, suggests that the find is of martial character. Taphonomic traces indicate that the bones were exposed to animal gnawing for a period of between 6 mo and 1 y before being deposited in the lake. Furthermore, the find situations, including collections of bones, ossa coxae threaded onto a stick, and cuts and scraping marks, provide evidence of the systematic treatment of the human corpses after the time of exposure. The finds are interpreted as the remains of an organized and possibly ritually embedded clearing of a battlefield, including the physical manipulation of the partly skeletonized bones of the deceased fighters and subsequent deposition in the lake. The date places the finds in the context of the Germanic region at the peak of the Roman expansion northward and provides the earliest direct archaeological evidence of large-scale conflict among the Germanic populations and a demonstration of hitherto unrecognized postbattle practices.

Fencing bodes a rapid collapse of the unique Greater Mara ecosystem.

With land privatization and fencing of thousands of hectares of communal grazing areas, East Africa is struggling with one of the most radical cultural and environmental changes in its history. The 668,500-hectare Greater Mara is of crucial importance for the great migrations of large mammals and for Maasai pastoralist culture. However, the magnitude and pace of these fencing processes in this area are almost completely unknown. We provide new evidence that fencing is appropriating land in this area at an unprecedented and accelerating speed and scale. By means of a mapped series of multispectral satellite imagery (1985-2016), we found that in the conservancies with the most fences, areal cover of fenced areas has increased with >20% since 2010. This has resulted in a situation where fencing is rapidly increasing across the Greater Mara, threatening to lead to the collapse of the entire ecosystem in the near future. Our results suggest that fencing is currently instantiating itself as a new permanent self-reinforcing process and is about to reach a critical point after which it is likely to amplify at an even quicker pace, incompatible with the region's role in the great wildebeest migration, wildlife generally, as well as traditional Maasai pastoralism.