The Roots of Agriculture in Southern Arabia (RASA) team (1998 – 2008) led by editors Joy McCorriston (PI) and Michael Harrower (Field Manager), has published a monograph summarizing the research findings of the ten-year-long AIYS and NSF-funded project based in the Wadi Sana region of southeastern Yemen. The monograph presents the field data, archival photographs and analysis results (such as the Bayesian analysis of the geomorphological and settlement chronology of the wadi) collected by the team. The research was focused on documenting the initiation and development of pastoral societies in the region, primarily over the Early – Middle Holocene (10kya – 7kya BP).

Katie is a PhD student in the Department of Geosciences at Penn State, and she has been working with the ASOM team for the past year. She has been conducting pollen analysis on rock hyrax middens, in order to reconstruct past vegetation communities and changes in their composition through the mid-Holocene to present.

Katie has just been awarded three research grants to support further paleoclimatic analysis of the leaf wax isotopes from the hyrax middens to better understand changes in rainfall in the past. She has received two departmental grants; The Michael Loudin Family Graduate Scholarship (1000 USD), and The R.J. Cuffey Fund for Paleontology (4000 USD), and the Elsevier Research Scholarship, co-sponsored by the journal Organic Geochemistry and the European Association of Organic Geochemists (3000 Euro).

Congratulations Katie!

A collaboration between ASOM team members Lawrence and Mark, and colleagues in the UK and Oman, has led to a publication in Human Ecology. Abstract: In the Dhofar Mountains of Oman stakeholders are concerned about the social and ecological sustainability of pastoralism. In this study we used interviews with pastoralists to examine the prevailing drivers of pastoralism and how they are changing. We find that people are committed to pastoralism for sociocultural reasons but also that this commitment is under pressure because of husbandry costs and changing values. We find that capital investment in feedstuff enables pastoralists to overcome the density- dependent regulation of livestock populations. However, high production costs deter investment in marketing and commercialization, and there is little off take of local livestock. Our study reveals how pastoral values, passed down within households, motivate pastoralists in the face of high husbandry costs, modernization and social change.

The publication is available here – open access thanks to awesome ASOM!

‘High on the craggy cliffs of Oman’s rocky desert landscape, Sarah Ivory squeezed into narrow, dark caves in search of a different kind of goldmine. Shaded away from the desert sun, Ivory tapped a dusty, gray rock with her hammer and heard the dull, hollow sound she’d been waiting for. She found a special kind of fossil that, when cut open, would reveal smooth golden-brown layers that can help scientists see deep into the past.

This was a fossil of a midden, a communal toilet used by generation after generation of a small, desert-dwelling animal. The same middens are sometimes used for tens of thousands of years. Ivory recently journeyed to Oman, on the tip of the Arabian Peninsula, to find middens tucked in these caves, dig them out and ship them back to her laboratory at Penn State for analyses. It’s a dirty job. But in one of the driest places in the world, middens may be the best evidence to understand how the climate changed in the past, and how plants, animals and even humans, responded.’

excerpt from; Digging Into the Past – Using hyrax middens to study the past is helping to understand future climate, IMPACT

…continue reading here

A recently published study by ASOM postdoc researcher Lawrence Ball and his PhD supervisor Joseph Tzanopoulos, has identified several impacts of livestock browsing on the Anogeissus cloud forest in western Dhofar. By measuring 3600 adult and 3600 juvenile woody plants across thirty sites with different stocking histories, the abiotic and livestock factors affecting species distributions were examined. The results found fog density, topographic position and long‐term stocking rates to be important factors affecting woody species composition. Lower species diversity and plant density, and higher frequencies of unpalatable species, occurred under higher stocking rates. Juveniles showed a stronger response to stocking rates than adults, and several common species exhibited stunted morphology under high stocking rates.

The results show that browsing by large‐bodied livestock, such as camels and cattle, can substantially alter the species composition, structure, and phytomorphology of woody vegetation in semi‐arid woodlands and forests. Juveniles are particularly susceptible to browsing which alters woody vegetation demography and inhibits regeneration potential. The results support previous suggestions of overstocking in Dhofar and highlight the importance of swift measures to reduce livestock browsing pressure in the Anogeissus cloud forests.

Access the article at https://doi.org/10.1111/avsc.12493

Hi everyone! My name is Katie Horisk, and I recently joined the ASOM team! I am a PhD student working with Dr. Sarah Ivory at Penn State. I am currently conducting pollen analysis on the rock hyrax (Procavia capensis) middens, in order to reconstruct past vegetation communities and changes in their composition through the mid-Holocene to present.

I had the opportunity to join the most recent field season in Oman, which was my first trip to the country.  It was an incredible experience. In Muscat, Sarah and I paid a visit to the Oman Botanic Garden, where I got to meet some of the plants responsible for the pollen I see under the microscope. We also met with the Ministry of Heritage and Culture in both Muscat and Salalah, where we updated our collaborators on the goals for that trip. After three weeks in the field in Dhofar, we managed to collect 63 more middens! This was a well-earned reward for long days surveying the hot desert wadis. The landscape looks barren from a distance, but there are so many small plants and flowers that thrive on the weathered slopes. There had been a long rainy season, which meant we got to enjoy a more verdant February than usual. Immersing myself in the unique environment of Dhofar helped to contextualize my work enormously.

In addition to toiling under the desert sun, we took long lunch breaks in shady caves. Who knew eating canned hummus could become one of the best parts of the day? Our ministry representative, Aly Al-Mehri, would make tea over an open fire, then use the coals to burn Frankincense! On the weekends we took trips to beautiful beaches, explored the Souq, and got to see archaeological sites excavated by the team as well as the site of Sumhuram (the ancient port city and center of the Frankincense trade).  I enjoyed getting to know our Omani colleagues and learning from them in the field. One day we worked with Ali Alkathiry, and I brought him a large Gastropod fossil I had found. He explained how his ancestors would seek out these stones when they had a stomachache, boil them in water, and then drink the water. Sarah and I shared that the fossils were calcium carbonate, a mineral used in medicines like Tums! He got a kick out of that. This small anecdote demonstrates the extensive knowledge the people of Dhofar have about the landscape. I feel grateful to have gotten to learn even a little about the ways in which they interact with their environment, and I hope to carry what I learned about the people and the place throughout my research. Inshallah we will meet again soon!

Excited to share this new research in the fantastic Remote Sensing in Ecology and Conservation journal.

The cloud forests in Dhofar may be the driest on earth. They receive just 200 mm of rain each year, but during the monsoon/khareef, as much moisture is intercepted from the fog by the forest canopy! This is critical to ecosystem functions and services. Therefore, we hypothesized that vegetation patterns might correlate with fog distributions, which themselves might be affected by the complex mountain topography.

To investigate this, we first needed to map fog distributions at a high resolution (to see the effects of the complex topography). We found that many Landsat scenes showed the fog events, with little interference from other cloud types. So, using Google Earth Engine we extracted fog cover from 257 scenes, and calculated mean (average fog distributions) and SD (fog variability). We used recursive partitioning to analyse how topographic variables influence fog distributions and how fog distributions influence vegetation patterns (NDVI).

We found that fog accumulates against steep windward slopes and landforms, resulting in hotspots of fog interception, while lower fog densities occur in leeward locations. We also found a strong positive correlation between fog density and vegetation greenness. We found hotspots of fog interception, with consistently high fog densities and cloud forest over rough terrain. Complex forest canopy structures intercept more fog moisture than a smooth canopy. We found fog distributions describe patterns of vegetation greenness more accurately than topographic variables alone, and thus, we propose that regional vegetation patterns more closely follow a fog gradient, than an altitudinal gradient as previously supposed.

The Dhofar mountains are home to endemic and threatened biodiversity, and a wealth of archaeological and geological heritage. We hope that our layer of fog density, which is hosted in the PANGAEA data repository (https://doi.org/10.1594/PANGAEA.902295…), will enable an improved understanding of how species and in Dhofar respond to local variability in topoclimatic conditions.

Daniel Peart presented preliminary results from our model of social-spatial patterns in pastoralism at the annual meetings of the American Anthropological Association in Vancouver, Canada. 

Work is underway to design an Agent-based model of contemporary pastoralism in Dhofar, which will then form the basis of the ancient model to test theories on pastoralist mobility, habitation and monument building in ancient Dhofar. In these photos, the team is busy creating conceptual diagrams of attributes and properties of the different agents in the model, and how they relate to one another.