Facilitating forest restoration to improve sustainability of swidden agriculture in Papua New Guinea

Becky Morris, Jake Snaddon

One of the greatest global challenges is to achieve food security in the face of an expanding world population. This challenge is particularly relevant to PNG, where 85% of the population depend on swidden agriculture, within the third largest area of tropical forest worldwide. A key part of the swidden agricultural cycle is the fallow period. Due to increased demand for agricultural plots because of population growth, fallow periods are reducing. One approach to adapting to this could be to speed up the ecological processes that take place during the fallow period by facilitating soil and forest restoration.


This would involve: (1) Quantifying biodiversity and ecosystem functioning, particularly below-ground, across a range of ages of fallow plots; (2) Testing novel ways of managing the fallow period to restore ecosystem functioning faster, e.g. soil inoculations or planting cover crops; (3) Investigating whether and which fallow management methods are likely to be adopted by local farmers using socio-ecological surveys; and (4) Determining which methods of fallow management are optimal to ensure the sustainability of swidden agriculture.


The student tackling this project will accomplish original science in a tropical ecosystem, alongside delivering feasible adaptations to address a challenge faced by many tropical countries.



The student will conduct fieldwork in Papua New Guinea, focusing on the food gardens where the local villagers plant their crops, and the surrounding primary and secondary forests. The student will employ both observational techniques and manipulative experiments to collect their data, focusing on the fallow period. Of particular interest to this project may be to test soil inoculation techniques (Wubs et al 2016) to enhance the restoration of soil and forest. All our projects involve a socio-ecological element, so we would expect the student to engage with social surveys and interviews with local villagers to ensure that our research is relevant for local communities. The student will work in local villages and with our local collaborators in PNG, and will have the input of our UK collaborators for the social science.


With the supervisors’ guidance and agreement, the student will have flexibility to develop the project to match their particular research interests. Alternative plans exist should data collection not be possible in person for part of the PhD due to continuing COVID-19 travel restrictions.


University of Southampton

The INSPIRE DTP programme provides comprehensive personal and professional development training alongside extensive opportunities for students to expand their multi-disciplinary outlook through interactions with a wide network of academic, research and industrial/policy partners. The student will be registered at the University of Southampton and hosted at the School of Biological Sciences. Specific training will include: planning and conducting tropical ecology field work, measurements of ecosystem functioning both above- and below-ground, experimental design, social data collection, and data analysis. Training will be carried out in Southampton, or using external collaborators or training providers, where appropriate. Additional training will be provided according to the student’s research interests. Ideally the student will already have experience of tropical fieldwork, but they will be guided in the field, and be working alongside local research assistants in Papua New Guinea.


Eligibility & Funding Details: 

Please see https://inspire-dtp.ac.uk/how-apply for details.

Background Reading: 

Hazenbosch, M. et al. (2021) Using locally available fertilisers to enhance the yields of swidden farmers in Papua New Guinea. Agricultural Systems, 192, 103089.

Wubs, E.R.J. et al. (2016) Soil inoculation steers restoration of terrestrial ecosystems. Nature Plants, 2, 16107.

Szefer, P, Molem, K, Sau, A, Novotny, V. Impact of pathogenic fungi, herbivores and predators on secondary succession of tropical rainforest vegetation. J Ecol. 2020; 108: 1978– 1988.