My Research Portfolio
Welcome to my research portfolio. Here, you’ll find a selection of my work. Explore my research projects to learn more about what I do.
Thank you!
Blending Tradition & Technology in Forest Fire Management
The core idea for this project stems from community-led forest management. Growing up in a Himalayan village in Nepal, I witnessed firsthand how local communities sustainably manage forests to optimize ecosystem services. Through routine volunteer efforts such as thinning, pruning, and deadwood harvesting, fuel loads are reduced, forest resources are made accessible at subsidized costs, and community members maintain a deep connection to their forests. The income generated from these activities is reinvested locally, reinforcing both ownership and responsibility toward forests.
A similar history of Indigenous forest stewardship exists in the Sierra Nevada-US, where paleoecological and archaeological evidence suggests regular human interactions with forests. Markwith and Paudel (2021) estimated the extent of historical fuel harvesting by Indigenous peoples in Sierras. Reflecting on my own experiences in Nepal, where large wildfires were rare in community-managed forests due to regular fuel reduction and sustainable resource use, and considering the historical evidence of Indigenous fire management in the Sierra Mountains, I began to question: Could Indigenous forest management principles be adapted to the U.S. forests? How can these approaches be contextualized and integrated with modern technology to enhance carbon benefits? In a developed world where mobilizing local communities for forest management is less feasible, one possible solution is employing a dedicated workforce — similar to firefighters or agricultural workers — to harvest dead fuels and process them into carbon-rich products, providing dual benefits: reducing fire risk and enhancing carbon sequestration. This paper explores that potential.
Key points:
-
Physical harvesting (Py) of downed wood may be a useful approach for fuel reduction treatment in the wildland-urban interface, valuable recreational areas, critical wildlife habitats, and other high-risk areas where mechanized treatments are constrained.
-
Integrating Py with thinning was effective in reducing wildfire hazards and emissions and increasing carbon credits, offering a non-intrusive, carbon-beneficial alternative approach to dead fuel reduction.
Link to article and news:
Parajuli, R., Paudel, A. & Markwith, SH. (2025). Journal of Environmental Management, 376, 124535.
Figures: Forest survey sites in the Sierra Nevada Mountains, USA (Photo credit: Florida Atlantic University).
Deadwood & Biodiversity: Global Meta-analysis
This project is a section of my Ph.D. research, which centers on forest ecosystems and aims to investigate the advantages of deadwood for biodiversity conservation and its role as a carbon stock, as well as its influence on wildfire hazards.
Deadwood is essential for maintaining forest biodiversity and plays a pivotal ecological role in biodiversity conservation, carbon cycling and storage, and nutrient dynamics. It serves as a critical habitat for numerous species, including saproxylic, epixylic, and non-saproxylic organisms.
Utilizing a meta-analytic approach, I have synthesized the relationships between deadwood and biodiversity in forest ecosystems by incorporating data from 40 studies conducted across 22 countries. This research has unveiled significant positive correlations between deadwood and biodiversity, regardless of the bioclimatic regions, forest types, and management practices. Nevertheless, notable differences have been observed among various types of deadwood and decay stages, indicating that both the quantity and quality of deadwood are crucial factors for forest biodiversity.
Key findings:
-
The biodiversity of all species combined and rare species had significantly positive correlations with the dead wood amount.
-
Variations in effects were not apparent among bioclimatic regions, forest types, stands, and management regimes.
-
Correlations varied among dead wood types and decay stages, implying that dead wood quality attributes are critically important for biodiversity.
Link to published article:
Parajuli, R. & Markwith, SH. (2023). Biological Conservation, 283.
Langtang Positive Interaction Research
During my master's studies in 2009/10, extensive engagements in research tours and expeditions in the Himalayas were crucial in instilling my interest in plant adaptations to harsh environments and the factors that shape high-elevation plant communities. I keenly observed the herbaceous species, including rare medicinal herbs, thriving beneath specific shrubs, cushions, or trees. This inspired my exploration of how these nurse species, like shrubs, sustain plant diversity and structure community assembly in the high-elevation Himalayas.
This concept, which had yet to be tested in the Himalayas, secured a competitive research grant from the Rufford Foundation, UK.
I conducted a study on plant species interactions, explicitly focusing on the facilitative roles of shrubs and cushions in maintaining plant biodiversity in the high-elevation alpine and subalpine regions of the Langtang region of the Himalayas. A portion of this research constituted my MS Thesis, primarily focusing on the nurse effect of Himalayan native Berberis shrubs on plant diversity, including medicinal herbs, in a high-altitude landscape in Nepal’s Central Himalayan region.
This research revealed that the facilitation provided by Berberis shrubs was critical for maintaining plant biodiversity and provided refugia for rare and threatened species, including high-value medicinal herbs and other species valued by humans. Moreover, this study shed light, for the first time, on the valuable ecosystem services provided by plant facilitation and how the outcomes of shrub-herb interaction patterns are influenced by elevation gradients, growing seasons, and their combinations.
Links:
Fig.: Dactylorhiza hatagirea, a threatened medicinal herb, protected by Berberis shrub in the Himalayas.
Global Cushion Diversity Experiment
In 2010, when I was doing my MS degree, I became a part of a global research project, the Cushion Diversity Experiment, collaborating with the Alpine Pals group representing Nepal's Himalayas. The project aimed to assess the effects of cushion foundation species on alpine plant diversity at a global scale. We researched 78 sites on five continents using a standardized sampling protocol. Our study examined whether facilitative plant interactions influence alpine plant biodiversity, particularly looking into the role of cushion species in community assembly and phylogenetic diversity in harsh alpine environments.
This research showed that nurse cushion species substantially contribute and serve as a 'safety net' for sustaining plant biodiversity in environmentally severe and ecologically sensitive alpine regions. Our results highlighted the importance of nurse cushion plants as 'micro-refugia' in maintaining phylogenetic diversity in alpine areas worldwide. The cushion species create unique niche spaces that benefit less stress and disturbance-tolerant species for their recruitment and establishment within the community. As a part of this collaborative project, I coauthored three articles published in high-impact journals such as Ecology Letters and Ecology.
Links to published articles:
Butterfield et al. 2013. Ecology Letters 16(4) 478-486