The sustainability of trade in wild plants-A data-integration approach tested on critically endangered Nardostachys jatamansi

Impacts of climate change on the distribution pattern of Himalayan Rhubarb (Rheum australe D. Don) in Nepal Himalaya

While there has been substantial consensus that climate change poses a severe threat to the Himalayan biota; we still lack comprehensive data on the potential impact of climate change on the important Himalayan medicinal plants connected with the livelihood of local people and the national economy. In this study, using MaxEnt, we modelled the distribution pattern of Rheum australe, a medicinal plant prioritized by the Government of Nepal for the nation's economic prosperity, for the current as well as all four future projections (SSP126, SSP245, SSP370, and SSP585) to all the data available periods (2021-2040, 2041-2060, 2061-2080, and 2081-2100). In addition, we performed spatial overlay analysis to identify the optimum zones that could be developed as potential planting/conservation sites for R. australe in any of the projected future climate scenarios. Our results revealed that the suitability area of R. australe is expected to contract in all the scenarios and periods with a significant loss expected to occur in SSP585 for 2081-2100. On the individual district level, northwestern districts are expected to have a huge loss of suitable habitats in the future, while four districts: Jumla, Kalikot, Dolpa, and Jajarkot of the Karnali Province are expected to gain suitable habitats remarkably. Therefore, we suggest that the forests and rangelands of the four districts at an elevation range of 3300 m - 4,400 m could be developed as potential planting areas for commercial cultivation/for establishing genetic resource conservation centres. This finding thus has wider policy implications for both government and conservation organizations.

Quantifying redox signalling regulatory transcriptional dynamics in Nardostachys jatamansi under abiotic stress response

Understanding the responses of Himalayan medicinal plants to multifactorial stresses is crucial in the face of increasing environmental challenges, primarily characterised by frequent temperature and water availability fluctuations. The present study investigates the physiological, biochemical, and transcript variations in the critically endangered Himalayan medicinal plant Nardostachys jatamansi subjected to cold (15 °C and 10 °C for 30 days), drought (6 % PEG for 30 days), and heat stress (30 °C for 24 h). The primary impact of stress was observed through reduced plant biomass and chlorophyll fluorescence. The effects of abiotic stresses were also evident in the modulation of electrolyte leakage, MDA content and H2O2 accumulation. Accumulation of reactive oxygen species was confirmed through DAB and NBT staining, alongside increased DPPH and ABTS radical scavenging activity. Differential expression profiling of the RBOH family transcripts further substantiated the production of ROS. Enhanced enzymatic and non-enzymatic activities were observed under each abiotic stress condition. Additionally, genes specific to the regulatory mevalonate (MVA) pathway (TPS9; HMGR) and the methylerythritol phosphate (MEP) pathway (DXS1; DXR) were found to be differentially regulated. Moreover, differential expression profiling of abiotic stress signalling regulatory transcripts CRLK1, CRLK2, CaM6 and ICE1 was also discovered. These findings provide valuable insights into the physiological and biochemical profiling of N. jatamansi in response to extreme environmental conditions, significantly aiding our understanding of the adaptation strategies of alpine vegetation for their conservation.

The ecology of plant extinctions

Extinctions occur when enough individual plants die without replacement to extirpate a population, and all populations are extirpated. While the ultimate drivers of plant extinctions are known, the proximate mechanisms at individual and population level are not. The fossil record supports climate change as the major driver until recently, with land-use change dominating in recent millennia. Climate change may regain its leading role later this century. Documented recent extinctions have been few and concentrated among narrow-range species, but population extirpations are frequent. Predictions for future extinctions often use flawed methods, but more than half of all plants could be threatened by the end of this century. We need targeted interventions tailored to the needs of each threatened species.

A roadmap to sustainable management of commercial medicinal and aromatic plants, fungi, and lichens in Nepal

Thousands of plants, fungi, and lichen species are traded every year. Although sustainable use is critical for livelihoods and biodiversity conservation, insufficient data prevent detailed sustainability assessments for most species. How can the sustainability of trade in such data-deficient species be enhanced? We considered a country-level example of 300 medicinal and aromatic plant, fungus, and lichen species traded in tens of thousands of tons worth tens of millions of US dollars in and from Nepal annually. Past interventions have not ensured sustainable trade, leaving species vulnerable to commercial harvesting and threatening rural household incomes, the processing industry, and government revenues. Building on documented evidence and stakeholder involvement, we used a theory of change approach to develop a sustainable management approach. We produced a draft plan (roadmap) by combining interventions proposed at annual key stakeholder dialogue meetings with recommendations extracted from a literature review on the trade and conservation of commercial medicinal and aromatic plants, fungi, and lichens in Nepal. The draft roadmap was discussed at a national workshop with sector-wide stakeholder representation to derive the final roadmap. The literature review showed the 41 causal assumptions and theoretical explanations for actions and outcomes. Feedback mechanisms included 6 bundles of mutually reinforcing actions, such as the relationship between increased cultivation and decreased wild harvesting. The roadmap has 5 pathways: increase cultivation, strengthen local management, support domestic businesses, improve sector governance, and increase international collaboration. Each pathway is associated with 2-5 actions (e.g., hand over high-elevation areas to local communities) that lead to outputs (2-5) (e.g., an increased area under local management) and outcomes (2-6) (e.g., less overharvesting). Accordingly, the roadmap offers stakeholders a structured approach to implement future activities and investments to enhance sustainable trade. The approach can be replicated for other countries and products.