Local Consequence of Global Process: Challenges of Maintaining Pastoral Production in High Mountain Pastures of Nepal

Grassland pastures are important livelihood resources for local people in agro-pastoral production in high mountainous areas of Nepal. The character of these pastures, as part of cultural landscape, result from historical interaction of human activities and local ecological processes. Fire and grazing are two important landscape drivers that have a direct impact on the structure, diversity and composition of pastures. Recently, grasslands in many semi-arid regions of world are undergoing rapid transformation as consequence of changes in fire and grazing regimes. One conspicuous change is an abrupt proliferation of native shrub species. Migration of herders away from marginal mountain areas has many local environmental consequences associated with land use change (Aide and Grau 2004). In this context, the present study explores the main ecological consequences of shrub invasion in selected grasslands of Nepalese mountain areas and discusses the management challenges associated with these ecological changes. In these mountain pastures, shrub invasions are either over-looked or underexplored

Seeing the wood for the trees: Carbon storage and conservation in temperate forests of the Himalayas

Forests have a prominent role to play in the success of the UN’s Agenda 2030, thus actions to halt deforestation are high on the international sustainability agenda. As humans are altering the composition and extent of forest ecosystems, from local to global scales, we are also affecting the provisioning of forest ecosystem goods and services. We tested how measures of biodiversity, structural diversity, forest disturbances and environmental variables affect above ground tree carbon storage as an essential ecosystem service in differing legally protected forest ecosystems in the central Himalayas. This region is part of a biodiversity hotspot as well as a developing country where rural livelihoods are profoundly dependent on forest resources. We analysed drivers of above ground tree carbon in 530 plots, measuring a total of 6879 individual trees across six forests in three regions in legally protected and un-protected forest ecosystems in the Nepalese Himalayas. The aboveground tree carbon was markedly higher in protected forests (164 ± 8 t/ha) compared to in unprotected forests (114 ± 5 t/ha) but varied across regions. Biodiversity matrices were weakly correlated with above ground tree carbon content (hereafter called ‘tree carbon’) while the matrices of structural diversity were strongly correlated. Tree size inequalities, canopy cover, elevation, management, tree density, ground disturbance and woody species richness had effects on the tree carbon in bivariate regression models. However, in a multiple linear regression model matrices of structural diversity outweighed biodiversity matrices; tree size inequalities have the largest effect size on tree carbon, followed by elevation, management regime and tree richness. Tree size inequality, elevation and management regime show positive effects while tree richness has negative effect on tree carbon when accounting for the random effects of regions. Our analysis gives an evidence-base in support of forest management that retains tree size inequality, with particular emphasis on protecting large trees, as the best strategy to enhance above ground tree carbon storage and their co-benefits in temperate forests of the Himalayas.publishedVersio

Formulation and in vitro evaluation of metformin hydrochloride loaded microspheres prepared with polysaccharide extracted from natural sources

The present work envisages utilisation of biodegradable and biocompatible material from natural sources for the development of controlled release microspheres of metformin hydrochloride (MetH). Natural polysaccharides extracted from Dillenia indica L. (DI), Abelmoschus esculentus L. (AE) and Bora rice flour were used in fabricating controlled release microspheres. The microspheres were prepared by the emulsion solvent diffusion technique with different proportions of natural materials and were studied for entrapment efficiency, particle size, particle shape, surface morphology, drug excipient compatibility, mucoadhesivity and in vitro release properties. The prepared microspheres showed mucoadhesive properties and controlled release of metformin hydrochloride. The study has revealed that natural materials can be used for formulation of controlled release microspheres and will provide ample opportunities for further study

The global abundance of tree palms

Aim Palms are an iconic, diverse and often abundant component of tropical ecosystems that provide many ecosystem services. Being monocots, tree palms are evolutionarily, morphologically and physiologically distinct from other trees, and these differences have important consequences for ecosystem services (e.g., carbon sequestration and storage) and in terms of responses to climate change. We quantified global patterns of tree palm relative abundance to help improve understanding of tropical forests and reduce uncertainty about these ecosystems under climate change. Location Tropical and subtropical moist forests. Time period Current. Major taxa studied Palms (Arecaceae). Methods We assembled a pantropical dataset of 2,548 forest plots (covering 1,191 ha) and quantified tree palm (i.e., ≥10 cm diameter at breast height) abundance relative to co‐occurring non‐palm trees. We compared the relative abundance of tree palms across biogeographical realms and tested for associations with palaeoclimate stability, current climate, edaphic conditions and metrics of forest structure. Results On average, the relative abundance of tree palms was more than five times larger between Neotropical locations and other biogeographical realms. Tree palms were absent in most locations outside the Neotropics but present in >80% of Neotropical locations. The relative abundance of tree palms was more strongly associated with local conditions (e.g., higher mean annual precipitation, lower soil fertility, shallower water table and lower plot mean wood density) than metrics of long‐term climate stability. Life‐form diversity also influenced the patterns; palm assemblages outside the Neotropics comprise many non‐tree (e.g., climbing) palms. Finally, we show that tree palms can influence estimates of above‐ground biomass, but the magnitude and direction of the effect require additional work. Conclusions Tree palms are not only quintessentially tropical, but they are also overwhelmingly Neotropical. Future work to understand the contributions of tree palms to biomass estimates and carbon cycling will be particularly crucial in Neotropical forests

31st Annual Meeting and Associated Programs of the Society for Immunotherapy of Cancer (SITC 2016) : part two

Background The immunological escape of tumors represents one of the main ob- stacles to the treatment of malignancies. The blockade of PD-1 or CTLA-4 receptors represented a milestone in the history of immunotherapy. However, immune checkpoint inhibitors seem to be effective in specific cohorts of patients. It has been proposed that their efficacy relies on the presence of an immunological response. Thus, we hypothesized that disruption of the PD-L1/PD-1 axis would synergize with our oncolytic vaccine platform PeptiCRAd. Methods We used murine B16OVA in vivo tumor models and flow cytometry analysis to investigate the immunological background. Results First, we found that high-burden B16OVA tumors were refractory to combination immunotherapy. However, with a more aggressive schedule, tumors with a lower burden were more susceptible to the combination of PeptiCRAd and PD-L1 blockade. The therapy signifi- cantly increased the median survival of mice (Fig. 7). Interestingly, the reduced growth of contralaterally injected B16F10 cells sug- gested the presence of a long lasting immunological memory also against non-targeted antigens. Concerning the functional state of tumor infiltrating lymphocytes (TILs), we found that all the immune therapies would enhance the percentage of activated (PD-1pos TIM- 3neg) T lymphocytes and reduce the amount of exhausted (PD-1pos TIM-3pos) cells compared to placebo. As expected, we found that PeptiCRAd monotherapy could increase the number of antigen spe- cific CD8+ T cells compared to other treatments. However, only the combination with PD-L1 blockade could significantly increase the ra- tio between activated and exhausted pentamer positive cells (p= 0.0058), suggesting that by disrupting the PD-1/PD-L1 axis we could decrease the amount of dysfunctional antigen specific T cells. We ob- served that the anatomical location deeply influenced the state of CD4+ and CD8+ T lymphocytes. In fact, TIM-3 expression was in- creased by 2 fold on TILs compared to splenic and lymphoid T cells. In the CD8+ compartment, the expression of PD-1 on the surface seemed to be restricted to the tumor micro-environment, while CD4 + T cells had a high expression of PD-1 also in lymphoid organs. Interestingly, we found that the levels of PD-1 were significantly higher on CD8+ T cells than on CD4+ T cells into the tumor micro- environment (p < 0.0001). Conclusions In conclusion, we demonstrated that the efficacy of immune check- point inhibitors might be strongly enhanced by their combination with cancer vaccines. PeptiCRAd was able to increase the number of antigen-specific T cells and PD-L1 blockade prevented their exhaus- tion, resulting in long-lasting immunological memory and increased median survival

The disturbance-diversity relationship: integrating biodiversity conservation and resource management in anthropogenic landscapes

Disturbance, natural or anthropogenic, is ubiquitous to forest and grassland ecosystems across the globe. Many of these ecosystems have evolved alongside centuries old anthropogenic disturbance regimes. Understanding how disturbance impacts biodiversity and ecosystem service delivery is a topic of paramount importance as high biodiversity is likely to provide a wide array of ecosystem goods and services to an ever-growing human population. There is a general consensus that disturbance is an integral part of ecosystems and plays a role in shaping their diversity and function. It has been theorized that a certain threshold of disturbance plays a positive role in maintaining ecosystem diversity and health. However, the relationship between disturbance and diversity is contested on theoretical as well empirical grounds. The disturbance-diversity relationship is not as simple as theorized and appears somewhat elusive given the fact that impacts of disturbance are contingent on the attributes of the disturbance itself as well on the ecosystems exposed to disturbance. Empirical studies assessing impacts of disturbance, mainly anthropogenic, on diversity also do not show a general pattern; rather impacts can be considered as either positive or negative. In this context, this thesis synthesizes findings of four case studies dealing with impacts of human disturbance on floral diversity and composition at a local scale in specific ecosystems, with the aim of giving a perspective on how anthropogenic disturbance can be integrated at a landscape or regional level to manage resources at the intersection of societal and ecological concerns in a complex and dynamic socioecological system. This thesis is anchored on four individual case studies from forests, grasslands and farmlands located at different elevations, ranging from tropical to subalpine climate, on the southern slopes and foot plains of the Himalaya in central Nepal. The study area comprises varying levels of anthropogenic disturbance from relatively little disturbed park area to visibly modified agroforests, and from government managed to privately owned resources. The main analyses include (i) a comparison of sites with different levels of disturbance and land-use to assess how natural and anthropogenic disturbance impacts floristic composition and richness (Paper I and II), (ii) a comparison of timegap vegetation data to assess the impacts of reduced disturbance (Paper III), and (iii) an analysis of vegetation and land-use change based on oral history and transect observations (Paper IV). A combination of quantitative and qualitative tools from vegetation and social sciences was used to collect and analyse the data. Vegetation data, mainly presence/absence and abundance of vascular plants collected in quadrats, are the main data for all study sites. This synthesis demonstrates that anthropogenic disturbance and changes to it can have profound impacts on floral richness and composition, and these impacts are contingent to the type and intensity of disturbance and ecosystems exposed to these disturbances. It is found that canopy gap disturbance is important in subtropical and temperate forests as it promotes tree regeneration and species diversity. However, higher richness in gaps of intermediate size was not confirmed in the subtropical forest. It is demonstrated that a decline in anthropogenic disturbance – fire and grazing – in grasslands as a consequence of land abandonment allowed encroachment of shrubs and trees into the grasslands with a subsequent loss of grassland-dependent flora until the grasslands are eventually converted into closed-canopy forests. Cessation of anthropogenic disturbance in forest, mainly lopping and felling of trees for firewood and fodder, led to increased forest canopy and a decline in floral richness over a short time span of two decades. Changes in richness across the life-forms were not consistent with the overall decline: whereas herbaceous flora declined substantially, woody flora increased. In an agricultural landscape, farmlands were consistently richer than nearby naturally regenerated secondary forests in terms of tree species richness at different scales. Retention and planting of a variety of tree species in the farmlands in response to a shortage of forest resources and new conservation policies is a likely explanation for the higher richness found on farms. This thesis demonstrates that anthropogenic disturbances associated with low intensity land-use practices of subsistence farming system help maintain floral richness and composition in human-modified landscapes at a local scale, which in turn contributes to the biodiversity and ecosystem services at a landscape and regional level. Alteration of the traditional practices of management/disturbance can have notable consequences not only for species richness but also for landscape patterns and processes. Mimicking near-natural disturbance in forests and pastures and considering human disturbance as an integral ecosystem process contributes to maintain biodiversity and ecosystem function, and can be regarded as an amicable strategy to produce food with a minimal ecological footprint in landscapes where human disturbance is inevitable due to people’s dependency on local natural resources

Seeing the wood for the trees: Carbon storage and conservation in temperate forests of the Himalayas

Forests have a prominent role to play in the success of the UN’s Agenda 2030, thus actions to halt deforestation are high on the international sustainability agenda. As humans are altering the composition and extent of forest ecosystems, from local to global scales, we are also affecting the provisioning of forest ecosystem goods and services. We tested how measures of biodiversity, structural diversity, forest disturbances and environmental variables affect above ground tree carbon storage as an essential ecosystem service in differing legally protected forest ecosystems in the central Himalayas. This region is part of a biodiversity hotspot as well as a developing country where rural livelihoods are profoundly dependent on forest resources. We analysed drivers of above ground tree carbon in 530 plots, measuring a total of 6879 individual trees across six forests in three regions in legally protected and un-protected forest ecosystems in the Nepalese Himalayas. The aboveground tree carbon was markedly higher in protected forests (164 ± 8 t/ha) compared to in unprotected forests (114 ± 5 t/ha) but varied across regions. Biodiversity matrices were weakly correlated with above ground tree carbon content (hereafter called ‘tree carbon’) while the matrices of structural diversity were strongly correlated. Tree size inequalities, canopy cover, elevation, management, tree density, ground disturbance and woody species richness had effects on the tree carbon in bivariate regression models. However, in a multiple linear regression model matrices of structural diversity outweighed biodiversity matrices; tree size inequalities have the largest effect size on tree carbon, followed by elevation, management regime and tree richness. Tree size inequality, elevation and management regime show positive effects while tree richness has negative effect on tree carbon when accounting for the random effects of regions. Our analysis gives an evidence-base in support of forest management that retains tree size inequality, with particular emphasis on protecting large trees, as the best strategy to enhance above ground tree carbon storage and their co-benefits in temperate forests of the Himalayas

Managing biodiversity: Impacts of Legal Protection in Mountain Forests of the Himalayas

Legal protection has been used as means of conserving forests and associated biodiversity in many regions of the world since the eighteenth century. However, most forests in the global south, even those within protected areas, are influenced by human activities. Himalayan forests harbour much of the biodiversity of the region, maintain subsistence livelihoods, and provide regional and global ecosystem services like water regulation, flood control, and carbon sequestration. Yet few studies have quantitatively studied the impacts of legal protection on forest health and biodiversity. We assess woody biodiversity and forest health in relation to legal protection and biomass extraction in forests inside and outside Langtang National Park in Nepal (n = 180). We found more woody species in protected forests. Of the 69 woody species recorded, 47% occurred at both sites. Within protected forests, we found differences in forest health largely related to the intensity of biomass extraction expressed as walking distance to settlement. The closer the forest was to settlements, the heavier degradation it suffered, showing that within agro-forestry systems in the Himalayas, the resource-consumer distance is typically determining the intensity of biomass extraction. Our research brings forth the need to better address the drivers of resource extraction from protected areas in order to mitigate this degradation. It also brings forth the need to contribute to the development of appropriate participatory management programmes outside areas of formal protection in order to sustain both biodiversity and ecosystem service delivery from these forests for the future

Do composition and richness of woody plants vary between gaps and closed canopy patches in subtropical forests?

Questions: Do composition and richness of woody plants differ between gaps and closed canopy in subtropical forests, and does this difference vary across life stages of tree species? Is tree species richness in gaps a function of regeneration density? Location: Subtropical Shorea robusta Gaertn (Sal) forest, central Nepal. Methods: We collected vegetation data from two old-growth S. robusta forest stands. We sampled 128 plots of 100 m2 equally spread between the two habitats: gap and closed canopy. In each plot, we recorded the total number of woody species, number of individuals of seedlings and saplings of tree species and measured the DBH of all saplings. We compared species richness and composition of total woody species, seedlings and saplings between the two habitats. We used ordination to analyse species composition, and an individual-based species accumulation curves to illustrate the effect of density on species richness. Results: The species composition of total woody species and seedlings was similar in both habitats, but species composition of saplings differed between habitats. Total woody and seedling richness were similar between habitats at one site, but were richer under closed canopy at the other site. Sapling richness was higher in gaps at both sites and was a function of stem density at one site, but not at the other site. Conclusions: Gaps are not always areas of higher woody species richness and therefore may be less important than expected for the overall species richness of woody plants. Instead, they are potentially important for enhancing local tree richness by increasing sapling richness. Gap disturbance is the primary driver of structural heterogeneity in forests where topographic and edaphic gradients are negligible

Forest canopy resists plant invasions: a case study of Chromolaena odorata in Sal (Shorea robusta) forests of Nepal

Accepted manuscript version, licensed CC BY-NC-ND 4.0. Invasive alien species are a major threat to global biodiversity due to the tremendous ecological and economic damage they cause in forestry, agriculture, wetlands, and pastoral resources. Understanding the spatial pattern of invasive alien species and disentangling the biophysical drivers of invasion at the forest stand level is essential for managing forest ecosystems and the wider landscape. However, forest-level and species-specific information on Invasive Alien Plant Species (IAPS) abundance and their spatial extent are largely lacking. In this context, we analysed the cover of one of the world’s worst invasive plants, Chromolaena odorata, in Sal (Shorea robusta) forest in central Nepal. Vegetation was sampled in four community forests using 0.01 ha square quadrats, covering the forest edge to the interior. C. odorata cover, floral richness, tree density, forest canopy cover, shrub cover, tree basal area, and disturbances were measured in each plot. We also explored forest and IAPS management practices in community forests. C. odorata cover was negatively correlated with forest canopy cover, distance to the road, angle of slope, and shrub cover. Tree canopy cover had the largest effect on C. odorata cover. No pattern of C. odorata cover was seen along native species richness gradients. In conclusion, forest canopy cover is the overriding biotic covariate suppressing C. odorata cover in Sal forests