RESUMEN
Comparisons of plant traits between native and invasive congeners are useful approaches for identifying characteristics that promote invasiveness. We compared germination patterns and seedling growth of locally sympatric populations of native Mimosa himalayana and two varieties of invasive M. diplotricha (var. diplotricha and var. inermis) growing in southeastern Nepal. Seeds were germinated under a 12-h photoperiod or complete dark, low (25/15°C day/night) and high (30/20°C) temperatures, different water stress levels (0, -0.1, -0.25, -0.5, -0.75 and -1.0 MPa), and soil depths (0, 2, and 4 cm). Plant height, biomass allocations, and relative growth rate (RGR) of seedlings were measured. Invasive M. diplotricha had higher germination percentage, rate, and shorter germination time compared with the native species. Germination of both congeners declined as water stress increased, but the decline was more pronounced in native species. Seedling emergence declined with increasing depth in all taxa. The seedlings of invasive species were taller with higher leaf number and allocated greater proportion of biomass to shoot, whereas the native congener allocated greater biomass to root. The RGR was nearly twice as high in invasive species as it was in the native congener. Seedling height and number of leaves were always higher in invasive than in native species, and the native-invasive differences increased over time. Better germination and higher growth performance of invasive species than the congeneric native one suggests that seed germination and seedling growth can be useful traits for the prediction of species' invasiveness in their introduced range during risk assessment process.
RESUMEN
Zoonosis-based epidemics are inevitable unless we revisit our relationship with the natural world, protect habitats, and regulate wildlife trade, including live animals and non-sustenance products. To prevent future zoonoses, governments must establish effective legislation addressing wildlife trade, protection of habitats, and reduction of the wildlife-livestock-human interface.
Asunto(s)
Animales Salvajes , Infecciones por Coronavirus , Pandemias , Neumonía Viral , Animales , Betacoronavirus , COVID-19 , Humanos , SARS-CoV-2 , Zoonosis/epidemiologíaRESUMEN
Alpine treelines are expected to shift upward due to recent climate change. However, interpretation of changes in montane systems has been problematic because effects of climate change are frequently confounded with those of land use changes. The eastern Himalaya, particularly Langtang National Park, Central Nepal, has been relatively undisturbed for centuries and thus presents an opportunity for studying climate change impacts on alpine treeline uncontaminated by potential confounding factors.We studied two dominant species, Abies spectabilis (AS) and Rhododendron campanulatum (RC), above and below the treeline on two mountains. We constructed 13 transects, each spanning up to 400 m in elevation, in which we recorded height and state (dead or alive) of all trees, as well as slope, aspect, canopy density, and measures of anthropogenic and animal disturbance.All size classes of RC plants had lower mortality above treeline than below it, and young RC plants (<2 m tall) were at higher density above treeline than below. AS shows little evidence of a position change from the historic treeline, with a sudden extreme drop in density above treeline compared to below. Recruitment, as measured by size-class distribution, was greater above treeline than below for both species but AS is confined to ~25 m above treeline whereas RC is luxuriantly growing up to 200 m above treeline. Synthesis. Evidence suggests that the elevational limits of RC have shifted upward both because (a) young plants above treeline benefited from facilitation of recruitment by surrounding vegetation, allowing upward expansion of recruitment, and (b) temperature amelioration to mature plants increased adult survival. We predict that the current pure stand of RC growing above treeline will be colonized by AS that will, in turn, outshade and eventually relegate RC to be a minor component of the community, as is the current situation below the treeline.
RESUMEN
A surprisingly large number of species potentially threatened by human harvest lack quantitative ecological studies incorporating harvest effects, especially clonal species in the alpine Himalayas. We studied density and biomass variation of a threatened medicinal herb, Neopicrorhiza scrophulariiflora, to examine the effect of harvest on plant performance. The study covered two regions with contrasting harvest situations-one with open-access and another protected from commercial harvesting. Four populations from each region were compared along an elevation gradient (3,800-4,800 m). Also, we conducted in situ interviews with 165 and 38 medicinal and aromatic plant users in open-access and protected regions, respectively, to assess the collection and use patterns of the target species. The quantity harvested per household for traditional healthcare use was similar in both regions. We found no evidence of trade-driven collection in the protected region but in the open-access region a trade-based annual collection of 35-465 kg dried rhizomes per household had a strong negative effect on both density and biomass. In the protected region, the effect of harvest intensity on plant density was positive for vegetative and negative for reproductive individuals, whereas in the open-access region, the effect was negative for both vegetative and reproductive individuals. The results indicated that a low harvest intensity had no adverse impact on N. scrophulariiflora populations; however, quantification of the optimum level of harvest remains to be explored. Shrub vegetation appeared to buffer the harvest impact on plant density, possibly through the retention of additional moisture. To maintain population viability, we suggest regulating harvest, for example, by introducing rotational harvest systems, ensuring that a sufficient number of reproductive individuals are left as a source of propagules in each harvested population and that populations are given time to recover between harvests.
RESUMEN
The management of invasive species is a complex, yet an essential component of biodiversity conservation and environmental management for sustainable futures. Despite a well-established linkage between biological invasions and human activities, the social dimension of invasive species management is less explored as compared to the ecological aspects. In recent years, the active participation of local communities, such as assessing levels of awareness and the selection of targeted species prioritized by communities, has been considered as a crucial element for managing invasive species. We conducted 32 focus group discussions (FGDs) including 218 participants in Chitwan-Annapurna Landscape (ChAL) of central Nepal, to assess knowledge and perceptions of agrarian and forest-dependent communities about invasive alien plants (IAPs), document the efforts of the community management of IAPs and prioritize IAPs for management. In the prioritization exercise, participants of each FGD were asked to rank three IAPs using scoring methods and to express their experience about the effects of the selected IAPs on humans and the environment. We found that communities had a living memory of the arrival of some of the IAPs in their locality without knowing the exotic nature of IAPs. Biodiversity loss, livestock poisoning, reduced agricultural production and forage supply, and negative impact on forest regeneration were reported as major negative impacts of IAPs. Communities also reportedly utilized IAPs for medicinal purposes, making compost by using biomass, and controlling floods and landslides. None of the government and non-governmental organizations working in the sectors of biodiversity conservation and environmental management has informed local forest-dependent agrarian communities about the consequences of biological invasions and management of IAPs. However, local communities had already started controlling the spread of some IAPs through manual uprooting. They were able to spot, identify and prioritize IAPs for management and some of the prioritized species were among the world's worst invasive species. Ageratum houstonianum was the top-ranked worst invasive species in agroecosystems while Chromolaena odorata and Ageratina adenophora were the top-ranked worst species in natural ecosystems. Our findings will be useful for guiding community education programs as well as the management of IAPs through formal policy and management plans, such as Nepal's National Biodiversity Strategy and Action Plan.
Asunto(s)
Especies Introducidas , Fenómenos Fisiológicos de las Plantas , Agricultura , Biodiversidad , Biomasa , Bosques , Actividades Humanas , Humanos , Nepal , Percepción , PlantasRESUMEN
Invasive alien plant species (IAPS) can pose severe threats to biodiversity and stability of native ecosystems, therefore, predicting the distribution of the IAPS plays a crucial role in effective planning and management of ecosystems. In the present study, we use Maximum Entropy (MaxEnt) modelling approach to predict the potential of distribution of eleven IAPS under future climatic conditions under RCP 2.6 and RCP 8.5 in part of Kailash sacred landscape region in Western Himalaya. Based on the model predictions, distribution of most of these invasive plants is expected to expand under future climatic scenarios, which might pose a serious threat to the native ecosystems through competition for resources in the study area. Native scrublands and subtropical needle-leaved forests will be the most affected ecosystems by the expansion of these IAPS. The present study is first of its kind in the Kailash Sacred Landscape in the field of invasive plants and the predictions of potential distribution under future climatic conditions from our study could help decision makers in planning and managing these forest ecosystems effectively.
Asunto(s)
Biodiversidad , Cambio Climático , Ecosistema , Especies Introducidas , Plantas , Geografía , Imágenes SatelitalesRESUMEN
Macrofungi constitute a group of the high-value forest resources worldwide. In this paper, we report species richness and composition of the macrofungi in sal (Shorea robusta) forests of mid-hill central Nepal, which were managed for 4-29 years by the local communities. The sal forests were rich in macrofungi (115 species) with Polyporaceae being the largest family followed by Clavariaceae. Saprotrophic fungi were more common than mycorrhizal species. The proportion of mycorrhiza was <40% of the total macrofungi species which might have indicated the deteriorated condition of the forests before the initiation of conservation management. However, the proportion of mycorrhizal species was slightly higher in the forests managed for >10 years than in the forests managed for short period. The species richness increased with increasing canopy and litter cover. Since silvicultural activities and resource utilization often have negative impacts to macrofungal diversity, these activities need to be optimized to keep balance between forest management and biodiversity conservation.
RESUMEN
Our ongoing studies of Nepalese medicinal plants has led to the isolation and characterization of five new triterpenes, two known triterpenes and two phenolic derivatives from Abies spectabilis (D.Don) Mirb leaves grown in the high mountain. The structures of the isolated compounds were characterized by means of 1D and 2D NMR spectroscopic and MS techniques.
Asunto(s)
Abies/química , Hojas de la Planta/química , Triterpenos/química , Espectroscopía de Resonancia Magnética , Estructura Molecular , NepalRESUMEN
One new glycoside derivative from syringic acid and one new phenol glycoside, curculigoside E (1) and orchioside D (2), were isolated and characterized from the rootstock of Curculigo orchioides collected in the Nawalparasi District (Nepal). The structures of the new isolated compounds were elucidated by means of spectroscopic methods such as 1D, 2D NMR and MS.
Asunto(s)
Curculigo/química , Glicósidos/aislamiento & purificación , Fenoles/aislamiento & purificación , Glicósidos/química , Estructura Molecular , Fenoles/química , Extractos Vegetales/química , Extractos Vegetales/aislamiento & purificación , Raíces de PlantasRESUMEN
Three new flavonoid glycosides, 3-O-[beta-D-glucopyranosyl-(1-->3)-(4-O-trans-p-coumaroyl)-alpha-L-rhamnopyranosyl-(1-->6)-beta-D-glucopyranosyl]-7-O-[beta-D-glucopyranosyl-(1-->3)-alpha-L-rhamnopyranosyl]kaempferol, 3-O-[beta-D-glucopyranosyl-(1-->3)-(4-O-trans-p-coumaroyl)-alpha-L-rhamnopyranosyl-(1-->6)-beta-D-glucopyranosyl]-7-O-[beta-D-glucopyranosyl-(1-->3)-alpha-L-rhamnopyranosyl]quercetin and 7-O-[beta-D-glucopyranosyl-(1-->3)-alpha-L-rhamnopyranosyl]quercetin were isolated from the aqueous extract of the aerial parts of Aconitum naviculare. Their structures were elucidated by spectral analysis (HRAPI-TOF MS, 1H, 13C NMR, HMQC, HMBC, DFQ-COSY, ROESY and TOCSY).