Does carbon addition to soil counteract disturbance-promoted alien plant invasions?

Abstract: Addition of carbon to the soil promotes microbial immobilization of plantavailable nutrients, and is being considered as a method to counter alien plant invasions, particularly in disturbed habitats. In the present study the response of three confamilial alien invasive species, Anthemis cotula, Conyza canadensis, and Galinsoga parviflora, to independent and interactive effects of soil tillage (soil disturbance) and sawdust incorporation into soil (carbon addition) was investigated in terms of plant density, height, number of capitula per plant, and root, shoot and whole-plant dry mass. These attributes were favourably promoted by soil disturbance, particularly in Anthemis cotula and Conyza canadensis, but the magnitude of increase in different traits was highly species-specific. Addition of sawdust significantly reduced disturbance-mediated increase in most of the investigated traits. Despite differences in response of alien invasive species to soil manipulations, carbon addition could be used as a countermeasure to effectively combat some alien plant invasions. Resumen: La adición de carbón al suelo promueve la inmovilización microbiana de nutrientes disponibles para las plantas y está siendo considerada como un método para contener las invasiones de plantas exóticas, particularmente en hábitats perturbados. En el presente estudio se investigó la respuesta de tres especies invasoras exóticas confamiliares, Anthemis cotula, Conyza canadensis y Galinsoga parviflora, a los efectos independientes e interactivos del arado del suelo (disturbio del suelo) y la incorporación de aserrín al suelo (adición de carbón), en términos de densidad de plantas, altura, número de capítulos por planta, y masa seca de la raíz, del vástago y de la planta completa. Estos atributos fueron promovidos favorablemente por el disturbio del suelo, particularmente en Anthemis cotula y Conyza canadensis, pero la magnitud del aumento de los diferentes rasgos fue claramente específica de la especie. La adición de aserrín redujo significativamente el incremento resultante del disturbio en la mayoría de los rasgos investigados. No obstante las diferencias en las respuestas de las especies invasoras exóticas a las manipulaciones del suelo, la adición de carbón podría ser usada como una medida de combate efectivo contra algunas invasiones de plantas exóticas. Resumo: A adição de carbono no solo promove a imobilização microbiana dos nutrientes disponíveis, e tem sido considerado como um método para conter a invasão de plantas alieligenas, particularmente em habitats disturbados. No estudo presente, a resposta de três espécies exóticas confamiliares invasivas, a Anthemis cotula, a Conyza canadensis, e a Galinsoga parviflora, para provocar efeitos independentes e interactivos da lavoura do solo (distúrbio no solo), e da incorporação da serradura no mesmo (adição de carbono) foi investigada em termos da densidade das plantas, altura, número de capítulos por planta, raízes e massa seca de todas as plantas. Estes atributos foram promovidos favoravelmente pelo distúrbio do solo, particularmente na Anthemis cotula e na Conyza Canadensis se bem que a dimensão do aumento das diferentes características fosse altamente específico da espécie. A adição da serradura reduziu significativamente o aumento mediado do distúrbio em muitas das características investigadas. Apesar das diferenças na resposta das espécies alienígena invasoras às manipulações do solo, a adição de carbono pode ser usada como uma contra medid

Characterization and identification of Russula firmula and Russula postiana from Himalayan moist temperate forests of Kashmir

Two ectomycorrhizal species of genus Russula: Russula postiana and Russula firmula (Basidiomycota, Agaricales) have been characterized and identified from Kashmir Himalaya using morpho-anatomical and molecular methods targeting its rDNA. The target internal transcribe spacer (ITS)-rDNA of both species was amplified using polymerase chain reaction (PCR) with universal fungal primers (ITS1 and ITS4), which generated 700 bp fragments. After sequencing of amplified product, the initial blast analysis revealed and confirmed the identification of both species by comparing the sequences of these respective species present in GenBank. Further, in phylogenetic analysis both species distinctly clustered with their respective groups. Morphological characteristics like shape, size and colour of pileus, stipe and gills, basidiospore size of both the species was measured and compared with data given in literature.Keywords: Ectomycorrhizal, morpho-anatomical, sequencing, phylogeneticAfrican Journal of Biotechnology Vol. 12(23), pp. 3643-364

Adventitious root formation in branch cuttings of Taxus wallichiana Zucc.(Himalayan yew): A clonal approach to conserve the scarce resource

Himalayan yew (Taxus wallichiana Zucc.), is an economically valuable plant and critically endangered due to overexploitation for the isolation of Taxol,an exciting anticancer drug from its bark and leaves. Since the species is unisexual and due to its long seed dormancy period and rapid loss of viability coupled with low survival percentage, its natural regeneration from seeds is very poor. As the seed raised plants add little growth, propagation by stem cuttings was tried under natural conditions and a considerable success was achieved after making use of different auxins (Indole-3- Acetic Acid-IAA, Indole Butyric Acid-IBA and Naphthalene Acetic Acid-NAA) in different concentrations. A Randomized block design (RBD) was adopted for laying the experiment of the present study. Of the ten treatments studied, IBA at 500ppm performed best of all the treatments and registered higher callusing percentage, rooting percentage, number of roots and length of roots in the juvenile shoot cuttings of the species. The results achieved through the application ofplant growth regulators (PGRs)by way of adventitious root formation (ARF) could be useful for the management of this understory coniferous tree species, whether for conservation, habitat restoration or for the production of Taxol,a promising anti-cancer agent. The technique evolved will be the most handy, quickest, inexpensive and can be applied any where in its natural habitat for the restoration and restocking of this valuable plant, which is otherwise facing the peril of extinction throughout the range of its distribution including Indian Himalayas

STANDARDIZATION OF SEED VIABILITY PROTOCOL FOR PINUS WALLICHIANA A.B.JACKSON IN KASHMIR, INDIA

ABSTRACT Pinus wallichiana seeds were subjected to tetrazolium test in order to evaluate their viability characteristics. Seeds were soaked in distilled water for 24 hours followed by soaking in 1% tetrazolium salt and incubated at 30 o C ±1 temperature in dark for 36 hours. Six staining patterns were recognized. Root mean square method was applied to determine the viable categories. Three staining patterns represented viable and three non-viable seeds. The tetrazolium staining, an established method of testing seed viability was compared with germination test. Nine seed lots were tested by each method .A close relationship was observed in the results of TTC test and germination test in the present investigation. The tetrazolium staining technique thus potentially provides an immediate and rapid method for determining seed viability

Typha orientalis Presl (Typhaceae): a new species record for India

Typha orientalis C. Presl (Typhaceae) is recorded for the first time from the Kashmir Himalaya, India.and for the first time in the entire Indian sub-continent. A detailed taxonomic description and photographs of the diagnostic characters are provided to facilitate its identification in the field. Also provided are diagnostic characters used to distinguish T. orientalis C. Presl from T. latifolia L

Effect of Some Alien Invasive Plant Species on Soil Microbial Structure and Function

key driver of global environmental change is the invasion of ecosystems by alien species, many of which attain sufficiently high abundance to alter ecosystem structure and function (D‘Antonio and Vitousek, 1992; Ogle et al., 2003; Meffin et al., 2010). Biological invasions affect virtually all ecosystems on earth, but the extent of invasion of different regions and biomes, and the quality of information emanating from them varies greatly (Foxcroft et al., 2010). The invasions by alien species are also known to impact ecosystem services (Charles and Dukes, 2008) and human well-being (Pejchar and Mooney, 2009; Vilà et al., 2011). Invasive alien plants, because of their ability to alter ecological processes, such as carbon and nitrogen cycling (Liao et al., 2008; Ehrenfeld, 2010), hydrological cycles (Calder and Dye, 2001), frequency and/or intensity of fire (Brooks et al., 2004) and alteration of the normal disturbance regimes in the native communities (D‗Antonio and Meyerson, 2002; Werner et al., 2010), have transformed many ecosystems by out competing native species (Lankau, 2010) and thus, are rightly regarded as one of the most substantial threats to biodiversity on earth (Cronk and Fuller, 1995; Chapin et al., 2000; Kowarik, 2003; Werner et al., 2010). Invasive species are known to directly compete for resources with native species (Werner et al., 2010), disrupt inherent co-evolved interactions among long-associated native species (Callaway and Aschehoug, 2000; Callaway et al., 2008; Werner et al., 2010; Zhang et al., 2010), like pollination (Butz Huryn, 1997; Simberloff and Von Holle, 1999; Chittka and Schürkens, 2001; Aizen et al., 2008) and seed dispersal (Knight, 1986; Riera et al., 2002; Traveset and Riera, 2005; Cavallero and Raffaele, 2010) and result in modification of interspecific interactions, community structure, and ecosystem processes in the native communities (Vitousek et al., 1997; Lonsdale, 1999; Richardson et al., 2000; Ehrenfeld et al., 2001; Le Maitre et al., 2002; Karl et al., 2005; Traveset and Richardson, 2006; Emer and Fonseca, 2011). Recent global meta-analysis of 199 A Ph. D Thesis 18 research studies dealing with 1041 field studies involving 135 alien plant taxa revealed that abundance and diversity of resident species decreased in invaded sites, whereas primary production and several other ecosystem processes were enhanced (Vilà et al., 2011). But most of the studies exploring the effects of plant invasions have focused on aboveground flora and fauna (Levine et al., 2003), although soil organisms play important roles in regulating ecosystem-level processes (Wardle et al., 2004), and soils contain much of the biodiversity of terrestrial ecosystems (Torsvik et al., 1990; Vandenkoornhuyse et al., 2002), because aboveground communities are relatively easy to observe and quantify (Belnap and Phillips, 2001) and also because there are methodological limitations in studying belowground diversity. As a result, few studies to date have considered the effects of invasive organisms on the abundance, composition and activity of the soil biota. However, the advent of tools and techniques that exploit presence of signature biomolecules, such as Phospholipid Fatty Acids (PLFA), Denaturing Gradient Gel Electrophoresis (DGGE), Terminal Restriction Fragment Length Polymorphism (T-RFLP) etc. has revolutionized the field of soil microbial ecology. These techniques have been used to monitor changes in microbial communities in many plant invasion studies (Meyer, 1994; Kourtev et al., 2002a, 2003; Angeloni et al., 2006; Batten et al., 2006; Li et al., 2006; Kulmatiski and Beard, 2008; Zhang et al., 2010), and the results have revealed that invasive alien plants may suppress harmful rhizosphere soil microbes (Bais et al., 2004a; Lorenzo et al., 2010) and enrich beneficial ones thereby establishing positive feedback which could contribute to their proliferation (Klironomos, 2002; Batten et al., 2006; Kulmatiski and Beard, 2008; Sanon et al., 2011) to the detriment of native biodiversity (Callaway et al., 2004a; Lorenzo et al., 2010). On the other hand, several studies have also revealed negative effect of invasive plants on soil fungi due to invasion by Bromus tectorum (Belnap et al., 2005), arbuscular mycorrhizal fungi in Ph. D Thesis 19 response to dominance of non-mycorrhizal Alliaria petiolata in North American forests (Roberts and Anderson, 2001; Wolfe and Klironomos, 2005; Stinson et al., 2006; Callaway et al., 2008; Wolfe et al., 2008; Pringle et al., 2009; Vogelsang and Bever, 2009), microbial biomass C and ratio of fungi to bacteria due to Falcataria moluccana (Allison et al., 2006), both soil fungi as well as bacteria due to Acacia dealbata invasion (Lorenzo et al., 2010). Invasive alien plants also significantly influence catabolic diversity of the soil microbial communities through their impact on the activity of soil enzymes, which represent a link between litter decomposition, microbial activity, and nutrient availability (Sinsabaugh et al., 2000; Elk, 2010). The influence of exotic plants on the activity of soil enzymes has been reported by several workers (Kourtev et al., 2002b; Allison et al., 2006; Chapuis-Lardy et al., 2006; Li et al., 2006; Fan et al., 2010). It is clear from the growing number of studies that invasive alien species can alter ecosystem processes through a wide variety of mechanisms, over a variety of spatial and temporal scales (Ehrenfeld, 2010). Indeed, multiple mechanisms have been indentified that interact and reinforce each other in bringing about ecosystem change. Thus, it is necessary to search for mechanisms of impact of invasive alien species through documentation of interacting mechanisms, rather than to focus on single causative pathways as a ―holy grail‘ of universal explanation (Simberloff, 2010). The need for studies that explore the impact of invasive alien species has assumed urgency in India and Kashmir in view of reported occurrence of 1,599 species, belonging to 842 genera in 161 families in India representing 8.5% of the total Indian vascular flora (Khuroo et al., 2011). Likewise, total alien flora of the Kashmir Himalaya is represented by 571 plant species, belonging to 352 genera and 104 families. Of the 787 and 436 species that have either escaped from Ph. D Thesis 20 intentional cultivation, or spread after unintentional introduction in India and Kashmir, respectively, 225 species are invasive in India (Khuroo et al., 2011) and 77 species are invasive in Kashmir (Khuroo et al., 2008). While studies related to demography phenotypic plasticity (Allaie et al., 2005), allelopathy (Allaie et al., 2006), mycorrhizal mutualism (Shah and Reshi, 2007; Shah et al., 2008a and b), herbivore induced over-compensatory growth (Rashid et al., 2006) and seed germination (Rashid et al., 2007) have been carried out on various invasive plant species in Kashmir, very few studies have documented the impact of alien species (Shah et al., 2008a; Khuroo et. al., 2010) in the Kashmir Valley. It is because of these lacunae that broad quantitative syntheses of how impacts vary in response to the attributes of recipient ecosystems and of the invaders themselves (Levine et al., 2003) are not available. This absence of a broad-scale assessment limits the ability to generalize and predict when and where impacts might be most deleterious (Vilà et al., 2011). Besides, there are many studies in which the same invasive alien species causes quite different impacts on ecosystem processes at different sites or at different times. This variability in effect emphasizes the importance of ecological context in understanding and anticipating impact on ecosystems. It is in this context that the present study was carried out to evaluate the impact of three invasive alien plant species, namely Conyza canadensis (L.) Cronq. Sambucus wightiana Wall. ex Wt. and Arn. and Anthemis cotula L. on soil microbial structure and function. While S. wightiana (Adoxaceae) invades the understory of coniferous forests in the Kashmir Valley, A. cotula and C. canadensis (both belonging to Asteraceae) are dominant elements of vegetation in ruderal habitats. The specific questions addressed during the present study were

Silicon Supplementation of Rescuegrass Reduces Herbivory by a Grasshopper

The theory of coevolution suggests that herbivores play an important role in the diversification and composition of plant communities. A prevalent idea holds that grasses and grazing animals participated in an evolutionary “arms race” as grassland ecosystems started spreading across the continents. In this race, besides other things, silicification in the form of phytoliths occurred in the grasses, and the graminivorous herbivores responded through specialized mandibles to feed on plants rich in phytoliths. It is important to understand whether these mandibles equip the herbivores in different environments or the grasses can augment their defense by channelizing their energy in high resource milieu. Here we used rescuegrass (Bromus catharticus; Family: Poaceae), an alien species of South America, to understand the mechanism of resistance offered by this species against a local insect herbivore (Oxya grandis; Family: Acrididae), graminivorous grasshopper, in different silicon-rich environments. We used different concentrations of silicon and observed the types of phytoliths formed after Si amendments and studied the effect of phytoliths on mandible wear of the grasshopper. Silicon concentrations increased ca. 12 fold in the highest supplementation treatments. The results reveal that higher foliar silica concentration in Si-rich plants did not result in changing the morphology of the phytoliths; still the leaf tissue consumption was lower in higher Si treatments, perhaps due to mandibular wear of the grasshoppers. The study opens a new dimension of investigating the role of Si amendments in reducing herbivory

Think globally, measure locally: The MIREN standardized protocol for monitoring plant species distributions along elevation gradients

Climate change and other global change drivers threaten plant diversity in mountains worldwide. A widely documented response to such environmental modifications is for plant species to change their elevational ranges. Range shifts are often idiosyncratic and difficult to generalize, partly due to variation in sampling methods. There is thus a need for a standardized monitoring strategy that can be applied across mountain regions to assess distribution changes and community turnover of native and non-native plant species over space and time. Here, we present a conceptually intuitive and standardized protocol developed by the Mountain Invasion Research Network (MIREN) to systematically quantify global patterns of native and non-native species distributions along elevation gradients and shifts arising from interactive effects of climate change and human disturbance. Usually repeated every five years, surveys consist of 20 sample sites located at equal elevation increments along three replicate roads per sampling region. At each site, three plots extend from the side of a mountain road into surrounding natural vegetation. The protocol has been successfully used in 18 regions worldwide from 2007 to present. Analyses of one point in time already generated some salient results, and revealed region-specific elevational patterns of native plant species richness, but a globally consistent elevational decline in non-native species richness. Non-native plants were also more abundant directly adjacent to road edges, suggesting that disturbed roadsides serve as a vector for invasions into mountains. From the upcoming analyses of time series, even more exciting results can be expected, especially about range shifts. Implementing the protocol in more mountain regions globally would help to generate a more complete picture of how global change alters species distributions. This would inform conservation policy in mountain ecosystems, where some conservation policies remain poorly implemented

Floristic composition and diversity patterns of vascular plants in mountain meadow of Gurez valley, Kashmir, India

Floristic composition and diversity patterns of vascular plants along an altitudinal transect (3300‒3900m a.s.l.) in relation to anthropogenic disturbance, edaphic variables and slope were studied in an alpine rangeland of Gurez valley, Kashmir. A total of 111 plant species belonging to 36 families and 86 genera were recorded over 245 quadrats that were placed at seven sites. Evaluated on species richness, diversity (alpha and beta) and composition was negatively correlated to altitude, though the relationship was not monotonic. Matching the changes in floristic composition and richness to various environmental variables through canonical correspondence analysis further strengthened the importance of altitude in influencing species composition. Species tolerant of trampling and other disturbances were dominant at largely disturbed lower altitudes (3700m) their dominance decreased considerably, suggesting that anthropogenic disturbance is also important in influencing species composition. Our results showed that species turnover rates were high at higher (>3500m) altitudes. The study provides an insight on the plant composition of this region and accentuates the need for its proper conservation