Plant Identity Research Articles

Host Phylogenetic Relatedness and Soil Nutrients Shape Ectomycorrhizal Community Composition in Native and Exotic Pine Plantations

Exotic non-native Pinus species have been widely planted or become naturalized in many parts of the world. Pines rely on ectomycorrhizal (ECM) fungi mutualisms to overcome barriers to establishment, yet the degree to which host specificity and edaphic preferences influence ECM community composition remains poorly understood. In this study, we used high-throughput sequencing coupled with soil analyses to investigate the effect of host plant identity, spatial distance and edaphic factors on ECM community composition in young (30-year-old) native (Pinus massoniana Lamb.) and exotic (Pinus elliottii Engelm.) pine plantations in China. The ECM fungal communities comprised 43 species with the majority belonging to the Thelephoraceae and Russulaceae. Most species were found associated with both host trees while certain native ECM taxa (Suillus) showed host specificity to the native P. massoniana. ECM fungi that are known to occur exclusively with Pinus (e.g., Rhizopogon) were uncommon. We found no significant effect of host identity on ECM communities, i.e., phylogenetically related pines shared similar ECM fungal communities. Instead, ECM fungal community composition was strongly influenced by site-specific abiotic factors and dispersal. These findings reinforce the idea that taxonomic relatedness might be a factor promoting ECM colonization in exotic pines but that shifts in ECM communities may also be context-dependent.

Feedbacks of plant identity and diversity on the diversity and community composition of rhizosphere microbiomes from a long‐term biodiversity experiment

Soil microbes are known to be key drivers of several essential ecosystem processes such as nutrient cycling, plant productivity and the maintenance of plant species diversity. However, how plant species diversity and identity affect soil microbial diversity and community composition in the rhizosphere is largely unknown. We tested whether, over the course of 11years, distinct soil bacterial communities developed under plant monocultures and mixtures, and if over this time frame plants with a monoculture or mixture history changed in the bacterial communities they associated with. For eight species, we grew offspring of plants that had been grown for 11years in the same field monocultures or mixtures (plant history in monoculture vs. mixture) in pots inoculated with microbes extracted from the field monoculture and mixture soils attached to the roots of the host plants (soil legacy). After 5months of growth in the glasshouse, we collected rhizosphere soil from each plant and used 16S rRNA gene sequencing to determine the community composition and diversity of the bacterial communities. Bacterial community structure in the plant rhizosphere was primarily determined by soil legacy and by plant species identity, but not by plant history. In seven of the eight plant species the number of individual operational taxonomic units with increased abundance was larger when inoculated with microbes from mixture soil. We conclude that plant species richness can affect below-ground community composition and diversity, feeding back to the assemblage of rhizosphere bacterial communities in newly establishing plants via the legacy in soil.

Documentation of Major Poisonous Plant on Livestock in Ethiopia

The review was conducted with the objective of documenting potentially poisonous plants in Ethiopia. One of the major causes of economic loss in the livestock industry is Poisonous plants especially in the developing country including Ethiopia. In each year poisonous plant affect 3 to 5 percent of the cattle, sheep, goat, and horses that graze ranges. Major loss caused by these plants result from death of livestock, abortions, photosensitization, decreased production, emaciation, and birth defects and also they have other losses due to increased management costs associated with such things as fencing to prevent access of animals to these plants , altered grazing programs, and loss of forage due to removal of these plants. Livestock mostly exposed to toxic plants in dry and early rainy season when feed is in short supply. In this documentation 71 different plants identified from four different area of the country were collected from different governmental and non-governmental organizations and published papers. A more extensive survey is required to document all poisonous plants in the rangelands and to identify the major toxic principles in the different species possibly pharmacological activity. This documentation review the current knowledge on the identity of plants known to have poisoned livestock and research conducted into these toxic plants.

A fitness cost resulting from Hamiltonella defensa infection is associated with altered probing and feeding behaviour in Rhopalosiphum padi.

Many herbivorous arthropods, including aphids, frequently associate with facultative endosymbiotic bacteria, which influence arthropod physiology and fitness. In aphids, endosymbionts can increase resistance against natural enemies, enhance aphid virulence and alter aphid fitness. Here, we used the electrical penetration graph technique to uncover physiological processes at the insect-plant interface affected by endosymbiont infection. We monitored the feeding and probing behaviour of four independent clonal lines of the cereal-feeding aphid Rhopalosiphum padi derived from the same multilocus genotype containing differential infection (+/-) with a common facultative endosymbiont, Hamiltonella defensa Aphid feeding was examined on a partially resistant wild relative of barley known to impair aphid fitness and a susceptible commercial barley cultivar. Compared with uninfected aphids, endosymbiont-infected aphids on both plant species exhibited a twofold increase in the number of plant cell punctures, a 50% reduction in the duration of each cellular puncture and a twofold higher probability of achieving sustained phloem ingestion. Feeding behaviour was also altered by host plant identity: endosymbiont-infected aphids spent less time probing plant tissue, required twice as many probes to reach the phloem and showed a 44% reduction in phloem ingestion when feeding on the wild barley relative compared with the susceptible commercial cultivar. Reduced feeding success could explain the 22% reduction in growth of H. defensa-infected aphids measured on the wild barley relative. This study provides the first demonstration of mechanisms at the aphid-plant interface contributing to physiological effects of endosymbiont infection on aphid fitness, through altered feeding processes on different quality host plants.

A Robust Auxin Response Network Controls Embryo and Suspensor Development through a Basic Helix Loop Helix Transcriptional Module.

Land plants reproduce sexually by developing an embryo from a fertilized egg cell. However, embryos can also be formed from other cell types in many plant species. Thus, a key question is how embryo identity in plants is controlled, and how this process is modified during nonzygotic embryogenesis. The Arabidopsis (Arabidopsis thaliana) zygote divides to produce an embryonic lineage and an extra-embryonic suspensor. Yet, normally quiescent suspensor cells can develop a second embryo when the initial embryo is damaged, or when response to the signaling molecule auxin is locally blocked. Here we used auxin-dependent suspensor embryogenesis as a model to determine transcriptome changes during embryonic reprogramming. We found that reprogramming is complex and accompanied by large transcriptomic changes before anatomical changes. This analysis revealed a strong enrichment for genes encoding components of auxin homeostasis and response among misregulated genes. Strikingly, deregulation among multiple auxin-related gene families converged upon the re-establishment of cellular auxin levels or response. This finding points to a remarkable degree of feedback regulation to create resilience in the auxin response during embryo development. Starting from the transcriptome of auxin-deregulated embryos, we identified an auxin-dependent basic Helix Loop Helix transcription factor network that mediates the activity of this hormone in suppressing embryo development from the suspensor.

The Epidemiology of Xylella fastidiosa; A Perspective on Current Knowledge and Framework to Investigate Plant Host-Vector-Pathogen Interactions.

Insect-transmitted plant diseases caused by viruses, phytoplasmas, and bacteria share many features in common regardless of the causal agent. This perspective aims to show how a model framework, developed originally for plant virus diseases, can be modified for the case of diseases incited by Xylella fastidiosa. In particular, the model framework enables the specification of a simple but quite general invasion criterion defined in terms of key plant, pathogen, and vector parameters and, importantly, their interactions, which determine whether or not an incursion or isolated outbreak of a pathogen will lead to establishment, persistence, and subsequent epidemic development. Hence, this approach is applicable to the wide range of X. fastidiosa-incited diseases that have recently emerged in southern Europe, each with differing host plant, pathogen subspecies, and vector identities. Of particular importance are parameters relating to vector abundance and activity, transmission characteristics, and behavior in relation to preferences for host infection status. Some gaps in knowledge with regard to the developing situation in Europe are noted.

Rhizosphere Microbial Communities of Spartina alterniflora and Juncus roemerianus From Restored and Natural Tidal Marshes on Deer Island, Mississippi.

The U. S. Gulf of Mexico is experiencing a dramatic increase in tidal marsh restoration actions, which involves planting coastal areas with smooth cordgrass (Spartina alterniflora) and black needlerush (Juncus roemerianus) for erosion control and to provide habitat for fish and wildlife. It can take decades for sedimentary cycles in restored marshes to approach reference conditions, and the contribution of the sediment microbial communities to these processes is poorly elucidated. In this study, we addressed this gap by comparing rhizosphere microbiomes of S. alterniflora and J. roemerianus from two restored marshes and a natural reference marsh located at Deer Island, MS. Our results revealed that plants from the restored and reference areas supported similar microbial diversity indicating the rapid colonization of planted grasses with indigenous soil microbiota. Although close in composition, the microbial communities from the three studied sites differed significantly in the relative abundance of specific taxa. The observed differences are likely driven by the host plant identity and properties of sediment material used for the creation of restored marshes. Some of the differentially distributed groups of bacteria include taxa involved in the cycling of carbon, nitrogen, and sulfur, and may influence the succession of vegetation at the restored sites to climax condition. We also demonstrated that plants from the restored and reference sites vary in the frequency of culturable rhizobacteria that exhibit traits commonly associated with the promotion of plant growth and suppression of phytopathogenic fungi. Our findings will contribute to the establishment of benchmarks for the assessment of the outcome of coastal restoration projects in the Gulf of Mexico and better define factors that affect the long-term resiliency of tidal marshes and their vulnerability to climate change.

Specificity of plant-plant communication for Baccharis salicifolia sexes but not genotypes.

Plants are able to adjust their anti-herbivore defenses in response to the volatile organic compounds (VOCs) emitted by herbivore-damaged neighbors, and some of these changes increase resistance against subsequent herbivory. This phenomenon of plant-plant communication is thought to be widespread, but recent investigations have cautioned that it can be context dependent, including variation in the strength of communication based on the identity of plants and their associated herbivores. Here, we performed three greenhouse experiments using multiple male and female genotypes of the dioecious woody shrub Baccharis salicifolia and its specialist aphid Uroleucon macolai to test for specificity of plant-plant communication with respect to plant sex and genotype. Moreover, we evaluated plant sexual dimorphism and genotypic variation in VOC emissions (i.e., the "speaking" side of the interaction) and response of plants to VOC exposure (i.e., the "listening" side of the interaction) in order to identify the chemical mechanisms underlying such specificity. We did not find genotypic specificity of communication; emitter plants damaged by U.macolai significantly reduced subsequent U.macolai performance on receivers, but these effects were indistinguishable for communication within vs. among genotypes. In contrast, we found sex specificity of communication; male emitter plants reduced subsequent U.macolai performance on male and female receiver plants equally, while female emitter plants only did so for female receivers. We found sexual (but not genotypic) dimorphism in speaking but not listening; of the seven compounds induced by U.macolai feeding (speaking), pinocarvone was approximately fivefold greater in female than in male plants, while exposure of plants to pinocarvone emissions (listening) reduced U.macolai performance equally in both male and female plants. Together, our study demonstrates novel evidence for sexually dimorphic specificity of plant-plant communication and the chemical mechanism underlying this effect.

Wing morphology in migratory North American monarchs: characterizing sources of variation and understanding changes through time

Abstract Monarch butterfly wing morphology varies substantially throughout their global range, both between resident and migratory populations and also within the migratory North American population. Here, we use a dataset comprising more than 1800 North American individuals collected between 1878-2017 to characterize the factors shaping continent-wide patterns of wing morphological variation. North American overwintering butterflies have forewings that are approximately 4.4% larger than those collected in summer breeding areas. Monarchs overwintering in Mexico have forewings that are approximately 1.8% larger than monarchs overwintering in California, conducive to the idea that migration distance is positively correlated with wing area. We find evidence for a latitudinal cline within North America, such that butterflies collected at higher latitudes have significantly larger and more elongated forewings. We also find a significant increase of approximately 4.9% in forewing area between 1878-2017, but no difference through time in wing elongation. This result is corroborated by a reanalysis of a recently published dataset of more than 600 butterflies from Mexican overwintering sites. We discuss possible reasons for this increase in wing size through time, including northward shifts in the monarch’s breeding range and changes in relative abundance of milkweed hosts, and present experimental data addressing the influence of larval host plant on adult wing morphology. Our analysis suggests that (1) migration is indeed an important selective force for monarch wing morphology; (2) wing size has increased through time in North America; (3) factors such as host plant identity must be considered to fully understand monarch wing morphological variation.

A hermaphrodite genotype in dioecious papaya progeny: sex reversal or contamination?

Carica papaya is a trioecious species, which means its plants can exist in three sex forms, namely female (XX), male (XY), and hermaphrodite (XYh). Though infrequent, sex reversal from XY to XYh or vice versa may occur in these plants. This study proposes to investigate the genetic identity of a hermaphrodite plant (M3) identified in a dioecious progeny, determining whether sex reversal or contamination occurred. The following 16 genotypes belonging to the active germplasm bank of papaya of UENF/Caliman were analyzed: eight genotypes of the dioecious progeny (seven females and one male), one hermaphrodite genotype (M3) and seven controls (three females and four hermaphrodites). PCR was performed with 66 loci from the HSY and autosomal regions, in addition to three locus-specific primers. The genetic dissimilarity matrix obtained by the weighted index was used to cluster the individuals via the UPGMA hierarchical method and to project the distances onto the two-dimensional plane. Heterozygosity and inbreeding coefficients were estimated for each accessed region. In terms of descriptive parameters, genotype M3 was similar to the hermaphrodite controls in the HSY region and to the dioecious genotypes in the autosomal region. In the cluster analysis, genotype M3 was near the dioecious genotypes for the HSY region and near the hermaphrodites for the autosomal region. The analysis of distance projection onto the two-dimensional plane corroborated the clustering observed for the 30 loci together. Based on the analysis of the male-specific locus, the hypothesis of occurrence of natural sex reversal was discarded, indicating probable contamination.

Grazer deterrence and fungal inhibition by the invasive marsh grass Phragmites australis and the native sedge Bolboschoenus robustus in a mesohaline marsh

Tidal marsh habitats provide many important functions to coastal areas and are a valuable economic resource. Polyhaline marshes dominated by Spartina alterniflora can experience top-down control by the snail Littoraria irrorata who primarily impact Spartina through facilitating fungal growth on wounds they create. This grazing pressure may have selected for the production of chemical defenses in Spartina and other polyhaline marsh plants that deter snail feeding and fungal growth. Both Spartina and Littoraria can co-occur in mesohaline marshes that line the Chesapeake Bay, but little is known about interactions between this snail and plants in this habitat. Plant diversity, identity, and consumer abundance can differ between poly- and mesohaline marshes, and this may yield different patterns in the two marsh types. We investigated whether two abundant plants in a Chesapeake Bay mesohaline marsh of salinity ~ 13ppt deterred snail feeding and inhibited fungal growth. Through a bioassay-guided fractionation approach, we assessed palatability to snails and growth of the fungus Phaeosphaeria spartinae in response to chemical components in the invasive marsh grass Phragmites australis and the native sedge Bolboschoenus robustus. Both plants possessed chemicals that significantly deterred snail feeding compared to Spartina chemicals. In addition, both plants inhibited fungal growth, mediated by multiple metabolites. Snail density in this marsh was low (25 snails m−2), but may be enough to select for defenses in Bolboschoenus, or deterrent and inhibitory metabolites may be selected for by other consumers or factors. Chemical defenses in invasive Phragmites may contribute to its success in the Chesapeake Bay.

The effect of plant identity and mixed feeding on the detection of seed DNA in regurgitates of carabid beetles.

Carabids are abundant in temperate agroecosystems and play a pivotal role as biocontrol agents for weed seed and pest regulation. While there is good knowledge regarding their effects on invertebrate pests, direct evidence for seed predation in the field is missing. Molecular approaches are ideally suited to investigate these feeding interactions; however, the effects of an omnivorous diet, which is characteristic for many carabid species, and seed identity on the detection success of seed DNA has not yet been investigated. In a series of feeding experiments, seeds of six different Central European weed species were fed to beetles of the species Pseudoophonus rufipes, to determine post‐feeding seed DNA detection rates and how these are affected by plant identity, meal size, and chemical seed composition. Moreover, we investigated the effect of a mixed diet of seeds and mealworm on prey DNA detection. Four out of six seed species were detectable for up to five days after consumption, and seed species identity significantly affected post‐feeding detection rates. Detectability was negatively influenced by protein content and seed mass, whereas oil content and meal size had a positive effect. The mixed diet led to both increased detection rates and post‐feeding detection intervals of seed DNA. This suggests that mixed feeding leads to an enhancement of food detection intervals in carabid beetles and that seed identity, their chemical composition, and meal size can affect DNA detection of consumed seeds. These aspects and potential implications of this non‐invasive approach are discussed as they can become highly relevant for interpreting field‐derived data.

Zingela (Asparagaceae, Scilloideae), a distinct new urgineoid genus from KwaZulu-Natal, South Africa

In the course of resolving the identity of plants usually named ‘Drimia indica’ from KwaZulu-Natal Province, South Africa, molecular and morphological data revealed the identity of more than one taxon carrying this name. Our studies support the establishment of a new urgineoid genus, Zingela gen. nov., to accommodate a species (Z. pooleyorum) collected and illustrated some 50 years ago, but never validly published. We here provide data on its morphology, ecology, and distribution.

Ultra-high-throughput DArTseq-based silicoDArT and SNP markers for genomic studies in macadamia.

Macadamia (Macadamia integrifolia, M. tetraphylla and hybrids) is an Australian native nut crop and has a significant economic value in the food industries worldwide. Long juvenility along with traditional breeding strategies impede quick genetic improvement of this crop. The existing cultivars constitute only second to fourth generation of the wild germplasm in the rainforest. The utilisation of molecular markers for genomic selection and genome-wide association studies may accelerate genetic gains. Identification of a robust, reproducible, and cost-effective marker system is instrumental in increasing the efficiency of genomic studies. This study is the first to report the potential of two ultra-high-throughput diversity array technology (DArT) markers (silicoDArT and SNP) in macadamia. Both markers were used to identify the genetic diversity and population structure in 80 macadamia cultivars. Parentage analysis of 25 scions in a rootstock trial was conducted to confirm plant identity where recorded identities did not corroborate with phenotypic field observations. A total of 22,280 silicoDArT and 7,332 SNP markers were reported, of which 11,526 silicoDArT and 3,956 SNP markers were used for analyses after screening with quality control parameters including >95% call rate, >95% reproducibility, and >0.05 one ratio. The average polymorphic information content (PIC) values of silicoDArT and SNP markers were 0.29 and 0.21, respectively. Genetic variance among the cultivars ranged from 0.003 to 0.738 in silicoDArT and 0.004 to 0.412 in SNP markers. Four distinct population groups were identified from SNP data analysis. Most of the accessions used in this study were descended from two or more populations. Cluster analysis clearly separated genotypes of distinct origins, such as the Hawaii Agricultural Experiment Station and Hidden Valley Plantation accessions. Two wild accessions of Macadamia jansenii and M. ternifolia were found to be distantly related to the cultivars. Wild germplasm individuals and their hybrids with cv. ‘660’ formed separate clusters, suggesting that crossing between wild and cultivated genepools can extend genetic diversity. DArTseq-based SNP markers were successfully utilized to confirm the genetic identity of 25 scions in a rootstock trial. Our study suggests that DArT platforms are a robust system for the facilitation of genomic studies with regard to macadamia.

Regulation of Division and Differentiation of Plant Stem Cells

A major challenge in developmental biology is unraveling the precise regulation of plant stem cell maintenance and the transition to a fully differentiated cell. In this review, we highlight major themes coordinating the acquisition of cell identity and subsequent differentiation in plants. Plant cells are immobile and establish position-dependent cell lineages that rely heavily on external cues. Central players are the hormones auxin and cytokinin, which balance cell division and differentiation during organogenesis. Transcription factors and miRNAs, many of which are mobile in plants, establish gene regulatory networks that communicate cell position and fate. Small peptide signaling also provides positional cues as new cell types emerge from stem cell division and progress through differentiation. These pathways recruit similar players for patterning different organs, emphasizing the modular nature of gene regulatory networks. Finally, we speculate on the outstanding questions in the field and discuss how they may be addressed by emerging technologies.

Conservation conundrum: Endangered predators eating endangered prey

Conservation conundrum: Endangered predators eating endangered prey

Waiting for the Flowers

Since the Royal Botanic Garden Edinburgh (RBGE) was established in 1670 as a collection of medicinal plants, taxonomy has been at its heart. Even before the publication of Linnaeus’s Species Plantarum it was important to establish the correct identity of medicinal plants for use by the doctors of the day. Over the years the location and focus of the Garden have evolved to serve many and varied functions. Taxonomy, however, has continued to play a key role in preserving the special nature of RBGE as a ‘botanic garden’. From the earliest years exotic plants were introduced to the Garden, giving it an international flavour, and this has continued with staff today collaborating with many different gardens and botanical institutions around the world. For over 300 years living plants have been brought to the Garden, grown to maturity and described. Many of the early novelties came from North America and China, especially gymnosperms and rhododendrons. Today, much of our effort is focused on plants from areas that are botanically rich but poorly known, such as the Malesian region, and on families Begoniaceae, Gesneriaceae, Ericaceae and Zingiberaceae. The expertise and ingenuity of the horticultural staff have been essential in cultivating unknown species and bringing them into flower so that they can be scientifically described. This has been aided by an enlightened policy of including horticulturists on collecting expeditions so that their knowledge can be used to bring plants back in good health but also to better understand the natural conditions in which they grow so that the plants can be grown to perfection in Edinburgh.

The mangrove flora and their physical habitat characteristics in Bunaken National Park, North Sulawesi, Indonesia

Djamaluddin R. 2018. The mangrove flora and their physical habitat characteristics in Bunaken National Park, North Sulawesi, Indonesia. Biodiversitas 19: 1303-1312. The mangrove forests of Bunaken National Park are among the most distinctive and unusual in Southeast Asia because of the species that the forests contain. This study investigated the identity and diversity of mangrove plants as well as physiographic factors and major physical processes of every type of sub-habitats. Seven surveys were conducted to collect and identify mangrove species of the park. Sub-habitats where specimen was found, aspects related to tidal inundation, nature of soil, freshwater influence and topography were observed as well as major physical processes influencing the condition of each sub-habitat. The results suggested that the park was floristically rich with at least 27 plant species and they were distributed over ten recognized sub-habitat types in different composition and diversity. Ceriops zippeliana Blume, Lumnitzera racemosa Willd, Lumnitzera littorea (Jack) Voigt., Sonneratia ovata Backer, and Camptostemon philippinense (Vidal) Becc. were found in Bunaken National Park and their presence confirmed the broader distribution limit of these species within Indo-Malesia region. A special notice was for C. philippinense as the distribution limit of this is rarely reported.

Identity of plant, lichen and moss species connects with microbial abundance and soil functioning in Maritime Antarctica.

We lack studies evaluating how the identity of plant, lichen and moss species relates to microbial abundance and soil functioning on Antarctica. If species identity is associated with soil functioning, distributional changes of key species, linked to climate change, could significantly affect Antarctic soil functioning. We evaluated how the identity of six Antarctic plant, lichen and moss species relates to a range of soil attributes (C, N and P cycling), microbial abundance and structure in Livingston Island, Maritime Antarctica. We used an effect size metric to predict the association between species (vs. bare soil) and the measured soil attributes. We observed species-specific effects of the plant and biocrust species on soil attributes and microbial abundance. Phenols, phosphatase and β-D-cellobiosidase activities were the most important attributes characterizing the observed patterns. We found that the evaluated species positively correlated with soil nutrient availability and microbial abundance vs. bare soil. We provide evidence, from a comparative study, that plant and biocrust identity is associated with different levels of soil functioning and microbial abundance in Maritime Antarctica. Our results suggest that changes in the spatial distribution of these species linked to climate change could potentially entail changes in the functioning of Antarctic terrestrial ecosystems.

Forage diversity, type and abundance influence winter resource selection by white‐tailed deer

AbstractQuestionsThe presence of a plant species can influence the selection of another plant species by herbivores. Natural communities encompass several plant species, and in these multi‐species environments, resource selection by herbivores could be partly explained by plant diversity. Our objective was to determine how winter consumption by a large herbivore (white‐tailed deer) varies relative to the diversity and composition of the plant community in a temperate forest. (a) Does browsing increases or decreases with diversity indices; and (b) are specific community compositions linked to high or low browsing by deer? We also aimed to determine whether neighbouring plant diversity and identity could modify browsing on a specific species, Pinus strobus (hereafter pine).LocationVallée de la Gatineau, Québec, Canada.MethodsWe sampled 102 plots in the sugar maple (Acer saccharum)–basswood (Tilia americana) subdomain, a deciduous type of forest in the northern temperate zone. Each plot was centred on a pine and browsing by deer, plot diversity and composition were measured.ResultsTotal browsing and browsing on focal pines decreased with increasing values of diversity indices, but only in plots with high resource abundance. This result is in accordance with optimal foraging principles, as diversified plots have a lower concentration of preferred species. Total consumption did not vary with plot composition, but browsing on the focal pine decreased with increased abundance of Diervilla lonicera and Lonicera canadensis, abundant deciduous shrubs. This associational defence could protect vulnerable pines from deer browsing.ConclusionWhile our study revealed a relationship between plant community diversity and winter browse use and selection by deer, it also highlighted the importance of resource abundance and community composition – variables influencing the resource selection process. Diversity measures can describe vegetation communities, but probably do not represent the way in which herbivores perceive their environment.