Contrasting patterns of intraspecific trait variability in native and non-native plant species along an elevational gradient on Tenerife, Canary Islands

Abstract Background and Aims Non-native plant species are not restricted to lowlands, but increasingly are invading high elevations. While for both native and non-native species we expected variability of plant functional traits due to the changing environmental conditions along elevational gradients, we additionally assumed that non-native species are characterized by a more acquisitive growth strategy, as traits reflecting such a strategy have been found to correlate with invasion success. Furthermore, the typical lowland introduction of non-native species coming from multiple origins should lead to higher trait variability within populations of non-native species specifically at low elevations, and they might therefore occupy a larger total trait space. Methods Along an elevational gradient ranging from 55 to 1925 m a.s.l. on Tenerife, we collected leaves from eight replicate individuals in eight evenly distributed populations of five native and six non-native forb species. In each population, we measured ten eco-morphological and leaf biochemical traits and calculated trait variability within each population and the total trait space occupied by native and non-native species. Key Results We found both positive (e.g. leaf dry matter content) and negative (e.g. leaf N) correlations with elevation for native species, but only few responses for non-native species. For non-native species, within-population variability of leaf dry matter content and specific leaf area decreased with elevation, but increased for native species. The total trait space occupied by all non-native species was smaller than and a subset of that of native species. Conclusions We found little evidence that intraspecific trait variability is associated with the success of non-native species to spread towards higher elevations. Instead, for non-native species, our results indicate that intermediate trait values that meet the requirements of various conditions are favourable across the changing environmental conditions along elevational gradients. As a consequence, this might prevent non-native species from overcoming abruptly changing environmental conditions, such as when crossing the treeline.

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Two Measurement Methods of Leaf Dry Matter Content Produce Similar Results in a Broad Range of Species

Annals of Botany ◽

10.1093/aob/mcm022 ◽

2007 ◽

Vol 99 (5) ◽

pp. 955-958 ◽

Cited By ~ 26

Author(s):

M. V. Vaieretti ◽

S. Diaz ◽

D. Vile ◽

E. Garnier

Keyword(s):

Dry Matter ◽

Matter Content ◽

Measurement Methods ◽

Dry Matter Content ◽

Leaf Dry Matter Content

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Emerging fungal pathogen of an invasive grass: Implications for competition with native plant species

PLoS ONE ◽

10.1371/journal.pone.0237894 ◽

2021 ◽

Vol 16 (3) ◽

pp. e0237894

Author(s):

Amy E. Kendig ◽

Vida J. Svahnström ◽

Ashish Adhikari ◽

Philip F. Harmon ◽

S. Luke Flory

Keyword(s):

Invasive Species ◽

Plant Species ◽

Fungal Pathogen ◽

Native Species ◽

Grass Species ◽

Leaf Spot Disease ◽

Native Plant ◽

Invasive Grass ◽

Native Plant Species ◽

Species Specific

Infectious diseases and invasive species can be strong drivers of biological systems that may interact to shift plant community composition. For example, disease can modify resource competition between invasive and native species. Invasive species tend to interact with a diversity of native species, and it is unclear how native species differ in response to disease-mediated competition with invasive species. Here, we quantified the biomass responses of three native North American grass species (Dichanthelium clandestinum, Elymus virginicus, and Eragrostis spectabilis) to disease-mediated competition with the non-native invasive grass Microstegium vimineum. The foliar fungal pathogen Bipolaris gigantea has recently emerged in Microstegium populations, causing a leaf spot disease that reduces Microstegium biomass and seed production. In a greenhouse experiment, we examined the effects of B. gigantea inoculation on two components of competitive ability for each native species: growth in the absence of competition and biomass responses to increasing densities of Microstegium. Bipolaris gigantea inoculation affected each of the three native species in unique ways, by increasing (Dichanthelium), decreasing (Elymus), or not changing (Eragrostis) their growth in the absence of competition relative to mock inoculation. Bipolaris gigantea inoculation did not, however, affect Microstegium biomass or mediate the effect of Microstegium density on native plant biomass. Thus, B. gigantea had species-specific effects on native plant competition with Microstegium through species-specific biomass responses to B. gigantea inoculation, but not through modified responses to Microstegium density. Our results suggest that disease may uniquely modify competitive interactions between invasive and native plants for different native plant species.

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Urban conservation gardening in the decade of restoration

10.32942/osf.io/p2syu ◽

2021 ◽

Author(s):

Ingmar Staude ◽

Josiane Segar ◽

Corey Thomas Callaghan ◽

Emma Ladouceur ◽

Jasper Meya ◽

...

Keyword(s):

Plant Species ◽

Native Species ◽

Species Conservation ◽

Plant Conservation ◽

Native Plant ◽

Nature Protection ◽

Urban Conservation ◽

Native Plant Species ◽

Native Seed ◽

Conservation Gardening

Global commitments to species conservation have failed to halt systematic widespread declines in plant species. Current policy interventions, such as protected areas and legal species legislation, remain insufficient, and there is an urgent need to engage novel approaches and actors in conservation. Here, we propose that urban conservation gardening, namely the cultivation of declining native plant species in public and private green spaces, can be one such approach. Conservation gardening can address key (a)biotic drivers of species decline, act as a critical dispersal pathway and increase the occupancy of declining native species. We identify policy mechanisms to upscale conservation gardening to a mainstream activity by reforming the existing horticultural market into an innovative nature protection instrument. This involves incentivizing the integration of the native seed sector, leveraging existing certification and labelling schemes, promoting consumer access, as well as building citizen-science projects to foster public engagement. Mainstreamed conservation gardening can be an economically viable, sustainable, and participatory measure that complements traditional approaches to plant conservation.

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Imperata cylindrica (cogon grass).

10.1079/cpc.28580.20210100324 ◽

2021 ◽

Author(s):

Chris Parker

Keyword(s):

Plant Species ◽

Environmental Conditions ◽

Imperata Cylindrica ◽

Environmental Damage ◽

Native Plant ◽

Natural Areas ◽

Native Plant Species ◽

Wide Range ◽

Allelopathic Effects

Abstract I. cylindrica is a serious weed not only in crops but also in natural areas, causing serious economic and environmental damage. The ability of I. cylindrica to effectively compete for water and nutrients, spread and persist through the production of seeds and rhizomes that can survive a wide range of environmental conditions, and its allelopathic effects and pyrogenic nature, allow it to exclude native plant species and other desirable plants and dominate large areas of land.

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Seed dispersal interactions promoting plant invasions.

Plant invasions: the role of biotic interactions ◽

10.1079/9781789242171.0090 ◽

2020 ◽

pp. 90-104

Author(s):

M. Celeste Díaz Vélez ◽

Ana E. Ferreras ◽

Valeria Paiaro

Keyword(s):

Seed Germination ◽

Seed Dispersal ◽

Seedling Establishment ◽

Native Species ◽

Native Plants ◽

Woody Species ◽

Native Plant ◽

Invasional Meltdown ◽

Native Plant Species ◽

Origin Life

Abstract Animal dispersers are essential for many non-native plants since they facilitate seed movement and might promote seed germination and seedling establishment, thereby increasing their chances of invasion. This chapter reviews the published literature on seed dispersal of non-native plant species by native and/or non-native animals. The following questions are addressed: (i) Are interactions between non-native plants and their animal dispersers evenly studied worldwide? (ii) Which are the distinctive traits (i.e. geographical origin, life form, dispersal strategy and propagule traits) of non-native plants that are dispersed by animals? (iii) Which are the most studied groups of dispersers of non-native plants around the world? (iv) Does the literature provide evidence for the Invasional Meltdown Hypothesis (non-native plant-non-native disperser facilitation)? (v) What is the role of animal dispersers at different stages of the non-native plant regeneration process? Our dataset of 204 articles indicates that geographical distribution of the studies was highly heterogeneous among continents, with the highest number coming from North America and the lowest from Asia and Central America. Most of the non-native plants involved in dispersal studies were woody species from Asia with fleshy fruits dispersed by endozoochory. More than the half of the animal dispersal agents noted were birds, followed by mammals, ants and reptiles. The dominance of bird-dispersal interactions over other animal groups was consistent across geographical regions. Although most of the studies involved only native dispersers, interactions among non-native species were detected, providing support for the existence of invasional meltdown processes. Of the total number of reviewed articles reporting seed removal, 74% evaluated seed dispersal, but only a few studies included seed germination (35.3%), seedling establishment (5.4%) or seed predation (23.5%). Finally, we discuss some research biases and directions for future studies in the area.

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Competition between native and non-native plants.

Plant invasions: the role of biotic interactions ◽

10.1079/9781789242171.0016 ◽

2020 ◽

pp. 291-307

Author(s):

Elizabeth M. Wandrag ◽

◽

Jane A. Catford ◽

◽

...

Keyword(s):

Plant Species ◽

Plant Communities ◽

Native Species ◽

Abiotic Factors ◽

Invasion Biology ◽

Competitive Interactions ◽

Native Plant ◽

Native Plant Species ◽

New Locations ◽

Strength Of Competition

The introduction of species to new locations leads to novel competitive interactions between resident native and newly-arriving non-native species. The nature of these competitive interactions can influence the suitability of the environment for the survival, reproduction and spread of non-native plant species, and the impact those species have on native plant communities. Indeed, the large literature on competition among plants reflects its importance in shaping the composition of plant communities, including the invasion success of non-native species. While competition and invasion theory have historically developed in parallel, the increasing recognition of the synergism between the two themes has led to new insights into how non-native plant species invade native plant communities, and the impacts they have on those plant communities. This chapter provides an entry point into the aspects of competition theory that can help explain the success, dominance and impacts of invasive species. It focuses on resource competition, which arises wherever the resources necessary for establishment, survival, reproduction and spread are in limited supply. It highlights key hypotheses developed in invasion biology that relate to ideas of competition, outlines biotic and abiotic factors that influence the strength of competition and species' relative competitive abilities, and describes when and how competition between non-native and native plant species can influence invasion outcomes. Understanding the processes that influence the strength of competition between non-native and native plant species is a necessary step towards understanding the causes and consequences of biological invasions.

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The Shack Idea

Stories From the Leopold Shack ◽

10.1093/oso/9780190463229.003.0014 ◽

2016 ◽

Author(s):

Estella B. Leopold

Keyword(s):

Native Species ◽

Agricultural Land ◽

Bird Species ◽

New Order ◽

Native Plant ◽

Native Plant Species ◽

Perfect Model ◽

Major Disruption ◽

The Right ◽

Splendid Isolation

As each of us siblings—Starker, Luna, Carl, Nina, and i— matured and entered our professional lives in different parts of the country, we carried with us a hankering to have a place in the country, a Shack of our own. It is not merely real estate, of course. Instead, it is a camping place for feeling close to the land, a place to work with the land and to observe the ecosystem and its fauna. To “own,” or as the first peoples saw it, to “belong” on a piece of land is exciting and special—a chance to become acquainted with a few favorite species, then to watch them grow. But of course it is way more than that. As Dad said, he chose his land for its backwardness, but it flourished in splendid isolation under our care. Shack land, as we conceived of it, had the potential of being inhabited by a vast number of native bird species, plus a diverse fauna of mammals, which got richer with time. We were excited that the Shack landscape itself had such physical variety; it had hills and dales, a grand river, a series of tributaries animated by spring and fall floods, a standing bottomland forest coursed by those floods and occupied by lively muskrats, with ducks flying in and out of the sloughs, as well as kingfishers and jays. Even though it was “degraded” agricultural land, Dad and Mother saw it as a land of opportunities for the family. While it had a “reduced level of complexity,” the soil was still there, and we could help improve it, which actually means that the right plants could make it better. Prairie is the perfect model for this kind of restoration and recovery. Dad described the upward flow of energy from soils through the plant community as a kind of circuit. After major disruption and loss of native species, the energy circuit is slowed and altered. He asked, “Can the land adjust itself to the new order?” He was sure it could if we reintroduced the native plant species on that cornfield, on that terrace, on that hill, in order for a genuine prairie, with its very efficient energy-flow, to become reestablished.

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Slash Pile Burn Scar Restoration: Tradeoffs between Abundance of Non-Native and Native Species

Forests ◽

10.3390/f11080813 ◽

2020 ◽

Vol 11 (8) ◽

pp. 813

Author(s):

Ian Sexton ◽

Philip Turk ◽

Lindsay Ringer ◽

Cynthia S. Brown

Keyword(s):

Plant Species ◽

Native Species ◽

Invasive Plant ◽

Chemical Properties ◽

Rocky Mountain ◽

Native Plant ◽

Burn Scar ◽

Native Plant Species ◽

Burned Areas ◽

Soil Scarification

The accumulation of live and dead trees and other vegetation in forests across the western United States is producing larger and more severe wildfires. To decrease wildfire severity and increase forest resilience, foresters regularly remove excess fuel by burning woody material in piles. This common practice could also cause persistent ecosystem changes such as the alteration of soil physical and chemical properties due to extreme soil heating, which can favor invasion by non-native plant species. The abundance and species richness of native plant communities may also remain depressed for many years after burning has removed vegetation and diminished propagules in the soil. This adds to the vulnerability of burned areas to the colonization and dominance by invasive species. Research into the use of revegetation techniques following pile burning to suppress invasion is limited. Studies conducted in various woodland types that investigated revegetation of pile burn scars have met with varying success. To assess the effectiveness of restoring pile burn scars in Rocky Mountain National Park, Colorado, we monitored vegetation in 26 scars, each about 5 m in diameter, the growing season after burning. Later that summer, we selected 14 scars for restoration that included soil scarification, seed addition, and pine duff mulch cover. We monitored the scars for four years, pre-restoration, and three years post-restoration and found that the cover of seeded species exceeded the surrounding unburned areas and unseeded controls. The restoration seeding suppressed cover of non-native species as well as native species that were not seeded during restoration. Our results suggest that restoration of pile burn scars could be a useful tool to retard the establishment of invasive plant species when there are pre-existing infestations near scars. However, this must be weighed against the simultaneous suppression of native species recruitment. Monitoring for periods more than three years will help us understand how long the suppression of native and non-native species by restoration species may persist.

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Tests of Hexazinone and Tebuthiuron for Control of Exotic Plants in Kauai, Hawaii

Forests ◽

10.3390/f10070576 ◽

2019 ◽

Vol 10 (7) ◽

pp. 576

Author(s):

Wang ◽

Awaya ◽

Zhu ◽

Motooka ◽

Nelson ◽

...

Keyword(s):

Invasive Plants ◽

Loblolly Pine ◽

Native Species ◽

Native Plants ◽

Early Period ◽

Metrosideros Polymorpha ◽

Native Plant ◽

Weed Species ◽

Invasive Weed ◽

Native Plant Species

Non-native plant species have become serious pests in Hawaii’s delicate island ecosystems. It is necessary to control invasive plants. The herbicides hexazinone and tebuthiuron were evaluated for defoliation efficacy to control several major invasive plants and for non-target effects on native plants at Site I in a rainforest at 1200 m elevation and Site II in a mesic area at 640 m elevation on the island of Kauai, Hawaii. The invasive weed species in the sites included daisy fleabane (Erigeron karvinskianus DC.), faya tree (Myrica faya Ait.), strawberry guava (Psidium cattleyanum Sabine), banana passion fruit (Passiflora mollissima Bailey), vaseygrass (Paspalum urvillei Steud.), and highbush blackberry (Rubus argutus Link. 1822). Native plants included ohia lehua (Metrosideros polymorpha Gaudich.), naupaka (Scaevola cerasifolia Labill.), pilo (Hedyotis mannii), hona (Urera glabra (Hook. & Arn.)), aalii (Dodonaea viscosa Jacq.), and amau (Sadleria sp.). The results showed that broadcast applications of hexazinone granules and tebuthiuron pellets were effective on some of those invasive species. Herbicidal tolerance varied among the native species. For example, D. viscosa showed high tolerance to hexazinone. S. cerasifolia was susceptible to hexazinone, but not to tebuthiuron. The inconsistent defoliation of Sadleria sp. occurred among different applications rates of the two herbicides. M. polymorpha, particularly when it was small, could tolerate hexazinone and tebuthiuron. U. glabra was severely injured by the two herbicides. H. mannii was moderately tolerant to hexazinone, but fairly sensitive to tebuthiuron. The invasive loblolly pine (Pinus taeda L.) was highly tolerant to hexazinone, but was very sensitive to tebuthiuron. M. faya was very sensitive to hexazinone, but very tolerant to tebuthiuron. P. cattleyanum was sensitive to both herbicides. Six and nine months after hexazinone and tebuthiuron treatment, respectively, native plants were transplanted into the Sites to observe injury from residual herbicides. Approximately less than 10% mortality was observed for the out-planted native species three months after planting (MAP), indicating that the native species showed less injury in the early period of transplant. The mortality of the three endangered species Kauai hau kuahiwi (Hibiscadelphis distans), Kauai delissea (Delissea rhytidosperma H.Mann) and kawawaenohu (Alsinidendron lynchnoides), however, increased as the MAP increased. Overall, broadcast treatments of hexazinone and tebuthiuron at rates higher than 1 kg active ingredient per hectare would be problematic. The dissipation half-life values of hexazinone and tebuthiuron in the 1-15 cm layer of soils at the two sites were approximately 7 days and greater than 180 days, respectively.

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