Spread Dynamics of Perennial Pepperweed (Lepidium latifolium) in Two Seasonal Wetland Areas

2012 ◽  
Vol 5 (1) ◽  
pp. 57-68 ◽  
Author(s):  
Mark J. Renz ◽  
Scott J. Steinmaus ◽  
David S. Gilmer ◽  
Joseph M. DiTomaso
Keyword(s):  
Invasive Plant ◽  
Average Rate ◽  
Abiotic Factors ◽  
Plant Cover ◽  
Leading Edge ◽  
Suppressive Effect ◽  
Stem Density ◽  
Wetland Ecosystems ◽  
Rate Of Spread ◽  
Dynamics Of Population

AbstractPerennial pepperweed is an invasive plant that is expanding rapidly in several plant communities in the western United States. In California, perennial pepperweed has aggressively invaded seasonal wetlands, resulting in degradation of habitat quality. We evaluated the rate and dynamics of population spread, assessed the effect of disturbance on spread, and determined the biotic and abiotic factors influencing the likelihood of invasion. The study was conducted at eight sites within two wetland regions of California. Results indicate that in undisturbed sites, spread was almost exclusively through vegetative expansion, and the average rate of spread was 0.85 m yr−1 from the leading edge. Spread in sites that were disked was more than three times greater than in undisturbed sites. While smaller infestations increased at a faster rate compared with larger populations, larger infestations accumulated more newly infested areas than smaller infestations from year to year. Stem density was consistently higher in the center of the infestations, with about 2.4 times more stems per square meter compared with the leading edge at the perimeter of the population. The invasion by perennial pepperweed was positively correlated with increased water availability but was negatively correlated with the cover of perennial and annual species. Thus, high cover of resident vegetation can have a suppressive effect on the rate of invasion, even in wetland ecosystems. On the basis of these results, we recommend that resident plant cover not be disturbed, especially in wet areas adjacent to areas currently infested with perennial pepperweed. For infested areas, management efforts should be prioritized to focus on controlling satellite populations as well as the leading edge of larger infestations first. This strategy could reduce the need for costly active restoration efforts by maximizing the probability of successful re-establishment of resident vegetation from the adjacent seedbank.

Predator Interference with the Cinnabar Moth (Tyria jacobaeae) for the Biological Control of Tansy Ragwort (Senecio jacobaea)

2011 ◽  
Vol 4 (3) ◽  
pp. 332-340 ◽  
Author(s):  
Kimberly K. Crider
Keyword(s):  
Biological Control ◽  
Invasive Plant ◽  
Abiotic Factors ◽  
Biological Control Agents ◽  
Moth Population ◽  
Tyria Jacobaeae ◽  
Carpenter Ants ◽  
Ant Predation ◽  
Cinnabar Moth ◽  
Tansy Ragwort

AbstractQuantification of interference with biological control agents can provide support for anecdotal claims of success or failure of agent establishment and efficacy. This study was initiated because of observed predation of cinnabar moth larvae by carpenter ants when releasing larvae for the control of tansy ragwort, an invasive plant in Montana. Biotic and abiotic factors were compared among three sites with historically variable moth population establishment. Two experiments were developed to (1) observe and document insect activity, predation, or disappearance on tansy ragwort stems either protected or accessible to ants; and (2) quantify the effects of ant exclusion on herbivory of tansy ragwort. Site comparisons indicated that ant colony density was highest at the driest of three sites, and, interestingly, no ant colonies were detected at the site with higher observed numbers of moth larvae and adults and lower densities of tansy ragwort. Available substrate (logs and stumps) for ant colonization did not differ between the three sites. In the ant exclusion experiments, a larger number of larvae were missing on plants accessible to ants (63%) compared with plants where ants were excluded (39%) after 36 h. Direct observation of predation of larvae by carpenter ants accounted for 9% of missing larvae on stems accessible to ants. Larvae were able to consume 81% of original flowers or buds on ant-excluded stems, compared with 18% consumption on ant-accessible stems, suggesting that ant predation could limit the efficacy of cinnabar moth larvae. These results provide one of many possible explanations for the anecdotal observations of large, persistent populations of cinnabar moths in moist areas. This work emphasizes the importance of post-release observation and monitoring to detect and, ideally, quantify factors to support anecdotal perceptions regarding the fate and subsequent efficacy of insect biological-control agents.

scholarly journals Analisis Keanekaragaman Tumbuhan Invasif Di Kawasan Hutan Pantai Balekambang Desa Srigonco Kecamatan Bantur Kabupaten Malang

2020 ◽  
Vol 6 (1) ◽  
pp. 46-53
Author(s):  
Miftahul Mukarromah ◽  
Ari Hayati ◽  
Hasan Zayadi
Keyword(s):  
Invasive Plants ◽  
Invasive Plant ◽  
Cynodon Dactylon ◽  
Diversity Index ◽  
Abiotic Factors ◽  
Coastal Forest ◽  
Mimosa Pudica ◽  
Belt Transect ◽  
Index Value ◽  
Sida Rhombifolia

Balekambang Beach is the most visited beach destination in Malang Regency until the end of 2015. One of the invasive pathways of invasive plants is Tourism. The purpose of this study was to identify invasive plant species, diversity and compare the value of the diversity index with abiotic factors.This research method is descriptive with systematic sampling techniques using Belt Transect, and measurements of abiotic factors include edafic factors and climatic micro factors. Invasive alien plant species found in the Balekambang coastal forest are identified as seventeen species namely (Hemighraphis glaucescens), (Oplismenus sp), (Amomum coccineum), (Arenga obtusifolia), (Leucaena leucochephana), (Mimosa sp), (Cassia siamea), (Eupatorium odoratum), (Hyptis capitata), (Cynodon dactylon), (Sida rhombifolia), (Synedrella nudiflora), (Chromolaena odorata),  (Leucaena leucochepala), (Mimosa pudica), and (Ruellia tuberosa) with the index value of invasive plant diversity in protected forests and production classified as high compared to mangroves. The results of the diversity index value with abiotic factors showed a positive (+) direction on soil sailinity where the R2 value was 0.5606 or 50%, which means it showed a relationship between soil salinity and an abundance of invasive plants in Balekambang coastal forest area of 50%.  Keywords:invasive plants, Balekambang beach, belt transect, diversity ABSTRAK Pantai Balekambang adalah destinasi wisata alam pantai di Kabupaten Malang yang paling banyak dikunjungi hingga akhir tahun 2015.Salah satu jalur invasi dari tumbuhan invasif adalah Tourism (Wisata). Tujuan dari penelitian ini adalah mengidentifikasi jenis tumbuhan invasif, keanekaragaman dan membandingkan nilai indeks keanekaragaman dengan faktor abiotik. Metode penelitian ini deskriptif dengan tehnik pengambilan sampling secara sistematis menggunakan Belt Transect, dan pengukuran faktor abiotik meliputi faktor edafik dan faktor mikro klimatik. Jenis spesies tumbuhan asing invasif yang terdapat di hutan pantai Balekambang diidentifikasi sebanyak tujuh belas spesies yaitu Hemighraphis glaucescens, Oplismenus sp, Amomum coccineum, Arenga obtusifolia, Leucaena leucochephana, Mimosa sp, Cassia siamea, Eupatorium odoratum, Hyptis capitata, Cynodon dactylon, Sida rhombifolia, Synedrella nudiflora.Chromolaena odorata, Leucaena leucochepala, Mimosa pudica, dan Ruellia tuberose dengan nilai indeks keanekaragaman tumbuhan invasif pada hutan lindung dan produksi tergolong tinggi dibanding mangrove. Hasil analisis uji korelasi nilai indeks keanekaragaman dengan faktor abiotik menunjukkan arah positif (+) pada salinitas tanah dimana nilai R2 sebesar 0.5606 atau 50%, yang artinya menunjukkan hubungan antara salinitas tanah dengan kelimpahan tumbuhan invasif di kawasan hutan pantai Balekambang sebesar 50%. Kata kunci: tumbuhan invasif, pantai Balekambang, belt transect, keanekaragaman

scholarly journals Diplazium esculentum (vegetable fern).

2020 ◽  
Author(s):  
Jeanine Vélez-Gavilán
Keyword(s):  
New Zealand ◽  
North America ◽  
Food Source ◽  
Average Rate ◽  
Rate Of Spread

Abstract Diplazium esculentum is a herbaceous fern native to Asia. It has been introduced into a number of countries in Africa, Oceania and North America as an ornamental and as a food source. As it produces a large number of spores it can easily escape cultivation and rapidly spread into new areas. The species is reported as having escaped cultivation and become invasive in Hawaii, USA, New Zealand and Australia. In Hawaii, D. esculentum grows abundantly in wet valleys and in sheltered moist areas at dry sites. It is also a frequent volunteer in gardens. In New Zealand it has escaped from cultivation, spreading rapidly and aggressively in riverbanks at an average rate of spread of 1 m per year. In Australia the species is widely cultivated for food and as an ornamental, naturalising in swampy areas of Queensland. Its impacts on other habitats or species are unknown.

Plasticity in extended phenotypes: how the antlion Myrmeleon crudelis adjusts the pit traps depending on biotic and abiotic conditions

2019 ◽  
Vol 66 (1-2) ◽  
pp. 41-47 ◽  
Author(s):  
Alejandro G. Farji-Brener ◽  
Sabrina Amador-Vargas
Keyword(s):  
Abiotic Factors ◽  
Plant Cover ◽  
Coarse Grained ◽  
Abiotic Conditions ◽  
Fine Grained ◽  
Fine Soil ◽  
Fine Grained Soil ◽  
Trap Size ◽  
Pit Depth ◽  
Pit Design

Abstract The physical structures built by animals are considered extended phenotypes that reflect how organisms make decisions and deal with changes in their biotic and abiotic environment. We summarize the results of several studies on Myrmeleon crudelis, a neuropteran larva that digs pit-traps in the soil to capture small arthropods (mostly ants) in the tropical dry forests of Costa Rica. Specifically, we showed how this species responds to varying biotic and abiotic conditions with changes in the design and/or location of its pit traps. Several experiments and field comparisons indicate that: 1) antlions adjust the pit design according to the abundance and type of prey. When prey is scarce, antlions increased trap diameter, an architectural adjustment that enhances the probability of prey encounter. Antlions that experienced high prey abundance, but the prey easily escaped, then increased pit depth, an adjustment that increases the chance of prey retention; 2) soil compaction strongly reduced pit-trap size and abundance; 3) antlions preferred soils with high proportion of fine-particle size to build pits. In fine-grained soil, pit-traps are larger and more efficient to capture prey than traps in coarse-grained soils; and 4) pit-traps may also be affected through indirect effects of soil structure and vegetation cover. Areas with fine-soil presented less plant cover, and plant cover could be beneficial for antlions because it acts as a shelter against direct sunlight and rainfall, or it may represent a cost because it is a source of leaflitter falling in the pits. The works summarized here how trap-building predators can exhibit considerable flexibility in trap construction in response to various biotic and abiotic factors, emphasizing how the study of extended phenotypes can be a useful approach to better understand the flexibility of foraging behaviors.

Divergent biotic and abiotic filtering of root endosphere and rhizosphere soil fungal communities along ecological gradients

2020 ◽  
Vol 96 (7) ◽  
Author(s):  
Candice Y Lumibao ◽  
Elizabeth R Kimbrough ◽  
Richard H Day ◽  
William H Conner ◽  
Ken W Krauss ◽  
...  
Keyword(s):  
Environmental Changes ◽  
Abiotic Factors ◽  
Canopy Cover ◽  
Host Density ◽  
Fungal Communities ◽  
Biotic Factors ◽  
Wetland Ecosystems ◽  
Rhizosphere Fungi ◽  
Salinity Levels ◽  
Salinity Water

ABSTRACT Plant roots assemble in two distinct microbial compartments: the rhizosphere (microbes in soil surrounding roots) and the endosphere (microbes within roots). Our knowledge of fungal community assembly in these compartments is limited, especially in wetlands. We tested the hypothesis that biotic factors would have direct effects on rhizosphere and endosphere assembly, while abiotic factors would have direct and indirect effects. Using a field study, we examined the influences of salinity, water level and biotic factors on baldcypress (Taxodium distichum) fungal communities. We found that endosphere fungi, unlike rhizosphere fungi, were correlated with host density and canopy cover, suggesting that hosts can impose selective filters on fungi colonizing their roots. Meanwhile, local abiotic conditions strongly influenced both rhizosphere and endosphere diversity in opposite patterns, e.g. highest endosphere diversity (hump-shaped) and lowest rhizosphere diversity (U-shaped) at intermediate salinity levels. These results indicate that the assembly and structure of the root endosphere and rhizosphere within a host can be shaped by different processes. Our results also highlight the importance of assessing how environmental changes affect plant and plant-associated fungal communities in wetland ecosystems where saltwater intrusion and sea level rise are major threats to both plant and fungal communities.

Dynamics and patterns of plant development in restored mining areas. Practical examples

2020 ◽  
Author(s):  
Carolina Martínez-Ruiz
Keyword(s):  
Soil Properties ◽  
Abiotic Factors ◽  
Plant Cover ◽  
Woody Species ◽  
Limiting Factors ◽  
Mine Wastes ◽  
Herbaceous Plant ◽  
Opencast Mining ◽  
Vegetation Establishment ◽  
Native Shrubs

<p>Opencast mining has altered large areas in many countries, generating major environmental impacts, whose restoration is an urgent need. The effective restoration of opencast mines is a complex process, hampered primarily by the total elimination of vegetation and soil. In the absence of plant cover, these areas may be subject to wind and water erosion, or leaching, polluting rivers, streams, aquifers, and arable lands, as well as being unsightly. Although revegetation of mine wastes can occur naturally, if given time, the process could be extremely slow due to the toxicity, and physical and nutritional shortcomings that wastes often present. Several revegetation approaches have been undertaken worldwide to promote faster vegetation development. However, the results have often been discouraging by a lack of knowledge of the ecological principles involved; the soil is one of the most important limiting factors for vegetation establishment in mine lands.</p><p>Topsoil addition over coal-mine wastes in northern Spain favours the establishment of native vegetation by improving physico-chemical and biological soil properties. Without topsoil, vegetation establishment is extremely slow resulting in very unstable plant communities even 40 years after the stop of mining. The addition of herbaceous plant seeds by hydroseeding is frequently used to compensate for the seeds scarcity in the added topsoil. However, hydroseeding is not always successful because of the use of commercial mixtures of non-native seeds. In any case, the installed grassland is being colonized by woody species from the surrounding forest. The structure of the new plant community varies not only in time (succession) but also in space (distance to the seed source), and the process is strongly determined by interactions between the forest edge and the initial grassland patch. The colonization pattern of woody species is affected by fine-scale variations in abiotic factors, including soil properties, which change from the forest to the mine. The native shrubs that colonize the mines (<em>Genista florida</em> and <em>Cytisus scoparius</em>) facilitate the establishment of native oaks (<em>Quercus pyrenaica</em> and <em>Q. petraea</em>) and thus the natural forest expansion. One of the mechanisms driving this facilitation shrub-tree process is the soil improvement mediated by native shrubs. Also, hillside topography, common in mines located in the mountains, has certain peculiarities regarding revegetation in flat areas since there is a segregation of vegetation along the slope with grasslands occupying the upper parts and shrublands of legumes the lower parts.</p><p>In order to improve the decision-making during restoration management, it is necessary to be based on the knowledge of the mechanisms that condition the establishment of vegetation and the underlying succession processes. The long-term monitoring of existing experimental devices and their extension to other areas and restoration objectives are essential to establish a protocol of performance to adjust decisions to the particular circumstances of each area to be restored and thus reconcile environmental restoration with the economic activity of the area.</p>

Three-Dimensional Fluid Flow Phenomena in the Blade End Wall Corner Region

1986 ◽  
Author(s):  
B. K. Hazarika ◽  
R. Raj ◽  
D. R. Boldman
Keyword(s):  
Flow Visualization ◽  
Relative Size ◽  
Three Dimensional ◽  
Leading Edge ◽  
Horseshoe Vortex ◽  
Mean Velocity ◽  
Corner Region ◽  
Rate Of Spread ◽  
Flow Phenomena ◽  
End Wall

The three-dimensional flow in the blade end wall corner region was investigated. The techniques used in the investigation included flow visualization, static and total pressure measurements with conventional probes, and mean volocity profile measurements with a single sensor inclined hot-wire probe. Six critical axial stations along the blade chord were chosen for detailed measurements based on the flow visualization results. A large number of data points were obtained very close to the corner walls at each axial location including all the components of the mean velocity. Based on the measurements, three vortices were identified. A horseshoe vortex started near the leading edge. A corner eddy was formed between the horseshoe vortex and the corner. Another vortex was formed at the rear portion of the corner due to the secondary flow of the second kind. The relative size and the rate of spread of the vortices in the streamwise direction are discussed.

HISTORY OF THE DUTCH ELM DISEASE IN THE PROVINCE OF QUEBEC, CANADA

1961 ◽  
Vol 37 (4) ◽  
pp. 356-367 ◽  
Author(s):  
Rene Pomerleau
Keyword(s):  
Relative Density ◽  
Average Rate ◽  
Dutch Elm Disease ◽  
Causal Organism ◽  
Rate Of Spread ◽  
History Of ◽  
Main Factor

The first cases of the Dutch elm disease in Canada were recorded in 1944 in the Province of Quebec, but there is evidence that the causal organism was introduced around Sorel before 1940. In 20 years the disease has extended over more than half the range of the white elm in the Province, or about 25,000 square miles, with an average rate of spread of some 1,200 square miles per year. Observations in 6 one-square-mile areas during a 13-year period indicate that between 5 and 30 per cent, or an average of 16 per cent, of the elm trees were killed by this disease. On this basis the Dutch elm disease has killed at least 600,000 trees during its 20-year history in Quebec. The relative density of elm trees appears to be the main factor which has determined the intensity and pattern of attack.

Restoration Ecology and Invasive Plants in the Semiarid West

2008 ◽  
Vol 1 (4) ◽  
pp. 399-413 ◽  
Author(s):  
Cynthia S. Brown ◽  
Val J. Anderson ◽  
Victor P. Claassen ◽  
Mark E. Stannard ◽  
Linda M. Wilson ◽  
...  
Keyword(s):  
Invasive Species ◽  
Invasive Plants ◽  
Restoration Ecology ◽  
Invasive Plant ◽  
Abiotic Factors ◽  
Plant Management ◽  
Ecosystem Development ◽  
Plant Materials ◽  
Invasive Plant Management ◽  
Complex Interactions

AbstractInvasive plants are a common problem in the management and restoration of degraded lands in the semiarid western United States, but are often not the primary focus of restoration ecologists. Likewise, restoring native vegetation has not been a major concern of weed scientists. But trends in the literature demonstrate increasing overlap of these fields, and greater collaboration between them can lead to improved efficacy of restoration efforts. Succession and ecosystem development are the products of complex interactions of abiotic and biotic factors. Our greatest restoration and invasive plant management successes should result when we take advantage of these natural processes. Recent shifts in management objectives have generated approaches to directing plant community development that utilize species that are strong competitors with invasive species as a bridge to the establishment of native perennial vegetation. Soil water and nutrient characteristics and their interactions can affect desired and undesired plant species differentially and may be manipulated to favor establishment and persistence of desired perennial plant communities. Selection of appropriate plant materials is also essential. Species assemblages that suppress or exclude invaders and competitive plant materials that are well adapted to restoration site conditions are important keys to success. We provide guidelines for restoration based on the fundamental ecological principles underlying succession. Knowledge of the complex interactions among the biotic and abiotic factors that affect successional processes and ecosystem development, and increased collaboration between weed scientists and restoration ecologists hold promise for improving restoration success and invasive species management.

scholarly journals Dispersal of Emerald Ash Borer within an Intensively Managed Quarantine Zone

2010 ◽  
Vol 36 (4) ◽  
pp. 160-163
Author(s):  
Chris Sargent ◽  
Michael Raupp ◽  
Dick Bean ◽  
Alan Sawyer
Keyword(s):  
Insect Pests ◽  
Emerald Ash Borer ◽  
Leading Edge ◽  
The United States ◽  
Agrilus Planipennis ◽  
Urban Trees ◽  
Annual Rate ◽  
Department Of Agriculture ◽  
Rate Of Spread ◽  
Intensively Managed

Emerald ash borer (EAB) (Agrilus planipennis) is one of the most destructive insect pests of urban trees in the United States. The objective of the current study was to determine the rate of spread of EAB in a quarantine zone where aggressive intervention tactics such as tree destruction occurred. Historical records were examined from the Maryland Department of Agriculture for the years 2003, 2006, 2007, and 2008, to determine the rate of spread of EAB in Maryland, U.S., within the quarantine zone. Despite attempts at eradication and public education, EAB persisted, and the leading edge of beetles moved away from the central infestation point at an average annual rate of 1 km per year and a maximum annual rate of 1.37 km per year between 2003 and 2008. This paper discusses the relative merits and limitations of this quarantine and eradication program and makes suggestions for future management of EAB.

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