scholarly journals Crocosmia x crocosmiiflora (montbretia).

2020 ◽  
Author(s):  
Julissa Rojas-Sandoval
Keyword(s):  
New Zealand ◽  
Environmental Conditions ◽  
Soil Types ◽  
Native Vegetation ◽  
Natural Forests ◽  
Riparian Areas ◽  
Blue Mountains ◽  
Wide Range

Abstract Crocosmia × crocosmiiflora has been widely cultivated as an ornamental and has escaped from cultivation to become invasive in disturbed sites, riverbanks, wasteland, along roadsides, and shrublands (Ensbey et al., 2011; Weeds of Australia, 2016, Weeds of New Zealand, 2016). This species is well adapted to grow in a wide range of environmental conditions and soil types (it may grow in any soil, wet or dry, poor or rich). It competes aggressively with native vegetation for resources such as water and nutrients and it has the potential to displace native vegetation primarily in riparian areas and moist shrublands. Once established, it moves rapidly down watercourses into natural forests. The mass of corms in the soil contributes to the breakdown and erosion of natural creek and riverbanks (Ensbey et al., 2011; Weeds of the Blue Mountains, 2016).

scholarly journals Strategic expansion of existing forest monitoring plots: a case study using a stratified GIS-based modelling approach

2020 ◽  
Vol 50 ◽  
Author(s):  
Thai Son Le ◽  
Justin Morgenroth
Keyword(s):  
New Zealand ◽  
Environmental Conditions ◽  
Full Range ◽  
Forest Monitoring ◽  
Soil Conditions ◽  
Natural Forests ◽  
Priority Index ◽  
Permanent Sample Plots ◽  
Priority Areas ◽  
The North

Background: Understanding the relationship between sites and the plant species they support is essential for effective vegetation management. Site-species matching requires knowledge of the growth response of a given species to the full range of environmental conditions in potential planting sites. This can be achieved by repeatedly measuring species growth at a comprehensive network of sample plots that cover a range of environmental conditions, including topography, climate, and soil factors. The New Zealand Dryland Forests Initiative has established permanent sample plots (PSPs) of a plantation species, Eucalyptus bosistoana F.Muell., across New Zealand. However, these PSPs do not cover the entire range of environmental conditions available for the species and hence there is a need to expand the network of sites. The aim of this study was to determine optimal locations for new PSPs to provide more unique information to support site-species matching studies for Eucalyptus bosistoana in New Zealand.Methods: A geographic information system (GIS) and stratified random sampling method were used to generate a model to identify optimal locations for E. bosistoana PSP establishment. The variables used in this study included topography, climate, and soil data. Redundancy between the initial set of potential explanatory variables was reduced by a multi-collinearity analysis. The potential habitat for the species was restricted to land with environmental conditions that could support E. bosistoana. All environmental variables were stratified and an initial priority index for each stratum in each variable was calculated. Then a weighted-overlay analysis was conducted to create the final priority index, which was mapped to identify high-priority areas for targeted PSP expansion.Results: The existing PSP network for E. bosistoana generally covers the environmental conditions in low-elevation New Zealand dry lands, which are located alongside the east coast of the South Island, and the southern part of the North Island. The model identified high priority areas for PSP expansion, including several large regions in the North Island, especially in Rangitikei and Taupo Districts.Conclusions: The model successfully allowed identification of areas for a strategic expansion of permanent sample plots for E. bosistoana. Newly identified areas expand upon the topographic, climatic, and soil conditions represented by the existing PSP network. The new area for PSP expansion has potential to provide valuable information for further site-species matching studies. The methodology in this paper has potential to be used for other plot networks of a different species, or even natural forests.

scholarly journals Chloris gayana (Rhodes grass).

2020 ◽  
Author(s):  
Julissa Rojas-Sandoval
Keyword(s):  
New Zealand ◽  
Costa Rica ◽  
Drought Resistance ◽  
Environmental Conditions ◽  
Native Species ◽  
New Caledonia ◽  
Rhodes Grass ◽  
Wide Range ◽  
Chloris Gayana

Abstract Chloris gayana is a robust, strongly stoloniferous grass native to Africa that has been extensively introduced as forage across tropical and subtropical regions. Traits such as its ability to grow in a wide range of environmental conditions, its drought-resistance and its ability to rapidly reproduce both by seeds and vegetatively have facilitated its escape from cultivation and subsequent naturalization. Once established, C. gayana often grows to form almost pure stands that smother native species. Currently, this species is regarded as an invasive in Australia, Spain, Argentina, Paraguay, Mexico, Costa Rica, Cuba, Anguilla, New Caledonia, New Zealand and Hawaii. It is also included in the Global Compendium of Weeds.

Seed ecology of Captain Cook tree [Cascabela thevetia (L.) Lippold] – germination and longevity

2017 ◽  
Vol 39 (4) ◽  
pp. 307 ◽  
Author(s):  
Faiz F. Bebawi ◽  
Shane D. Campbell ◽  
Robert J. Mayer
Keyword(s):  
Management Strategies ◽  
Soil Types ◽  
Light Conditions ◽  
Riparian Areas ◽  
Experimental Conditions ◽  
Ambient Temperatures ◽  
Seed Ecology ◽  
Australian Continent ◽  
Wide Range ◽  
Temperature Experiment

Cascabela thevetia (L.) Lippold (Apocynaceae), commonly known as Captain Cook tree or yellow oleander, has established large infestations in riparian areas along several creeks and rivers in northern Queensland. To better understand the ecology of C. thevetia and the implications for its spread and management, this study reports seven experiments related to the seed ecology of its yellow and peach biotypes. We quantified its germination response to ambient (Experiment 1a and 1b), alternating and constant temperature (Experiment 2a and 2b) regimes and exposure to different light conditions (Experiment 3). Seed longevity under two soil types, two levels of pasture cover and three burial depths was also determined (Experiment 4a and 4b). Both loose seeds and seeds still within pods (kernels) of the two biotypes of C. thevetia were able to germinate in all months of the year in northern Queensland, irrespective of the large differences in monthly ambient temperatures experienced at the Charters Towers study site. Both biotypes also germinated across a wide range of alternating day/night temperatures from 16/12°C to 47/37°C and constant temperatures from 17°C to 44.0°C. Germination of the two biotypes was significantly greater (4-fold) and faster (7 days earlier) under shade than under natural light conditions. Over all biotypes, soil types, levels of pasture cover and burial depths, no seeds of C. thevetia remained viable after 2 years: longevity was much less in many circumstances. The results demonstrate that C. thevetia seeds can germinate over a wide temperature range, whereas the ability of seed to remain viable at low temperatures highlights the potential for expansion of its current potential distribution towards southern latitudes of the Australian continent. Across all experimental conditions, the yellow biotype displayed superior seed germination and viability traits compared with the peach biotype. Seed banks of the peach and yellow biotypes of C. thevetia are short-lived (2 years), which may be exploited when developing management strategies to reduce its impacts.

scholarly journals The Distribution and Influence of the Introduced Alga Colpomenia Bullosa in the Rocky Intertidal

2021 ◽  
Author(s):  
◽  
Daniel Francis McNaughtan
Keyword(s):  
New Zealand ◽  
Spatial Variation ◽  
Environmental Conditions ◽  
Desiccation Tolerance ◽  
Brown Alga ◽  
Littoral Zone ◽  
Rocky Intertidal ◽  
Macroalgal Species ◽  
Native Communities ◽  
Wide Range

<p>The brown alga Colpomenia bullosa was first observed in New Zealand more than 20 years ago, yet very little is known about its current intertidal distribution or possible effects it may be having on native communities. This study addresses some of these issues. Surveys indicate little spatial variation in abundance around the Wellington region, however, the sporophytic crustose phase is restricted to pools high in the littoral zone while the gametophytic upright has a low- to sub-littoral distribution. Physiology experiments indicate that C. bullosa can tolerate a wide range of environmental conditions, but the crustose phase has a poor desiccation tolerance. A series of tranplant and competition experiments confirmed this and suggested that the crustose phase requires some level of facilitation by molluscan herbivores in order to become established. These experiments also revealed that crustose C. bullosa does not compete well against more upright macroalgal species. The effects of this introduced algae on native communities are likely to be minimal given its restricted intertidal distribution and its inability to compete against more upright species.</p>

scholarly journals Agave americana (century plant).

2020 ◽  
Author(s):  
Julissa Rojas-Sandoval ◽  
Duilio Iamonico
Keyword(s):  
South Africa ◽  
New Zealand ◽  
High Temperatures ◽  
New Caledonia ◽  
Salt Spray ◽  
Soil Types ◽  
Bare Sand ◽  
Wide Range ◽  
Agave Americana ◽  
Environmental Weed

Abstract A. americana is a large, rhizomatous succulent that grows in a wide range of habitats and soil types. Additionally, it is tolerant to salt spray, high temperatures, and extreme drought. Because this species spread by seeds, but also vegetatively by bulbils and rhizomes, it has the potential to escape from cultivation and rapidly colonize disturbed sites, roadsides, bare sand and coastal areas (ISSG, 2016). Currently, A. americana is considered a serious environmental weed by the IUCN (ISSG, 2016) and it is listed as invasive in many countries in Europe as well as in China, Japan, South Africa, Namibia, Tanzania, Bermuda, Australia, New Zealand, and New Caledonia among others (BioNET-EAFRINET, 2016; ISSG, 2016; DAISIE, 2016; PIER, 2016; Weeds of Australia, 2016). It is also known to have become invasive in Ethiopia, Kenya, Malawi, Rwanda, and Uganda.

scholarly journals The Distribution and Influence of the Introduced Alga Colpomenia Bullosa in the Rocky Intertidal

2021 ◽  
Author(s):  
◽  
Daniel Francis McNaughtan
Keyword(s):  
New Zealand ◽  
Spatial Variation ◽  
Environmental Conditions ◽  
Desiccation Tolerance ◽  
Brown Alga ◽  
Littoral Zone ◽  
Rocky Intertidal ◽  
Macroalgal Species ◽  
Native Communities ◽  
Wide Range

<p>The brown alga Colpomenia bullosa was first observed in New Zealand more than 20 years ago, yet very little is known about its current intertidal distribution or possible effects it may be having on native communities. This study addresses some of these issues. Surveys indicate little spatial variation in abundance around the Wellington region, however, the sporophytic crustose phase is restricted to pools high in the littoral zone while the gametophytic upright has a low- to sub-littoral distribution. Physiology experiments indicate that C. bullosa can tolerate a wide range of environmental conditions, but the crustose phase has a poor desiccation tolerance. A series of tranplant and competition experiments confirmed this and suggested that the crustose phase requires some level of facilitation by molluscan herbivores in order to become established. These experiments also revealed that crustose C. bullosa does not compete well against more upright macroalgal species. The effects of this introduced algae on native communities are likely to be minimal given its restricted intertidal distribution and its inability to compete against more upright species.</p>

Natural enemies of bridal creeper Asparagus asparagoides in New Zealand

2008 ◽  
Vol 61 ◽  
pp. 362-367
Author(s):  
H.M. Harman ◽  
N.W. Waipara ◽  
C.J. Winks ◽  
L.A. Smith ◽  
P.G. Peterson ◽  
...  
Keyword(s):  
New Zealand ◽  
Natural Enemies ◽  
Invertebrate Fauna ◽  
Classical Biocontrol ◽  
Wide Range

Bridal creeper is a weed of natural and productive areas in the northern North Island of New Zealand A classical biocontrol programme was initiated in 20052007 with a survey of invertebrate fauna and pathogens associated with the weed in New Zealand Although bridal creeper was attacked by a wide range of generalist invertebrates their overall damage affected

scholarly journals Predictive modelling of soils’ hydraulic conductivity using artificial neural network and multiple linear regression

2021 ◽  
Vol 3 (2) ◽  
Author(s):  
Charles Gbenga Williams ◽  
Oluwapelumi O. Ojuri
Keyword(s):  
Neural Network ◽  
Artificial Neural Network ◽  
Hydraulic Conductivity ◽  
Linear Regression ◽  
Multiple Linear Regression ◽  
Coarse Grained ◽  
Soil Types ◽  
Wide Range ◽  
Artificial Neural ◽  
Input Variables

AbstractAs a result of heterogeneity nature of soils and variation in its hydraulic conductivity over several orders of magnitude for various soil types from fine-grained to coarse-grained soils, predictive methods to estimate hydraulic conductivity of soils from properties considered more easily obtainable have now been given an appropriate consideration. This study evaluates the performance of artificial neural network (ANN) being one of the popular computational intelligence techniques in predicting hydraulic conductivity of wide range of soil types and compared with the traditional multiple linear regression (MLR). ANN and MLR models were developed using six input variables. Results revealed that only three input variables were statistically significant in MLR model development. Performance evaluations of the developed models using determination coefficient and mean square error show that the prediction capability of ANN is far better than MLR. In addition, comparative study with available existing models shows that the developed ANN and MLR in this study performed relatively better.

scholarly journals Urban Fire Severity and Vegetation Dynamics in Southern California

2020 ◽  
Vol 13 (1) ◽  
pp. 19
Author(s):  
Lauren E. H. Mathews ◽  
Alicia M. Kinoshita
Keyword(s):  
Vegetation Cover ◽  
Vegetation Index ◽  
Normalized Difference Vegetation Index ◽  
Current Knowledge ◽  
Fire Severity ◽  
Satellite Image ◽  
Burn Severity ◽  
Native Vegetation ◽  
Riparian Areas ◽  
The Impact

A combination of satellite image indices and in-field observations was used to investigate the impact of fuel conditions, fire behavior, and vegetation regrowth patterns, altered by invasive riparian vegetation. Satellite image metrics, differenced normalized burn severity (dNBR) and differenced normalized difference vegetation index (dNDVI), were approximated for non-native, riparian, or upland vegetation for traditional timeframes (0-, 1-, and 3-years) after eleven urban fires across a spectrum of invasive vegetation cover. Larger burn severity and loss of green canopy (NDVI) was detected for riparian areas compared to the uplands. The presence of invasive vegetation affected the distribution of burn severity and canopy loss detected within each fire. Fires with native vegetation cover had a higher severity and resulted in larger immediate loss of canopy than fires with substantial amounts of non-native vegetation. The lower burn severity observed 1–3 years after the fires with non-native vegetation suggests a rapid regrowth of non-native grasses, resulting in a smaller measured canopy loss relative to native vegetation immediately after fire. This observed fire pattern favors the life cycle and perpetuation of many opportunistic grasses within urban riparian areas. This research builds upon our current knowledge of wildfire recovery processes and highlights the unique challenges of remotely assessing vegetation biophysical status within urban Mediterranean riverine systems.

scholarly journals Regional environmental controllers influence continental scale soil carbon stocks and future carbon dynamics

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Daniel Ruiz Potma Gonçalves ◽  
Umakant Mishra ◽  
Skye Wills ◽  
Sagar Gautam
Keyword(s):  
Environmental Factors ◽  
Land Cover ◽  
Environmental Conditions ◽  
Climate Feedback ◽  
Soil Types ◽  
Climatic Data ◽  
Earth System ◽  
Land Cover Types ◽  
Continental Scale ◽  
Soc Stocks

AbstractUnderstanding the influence of environmental factors on soil organic carbon (SOC) is critical for quantifying and reducing the uncertainty in carbon climate feedback projections under changing environmental conditions. We explored the effect of climatic variables, land cover types, topographic attributes, soil types and bedrock geology on SOC stocks of top 1 m depth across conterminous United States (US) ecoregions. Using 4559 soil profile observations and high-resolution data of environmental factors, we identified dominant environmental controllers of SOC stocks in 21 US ecoregions using geographically weighted regression. We used projected climatic data of SSP126 and SSP585 scenarios from GFDL-ESM 4 Earth System Model of Coupled Model Intercomparison Project phase 6 to predict SOC stock changes across continental US between 2030 and 2100. Both baseline and predicted changes in SOC stocks were compared with SOC stocks represented in GFDL-ESM4 projections. Among 56 environmental predictors, we found 12 as dominant controllers across all ecoregions. The adjusted geospatial model with the 12 environmental controllers showed an R2 of 0.48 in testing dataset. Higher precipitation and lower temperatures were associated with higher levels of SOC stocks in majority of ecoregions. Changes in land cover types (vegetation properties) was important in drier ecosystem as North American deserts, whereas soil types and topography were more important in American prairies. Wetlands of the Everglades was highly sensitive to projected temperature changes. The SOC stocks did not change under SSP126 until 2100, however SOC stocks decreased up to 21% under SSP585. Our results, based on environmental controllers of SOC stocks, help to predict impacts of changing environmental conditions on SOC stocks more reliably and may reduce uncertainties found in both, geospatial and Earth System Models. In addition, the description of different environmental controllers for US ecoregions can help to describe the scope and importance of global and local models.

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