Alien and native plant richness and abundance respond to different environmental drivers across multiple gravel floodplain ecosystems

2016 ◽  
Vol 22 (7) ◽  
pp. 823-835 ◽  
Author(s):  
T. J. Brummer ◽  
A. E. Byrom ◽  
J. J. Sullivan ◽  
P. E. Hulme
2011 ◽  
Vol 59 (4) ◽  
pp. 369 ◽  
Author(s):  
Suzanne M. Prober ◽  
Rachel J. Standish ◽  
Georg Wiehl

Emerging ecological theory predicts that vegetation changes caused by introduction of livestock grazing may be irreversible after livestock are removed, especially in regions such as Australia that have a short evolutionary exposure to ungulate grazing. Despite this, fencing to exclude livestock grazing is the major tool used to restore vegetation in Australian agricultural landscapes. To characterise site-scale benefits and limitations of livestock exclusion for enhancing biodiversity in forb-rich York gum (Eucalyptus loxophleba Benth. subsp. loxophleba)–jam (Acacia acuminata Benth.) woodlands, we compared 29 fenced woodlands with 29 adjacent grazed woodlands and 11 little-grazed ‘benchmark’ woodlands in the Western Australian wheatbelt. We explored the following two hypotheses: (1) fencing to exclude livestock facilitates recovery of grazed woodlands towards benchmark conditions, and (2) without additional interventions after fencing, complete recovery of grazed woodlands to benchmark conditions is constrained by ecological or other limits. Our first hypothesis was supported for vegetation parameters, with fenced woodlands being more similar to benchmark woodlands in tree recruitment, exotic plant cover, native plant cover, native plant richness and plant species composition than were grazed woodlands. Further, exotic cover decreased and frequency of jam increased with time-since-fencing (2–22 years). However, we found no evidence that fencing led to decline in topsoil nutrient concentrations towards concentrations at benchmark sites. Our second hypothesis was also supported, with higher topsoil nutrient concentrations and exotic plant cover, and lower native plant richness in fenced than in benchmark woodlands, and different plant species composition between fenced and benchmark woodlands. Regression analyses suggested that recovery of native species richness is constrained by exotic species that persist after fencing, which in turn are more persistent at higher topsoil nutrient concentrations. We conclude that fencing to exclude livestock grazing can be valuable for biodiversity conservation. However, consistent with ecological theory, additional interventions are likely to be necessary to achieve some conservation goals or to promote recovery at nutrient-enriched sites.


2014 ◽  
Vol 26 (1) ◽  
pp. 80-88 ◽  
Author(s):  
David Bart ◽  
Tara Davenport ◽  
Quentin Carpenter

Author(s):  
Rossano Bolpagni ◽  
Alice Dalla Vecchia

A huge knowledge gap exists on riverine pioneer herbaceous vegetation. Despite its relevance in regulating the C metabolism at the catchment scale, and the triggering role in shrubs and trees establishment along riverbanks, little data is available on its environmental determinants. Indeed, most existing knowledge in this field refers to woody species or aquatic macrophytes neglecting the ecosystem relevance of ephemeral herbaceous vegetation. Focusing on three gravel bed rivers located in northern Italy (Baganza, Nure and Parma streams), the present study is aimed to evaluate the riverine ephemeral plant richness, considering both native and alien taxa, and the role of hydrogeomorphological disturbance and sediment quality in the observed richness patterns. At higher disturbance rates (e.g., larger river sizes), our data indicates a progressive decrease in overall plant richness, but also an increase in the coverage-abundance rates mainly due to alien species. This evidence confirms that variations in hydrology imply changes in pioneer plant species richness at in-stream periodically exposed sediments. More attention must be given to the vulnerability of pioneer vegetation to climate change and direct human impacts to fully understand the functioning of lotic ecosystems, especially the non-perennial ones.


2020 ◽  
Vol 34 (2) ◽  
pp. 472-481 ◽  
Author(s):  
Huixuan Liao ◽  
Huijie Wang ◽  
Qiaohong Dong ◽  
Feihong Cheng ◽  
Ting Zhou ◽  
...  

2018 ◽  
Vol 45 (5) ◽  
pp. 383 ◽  
Author(s):  
Jade E. Keehn ◽  
Chris R. Feldman

Context The global benefits of increased renewable energy production may come at a cost to local biotic communities and even regional ecosystems. Wind energy developments, in particular, are known to cause bird and bat mortalities, and to fragment habitat for terrestrial vertebrates within developed project areas. Effects on species sensitive to wind turbines (and increased prevalence of species tolerant to this disturbance) might alter community-level patterns of occurrence, with potentially detrimental changes to wildlife habitat and ecosystem health. Aims The present study assessed whether wind energy developments produced downstream ecological costs. Specifically, community composition and diversity were compared between wind farms and nearby areas without energy development. Methods Traditional diversity measures and non-metric multidimensional scaling (NMDS) were used to map ecological dissimilarity across four wind farms and five reference (control) areas in Southern California, USA. Key results Wind farms had more noise and road disturbance than sites without turbine installations. Noise and disturbance were correlated with reduced plant richness, particularly for endemic plant species and, conversely, with increased non-native plant richness. Animal communities at wind farms were less diverse, with fewer species and lower evenness relative to reference areas with minor or no disturbances. Wind farms had fewer rare and unique species and, for some species of avian predators, encounter rates were lower at wind farms. Conclusions Renewable wind energy may indeed cause shifts in local communities. Although wind farms still supported many of the same species found in natural areas, suggesting that renewable wind energy facilities can provide useable habitat for some wildlife, these communities were also less rich and diverse. Implications Non-native species were more prevalent at wind farms, which may then facilitate further invasions into surrounding habitats. In addition, reduced overall plant and predator diversity at wind farms, and lower encounter rates for specific taxa (particular birds), may significantly affect community structure and function.


PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e5514
Author(s):  
Mariela G. Gantchoff ◽  
Clay M. Wilton ◽  
Jerrold L. Belant

Exotic species introductions are a global phenomenon and protected areas are susceptible to them. Understanding the drivers of exotic species richness is vital for prioritizing natural resource management, particularly in developing countries with limited resources. We analyzed the influence of coarse resolution factors on exotic species richness (plants, mammals, and birds) in Argentina’s National Parks System. We collected data on native species richness, year of park formation, park area, region, elevation range, number of rivers crossing area boundaries, roads entering area, mean annual rainfall, mean annual temperature, mean annual number of visitors, and Human Influence Index within and surrounding each park. We compiled 1,688 exotic records in 36 protected areas: 83% plants and 17% animals (9.5% mammals, 5.5% birds, 1.5% fishes, 0% amphibians, 0% reptiles). The five parks with the most exotic species (all taxa combined) were in north Patagonia. Exotic grasses were the most common exotic plants, and within animals, lagomorphs and feral ungulates were remarkably widespread. Exotic plant richness was mostly influenced by temperature and native plant richness, while exotic mammal and bird richness was driven mostly by anthropogenic variables, with models explaining 36–45% of data deviance. Most variables that positively influenced exotic taxa were indirectly related to an increase in spatial heterogeneity (natural or anthropogenic), suggesting greater niche space variability as facilitators of exotic richness increase. Additional data are needed to further investigate the patterns and mechanisms of exotic species richness in protected areas, which will help to prioritize the greatest needs of monitoring and management.


2014 ◽  
Vol 170 ◽  
pp. 282-291 ◽  
Author(s):  
Eva M. Cañadas ◽  
Giuseppe Fenu ◽  
Julio Peñas ◽  
Juan Lorite ◽  
Efisio Mattana ◽  
...  

EDIS ◽  
2017 ◽  
Vol 2017 (5) ◽  
Author(s):  
Mary C. Bammer ◽  
Josh Campbell ◽  
Chase B. Kimmel ◽  
James D.. Ellis ◽  
Jaret C. Daniels

The establishment of native wildflower plantings in Florida can benefit agricultural producers as well as native pollinators and other beneficial insects (predators and parasitoids). The plantings do this by:  providing forage and nesting sites for bees, butterflies, and other pollinators, increasing wild bee numbers possibly across the farm, and increasing natural enemies of insect pests (that also depend on forage and nesting sites). This document discusses choosing the right mix of native plant species to benefit many pollinator species, as well as proper site selection, planting practices, and weed control techniques. Wildflower plots should be practical to manage, maximize benefits to wildlife, and fit into the overall management practices of the property. 


2019 ◽  
Vol 617-618 ◽  
pp. 221-244 ◽  
Author(s):  
MR Baker ◽  
ME Matta ◽  
M Beaulieu ◽  
N Paris ◽  
S Huber ◽  
...  

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