scholarly journals Effects of Patch Size, Fragmentation, and Invasive Species on Plant and Lepidoptera Communities in Southern Texas

Insects ◽  
2021 ◽  
Vol 12 (9) ◽  
pp. 777
Author(s):  
James A. Stilley ◽  
Christopher A. Gabler
Keyword(s):  
Invasive Species ◽  
Patch Size ◽  
Plant Cover ◽  
Common Species ◽  
Private Lands ◽  
Plant Richness ◽  
Management Plans ◽  
Landscape Alteration ◽  
Biotic Disturbance ◽  
Abundance And Diversity

Habitat loss, fragmentation, and invasive species are major threats to biodiversity. In the Lower Rio Grande Valley (LRGV) of southern Texas, a conservation hotspot, few studies have examined how land use change and biotic disturbance influence biodiversity, particularly among Lepidoptera. We surveyed 24 habitat fragments on private lands in the LRGV and examined how patch size, edge to interior ratio (EIR), prevalence of invasive, exotic, and pest (IEP) plant species, and other environmental factors influenced plant and Lepidoptera communities within four habitat classes. Biotic disturbance was widespread and intense. IEP plants represented three of the four most common species in all but one habitat class; yet, classes largely had distinctive plant and Lepidoptera communities. Larger habitat patches had lower IEP prevalence but also lower plant richness and lower Lepidoptera richness and abundance. Conversely, patches with higher EIRs had greater IEP prevalence, plant richness, and Lepidoptera richness and abundance. IEP prevalence was negatively related to plant diversity and positively related to woody dominance, blooming plant abundance, and, surprisingly, both plant cover and richness. However, plant richness, abundance, and diversity were higher where a greater proportion of the plants were native. Lepidoptera diversity increased with plant cover, and Lepidoptera richness and abundance increased with plant richness. More individual Lepidoptera species were influenced by habitat attributes than by availability of resources such as host plants or nectar sources. Our results illustrate extensive landscape alteration and biotic disturbance and suggest that most regional habitats are at early successional stages and populated by a novel species pool heavy in IEP species; these factors must be considered together to develop effective and realistic management plans for the LRGV.

scholarly journals Effects of a Short-Term Trampling Experiment on Alpine Vegetation in the Tatras, Slovakia

2021 ◽  
Vol 13 (5) ◽  
pp. 2750
Author(s):  
Veronika Piscová ◽  
Michal Ševčík ◽  
Juraj Hreško ◽  
František Petrovič
Keyword(s):  
Outdoor Recreation ◽  
Plant Cover ◽  
Short Term ◽  
Recreational Activities ◽  
Small Areas ◽  
Management Plans ◽  
Deciduous Shrubs ◽  
Negative Impacts ◽  
Potential Damage ◽  
Alpine Communities

Over the past decades, outdoor recreation in mountains has become progressively more important and as a result human induced potential damage has increased. Alpine communities are particularly susceptible to human recreational activities, such as tourist trampling. Although there are a number of studies that explicitly assess the effects of trampling on alpine communities, they do not reflect on terrains with a rich topography and the presence of more communities in very small areas. In this study, effects of short-term trampling on some alpine communities in the Tatras, the highest mountains of the Carpathians, were studied experimentally. Vulnerability to disturbance was compared among plant communities in terms of resistance and resilience, which are based on cover measurements. With proximity to trampling intensity, we found a significant decrease in plant cover and abundance of deciduous shrubs, lichens, and mosses. These results demonstrate that human trampling in alpine communities has major negative impacts on lichen and moss abundance and species richness. A short-term trampling experiment required several years of community regeneration. Therefore, management plans should discourage hiking activity off paths and restrict recreational activities.

Cooperative bargaining to manage invasive species in jurisdictions with public and private lands

2018 ◽  
Vol 32 ◽  
pp. 72-83
Author(s):  
Shyamani D. Siriwardena ◽  
Kelly M. Cobourn ◽  
Gregory S. Amacher ◽  
Robert G. Haight
Keyword(s):  
Invasive Species ◽  
Private Lands ◽  
Public And Private ◽  
Cooperative Bargaining

Biomasse et espèces de lichens terrestres disponibles pour le caribou dans le nord du Québec

1990 ◽  
Vol 68 (10) ◽  
pp. 2047-2053 ◽  
Author(s):  
Michel Crête ◽  
Claude Morneau ◽  
René Nault
Keyword(s):  
Plant Cover ◽  
Ground Cover ◽  
Dry Weight ◽  
Common Species ◽  
The West ◽  
The North ◽  
Precipitation Zone ◽  
Annual Consumption ◽  
Mat Thickness ◽  
Primary Unit

Following a two-stage sampling plan, 44 1-km2 primary units were systematically allocated between 53 and 59 ° latitude throughout northern Québec to estimate the biomass of terrestrial lichens. Lichens were collected in two secondary units (0.25 m2) located in parts of each primary unit where lichens were visible from a helicopter (lichen stratum). Overall, the lichen stratum covered 51% of the study area and lichen biomass averaged 1223 kg/ha (dry weight; SE = 201; n = 44). Almost 85% of the variance of this mean was attributable to variability between primary units. The biomass in the west was greater than in the east; it was the highest in the [Formula: see text]700-mm precipitation zone and the lowest in the 500- to 599-mm zone. Data on percent plant cover indicated mat mosses increased in importance over lichens in the east. There was a clear relationship between lichen biomass in secondary units on one hand and mat thickness and percent lichen ground cover on the other. Cladinia stellaris (Opiz) Brodo was the most common species; Alectoria ochroleuca (Hoffm.) Mass. and Cornicularia divergens Ach. were typical of the north, whereas Cladina mitis (Sandst.) Hustich characterized the south of the study area. The annual consumption of lichens by caribou was probably 0.5-0.9% of the available biomass in 1987. Key words: biomass, caribou, Cladina, lichens, Quebec.

After the fence: vegetation and topsoil condition in grazed, fenced and benchmark eucalypt woodlands of fragmented agricultural landscapes

2011 ◽  
Vol 59 (4) ◽  
pp. 369 ◽  
Author(s):  
Suzanne M. Prober ◽  
Rachel J. Standish ◽  
Georg Wiehl
Keyword(s):  
Species Composition ◽  
Plant Species ◽  
Plant Cover ◽  
Agricultural Landscapes ◽  
Livestock Grazing ◽  
Nutrient Concentrations ◽  
Plant Species Composition ◽  
Exotic Plant ◽  
Native Plant ◽  
Plant Richness

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.

scholarly journals Medium Plant Cover has the Highest Heterogeneity of Fine-Scale Spatial Vegetation Patterns in Humid grasslands

2021 ◽  
Author(s):  
Qin Yang ◽  
Hua Cheng ◽  
Hongmei Pu ◽  
Xuechun Zhao ◽  
Rui Dong ◽  
...  
Keyword(s):  
Large Scale ◽  
Patch Size ◽  
Management Practices ◽  
Plant Cover ◽  
Rapid Expansion ◽  
Edge Density ◽  
Vegetation Patterns ◽  
Fine Scale ◽  
Ecological Processes ◽  
Patch Density

Abstract Context Fine-scale spatial vegetation patterns are ubiquitous and can have profound impacts on large scale ecological processes including surface runoff, soil erosion, and livestock forage efficiency. However, we have limited knowledge of the fine-scale spatial vegetation patterns in humid grasslands.Objectives The objectives were to characterize the spatial vegetation patterns at centimeter scale in humid grasslands, quantify the vegetation patterns variation under different image pixel sizes and plant covers, and explore the potential ecological implications of the spatial vegetation patterns.Methods Seventy plots with plant covers ranging from 30.8–99.3% were selected from seven humid grasslands in southwest China and their spatial vegetation patterns quantified at image pixel sizes of 0.04, 0.25, 1, and 4 cm.Results With increasing pixel size, plant patch density and total edge density decreased, plant patch size increased, and the plant patch shape became more regular. At a plant cover level below 50%, increasing plant cover will result in increasing patch density and patch size, leading to greater spatial heterogeneity. At plant cover levels above 50%, increasing plant cover will cause the rapid expansion of patch size, along with a lower patch density, forming a more homogeneous landscape dominated by plant patches. The small stems, branches, and leaves of grasses fragmented non-plant patches into smaller patches with increasing plant cover; this fragmentation resembles road-induced landscape fragmentation processes.Conclusions Medium plant cover has the highest heterogeneity of spatial vegetation pattern at the fine scale, which may have significant implications on ecological processes and related management practices.

Abundance and Diversity of Seedlings of the Soil Seed Bank in the Thickets of the Invasive Species Acer negundo L.

2018 ◽  
Vol 9 (2) ◽  
pp. 108-113 ◽  
Author(s):  
D. V. Veselkin ◽  
O. A. Kiseleva ◽  
E. D. Ekshibarov ◽  
O. S. Rafikova ◽  
A. A. Korzhinevskaya
Keyword(s):  
Invasive Species ◽  
Seed Bank ◽  
Soil Seed Bank ◽  
Acer Negundo ◽  
Abundance And Diversity

The importance of piled wood debris on the distribution of bird-dispersed plants in burned and logged Mediterranean pine forests

2012 ◽  
Vol 21 (1) ◽  
pp. 79 ◽  
Author(s):  
J. Rost ◽  
J. M. Bas ◽  
P. Pons
Keyword(s):  
Necessary Conditions ◽  
Plant Cover ◽  
Common Species ◽  
Pine Forests ◽  
Plant Dispersal ◽  
Burned Areas ◽  
Wood Debris ◽  
Restoration Measure ◽  
Mediterranean Pine ◽  
Slope Orientation

Plant dispersal and colonisation are important processes in vegetation recovery after fire and, for several species, depend on the presence of frugivorous avian seed dispersers. In burned and salvage-logged Mediterranean pine forests, the occurrence of disperser birds is enhanced by the presence of wood debris piles built as erosion barriers, which become seed dispersal foci. We hypothesised that the distribution of bird-dispersed plants after fire could be determined by the presence of wood piles. We analysed the differences in species richness and overall cover of bird-dispersed plants, as well as the cover of the most common species, within piles and outside them. We also tested if micro-environmental conditions (slope orientation and pile size) might influence plant occurrence. We found more species and overall cover within piles, when located on southern and south-eastern slopes, than outside them. Moreover, taller piles showed higher values of bird-dispersed plant cover and richness. Therefore, wood piles may provide the necessary conditions for bird-dispersed plant recruitment in dry burned areas. To our knowledge, this is the first reported man-made structure that clearly benefits the recovery of bird-dispersed plants in burned areas, and suggests that piles may be a useful restoration measure when logging Mediterranean burned forests.

The establishment of an invasive pest mite, Raoiella indica, affects mite abundance and diversity on coconut plants

2020 ◽  
Vol 25 (5) ◽  
pp. 881-894
Author(s):  
Maria Edvânia Neves Barros ◽  
Debora B. Lima ◽  
Jairo A. Mendes ◽  
Manoel G. C. Gondim Jr. ◽  
José Wagner Da Silva Melo
Keyword(s):  
Invasive Species ◽  
Keystone Species ◽  
Invasive Pest ◽  
Ecosystem Structure ◽  
Feeding Mode ◽  
Phytoseiid Mites ◽  
Red Palm Mite ◽  
Raoiella Indica ◽  
Pest Mite ◽  
Abundance And Diversity

The introduction and establishment of an invasive species in a new habitat represents a major threat to biodiversity and ecosystem structure. A recent example of a mite that has become an invasive species is the red palm mite, Raoiella indica Hirst (Acari: Tenuipalpidae). After its introduction in the Americas, this species has considerably expanded the number of hosts and has been reported as a key pest of some of these. In the present study we investigated the possibility of mitefauna alteration on coconut leaflets (abundance and diversity) mediated by the introduction and establishment of R. indica. A survey was conducted over a period of 1 year in two areas of coconut cultivation: one infested and one free of R. indica. The results of the present study suggest that the introduction of R. indica modifies the mitefauna existing in coconut leaflets. Differences were detected in the abundance and diversity of mites at the level of the taxonomic categories (family and species) and at the level of the trophic groups (predators, herbivores and mites with undefined feeding mode). Additionally, in plants infested by the invasive species, a similar pattern was observed between the fluctuation of the phytoseiid mites and other tenuipalpid mites. In these plants, the density of the tenuipalpid mites (including R. indica) was also the variable that most contributed to explain the fluctuation of phytoseiid mites. This suggests that the invasive species, R. indica, acts as a keystone species, structuring the mitefauna in coconut plants.

scholarly journals Loss of reproductive output caused by an invasive species

2016 ◽  
Vol 3 (4) ◽  
pp. 150481 ◽  
Author(s):  
Maude E. M. Tremblay ◽  
Todd J. Morris ◽  
Josef D. Ackerman
Keyword(s):  
Invasive Species ◽  
Hot Spots ◽  
Native Species ◽  
Reproductive Output ◽  
Conservation Status ◽  
Common Species ◽  
Neogobius Melanostomus ◽  
Great Lakes Region ◽  
Infection Rates ◽  
Novel Method

We investigated whether Neogobius melanostomus , an invader of biodiversity ‘hot-spots’ in the Laurentian Great Lakes region, facilitates or inhibits unionid mussel recruitment by serving as a host or sink for their parasitic larvae (glochidia). Infestation and metamorphosis rates of four mussel species with at-risk (conservation) status ( Epioblasma torulosa rangiana , Epioblasma triquetra , Lampsilis fasciola and Villosa iris ) and one common species ( Actinonaias ligamentina ) on N. melanostomus were compared with rates on known primary and marginal hosts in the laboratory. All species successfully infested N. melanostomus, but only E. triquetra, V. iris and A. ligamentina successfully metamorphosed into juveniles, albeit at very low rates well below those seen on even the marginal hosts. Neogobius melanostomus collected from areas of unionid occurrence in the Grand and Sydenham rivers (Ontario, Canada) exhibited glochidial infection rates of 39.4% and 5.1%, respectively, with up to 30 glochidia representing as many as six unionid species per fish. A mathematical model suggests that N. melanostomus serve more as a sink for glochidia than as a host for unionids, thereby limiting recruitment success. This represents a novel method by which an invasive species affects a native species.

scholarly journals Importance of fish biodiversity in conservation planning of Brazilian National Parks

2021 ◽  
Vol 10 (10) ◽  
pp. e106101018769
Author(s):  
Thercia Gonçalves Ribeiro Monroe ◽  
Selma Patricia Diniz Cantanhêde ◽  
Natanael Bezerra Monroe ◽  
Fabrício Silva Garcez ◽  
Ligia Tchaicka
Keyword(s):  
Invasive Species ◽  
National Parks ◽  
Fish Fauna ◽  
Ecological Assessment ◽  
Essential Information ◽  
Freshwater Fish Fauna ◽  
Management Plans ◽  
Parks Management ◽  
Rapid Ecological Assessment

Protected areas are essential for the maintenance of biodiversity. In Brazil, national parks encompass one of the most important portions of this area (26.864.003,74ha) that needs to be adequately managed to achieve conservation. Aiming to understand how the ichthyofauna data is included in management plans of  Brazilian National Parks, we review 55 Brazilian national parks management plans to compare how data of freshwater fish fauna are included in these documents. The data evaluated from management plans were Hydrography, ichthyofauna list, participation of professionals trained in rapid ecological assessment and species richness, endangered and invasive species. This information was used to categorize the management plans through two sets of assessing: quality of rapid ecological assessment and coverage of species diversity. The categorization results were assumed as an indicator of the potential for biodiversity conservation of the management plans.   We compare obtained results between biomes.   We were able to understand that many of the Brazilian National Parks do not have management plans, and among the plans that are prepared, the lack of essential information compromises their potential for the conservation of biodiversity. We highlight the need to improve management plans for the Caatinga parks and expand the analysis of invasive species for all biomes.

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