scholarly journals Ecology of the Possum (Trichosurus Vulpecula Kerr) in the Karori Water Supply Reserve, Wellington, Sounds Ecological District

2021 ◽  
Author(s):  
◽  
Hans Stoffregen
Keyword(s):  
Exotic Species ◽  
Plant Species ◽  
Native Species ◽  
Reproductive Output ◽  
Native Plants ◽  
Significant Proportion ◽  
Response Characteristic ◽  
Cytisus Scoparius ◽  
Compensatory Response ◽  
Weight For Age

<p>The abundance and condition of possums in various areas of the Karori Reserve, Wellington - Sounds Ecological District was assessed. Possums were most abundant in the upper part of the reserve in an area dominated by bishop and radiata pines with an undergrowth of native species and in an area dominated by gorse and flax shrublands. In the lower part of the reserve, possums were less abundant and there a number of characteristics were observed: possums had a higher body weight for age, their reproductive output was higher and the population was marked by a higher proportion of females and juveniles. This was interpreted as a "compensatory response" characteristic of possum populations maintained at low densities. Possum stomachs were sampled in spring and their contents analysed in order to investigate the importance of Fuchsia excorticata and other plant species to possum diet. In the lower part of the reserve the leaves of Fuchsia excorticata and the flowers of Cytisus scoparius made up more than 50 percent of the possums' forage. In the upper part of the reserve exotic species such as the flowers of Cytisus scoparius and Ulex europeans as well as the leaves of native species such as Aristotelia serrata, Pseudopanax arboreus and Coprosma robusta made up the bulk of possum forage. Exotic plants accounted for a significant proportion of the spring possum diet in the reserve. Whereas most leaves originated from native plants, the exotic species contributed mainly carbohydrate-rich flowers and pollen. The canopy condition of two possum-susceptible tree species Fuchsia excorticata and Pseudopanax arboreus was assessed early in autumn over the years 1993, 1995 and 1996. Over these years, 47 percent of marked fuchsia trees were completely defoliated and most trees are unlikely to recover even if possums are eradicated from the reserve. All defoliated fuchsia trees were located in the upper part of the reserve. On the other hand, 37 percent of marked fuchsia trees exhibited only a little possum damage. Most of these trees were located in the lower part of the reserve where possum density was lower. Increasing possum densities could therefore be correlated with an increasing level of possum damage to fuchsia canopies. Even though Pseudopanax arboreus leaves and petioles were encountered in 10 percent of possum stomachs, the canopies leaves and petioles were encountered in 10 percent of possum stomachs, the canopies of assessed trees did not seem to be greatly affected. It appeared that due to the high abundance of this plant species in the reserve the effects of possum browse were spread over the whole reserve to levels which could be tolerated by an individual Pseudopanax arboreus tree.</p>

scholarly journals Ecology of the Possum (Trichosurus Vulpecula Kerr) in the Karori Water Supply Reserve, Wellington, Sounds Ecological District

2021 ◽  
Author(s):  
◽  
Hans Stoffregen
Keyword(s):  
Exotic Species ◽  
Plant Species ◽  
Native Species ◽  
Reproductive Output ◽  
Native Plants ◽  
Significant Proportion ◽  
Response Characteristic ◽  
Cytisus Scoparius ◽  
Compensatory Response ◽  
Weight For Age

<p>The abundance and condition of possums in various areas of the Karori Reserve, Wellington - Sounds Ecological District was assessed. Possums were most abundant in the upper part of the reserve in an area dominated by bishop and radiata pines with an undergrowth of native species and in an area dominated by gorse and flax shrublands. In the lower part of the reserve, possums were less abundant and there a number of characteristics were observed: possums had a higher body weight for age, their reproductive output was higher and the population was marked by a higher proportion of females and juveniles. This was interpreted as a "compensatory response" characteristic of possum populations maintained at low densities. Possum stomachs were sampled in spring and their contents analysed in order to investigate the importance of Fuchsia excorticata and other plant species to possum diet. In the lower part of the reserve the leaves of Fuchsia excorticata and the flowers of Cytisus scoparius made up more than 50 percent of the possums' forage. In the upper part of the reserve exotic species such as the flowers of Cytisus scoparius and Ulex europeans as well as the leaves of native species such as Aristotelia serrata, Pseudopanax arboreus and Coprosma robusta made up the bulk of possum forage. Exotic plants accounted for a significant proportion of the spring possum diet in the reserve. Whereas most leaves originated from native plants, the exotic species contributed mainly carbohydrate-rich flowers and pollen. The canopy condition of two possum-susceptible tree species Fuchsia excorticata and Pseudopanax arboreus was assessed early in autumn over the years 1993, 1995 and 1996. Over these years, 47 percent of marked fuchsia trees were completely defoliated and most trees are unlikely to recover even if possums are eradicated from the reserve. All defoliated fuchsia trees were located in the upper part of the reserve. On the other hand, 37 percent of marked fuchsia trees exhibited only a little possum damage. Most of these trees were located in the lower part of the reserve where possum density was lower. Increasing possum densities could therefore be correlated with an increasing level of possum damage to fuchsia canopies. Even though Pseudopanax arboreus leaves and petioles were encountered in 10 percent of possum stomachs, the canopies leaves and petioles were encountered in 10 percent of possum stomachs, the canopies of assessed trees did not seem to be greatly affected. It appeared that due to the high abundance of this plant species in the reserve the effects of possum browse were spread over the whole reserve to levels which could be tolerated by an individual Pseudopanax arboreus tree.</p>

scholarly journals Alien woody plants are more versatile than native, but both share similar therapeutic redundancy in South Africa

PLoS ONE ◽  
2021 ◽  
Vol 16 (11) ◽  
pp. e0260390
Author(s):  
Kowiyou Yessoufou ◽  
Annie Estelle Ambani ◽  
Hosam O. Elansary ◽  
Orou G. Gaoue
Keyword(s):  
Plant Species ◽  
Native Species ◽  
Native Plants ◽  
Invasion Biology ◽  
Alien Plants ◽  
Parasitic Infections ◽  
Alien Plant Species ◽  
Secondary Chemistry ◽  
Alien Plant ◽  
Medicinal Flora

Understanding why alien plant species are incorporated into the medicinal flora in several local communities is central to invasion biology and ethnobiology. Theories suggest that alien plants are incorporated in local pharmacopoeias because they are more versatile or contribute unique secondary chemistry which make them less therapeutically redundant, or simply because they are locally more abundant than native species. However, a lack of a comprehensive test of these hypotheses limits our understanding of the dynamics of plants knowledge, use and potential implications for invasion. Here, we tested the predictions of several of these hypotheses using a unique dataset on the woody medicinal flora of southern Africa. We found that the size of a plant family predicts the number of medicinal plants in that family, a support for the non-random hypothesis of medicinal plant selection. However, we found no support for the diversification hypothesis: i) both alien and native plants were used in the treatment of similar diseases; ii) significantly more native species than alien contribute to disease treatments particularly of parasitic infections and obstetric-gynecological diseases, and iii) alien and native species share similar therapeutic redundancy. However, we found support for the versatility hypothesis, i.e., alien plants were more versatile than natives. These findings imply that, although alien plant species are not therapeutically unique, they do provide more uses than native plants (versatility), thus suggesting that they may not have been introduced primarily for therapeutic reasons. We call for similar studies to be carried out on alien herbaceous plants for a broader understanding of the integration of alien plants into the pharmacopoeias of the receiving communities.

Exotic plant invasion and understorey species richness: a comparison of two types of eucalypt woodland in agricultural Western Australia

1998 ◽  
Vol 4 (1) ◽  
pp. 21 ◽  
Author(s):  
Max Abensperg-Traun ◽  
Lyn Atkins ◽  
Richard Hobbs ◽  
Dion Steven
Keyword(s):  
Species Richness ◽  
Exotic Species ◽  
Plant Species ◽  
Plant Invasion ◽  
Native Plants ◽  
Exotic Plants ◽  
Exotic Plant ◽  
Native Plant ◽  
Road Verge ◽  
Exotic Plant Invasion

Exotic plants are a major threat to native plant diversity in Australia yet a generic model of the invasion of Australian ecosystems by exotic species is lacking because invasion levels differ with vegetation/soil type and environmental conditions. This study compared relative differences in exotic species invasion (percent cover, spp. richness) and the species richness of herbaceous native plants in two structurally very similar vegetation types, Gimlet Eucalyptus salubris and Wandoo E. capillosa woodlands in the Western Australian wheatbelt. For each woodland type, plant variables were measured for relatively undisturbed woodlands, woodlands with >30 years of livestock grazing history, and woodlands in road-verges. Grazed and road-verge Gimlet and Wandoo woodlands had significantly higher cover of exotic species, and lower species richness of native plants, compared with undisturbed Gimlet and Wandoo. Exotic plant invasion was significantly greater in Gimlet woodlands for both grazed (mean 78% cover) and road-verge sites (mean 42% cover) than in comparable sites in Wandoo woodlands (grazed sites 25% cover, road-verge sites 19% cover). There was no significant difference in the species richness of exotic plants between Wandoo and Gimlet sites for any of the three situations. Mean site richness of native plants was not significantly different between undisturbed Wandoo and undisturbed Gimlet woodlands. Undisturbed woodlands were significantly richer in plant species than grazed and road-verge woodlands for both woodland types. Grazed and road-verge Wandoo sites were significantly richer in plant species than communities in grazed and road-verge Gimlet. The percent cover of exotics was negatively correlated with total (native) plant species richness for both woodland types (Wandoo r = ?0.70, Gimlet r = ?0.87). Of the total native species recorded in undisturbed Gimlet, 83% and 61% were not recorded in grazed and road-verge Gimlet, respectively. This compared with 40% and 33% for grazed and road-verge Wandoo, respectively. Grazed Wandoo and grazed Gimlet sites had significantly fewer native plant species than did road-verge Wandoo and road-verge Gimlet sites. Ecosystem implications of differential invasions by exotic species, and the effects of grazing (disturbance) and other factors influencing susceptibility to exotic plant invasion (landscape, competition and allelopathy) on native species decline are discussed. Exclusion of livestock and adequate methods of control and prevention of further invasions by exotic plants are essential requirements for the conservation of these woodland systems.

scholarly journals Species diversity, composition and the regeneration potential of native plants at the Wainiveiota Mahogany Plantation, Viti Levu, Fiji Islands

2012 ◽  
Vol 30 (1) ◽  
pp. 51 ◽  
Author(s):  
Senilolia H. Tuiwawa ◽  
Gunnar Keppel
Keyword(s):  
Plant Species ◽  
Native Species ◽  
Native Plants ◽  
Line Transect ◽  
Native Plant ◽  
Regeneration Potential ◽  
Native Plant Species ◽  
Fiji Islands ◽  
Lowland Rainforest ◽  
Over Time

Mahogany (Swietenia macrophylla King) plantations cover a considerable area on the south-eastern parts of Viti Levu, Fiji. The understorey of these plantations often comprise a diverse, but undocumented, assemblage of native plant species. This study investigates the diversity, composition and regeneration potential of native plant species in the Wainiveiota mahogany plantation 40?50 years after establishment. Ten 10 m x 10 m plots were alternately placed at 10 m intervals perpendicular to a 200 m line transect. A total of 491 individual plants with dbh ≥ 1 cm, comprising 69 species, 51 genera and 34 families, were sampled. In addition to the exotic mahogany, there were 68 native (39 endemic, 24 indigenous and 5 identified to genus only) species recorded. Girronniera celtidifolia Gaud., Dillenia biflora (A.Gray) Martelli ex Dur. & Jacks and Barringtonia edulis Seem. had the highest recruitment and Endospermum macrophyllum (Muell.Arg.) Pax & Hoffm. was the dominant native species. Syzygium Gaertn. (Myrtaceae) was the most diverse genus and Myrtaceae the most diverse family. With 98% of the sapling recruitment consisting of native species, there is potential for re-establishment of a lowland rainforest dominated by native species over time.

Survival of native plants of Hawkesbury Sandstone communities with additional nutrients: effect of plant age and habitat

2004 ◽  
Vol 52 (2) ◽  
pp. 141 ◽  
Author(s):  
V. P. Thomson ◽  
M. R. Leishman
Keyword(s):  
Plant Species ◽  
Native Species ◽  
Native Plants ◽  
Soil Nutrient ◽  
Nutrient Concentrations ◽  
Native Plant ◽  
Native Plant Species ◽  
Run Off ◽  
High Concentrations ◽  
Disturbed Soils

Australian soils are naturally low in nutrient concentrations, particularly nitrogen (N) and phosphorus (P). Native plants are well adapted to low-nutrient soils, and can be adversely affected when exposed to higher concentrations of nutrients. The Hawkesbury Sandstone soils in northern Sydney are naturally low in nutrients, but often receive additional nutrient input from urban stormwater run-off. Increases in soil nutrients in urban bushland are associated with the presence of exotic species, and the decline in the diversity of native species. This study tested the hypothesis that high concentrations of nutrients, in particular P, in the disturbed soils of urban bushland, reduce survival of native plants. We examined the survival of native species under five different nutrient concentrations that are typical of nutrient-enriched urban bushland soil, in two glasshouse experiments. The experiments examined both survival of seedlings and survival of 6-month-old plants. We used native species that are adapted to both nutrient-poor and nutrient-rich soils. In general, the survival of native plants decreased with increasing nutrient concentrations. At soil total-P concentrations >200 mg kg–1, most plants died. Seedlings were more sensitive to added nutrients than the 6-month-old plants. Species that were from higher-nutrient soil had consistently higher survival than species from low-nutrient soils, under the nutrient addition treatments. These results suggest that at high soil nutrient concentrations typical of stormwater-affected urban bushland, native plant species of low-nutrient soils will be unable to survive. If ecological restoration works are to be done in such areas, replanting with more mature plants from naturally high-nutrient habitats is likely to be the most successful. However, restoration of these areas may have limited success and they are likely to remain dominated by exotic plant species.

scholarly journals Alien Plants are Less Palatable to Pest Herbivores than Native Plants: Evidence from Cafeteria Experiments in Search of Suitable Plant Species to Restore Degraded Ecosystems

2021 ◽  
Vol 40 (1) ◽  
pp. 16-24
Author(s):  
Mouldi Gamoun ◽  
Mounir Louhaichi
Keyword(s):  
Alien Species ◽  
Plant Species ◽  
Native Species ◽  
Native Plants ◽  
Feeding Preference ◽  
Alien Plants ◽  
General Tendency ◽  
Native Plant ◽  
Evolutionary Potential ◽  
Wide Range

Abstract Nowadays, the ecology and evolutionary potential of alien species are the subjects of several ecological studies. The goal of this study was to compare the feeding preference of Arion ater on seedlings and leaves of alien and native plant species. Seedlings of three native species and one alien species were offered to slugs individually and in combination. Afterward, leaf discs from the native and alien species collected from the same source site of slug’s habitat were offered individually and in combination for slugs. When the new plant emerges, it constitutes a generous source of potential food and slugs would even feed on seedlings, which are not particularly palatable. Nonetheless, when given a choice, slug often preferentially feeds on some food items while ignoring others. Alien plants are more resistant to herbivory than native plants. There is a general tendency for alien species to be less palatable than native species. In general, slugs may eat a wide range of seedlings that are much more attractive than mature plants of the same species. Therefore, the native herbivores were found to attack native plants and promoted alien plants. Consequently, highly unacceptable alien species such as Eucalyptus globulus may play an important role in the restoration process.

scholarly journals Landscape Architects' Use of Native Plants in the Southeastern United States

2007 ◽  
Vol 17 (1) ◽  
pp. 78-81 ◽  
Author(s):  
Robert F. Brzuszek ◽  
Richard L. Harkess ◽  
Susan J. Mulley
Keyword(s):  
United States ◽  
Plant Species ◽  
Native Plants ◽  
Southeastern United States ◽  
Significant Proportion ◽  
Survey Study ◽  
Native Plant ◽  
Native Plant Species ◽  
Local Species ◽  
Survey Results

In their efforts to provide better land stewardship and management, landscape architects are increasingly addressing site ecology in a wide variety of project types. From urban developments to rural properties, designers are using more sustainable design and management techniques, which include the expanded use of regional native plants. This survey study explores the use of native plants by landscape architects in the southeastern United States. Survey results show that southeastern United States designers are using a significant proportion of regional native plant species in their project specifications. Rather than using native plants strictly for conservation measures, landscape architects have found local species to be better suited to difficult or unique site conditions. The findings show that there is potential for expansion in the production and marketing of plant species indigenous to the southeastern United States.

scholarly journals Alien plant species on roadsides of the northwestern Patagonian steppe (Argentina)

PLoS ONE ◽  
2021 ◽  
Vol 16 (2) ◽  
pp. e0246657
Author(s):  
Giselle Ailin Chichizola ◽  
Sofía Laura Gonzalez ◽  
Adriana Edit Rovere
Keyword(s):  
Exotic Species ◽  
Plant Species ◽  
Seed Bank ◽  
Native Species ◽  
Seed Banks ◽  
Patagonian Steppe ◽  
Invasive Exotic Species ◽  
Perennial Herbs ◽  
Invasive Exotic ◽  
Reference Areas

The introduction of alien species represents one of the greatest threats to biodiversity worldwide. Highway construction increases the dispersal and invasion of exotic plant species. This study examined the assembly process of the plant communities to determine whether the roadsides of the Patagonian steppe represent a reservoir and dispersal source of invasive exotic species. We analyzed the composition of exotic and native species and functional groups present in the established vegetation and seed banks of roadsides and reference areas nearby. The type of dispersal of exotic and native species at the roadsides was also evaluated. Total cover and that of exotic and native species was lower at the roadsides than in the reference areas; however, at the roadsides the cover and seed abundance of exotic species was higher than that of native species. In the roadsides vegetation, native shrubs such as Acaena splendens predominated, along with exotic perennial herbs and grasses which were mainly represented by Rumex acetosella. In the seed bank the predominant species were exotic perennial herbs, also represented by R. acetosella, annual exotic species such as Epilobium brachycarpum and Verbascum thapsus, and annual native species such as Heliotropium paronychioides. No exotic shrubs were found either at the roadsides or in the reference areas. The species at the roadsides did not present a dominant type of dispersal. The abundance of exotic species at the roadsides, both in the aboveground vegetation and the seed bank, may be due to the stressful environment and the characteristics of the species themselves, such as the ability to form seed banks. This work revealed that the roadsides of the Patagonian steppe constitute reservoirs of invasive exotic species, highlighting the importance of identifying them and controlling their spread, with a view to generating ecosystem management programs.

Restoration of seed dispersal interactions in communities invaded by non-native plants.

2020 ◽  
pp. 391-401
Author(s):  
Fernanda Ribeiro da Silva ◽  
Marco Aurélio Pizo
Keyword(s):  
Seed Dispersal ◽  
Tropical Forests ◽  
Plant Species ◽  
Native Species ◽  
Native Plants ◽  
Open Systems ◽  
Bird Species ◽  
Negative Influence ◽  
Native Plant ◽  
Native Plant Species

Abstract Restoration aims to rebuild not only species but also the tangled interactions between species that ensure communities perpetuate by themselves. In tropical forests, restoration of seed dispersal interactions is essential because most plant species depend on animals to spread their seeds. A big challenge in restoring such forests is dealing with invasion by non-native species. Non-native plant species may outcompete and eliminate native species from the community, potentially disrupting or arresting the restoration process. Once established, invasive non-native plants are usually incorporated into the local seed dispersal network, potentially causing loss of biodiversity by competition with native species. This chapter reports on a case study of a 25-year old restored forest invaded by several bird-dispersed plant species. We assessed network metrics at the species level to specifically evaluate the role performed by invasive non-native species in the structure of the bird - seed dispersal network. The removal of invasive non-native plants and the re-establishment of native plant communities should be considered for the restoration of habitats invaded by non-native plants. For this reason, we discuss the impacts of removing such non-native plants and explore the consequences for the structure of the overall network. Because restoration areas are open systems, even after the removal of invasive non-native plant species they can return via seed dispersal. So, both the control and management of invasive non-native species would be more effective if planned with a landscape perspective. We also point out relevant management aspects to avoid the negative influence of invasive non-native plants on the seed dispersal interactions occurring between native plant and bird species in restored tropical forests.

scholarly journals Performance of 67 Native Midwestern U.S. Perennials in a Low-maintenance Landscape

2004 ◽  
Vol 14 (3) ◽  
pp. 381-388 ◽  
Author(s):  
Andrew L. Thomas ◽  
Denny Schrock
Keyword(s):  
United States ◽  
Plant Species ◽  
Seasonal Changes ◽  
Native Species ◽  
Urban Landscape ◽  
Native Plants ◽  
Growth Habit ◽  
Midwestern United States ◽  
Perennial Plant ◽  
Size Growth

Hundreds of perennial plant species native to the midwestern United States have potential as ornamentals, but information on how best to use such plants in the landscape remains scarce. Many horticulturists are looking for species that perform well under low-maintenance conditions and that also attract and benefit desirable fauna, such as butterflies and birds. While many of our native plants may fit into this category, not all such species will meet aesthetic criteria for home landscapes. Some native species respond to seasonal changes in temperature and rainfall by browning or going dormant. Others have very specific site requirements for moisture, soil, and humidity that may be difficult to meet in an urban landscape, or their size, growth habit, or other characteristics may make them aesthetically undesirable in the typical home landscape. This study evaluated the performance of 67 plant taxa native to the midwestern United States selected for their promising potential in a low-maintenance landscape situation.

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