scholarly journals Similar seed dispersal systems by local frugivorous birds in native and alien plant species in a coastal seawall forest

PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e11672
Author(s):  
Bin Liu ◽  
Guohai Wang ◽  
Yuting An ◽  
Dandan Xue ◽  
Libo Wang ◽  
...  

Frugivorous birds play an important role in seed dispersal. Alien plant species’ seeds are dispersed by local birds in order to establish populations in new habitats. Alien plant species that produce fruits similar to that of native species have the potential to attract local birds, creating new mutualistic systems that are similar to the local ones. In autumn 2018 and 2019, we studied the seed dispersal systems of an alien plant species, Phytolacca americana, and a native species, Cayratia japonica, in a coastal seawall forest. Both plant species’ fruit, frugivorous bird foraging behaviors, seed germination rates, and seedling microhabitats were examined to determine whether the alien species had a similar seed dispersal system to that of the native species. Our results showed that P. americana and C. japonica had similar fruit type, color, and ripening period. There was a positive correlation between the percentage rate of fruit ripening and the percentage rate of fruit missing for both plant species, indicating that local frugivorous birds have the potential to sufficiently disperse the alien seeds to enable its spread in the coastal seawall forest (simple linear regression, P. americana: β = 0.863 ± 0.017, R2adj = 0.978, P < 0.01; C. japonica: β = 0.787 ± 0.034, R2adj = 0.898, P < 0.01). Eleven bird species consumed the fruits of the alien species or native species during the study period. Similar results were shown across alien and native species in bird foraging behavior (feeding frequency, feeding duration and first stop distance) indicating that a similar seed dispersal relationship had been established between local frugivorous and both plant species. The alien plant had a higher number of fruits carried by birds, suggesting that P. americana had a slightly higher fruit consumption than that of C. japonica (t-test, P < 0.01). Alien plant seedlings grow more abundant in forest gap microhabitat (t-test, P < 0.01). Our results confirmed that bird digestion promotes seed germination success in both plant species. Our study suggests that in a narrow coastal seawall forest, alien plant species can successfully establish their populations by relying on similar seed dispersal systems as the local species.

2021 ◽  
Vol 15 (1) ◽  
pp. 79-92
Author(s):  
T. V. Shupova ◽  

Introduction. In urban conditions, alien species of biota have become an integral part of the cultural landscape. Today, an overall assessment of the influence of alien species on the functioning of ecosystems of their secondary range as is relevant. Such an assessment requires knowledge of the connections formed by alien species in the secondary habitat. The purpose of the study was to find the connections of alien bird species with alien plant species in the parks and botanical gardens of Kyiv. Methods. Assessment was carried out in 10 forest parks, 3 botanical gardens, and 14 urban parks. In parks and botanical gardens, there is a wide range of plants alien to Kyiv Region, in contrast to forest parks. The number and distribution of birds were determined using the method of transect counts. The total area under study was about 370 hectares. Principal Component Analysis of the characteristics of habitats on which the number of alien birds may depend has been carried out. In the research, α-diversity indices of bird communities; number of people (individuals/km); number of pets (individuals/km); park’s area (ha); part of the territory; under the trees (%); part of alien species on plants communities (%) were analyzed. Results. Parus major, Turdus merula, Erithacus rubecula, Fringilla сoelebs dominate in all communities. Columba palumbus, Ficedula albicollis, Turdus pilaris, Columba livia, Apus apus, Sturnus vulgaris, Passer domesticus sometimes dominate in bird communities in parks and botanical gardens. There are no alien species in forest parks. 4 alien species nest in parks and botanical gardens: Streptopelia decaocto, Dendrocopos syriacus, Phoenicurus ochruros, Serinus serinus (from the last century). Phylloscopus trochiloides was observed for the first time. Nesting of Ph. trochiloides was not confirmed. Alien birds are not evenly distributed (0–3 species). Nest density is low: S. decaocto 0.013±0.01–0.021±0.01, D. syriacus 0.031±0.01–0.043±0.04, Ph. ochruros 0–0.034±0.02, S. serinus 0.013±0.01–0.017±0.01. We assume that alien bird species is an element that replaces the species that were eliminated from the community. Their nesting in forest parks is an indicator of a disruption of the functioning of the forest ecosystem as a result of anthropogenic transformation of the forest. The presence of alien species of birds in modern parks and botanical gardens is normal. Their biotopes were created on the sites of destroyed landscapes and with using alien plant species. Conclusion. In parks and botanical gardens, a specific structure of the plant community has developed due to the introduction of alien plant species, with a tree height of 3–5 m. As a consequence, alien birds find nesting stations in communities of nesting birds, which were not occupied by native species due to the absence of many species of tree canopy nesters and ground nesters birds. Alien species of birds also get access to vacant food resources. Alien birds use vacant resources. It was found that the area of parks has the most profound positive impact on the number of species of alien birds (+0.517), as well as the ratio of alien birds (+0.227). Other important correlations observed were the following: the number of species of alien birds in the bird communities – a part of alien species in plant communities (+0.084), the ratio of alien birds – part of alien species in plant communities (+0.041). The strongest negative connection is as follows: the number of species of alien birds in the bird communities – the number of pets (-0.213), the ratio of alien birds – the number of pets (-0.384).


2012 ◽  
Vol 18 (1) ◽  
pp. 3-12 ◽  
Author(s):  
Rasa Dobravolskaitė

Abstract Dobravolskaitė R., 2012: Alien species Impatiens parviflora invasion into forest communities of Lithuania [Svetimžemės rūšies Impatiens parviflora invazija į Lietuvos miškų bendrijas]. - Bot. Lith., 18(1): 3-12. Alien plants threaten native communities by altering their species composition and reducing native biodiversity. Forests are considered to be relatively stable ecosystems and resistant to plant invasions. Impatiens parviflora DC. is one of the most intensively spreading alien plant species in the forests of Lithuania. Phenotypic variations among I. parviflora populations in three different habitat types (with different species of dominant tree and the coverage of the first tree layer) in the environs of Vilnius (South East Lithuania) were analysed. The results of the investigation enabled to evaluate alien plant species I. parviflora invasion into different forest communities and estimate relationships between plants of forest communities and I. parviflora. The study has shown that this invasive species is spreading not only in disturbed areas, but also in places where other species do not grow due to the lack of the light. However, the number of individuals is increasing in proportion while the coverage of trees and shrubs is decreasing. The rise of the level of illumination increases not only the number of individuals in the populations, but also the above-ground biomass of I. parviflora: plants are larger, produce more side shoots. The correlation between the coverage of I. parviflora and native species statistically is significantly negative (r = -0.78) in the disturbed places.


NeoBiota ◽  
2020 ◽  
Vol 58 ◽  
pp. 55-74
Author(s):  
Marija Milanović ◽  
Sonja Knapp ◽  
Petr Pyšek ◽  
Ingolf Kühn

The success of alien plant species can be attributed to differences in functional traits compared to less successful aliens as well as to native species, and thus their adaptation to environmental conditions. Studies have shown that alien (especially invasive) plant species differ from native species in traits such as specific leaf area (SLA), height, seed size or flowering period, where invasive species showed significantly higher values for these traits. Different environmental conditions, though, may promote the success of native or alien species, leading to competitive exclusion due to dissimilarity in traits between the groups. However, native and alien species can also be similar, with environmental conditions selecting for the same set of traits across species. So far, the effect of traits on invasion success has been studied without considering environmental conditions. To understand this interaction we examined the trait–environment relationship within natives, and two groups of alien plant species differing in times of introduction (archaeophytes vs. neophytes). Further, we investigated the difference between non-invasive and invasive neophytes. We analyzed the relationship between functional traits of 1,300 plant species occurring in 1000 randomly selected grid-cells across Germany and across different climatic conditions and land-cover types. Our results show that temperature, precipitation, the proportion of natural habitats, as well as the number of land-cover patches and geological patches affect archaeophytes and neophytes differently, regarding their level of urbanity (in neophytes negative for all non-urban land covers) and self-pollination (mainly positive for archaeophytes). Similar patterns were observed between non-invasive and invasive neophytes, where additionally, SLA, storage organs and the beginning of flowering were strongly related to several environmental factors. Native species did not express any strong relationship between traits and environment, possibly due to a high internal heterogeneity within this group of species. The relationship between trait and environment was more pronounced in neophytes compared to archaeophytes, and most pronounced in invasive plants. The alien species at different stages of the invasion process showed both similarities and differences in terms of the relationship between traits and the environment, showing that the success of introduced species is context-dependent.


2021 ◽  
Vol 2021 ◽  
pp. 1-7
Author(s):  
Markos Kuma ◽  
Zewde Achiso ◽  
Alefu Chinasho ◽  
Dalga Yaya ◽  
Samuel Tessema

Deliberate and unintentional introduction of invasive alien plant species on native biodiversity by aid agencies and other bodies directly or indirectly are being a series of problems on the economy, ecology, politics, and health of life on earth. Identifying and compiling floristics and the status of invasive alien species and identifying which have viable populations are necessary to manage the ecosystems. The present study is therefore intended to provide information for concerned bodies on the area which needs management priority computing the composition, structure, and diversity of invasive alien plants. A field assessment was conducted to determine the distribution and heterogeneity of invasive alien plant species, and then, six kebeles were chosen and transact lines were laid using a purposeful sampling technique. The vegetation and environment data were collected from farmland, grazing land, fallow land, and road sides using 95 subquadrats (5 m × 5 m) set in the center and corner of 19 main quadrats (20 m × 20 m). The voucher specimens collected were taken to the Herbarium of Ethiopia (ETH) for taxonomic identification and future reference. The frequency and density of floristics data were analyzed using MS Excel version 2010, and species diversity was calculated using Shannon (H′), Simpson (D), and evenness (E) indices. Among 35 alien plant species invading natural vegetation in Ethiopia, 25 alien plant species were found in the Humbo district of the Wolaita zone. The densest invasive alien plant species in the area were Parthenium hysterophorus consisting of 15197 individuals/ha, followed by Richardia scabra consisting of 11908 individuals/ha, Xanthium strumarium consisting of 7292 individuals/ha, and Ocimum forskolei consisting of 6280 individuals/ha. The highest species diversity was computed in fallow land (H′ = 2.369), which is followed by farmland (H′ = 1.627) and grazing land (H′ = 1.419). The higher the density of the invasive alien species, the higher the ability to change the structure and diversity of native species of the area results in a decrease in the function and services of the ecosystem. Therefore, management methods must prioritize land types that had the highest diversity of invasive alien species.


Biologia ◽  
2017 ◽  
Vol 72 (2) ◽  
Author(s):  
Emilia Grzędzicka ◽  
Katarzyna Kowalik ◽  
Barbara Bacler-Żbikowska

AbstractInvasive plants are non-native, but in most cases naturalised, species that have successfully spread outside of their native range. Aliens invaded all habitats, are competing with native plants, thus, after the direct destruction of habitats, invasions are recognised as the second largest danger for biodiversity. Northern Red Oak is one of the most common invasive tree species dispersed primarily by birds, but new studies have shown that it is also spread continuously in a forest stand. The main aim of our research was to check how strong is the invasion of Northern Red Oak in Silesia Park, where it was introduced together with other alien plant species, and how this invasion interacts with bird diversity. Silesia Park was created 65 years ago on the surface largely ravaged by coal industry. Because many studies indicate birds as vectors of alien plants invasion, we examined the bird fauna in a described area, looking for species that can contribute to spreading oaks. Research showed the diversity of 50 bird species. Surface with a presence of Northern Red Oak was characterised by greater participation of alien plant species than the patch of natural forest, which existed there long before the park creation. The greatest bird diversity was found in the most natural part of Silesia Park, and the lowest in the area of invasion, especially in the case of species classified as “forest birds”. The presence of alien plants increased number of “non-forest” birds, mostly synanthropic species. We also found that Northern Red Oak spreads by spontaneous seed dispersal.


2021 ◽  
Vol 45 (1) ◽  
Author(s):  
Minwoo Oh ◽  
Yoonjeong Heo ◽  
Eun Ju Lee ◽  
Hyohyemi Lee

Abstract Background As trade increases, the influx of various alien species and their spread to new regions are prevalent, making them a general problem globally. Anthropogenic activities and climate change have led to alien species becoming distributed beyond their native range. As a result, alien species can be easily found anywhere, with the density of individuals varying across locations. The prevalent distribution of alien species adversely affects invaded ecosystems; thus, strategic management plans must be established to control them effectively. To this end, this study evaluated hotspots and cold-spots in the degree of distribution of invasive alien plant species, and major environmental factors related to hot spots were identified. We analyzed 10,287 distribution points of 126 species of alien plant species collected through a national survey of alien species using the hierarchical model of species communities (HMSC) framework. Results The explanatory and fourfold cross-validation predictive power of the model were 0.91 and 0.75 as area under the curve (AUC) values, respectively. Hotspots of invasive plants were found in the Seoul metropolitan area, Daegu metropolitan city, Chungcheongbuk-do Province, southwest shore, and Jeju Island. Hotspots were generally found where the highest maximum summer temperature, winter precipitation, and road density were observed. In contrast, seasonality in temperature, annual temperature range, precipitation during summer, and distance to rivers and the sea were negatively correlated to hotspots. The model showed that functional traits accounted for 55% of the variance explained by environmental factors. Species with a higher specific leaf area were found where temperature seasonality was low. Taller species were associated with a larger annual temperature range. Heavier seed mass was associated with a maximum summer temperature > 29 °C. Conclusions This study showed that hotspots contained 2.1 times more alien plants on average than cold-spots. Hotspots of invasive plants tended to appear under less stressful climate conditions, such as low fluctuations in temperature and precipitation. In addition, disturbance by anthropogenic factors and water flow positively affected hotspots. These results were consistent with previous reports on the ruderal and competitive strategies of invasive plants, not the stress-tolerant strategy. Our results supported that the functional traits of alien plants are closely related to the ecological strategies of plants by shaping the response of species to various environmental filters. Therefore, to control alien plants effectively, the occurrence of disturbed sites where alien plants can grow in large quantities should be minimized, and the waterfront of rivers must be managed.


PLoS ONE ◽  
2021 ◽  
Vol 16 (11) ◽  
pp. e0260390
Author(s):  
Kowiyou Yessoufou ◽  
Annie Estelle Ambani ◽  
Hosam O. Elansary ◽  
Orou G. Gaoue

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.


2020 ◽  
Vol 30 (1) ◽  
pp. 21-31 ◽  
Author(s):  
R. Chaudhary ◽  
B. B. Shrestha ◽  
H. Thapa ◽  
M. Siwakoti

Extent of plant invasions has been expected to be low in protected areas such as national parks due to low anthropogenic activities and high wilderness. However, recent researches across the world have revealed that plant invasions can be severe in the national parks with negative impacts on the protected species and ecosystems. Unfortunately, the status of plant invasions in the national parks of Nepal is mostly unknown. In this study, we sampled at seven locations inside the Parsa National Park (PNP) to document diversity and abundance of invasive alien plant species (IAPS) and their impacts on tree regeneration. Altogether, 130 quadrats of 10 m × 10 m were sampled. We recorded 14 IAPS in the PNP. Three of the IAPS (Chromolana odorata, Lantana camara and Mikania micrantha) were among the 100 of the world’s worst invasive alien species. C. odorata was found to be the most frequent IAPS with the highest cover. The frequency and cover of the IAPS were higher at the sites close to the settlements than at the sites away from the settlements. The species richness of the IAPS was also higher at the sites closer to the settlements than away. The sapling density of the tree species was found to have declined with the increasing cover of the IAPS suggesting that the IAPS had negatively affected tree regeneration. Our data revealed that the PNP has already witnessed massive plant invasions with widespread occurrence of three of the world’s worst invasive species. Therefore, it is high time to integrate management of invasive alien species in the management plan of the park.


2011 ◽  
Vol 12 (3) ◽  
pp. 244-250 ◽  
Author(s):  
Thomas Chrobock ◽  
Anne Kempel ◽  
Markus Fischer ◽  
Mark van Kleunen

2021 ◽  
Author(s):  
Farzaneh Bordbar ◽  
Pierre Meerts

Abstract The Democratic Republic of the Congo (D.R. Congo) represents a striking gap of knowledge on alien plant species. In this paper, we use digitised herbarium collections to assemble a checklist of alien plant species in D.R. Congo and to examine patterns in the alien flora. The new checklist comprises 426 alien species i.e., 182 (42.5%) casuals, 244 (57.5%) naturalised of which 80 (19% of aliens) are invasive. Discrepancies with previous databases are discussed. For many species in previous databases, we failed to find evidence for occurrence outside cultivation. A total of 158 taxa were not included in previous lists, 44 of which are new to D.R. Congo. Considering the size of the country and its rich native flora, the alien flora of D.R. Congo does not appear to be species rich. The alien flora is particularly rich in Fabaceae (15%) and in annual species (36%). America is by far the most important source continent (65%) and the proportion of annuals of American origin is particularly large among the most widespread species. Invasive success is discussed in terms of residence time. The very low number of new species records after 1960 is most likely accounted for by decreasing sampling effort. The results illustrate how herbarium collections can be used to critically revise existing checklists of alien species in tropical Africa. Field work is urgently needed to improve coverage of recent introductions and to monitor the status of alien species, especially in protected areas and around botanic gardens.


Sign in / Sign up

Export Citation Format

Share Document