host trees
Recently Published Documents


TOTAL DOCUMENTS

400
(FIVE YEARS 105)

H-INDEX

34
(FIVE YEARS 4)

2021 ◽  
Vol 7 (2) ◽  
pp. 49-56
Author(s):  
Rizkia Adhatirana ◽  
Nina Ratna Djuita ◽  
Sulistijorini Sulistijorini ◽  
Taufikurrahman Nasution

Epiphytic ferns can be found in host trees from the Angiosperm and Gymnosperm groups. Epiphytic ferns in Angiosperm plants host have been widely studied, but there is little known for Gymnosperm plants host. The aim of this study was to identify the species of epiphytic ferns in the Gymnosperm plants host at Cibodas Botanical Garden and to analyze the diversity of epiphytic ferns based on microclimate conditions and the surface texture of Gymnosperms plants host. Epiphytic ferns diversity data was obtained using purposive random sampling method. Factors that influence the occupancy of ferns are analyzed using Principal Component Analysis. Epiphytic ferns in Gymnosperm host at Cibodas Botanical Garden were identified as 18 species including 7 family. The most dominant species of epiphytic fern is Davallia denticulata (59.45%). Diversity of epiphytic fern on Gymnosperm at Cibodas Botanical Garden is moderate (H’ = 1.81).


Fossil Record ◽  
2021 ◽  
Vol 24 (2) ◽  
pp. 379-393
Author(s):  
Corentin Jouault ◽  
Arvid Aase ◽  
André Nel

Abstract. Paleoxyela nearctica gen. et sp. nov., is described from the upper Eocene of Florissant Formation in Colorado. We placed Paleoxyela gen. nov. in the subfamily Macroxyelinae and the tribe Macroxyelini based on the numerous wing venation characters visible on the specimen. Proxyelia pankowskii gen. et sp. nov. is described from the lower Eocene Fossil Lake deposits of the Green River Formation in Wyoming. We placed Proxyelia gen. nov. in the subfamily Macroxyelinae and the tribe Xyeleciini based on the numerous wing venation characters visible on the specimen. These new records of the family Xyelidae are of particular importance to better understand the past diversity of the clade and propose hypotheses about their diversification. Extant Xyelidae inhabit temperate Northern Hemisphere forests, and most of their larvae feed on conifers, which may explain why they are relatively poorly diversified compared to the other symphytan families. We suggest that the global decline in conifers and the reduced diversity of extant host trees partly explain the diversity of extant Xyelidae. We correlate the biome repartition during the Eocene to that of the extant xyelid.


2021 ◽  
Author(s):  
◽  
Kirsty Yule

<p>Parasites are ubiquitous and the antagonistic relationships between parasites and their hosts shape populations and ecosystems. However, our understanding of complex parasitic interactions is lacking. New Zealand’s largest endemic moth, Aenetus virescens (Lepidoptera: Hepialidae) is a long-lived arboreal parasite. Larvae grow to 100mm, living ~6 years in solitary tunnels in host trees. Larvae cover their tunnel entrance with silk and frass webbing, behind which they feed on host tree phloem. Webbing looks much like the tree background, potentially concealing larvae from predatory parrots who consume larvae by tearing wood from trees. Yet, the ecological and evolutionary relationships between the host tree, the parasitic larvae, and the avian predator remain unresolved.  In this thesis, I use a system-based approach to investigate complex parasite-host interactions using A. virescens (hereafter “larvae”) as a model system. First, I investigate the mechanisms driving intraspecific parasite aggregation (Chapter 2). Overall, many hosts had few parasites and few hosts had many, with larvae consistently more abundant in larger hosts. I found no evidence for density-dependent competition as infrapopulation size had no effect on long-term larval growth.  Host specificity, the number of species utilised from the larger pool available, reflects parasite niche breadth, risk of extinction and ability to colonise new locations. In Chapter 3, I investigate larvae host specificity in relation to host nutritional rewards (phloem turnover and phloem sugar content) and host defences (bark thickness and wood density). The number of species parasitized was not explained by tree abundance, nutritional rewards or wood density. However, the number of trees parasitised declined significantly with increasing bark thickness indicating host external defences are an important driver of host specificity.  Camouflage in animals has traditionally been considered an anti-predator adaptation. Yet the adaptive consequences of camouflage, i.e. increased survivability via predator avoidance, has rarely been tested. In Chapter 4, I show that larvae webbing is visually cryptic to predating kaka, yet did not protect larvae from attack. Instead, cryptic webbing aids larvae thermoregulation suggesting crypsis is non-adaptive. These results support an exciting newly emerging paradigm shift that indicates the evolution of camouflage in animals may be more to do with abiotic conditions than biotic signalling.  Males are often the “sicker sex”, experiencing higher pathogen and parasite loads than females. In Chapter 5, I construct the largest host-parasite database to date, spanning 70 animal and 22 plant families, from which I conduct a meta-analysis testing for male biased susceptibility (MBS). Then, I develop a theoretical model that explain MBS as a result of parasite-offspring competition for female resources. I present the first, unified model that explains male-biased susceptibility in animals and plants and provide parameters for model replication, applicable to almost all host-parasite pairings on Earth.  This thesis presents the first investigations of the natural history of Aenetus virescens larvae, their relationships with host trees, and the interactions with their avian predator. The results herein support existing theories of parasite aggregation and host specificity from a novel perspective. Furthermore, results support a newly emerging paradigm shift in animal camouflage evolution, and suggest a unified explanation for male biased susceptibility in animals and plants. The results herein help further our understanding of complex antagonistic relationships between parasites and their hosts, presenting novel theories on which future research can be built.</p>


2021 ◽  
Author(s):  
◽  
Kirsty Yule

<p>Parasites are ubiquitous and the antagonistic relationships between parasites and their hosts shape populations and ecosystems. However, our understanding of complex parasitic interactions is lacking. New Zealand’s largest endemic moth, Aenetus virescens (Lepidoptera: Hepialidae) is a long-lived arboreal parasite. Larvae grow to 100mm, living ~6 years in solitary tunnels in host trees. Larvae cover their tunnel entrance with silk and frass webbing, behind which they feed on host tree phloem. Webbing looks much like the tree background, potentially concealing larvae from predatory parrots who consume larvae by tearing wood from trees. Yet, the ecological and evolutionary relationships between the host tree, the parasitic larvae, and the avian predator remain unresolved.  In this thesis, I use a system-based approach to investigate complex parasite-host interactions using A. virescens (hereafter “larvae”) as a model system. First, I investigate the mechanisms driving intraspecific parasite aggregation (Chapter 2). Overall, many hosts had few parasites and few hosts had many, with larvae consistently more abundant in larger hosts. I found no evidence for density-dependent competition as infrapopulation size had no effect on long-term larval growth.  Host specificity, the number of species utilised from the larger pool available, reflects parasite niche breadth, risk of extinction and ability to colonise new locations. In Chapter 3, I investigate larvae host specificity in relation to host nutritional rewards (phloem turnover and phloem sugar content) and host defences (bark thickness and wood density). The number of species parasitized was not explained by tree abundance, nutritional rewards or wood density. However, the number of trees parasitised declined significantly with increasing bark thickness indicating host external defences are an important driver of host specificity.  Camouflage in animals has traditionally been considered an anti-predator adaptation. Yet the adaptive consequences of camouflage, i.e. increased survivability via predator avoidance, has rarely been tested. In Chapter 4, I show that larvae webbing is visually cryptic to predating kaka, yet did not protect larvae from attack. Instead, cryptic webbing aids larvae thermoregulation suggesting crypsis is non-adaptive. These results support an exciting newly emerging paradigm shift that indicates the evolution of camouflage in animals may be more to do with abiotic conditions than biotic signalling.  Males are often the “sicker sex”, experiencing higher pathogen and parasite loads than females. In Chapter 5, I construct the largest host-parasite database to date, spanning 70 animal and 22 plant families, from which I conduct a meta-analysis testing for male biased susceptibility (MBS). Then, I develop a theoretical model that explain MBS as a result of parasite-offspring competition for female resources. I present the first, unified model that explains male-biased susceptibility in animals and plants and provide parameters for model replication, applicable to almost all host-parasite pairings on Earth.  This thesis presents the first investigations of the natural history of Aenetus virescens larvae, their relationships with host trees, and the interactions with their avian predator. The results herein support existing theories of parasite aggregation and host specificity from a novel perspective. Furthermore, results support a newly emerging paradigm shift in animal camouflage evolution, and suggest a unified explanation for male biased susceptibility in animals and plants. The results herein help further our understanding of complex antagonistic relationships between parasites and their hosts, presenting novel theories on which future research can be built.</p>


2021 ◽  
Author(s):  
◽  
Amanda Taylor

<p>Vascular epiphytes, which are specialised to spend their entire life cycle within trees, are significant contributors to local ecosystem services. However, our current understanding of epiphyte distributions, co-occurrences, and general ecology lags far behind that of terrestrial plants. Furthermore, the majority of epiphyte research is undertaken in tropical forests, with comparatively few studies extending into temperate climates. As such, whether epiphytic plant assemblage structure varies geographically, or is influenced by area and isolation effects needs further scrutiny. In addition, how epiphytes are distributed in relation to host tree ontogeny and microclimates specific to south-temperate forests is poorly understood. Here, I attempt to bridge this gap by researching epiphyte distributions and assemblage structure in New Zealand, southern Chile, and Australia.  In the first biogeographic study of epiphyte-host interactions, I determined if epiphyte-host network structure (i.e. nestedness, species co-occurrences, species specialisation) varied among New Zealand and Chilean temperate forests (Chapter 2). At the forest stand level, network structure was consistent with stochastic structuring, which suggests that dispersal and disturbances are important drivers of epiphyte distributions at a biogeographic scale. However, deterministic structure was observed in New Zealand networks with regards to nestedness (i.e. when specialists interact with generalists), which suggests that positive species interactions influence epiphyte distributions at a within-tree scale.  Second, I determined whether the composition of plant communities residing in epiphytic birds’ nest ferns (Asplenium goudeyi) on Lord Howe Island, Australia, are influenced by fern size, isolation from a major propagule source and resident plant community richness (Chapter 3). Results suggest that plant communities are structured by dispersal. For one, there was a significant isolation effect on resident plant community richness. Additionally, wind-dispersed taxa were well represented in isolated ferns, while animal-dispersed taxa and taxa with no specific dispersal strategies were absent. This is the first study to test the combined effects of area, isolation and resident plant richness on epiphytic plant assemblage structure.  Third, using Darwin’s geological theory of island ontogeny as a theoretical construct, I explored changes in epiphyte species richness throughout tree ontogeny (Chapter 4). Theoretical frameworks have helped bridge the gap between our understanding of vascular epiphytes and terrestrial plants, however, none have been implemented to guide investigations on epiphyte assemblage development. Based on the general features of island ontogeny, I found three stages of epiphyte assemblage development: (i) an initial stage where host trees are devoid of epiphytes, (ii) a second stage where trees acquire epiphytes into maturity, and (iii) a hypothetical stage where epiphyte assemblages follow a period of species decline following host tree mortality. In addition to these results, I found interspecific variation in the ontogenetic stage at which host trees become favourable for epiphyte establishment and the rate at which epiphyte assemblages develop.  Lastly, I explored the systematic distribution of epiphytes and mistletoes in relation to microclimate gradients around the trunks of trees (Chapter 5). In addition, I tested the physiological responses of epiphytes and mistletoes to reductions in their most limiting resources to determine if the responses were consistent with their distribution patterns. The radial distributions of epiphytes and mistletoes were highly directional, and paralleled gradients of humidity, light and water. Additionally, the photochemical efficiency of epiphytes and CO₂ assimilation in mistletoe leaves decreased in plants growing in environments with lower water and light availability, respectively. However, mistletoe leaves still assimilated CO₂ in lower light conditions, which suggests a high plasticity of mistletoes to growing in a canopy environment. Despite over 120 years of recognising the importance of vertical microclimates on epiphyte distributions, this is the first systematic study of epiphytic plant distributions in relation to microclimate gradients around the trunks of trees.  This thesis has increased our understanding of epiphytic plant assemblage structure, and how it is influenced by host tree species, isolation, area and resident plant species richness. In addition, this thesis has increased our understanding of the effect of host tree ontogeny and microclimate on epiphyte distribution patterns. Together, these studies may be built upon more broadly to further elucidate drivers of epiphyte assembly and distribution patterns.</p>


2021 ◽  
Author(s):  
◽  
Amanda Taylor

<p>Vascular epiphytes, which are specialised to spend their entire life cycle within trees, are significant contributors to local ecosystem services. However, our current understanding of epiphyte distributions, co-occurrences, and general ecology lags far behind that of terrestrial plants. Furthermore, the majority of epiphyte research is undertaken in tropical forests, with comparatively few studies extending into temperate climates. As such, whether epiphytic plant assemblage structure varies geographically, or is influenced by area and isolation effects needs further scrutiny. In addition, how epiphytes are distributed in relation to host tree ontogeny and microclimates specific to south-temperate forests is poorly understood. Here, I attempt to bridge this gap by researching epiphyte distributions and assemblage structure in New Zealand, southern Chile, and Australia.  In the first biogeographic study of epiphyte-host interactions, I determined if epiphyte-host network structure (i.e. nestedness, species co-occurrences, species specialisation) varied among New Zealand and Chilean temperate forests (Chapter 2). At the forest stand level, network structure was consistent with stochastic structuring, which suggests that dispersal and disturbances are important drivers of epiphyte distributions at a biogeographic scale. However, deterministic structure was observed in New Zealand networks with regards to nestedness (i.e. when specialists interact with generalists), which suggests that positive species interactions influence epiphyte distributions at a within-tree scale.  Second, I determined whether the composition of plant communities residing in epiphytic birds’ nest ferns (Asplenium goudeyi) on Lord Howe Island, Australia, are influenced by fern size, isolation from a major propagule source and resident plant community richness (Chapter 3). Results suggest that plant communities are structured by dispersal. For one, there was a significant isolation effect on resident plant community richness. Additionally, wind-dispersed taxa were well represented in isolated ferns, while animal-dispersed taxa and taxa with no specific dispersal strategies were absent. This is the first study to test the combined effects of area, isolation and resident plant richness on epiphytic plant assemblage structure.  Third, using Darwin’s geological theory of island ontogeny as a theoretical construct, I explored changes in epiphyte species richness throughout tree ontogeny (Chapter 4). Theoretical frameworks have helped bridge the gap between our understanding of vascular epiphytes and terrestrial plants, however, none have been implemented to guide investigations on epiphyte assemblage development. Based on the general features of island ontogeny, I found three stages of epiphyte assemblage development: (i) an initial stage where host trees are devoid of epiphytes, (ii) a second stage where trees acquire epiphytes into maturity, and (iii) a hypothetical stage where epiphyte assemblages follow a period of species decline following host tree mortality. In addition to these results, I found interspecific variation in the ontogenetic stage at which host trees become favourable for epiphyte establishment and the rate at which epiphyte assemblages develop.  Lastly, I explored the systematic distribution of epiphytes and mistletoes in relation to microclimate gradients around the trunks of trees (Chapter 5). In addition, I tested the physiological responses of epiphytes and mistletoes to reductions in their most limiting resources to determine if the responses were consistent with their distribution patterns. The radial distributions of epiphytes and mistletoes were highly directional, and paralleled gradients of humidity, light and water. Additionally, the photochemical efficiency of epiphytes and CO₂ assimilation in mistletoe leaves decreased in plants growing in environments with lower water and light availability, respectively. However, mistletoe leaves still assimilated CO₂ in lower light conditions, which suggests a high plasticity of mistletoes to growing in a canopy environment. Despite over 120 years of recognising the importance of vertical microclimates on epiphyte distributions, this is the first systematic study of epiphytic plant distributions in relation to microclimate gradients around the trunks of trees.  This thesis has increased our understanding of epiphytic plant assemblage structure, and how it is influenced by host tree species, isolation, area and resident plant species richness. In addition, this thesis has increased our understanding of the effect of host tree ontogeny and microclimate on epiphyte distribution patterns. Together, these studies may be built upon more broadly to further elucidate drivers of epiphyte assembly and distribution patterns.</p>


Forests ◽  
2021 ◽  
Vol 12 (11) ◽  
pp. 1549
Author(s):  
Xu Chu ◽  
Qiuyu Ma ◽  
Meijiao Yang ◽  
Guoqiang Li ◽  
Jinyan Liu ◽  
...  

The vectors of pinewood nematode of Bursaphelenchus xylophilus (Steiner & Bührer, 1934) are mainly known as xylophagous beetles. Understanding the composition and distribution of these xylophagous beetles in host pine trees infected by PWN is critical to control the spread of PWN. In this study, we investigated the community structures of the xylophagous beetles in two main host trees in Fujian and Shandong, Pinus massoniana Lamb. and Pinus thunbergia Parl., in different stages of infection. All beetles were collected by dissecting the whole pine trees and then identified by their morphological characteristics and COI genes. The results showed that the diversity of xylophagous beetles was different not only between the two host pine trees but also among the different infection stages. The diversity of P. massoniana xylophagous beetles was significantly higher than that of P. thunbergii, and there were also significant differences in the different stages of PWN infection. In total, Scolytinae was the most common (53.70%), followed by Curculionidae (18.26%), Cerambycidae (16.31%), and Cleridae (6.04%). Monochamus alternatus, the most important vector of PWN, occupied a large niche and showed different aggregation positions during the three infection stages in both host trees. This result might be related to the resistance of bark beetles to host trees and competition with other xylophagous beetles. The community diversity of xylophagous beetles was jointly affected by both the infection stages of PWN and the spatial niche of xylophagous beetles. Knowledge of the diversity and competitive relationships among xylophagous beetles might help regulate the population dynamics of these beetles.


2021 ◽  
Vol 157 (4) ◽  
pp. 261-268
Author(s):  
Roger A. Beaver

The scolytine beetles found breeding in the petioles of the fallen leaves of Fijian trees are listed together with their host trees, and information is provided on the biology of the species. The majority of species are known to breed in other habitats. Brood sizes are generally low, and the leafstalks may provide a 'refuge' when more suitable habitat is not available. The community found in Fiji is compared with the communities found in petioles in West Malaysia and Costa Rica.


Life ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 1081
Author(s):  
Stephan Kambach ◽  
Christopher Sadlowski ◽  
Derek Peršoh ◽  
Marco Alexandre Guerreiro ◽  
Harald Auge ◽  
...  

Symbiotic foliar fungal endophytes can have beneficial effects on host trees and might alleviate climate-induced stressors. Whether and how the community of foliar endophytes is dependent on the tree neighborhood is still under debate with contradicting results from different tree diversity experiments. Here, we present our finding regarding the effect of the tree neighborhood from the temperate, densely planted and 12-years-old Kreinitz tree diversity experiment. We used linear models, redundancy analysis, Procrustes analysis and Holm-corrected multiple t-tests to quantify the effects of the plot-level tree neighborhood on the diversity and composition of foliar fungal endophytes in Fagus sylvatica, Quercus petraea and Picea abies. Against our expectations, we did not find an effect of tree diversity on endophyte diversity. Endophyte composition, however, was driven by the identity of the host species. Thirteen endophytes where overabundant in tree species mixtures, which might indicate frequent spillover or positive interactions between foliar endophytes. The independence of the diversity of endophytes from the diversity of tree species might be attributed to the small plot size and the high density of tree individuals. However, the mechanistic causes for these cryptic relationships still remain to be uncovered.


2021 ◽  
Vol 27 (4) ◽  
pp. 197-201
Author(s):  
Balram Lodhi ◽  
◽  
Pratibha Bhatnagar ◽  
Vijay Bahadur Singh ◽  
Jatashankar . ◽  
...  

The study pertains to data collected from randomly selected 67 lac growers of 10 villages in Mandla district of Madhya Pradesh for the year 2020-2021. The study indicates that more than 80% lac growers in Mandla district are small, semi medium and medium farmers. Majority of farmers (34.32%) belong to middle age group followed by young age group (31.34%). The study revealed that 59.7% lac growers have family members up to 5-7 and educated up to middle school level (40.3%). The resources endowment in terms of the availability of host trees for lac cultivation varies from >25 to <200 trees. In terms of production maximum lac growers (38.81%) average production of 70.91 kg followed by 16.42% had average production 124.28 kg, 16.42% had 38.18 kg average production. Amongst the different source of income of lac growers, Agriculture crop ranked 1st (50.62%) followed by Lac crop (22.9%). Income of selected farmers from lac crop in the study 31.34% farmers earn between Rs. 10,001-20,000 followed by 23.88% farmers between 5001 to 10000 and 23.88% farmers get upto 5000, 10.45% farmers earn more than 40001, 7.46% earn Rs 20001-30000 and only 2.99% farmers get between Rs. 30,000-40,000 annually from lac production. In term of income sharing the maximum number of the farmers (32.84%) contributed 10-20% while only 11.94% farmers contributed more than 40% by lac. Implications of the present study will be helpful in strengthening the socio-economic condition of lac growers and lac marketing scenario of Madhya Pradesh.


Sign in / Sign up

Export Citation Format

Share Document