Composition patterns and network structure of epiphyte–host interactions in Chilean and New Zealand temperate forests

2021 ◽  
Author(s):  
A Taylor ◽  
A Saldaña ◽  
G Zotz ◽  
C Kirby ◽  
I Díaz ◽  
...  
Keyword(s):  
New Zealand ◽  
Host Species ◽  
Species Interactions ◽  
Temperate Forests ◽  
Null Model ◽  
Host Interactions ◽  
Host Trees ◽  
Specific Host ◽  
Random Patterns ◽  
Epiphyte Species

Ecological networks are becoming increasingly used as a framework to study epiphyte–host interactions. However, efforts to quantify the properties of epiphyte–host networks have produced inconsistent results. Epiphyte–host interactions in New Zealand and Chilean temperate forests were quantified to test for non-random patterns in nestedness, negative co-occurrences, number of links, and network specialisation. Results showed that three out of five New Zealand networks were significantly more nested than null model expectations, compared with just one out of four Chilean networks. Epiphytes co-occurred more often than null model expectations in one New Zealand network and one in Chile. In all cases, the number of links maintained by each epiphyte and host species was consistent with null model expectations. Lastly, two New Zealand networks and one in southern Chile were significantly less specialised than null model expectations, with all remaining networks returning low specialisation scores. As such, aside from the tendency for greater nestedness in New Zealand networks, most epiphyte species were distributed on their host trees at random. We attribute the result of nestedness in New Zealand to the abundance of large nest epiphytes (Astelia spp. in particular), which may facilitate the sequential colonisation of epiphyte species on developing host trees. The lack of negative co-occurrences suggests that negative species interactions are not an important determinant of species assemblage structure. Low network specialisation scores suggest that epiphytes are selecting for specific host traits, rather than specific host species for colonisation.

Composition patterns and network structure of epiphyte–host interactions in Chilean and New Zealand temperate forests

2021 ◽  
Author(s):  
A Taylor ◽  
A Saldaña ◽  
G Zotz ◽  
C Kirby ◽  
I Díaz ◽  
...  
Keyword(s):  
New Zealand ◽  
Host Species ◽  
Species Interactions ◽  
Temperate Forests ◽  
Null Model ◽  
Host Interactions ◽  
Host Trees ◽  
Specific Host ◽  
Random Patterns ◽  
Epiphyte Species

Ecological networks are becoming increasingly used as a framework to study epiphyte–host interactions. However, efforts to quantify the properties of epiphyte–host networks have produced inconsistent results. Epiphyte–host interactions in New Zealand and Chilean temperate forests were quantified to test for non-random patterns in nestedness, negative co-occurrences, number of links, and network specialisation. Results showed that three out of five New Zealand networks were significantly more nested than null model expectations, compared with just one out of four Chilean networks. Epiphytes co-occurred more often than null model expectations in one New Zealand network and one in Chile. In all cases, the number of links maintained by each epiphyte and host species was consistent with null model expectations. Lastly, two New Zealand networks and one in southern Chile were significantly less specialised than null model expectations, with all remaining networks returning low specialisation scores. As such, aside from the tendency for greater nestedness in New Zealand networks, most epiphyte species were distributed on their host trees at random. We attribute the result of nestedness in New Zealand to the abundance of large nest epiphytes (Astelia spp. in particular), which may facilitate the sequential colonisation of epiphyte species on developing host trees. The lack of negative co-occurrences suggests that negative species interactions are not an important determinant of species assemblage structure. Low network specialisation scores suggest that epiphytes are selecting for specific host traits, rather than specific host species for colonisation.

Composition patterns and network structure of epiphyte–host interactions in Chilean and New Zealand temperate forests

2016 ◽  
Vol 54 (2) ◽  
pp. 204-222 ◽  
Author(s):  
A Taylor ◽  
A Saldaña ◽  
G Zotz ◽  
C Kirby ◽  
I Díaz ◽  
...  
Keyword(s):  
New Zealand ◽  
Network Structure ◽  
Temperate Forests ◽  
Host Interactions

Spatial ecology and host diversity of three arboreal plants from Lord Howe Island

2020 ◽  
Vol 68 (6) ◽  
pp. 458
Author(s):  
Thomas N. Dawes ◽  
Ian Hutton ◽  
Kevin C. Burns
Keyword(s):  
Host Specificity ◽  
Spatial Ecology ◽  
Null Model ◽  
Future Research ◽  
Lord Howe Island ◽  
Host Trees ◽  
Acquisition Strategies ◽  
Spatial Niche ◽  
Epiphyte Species

In canopy ecology, it has long been understood that different guilds of arboreal plants have different spatial distributions and degrees of host specificity. Here, we present a case study looking at how within-crown spatial niche and host specificity vary between three very different morphologies of arboreal plant on Lord Howe Island, interpreting these in terms of different water acquisition strategies. We quantify within-crown spatial niche and created a null model to test host specificity in three species with very different water acquisition strategies (a mistletoe, an orchid and a detritus-collecting fern). The mistletoe had greater host specificity than the two epiphyte species, and was restricted to thinner branches. The fern occurred further from the outer crown than the other species including on the trunks of host trees, and was the only species to show no indication of host specificity. Differences in distribution are consistent with differences in water acquisition strategy, providing an initial link between traits and spatial distribution, a potentially fruitful avenue of future research.

scholarly journals Diversity and Distribution of Vascular Epiphytic Flora in Sub-temperate Forests of Darjeeling Himalaya, India

2020 ◽  
pp. 63-81
Author(s):  
Preshina Rai ◽  
Saurav Moktan
Keyword(s):  
Host Species ◽  
Temperate Forests ◽  
Host Tree ◽  
Eastern Himalaya ◽  
Vascular Epiphytes ◽  
Tree Distribution ◽  
Darjeeling Himalaya ◽  
Host Trees ◽  
Epiphytic Plant ◽  
Study Sites

Aims: This communication deals with the diversity and distribution including host species distribution of vascular epiphytes also reflecting its phenological observations. Study Design: Random field survey was carried out in the study site to identify and record the taxa. Host species was identified and vascular epiphytes were noted. Study Site and Duration: The study was conducted in the sub-temperate forests of Darjeeling Himalaya which is a part of the eastern Himalaya hotspot. The zone extends between 1200 to 1850 m amsl representing the amalgamation of both sub-tropical and temperate vegetation. The study was conducted during the year 2018-2019. Methodology: Process of random sampling collection was followed. Host trees with CBH >30 cm were identified and percentage of distribution of epiphytes in the host tree was analyzed and divided into two zones depending on the abundance of epiphytes. Data for the epiphytic plant specimens were collected in the field. Exsiccates were made with the collected voucher specimens and were deposited at the Calcutta University Herbarium (CUH) following the conventional methodology. Study on the taxa are based on their host tree distribution, micro-habitat and phenological status. The location and altitude of the study sites were recorded by global positioning system. Results: A total number of 115 species under 70 genera and 31 families have been identified with 65% other vascular angiosperms (basal angiosperms and eudicots) and 16% monocots. Orchidaceae among the monocots represented 36% with 41 species and 18 genera. Ferns and lycophytes include 25% of the diversity with 29 taxa under 6 families. Most favorable host trees were Ficus auriculata Lour., Ficus neriifolia Sm., Saurauia nepalensis DC., Erythrina variegata L., Macaranga denticulata (Blume) Müll. Arg., Cryptomeria japonica (Thunb. ex L.f.) D. Don and Engelhardia spicata Lechen ex Blume. Conclusion: The other vascular angiosperms preferred wet monsoon for flowering whereas spring season was most favourable for Orchidaceae. Although a healthy number of vascular epiphytes have been identified, a number of threats are still prevailing in the regions which are mostly anthropogenic. Proper collaborative strategies have to be maintained for its conservation.

scholarly journals Will Peri-Urban Cydia pomonella (Lepidoptera: Tortricidae) Challenge Local Eradication?

Insects ◽  
2020 ◽  
Vol 11 (4) ◽  
pp. 207 ◽  
Author(s):  
Rachael Horner ◽  
Georgia Paterson ◽  
James T.S. Walker ◽  
George L.W. Perry ◽  
Rodelyn Jaksons ◽  
...  
Keyword(s):  
New Zealand ◽  
Spatial Interpolation ◽  
Spatial Clustering ◽  
Cydia Pomonella ◽  
Codling Moth ◽  
Catch Rate ◽  
Trap Catch ◽  
Urban Populations ◽  
Host Trees ◽  
The City

Codling moth, Cydia pomonella (Lepidoptera: Tortricidae), is a phytosanitary pest of New Zealand’s export apples. The sterile insect technique supplements other controls in an eradication attempt at an isolated group of orchards in Hawke’s Bay, New Zealand. There has been no attempt in New Zealand to characterize potential sources of uncontrolled peri-urban populations, which we predicted to be larger than in managed orchards. We installed 200 pheromone traps across Hastings city, which averaged 0.32 moths/trap/week. We also mapped host trees around the pilot eradication orchards and installed 28 traps in rural Ongaonga, which averaged 0.59 moths/trap/week. In Hastings, traps in host trees caught significantly more males than traps in non-host trees, and spatial interpolation showed evidence of spatial clustering. Traps in orchards operating the most stringent codling moth management averaged half the catch rate of Hastings peri-urban traps. Orchards with less rigorous moth control had a 5-fold higher trap catch rate. We conclude that peri-urban populations are significant and ubiquitous, and that special measures to reduce pest prevalence are needed to achieve area-wide suppression and reduce the risk of immigration into export orchards. Because the location of all host trees in Hastings is not known, it could be more cost-effectively assumed that hosts are ubiquitous across the city and the area treated accordingly.

Light or presence of host trees: which is more important for the strangler fig?

1999 ◽  
Vol 15 (5) ◽  
pp. 589-602 ◽  
Author(s):  
Vidya R. Athreya
Keyword(s):  
Host Species ◽  
National Park ◽  
Canopy Cover ◽  
Light Level ◽  
Southern India ◽  
Evergreen Forest ◽  
Primary Forest ◽  
Light Levels ◽  
Host Trees ◽  
Main Host

Strangler fig density varied considerably in the evergreen forest of Karian Shola National Park, southern India, with 11 individuals ha−1 in an open trail area and 5.6 individuals ha−1 within the primary forest area. The index of light level was assessed by estimating the percentage of upper canopy cover along the longitudinal centre of ten, 500-m × 20-m plots in each of the two areas of the evergreen forest. However, the increase in strangler fig density was not correlated to light levels but was significantly correlated to the numbers of their main host species in the two areas. In Karian Shola National Park, strangler figs occurred predominantly on a few host species with 20 and 50% of strangler figs growing on Vitex altissima, Diospyros bourdilloni and Eugenia/Syzygium spp. in the primary forest and trail areas respectively. Both young and established strangler figs were recorded mainly on larger individuals of their host trees indicating that older host trees are likely to be more suitable for the germination and establishment of strangler figs. The reason for the above could be the higher incidence of humus-filled and decaying regions in the older host trees which would provide an assured supply of nutrients for the establishing strangler fig.

scholarly journals Do parasites adopt different strategies in different intermediate hosts? Host size, not host species, influences Coitocaecum parvum (Trematoda) life history strategy, size and egg production

Parasitology ◽  
2012 ◽  
Vol 140 (2) ◽  
pp. 275-283 ◽  
Author(s):  
R. RUIZ DANIELS ◽  
S. BELTRAN ◽  
R. POULIN ◽  
C. LAGRUE
Keyword(s):  
Host Species ◽  
Egg Production ◽  
Life History Strategy ◽  
Host Size ◽  
Life Strategy ◽  
Amphipod Species ◽  
Intermediate Hosts ◽  
Host Interactions ◽  
Resource Limitations ◽  
Coitocaecum Parvum

SUMMARYHost exploitation induces host defence responses and competition between parasites, resulting in individual parasites facing highly variable environments. Alternative life strategies may thus be expressed in context-dependent ways, depending on which host species is used and intra-host competition between parasites. Coitocaecum parvum (Trematode) can use facultative progenesis in amphipod intermediate hosts, Paracalliope fluviatilis, to abbreviate its life cycle in response to such environmental factors. Coitocaecum parvum also uses another amphipod host, Paracorophium excavatum, a species widely different in size and ecology from P. fluviatilis. In this study, parasite infection levels and strategies in the two amphipod species were compared to determine whether the adoption of progenesis by C. parvum varied between these two hosts. Potential differences in size and/or egg production between C. parvum individuals according to amphipod host species were also investigated. Results show that C. parvum life strategy was not influenced by host species. In contrast, host size significantly affected C. parvum strategy, size and egg production. Since intra-host interactions between co-infecting parasites also influenced C. parvum strategy, size and fecundity, it is highly likely that within-host resource limitations affect C. parvum life strategy and overall fitness regardless of host species.

scholarly journals Community Ecology of Epiphytes and other Arboreal Plants in the New Zealand Eco-region

2021 ◽  
Author(s):  
◽  
Thomas Dawes
Keyword(s):  
New Zealand ◽  
Seed Size ◽  
Host Species ◽  
Spatial Ecology ◽  
Scale Insects ◽  
Tree Fern ◽  
Sooty Mould ◽  
Tree Ferns ◽  
Epiphytic Fern ◽  
Epiphyte Community

<p><b>Epiphytes and other structurally-dependent plants have a spatial ecology and community structure intrinsically linked to that of the host trees in the forest, unlike fully terrestrial plants. Understanding of the ecological implications of this from a theoretical perspective is in its infancy. New Zealand’s south temperate rainforest, whilst not as species rich as tropical forests, hosts one of the richest temperate epiphyte floras. Our understanding of the ecological processes structuring the epiphyte communities of New Zealand forests is however lacking. Here, I present four key studies seeking to add to our knowledge of epiphyte community structure, host specificity and spatial ecology in the New Zealand eco-region.</b></p> <p>First, I tested if seed size determined the likelihood of woody plant species occurring epiphytically on tree ferns (their arboreality) – Chapter 2. Arboreality was negatively related to seed size, with only smaller-seeded species commonly occurring on tree ferns. However, the effect of seed size reduced in later life history stages, as expected. These small-seeded species, most notably Weinmannia racemosa, appear to be utilising an alternative recruitment strategy by establishing epiphytically on the tree fern trunks.</p> <p>Second, on Cyathea dealbata host tree ferns, I tested patterns of species accumulation, metacommunity network structure, and differences in vertical stratification (Chapter 3). Epiphytes and climbers followed a species accumulation model of succession between tree ferns of different sizes and between older and younger portions of the tree fern. The metacommunity network showed patterns of species co-occurrence and nestedness consistent with null expectations. Epiphytes of different habits and different dispersal syndromes show different vertical profiles of occurrence, with bird-dispersed species occurring more often near the top of the tree fern than other taxa.</p> <p>To understand an unusual pattern in epiphyte between-host structuring, I quantified the relationship between epiphytic plant and sooty mould assemblages in New Zealand montane beech forest (Chapter 4). Due to the presence of host specific scale insects, the sooty mould was limited to two of three co-dominant canopy tree species. On these two host species, epiphyte richness was significantly reduced. The host size-richness relationship in these two species was also removed, with species composition significantly altered compared to the mould free host species. My results are consistent with the sooty mould amensally excluding the epiphytes and it can be considered as a part of a keystone species complex (with the host beeches and scale insects). This produces a strong pattern of parallel host specificity otherwise not seen in epiphyte assemblages.</p> <p>Lastly, I compared the differences in spatial niche and host species diversity between three arboreal plants, with divergent ecophysiology, on Lord Howe Island (Chapter 5). These focal species were a dwarf mistletoe, an epiphytic orchid and an epiphytic fern. The mistletoe was restricted to thinner branches, and had a significantly different niche to both epiphyte taxa. The host diversity of the mistletoe and orchid both differed significantly from null model expectations. However, the epiphytic fern (Platycerium bifurcatum) had a host diversity consistent with null expectations.</p> <p>Taken together, these studies increase our understanding of epiphyte community assembly in New Zealand and provide a platform to encourage further work in this field. They also provide results that expand understanding of spatial patterns between host and up vertical clines.</p>

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