Impact of Phytophthora cinnamomi on the taxonomic and functional diversity of forest plants in a mediterranean-type biodiversity hotspot
Creators
- 1. Murdoch University
- 2. University of Camerino
Description
Aim
Diversity-rich mediterranean-type sclerophyllous forests are home to 20% of described species on Earth. In the Eucalyptus marginata (jarrah) forest of southwest of Western Australia diversity is being reduced by extensive human use and the introduction of the plant pathogen Phytophthora cinnamomi. This study investigated the influence of P. cinnamomi infestation on the structure, taxonomic and functional diversity, and species composition of the forest.
Location: Jarrah forest of southwestern Australia
Methods
Species abundance, understorey cover and canopy cover were assessed along 22, 30-m long transects which crossed infested and non-infested zones in five reserves in the jarrah forest. A trait database was assembled for 137 plants using 13 traits related to nutrient- and carbon acquisition, disturbance tolerance and reproduction. The responses of canopy cover, understorey cover, species richness, Shannon diversity, evenness, abundance, and functional diversity for trait groups, and all groups combined were modelled against reserve and zone as fixed effects and transect and transect section as random effects. To assess the species composition, NMDS ordination based on Bray Curtis resemblance and indicator species analyses were used.
Results
Significantly higher understorey cover, species richness, Shannon diversity and evenness were recorded in non-infested compared to infested zones, but there were no changes in the canopy cover and overall abundance. In non-infested zones, the functional diversity of nutrient acquisition and reproductive traits was higher, but the functional diversity of carbon acquisition traits was lower. No difference in functional diversity was recorded in disturbance tolerance and overall traits between the two zones. NMDS ordination and ANOSIM revealed a significant difference in the species composition between the two zones, and 11 indicator species significantly associated with infested and non-infested zones were identified.
Conclusion
Phytophthora cinnamomi has significantly affected the forest structure, taxonomic and functional diversity, and species composition. Contrasting responses of functional trait groups obscured overall trait responses to P. cinnamomi.
Notes
Funding provided by: Shire of Mundaring*
Crossref Funder Registry ID:
Award Number:
Funding provided by: Murdoch University
Crossref Funder Registry ID: https://ror.org/00r4sry34
Award Number:
Funding provided by: Holsworth Wildlife Research Endowment
Crossref Funder Registry ID: http://dx.doi.org/10.13039/100008190
Award Number:
Methods
This dataset was collected between October and November in 22 transects set up in five reserves (Alps Street, Black Cockatoo, Falls Road, Quail Street and Super Block) of the jarrah (Eucalyptus marginata) forest using the line transect method. These reserves were impacted by the plant pathogen Phytophthora cinnamomi and transects were set up at the right angles across the dieback front. A 45-m transect was marked from the active disease edge in both infested and non-infested zones and the first 15 m of the transect in both directions was excluded as it was considered a transitional area. The data was collected along the 30-m transect from both infested and non-infested zones. Each 30-m transect was further divided into 4 equal sections (7.5 m) to improve the statistical power of the data analyses. The abundance and cover (as cm long) of each species ≤ 2 m height occurring in the understorey and percentage canopy cover averaged from four readings using a spherical densitometer oriented North, South, East, and West were recorded along four 7.5-m sections of each 30 m transect. Abundance data includes counts and cover data includes cover of each understorey species recorded. Species richness, abundance, Shannon diversity, evenness and understory cover were calculated for each 7.5-m transect section based on the preliminary data using R software.
Plant functional trait data (Trait data) were collected for ten categorical and three qualitative traits, grouped according to nutrient acquisition, carbon acquisition, disturbance tolerance and reproduction. The trial data sheet was prepared based on the trait data collected from the field observations or literature for all recorded species.
Files
Files
(18.9 kB)
| Name | Size | Download all |
|---|---|---|
|
md5:93a2f049ab7b2a7d99b66f7561d36781
|
9.0 kB | Download |
|
md5:8f933b486b765dd5967488b253a40cb6
|
6.9 kB | Download |
|
md5:7d545471d03cdb28490e7bde853652e7
|
2.9 kB | Download |
Additional details
Related works
- Is source of
- 10.5061/dryad.w0vt4b8zk (DOI)