Vegetation Damage Caused by Phytophthora cinnamomi on Disturbed Sites in Temperate Rain-Forest in Western Tasmania

1989 ◽  
Vol 37 (6) ◽  
pp. 443 ◽  
Author(s):  
FD Podger ◽  
MJ Brown

Phytophthora cinnamomi has been isolated directly from 558 diseased plants among 39 species including 1 fern, 4 graminoids and 34 woody dicotyledons, all indigenous to the cool temperate rainforest of Tasmania. Pathogenicity has been proved by greenhouse tests (20 spp.) and by field inoculation at two localities (19 spp.). Of the 142 species in the rainforest flora, 69 were rated for the susceptibility of field populations; 30% were highly susceptible and less than 5% highly resistant. High proportions of susceptible species occurred in Epacridaceae, Eucryphiaceae and Proteaceae. All 93 isolates tested were the common A2 mating type. The fungus was constantly associated with disease at 47 survey localities. Diseased plants were widely but patchily distributed along exposed road and track edges within unburned rainforest and in recently burned rainforest. The fungus was not recovered from samples taken beneath healthy roadside regeneration, beneath undisturbed rainforest or above 900 m elevation. The disease has the characteristics of attack by a recent invader and appears to be dependent upon disturbance which elevates soil temperatures above 15°C, the lower threshold for infection by P. cinnamomi. Post-fire recovery of forest canopy is expected to allow re-establishment from external sources of seed of those susceptible species which are both efficiently dispersed and tolerant of shade. Species lacking such characteristics are at risk of local elimination but no single rainforest species appears to be under threat of extinction from this pathogen.

2016 ◽  
Vol 4 (9) ◽  
pp. 1 ◽  
Author(s):  
Cecilia Smith-Ramírez ◽  
Paula Martínez ◽  
Iván Díaz ◽  
Marcelo Galaz ◽  
Juan J. Armesto

Ecological processes in the upper canopy of temperate forests have been seldom studied because of the limited accessibility. Here, we present the results of the first survey of the pollinator assemblage and the frequency of insect visits to flowers in the upper branches of ulmo, Eucryphia cordifolia Cav., an emergent 30-40 m-tall tree in rainforests of Chiloé Island, Chile. We compared these findings with a survey of flower visitors restricted to lower branches of E. cordifolia 1- in the forest understory, 2- in lower branches in an agroforestry area. We found 10 species of pollinators in canopy, and eight, 12 and 15 species in understory, depending of tree locations. The main pollinators of E. cordifolia in the upper canopy differed significantly from the pollinator assemblage recorded in lower tree branches. We conclude that the pollinator assemblages of the temperate forest canopy and interior are still unknown.


2009 ◽  
Vol 5 (1) ◽  
pp. 369-461 ◽  
Author(s):  
R. Marchant ◽  
S. P. Harrison ◽  
H. Hooghiemstra ◽  
V. Markgraf ◽  
J. H. van Boxel ◽  
...  

Abstract. The biomisation method is used to reconstruct Latin American vegetation at 6000±500 and 18 000±1000 radiocarbon years before present (14C yr BP) from pollen data. Tests using modern pollen data from 381 samples derived from 287 locations broadly reproduce potential natural vegetation. The strong temperature gradient associated with the Andes is recorded by a transition from high altitude cool grass/shrubland and cool mixed forest to mid-altitude cool temperate rain forest, to tropical dry, seasonal and rain forest at low altitudes. Reconstructed biomes from a number of sites do not match the potential vegetation due to local factors such as human impact, methodological artefacts and mechanisms of pollen representivity of the parent vegetation. At 6000±500 14C yr BP 255 samples are analysed from 127 sites. Differences between the modern and the 6000±500 14C yr BP reconstruction are comparatively small. Patterns of change relative to the modern reconstruction are mainly to biomes characteristic of drier climate in the north of the region with a slight more mesic shift in the south. Cool temperate rain forest remains dominant in western South America. In northwestern South America a number of sites record transitions from tropical seasonal forest to tropical dry forest and tropical rain forest to tropical seasonal forest. Sites in Central America also show a change in biome assignment to more mesic vegetation, indicative of greater plant available moisture, e.g. on the Yucatán peninsula sites record warm evergreen forest, replacing tropical dry forest and warm mixed forest presently recorded. At 18 000±1000 14C yr BP 61 samples from 34 sites record vegetation that reflects a generally cool and dry environment. Cool grass/shrubland prevalent in southeast Brazil, Amazonian sites record tropical dry forest, warm temperate rain forest and tropical seasonal forest. Southernmost South America is dominated by cool grass/shrubland, a single site retains cool temperate rain forest indicating that forest was present at some locations at the LGM. Some sites in Central México and lowland Colombia remain unchanged in their biome assignments, although the affinities that these sites have to different biomes do change between 18 000±1000 14C yr BP and present. The "unresponsive" nature of these sites results from their location and the impact of local edaphic influence.


2009 ◽  
Vol 5 (4) ◽  
pp. 725-767 ◽  
Author(s):  
R. Marchant ◽  
A. Cleef ◽  
S. P. Harrison ◽  
H. Hooghiemstra ◽  
V. Markgraf ◽  
...  

Abstract. The biomisation method is used to reconstruct Latin American vegetation at 6000±500 and 18 000±1000 radiocarbon years before present (14C yr BP) from pollen data. Tests using modern pollen data from 381 samples derived from 287 locations broadly reproduce potential natural vegetation. The strong temperature gradient associated with the Andes is recorded by a transition from high altitude cool grass/shrubland and cool mixed forest to mid-altitude cool temperate rain forest, to tropical dry, seasonal and rain forest at low altitudes. Reconstructed biomes from a number of sites do not match the potential vegetation due to local factors such as human impact, methodological artefacts and mechanisms of pollen representivity of the parent vegetation. At 6000±500 14C yr BP 255 samples are analysed from 127 sites. Differences between the modern and the 6000±500 14C yr BP reconstruction are comparatively small; change relative to the modern reconstruction are mainly to biomes characteristic of drier climate in the north of the region with a slight more mesic shift in the south. Cool temperate rain forest remains dominant in western South America. In northwestern South America a number of sites record transitions from tropical seasonal forest to tropical dry forest and tropical rain forest to tropical seasonal forest. Sites in Central America show a change in biome assignment, but to more mesic vegetation, indicative of greater plant available moisture, e.g. on the Yucatán peninsula sites record warm evergreen forest, replacing tropical dry forest and warm mixed forest presently recorded. At 18 000±1000 14C yr BP 61 samples from 34 sites record vegetation reflecting a generally cool and dry environment. Cool grass/shrubland is prevalent in southeast Brazil whereas Amazonian sites record tropical dry forest, warm temperate rain forest and tropical seasonal forest. Southernmost South America is dominated by cool grass/shrubland, a single site retains cool temperate rain forest indicating that forest was present at some locations at the LGM. Some sites in Central Mexico and lowland Colombia remain unchanged in the biome assignments of warm mixed forest and tropical dry forest respectively, although the affinities that these sites have to different biomes do change between 18 000±1000 14C yr BP and present. The "unresponsive" nature of these sites results from their location and the impact of local edaphic influence.


2006 ◽  
Vol 138 (1) ◽  
pp. 72-83 ◽  
Author(s):  
Neville N. Winchester

AbstractThis paper is a tribute to Dr. R.A. Ring upon his retirement. During the past 12 years (1993–2005), an emerging canopy research program has established a wealth of baseline information on the structure and functioning of temperate rain forest canopy arthropod communities. Studies from research sites on Vancouver Island, British Columbia, have shown that ancient temperate rain forest canopy ecosystems contain a largely undescribed fauna that is specific to habitat features found only in these canopies. In particular, diverse assemblages of free-living mites have been shown to dominate conifer species and canopy microhabitats. For example, oribatid mites are the dominant arthropod fauna on branches, branches with attached lichens, and suspended soil accumulations. Species composition differs significantly between the ground and the canopy at both the family and the species level. Arboreal specificity may be due to intrinsic variation in habitat quality, habitat architecture, patchiness, and (or) resource availability. The prevalent patterns of habitat specialization, low vagility, and restricted distribution displayed by a large percentage of the resident canopy microarthropods are features often associated with forest ecoregions that have enjoyed relatively stable conditions for long periods of time, as have the ancient forests on Vancouver Island. Investigators in the “one-Ring lab” continue to document the diversity and abundance of canopy arthropods of temperate forests in British Columbia. In particular, studies are concerned with defining the organizing principles that elicit community patterns associated with the various levels of complexity in arboreal communities. Our long-term goal is to provide a greater degree of predictability when addressing temperate forest diversity issues. To meet the stated goals of sustainable forest management and retention of biodiversity, an extensive plan of ecological research that features arthropods is needed. This plan, fostered by Dr. Ring, should have as a priority the inventory and cataloguing of species assemblages and should address dynamic processes such as organismal dispersal and the effects of habitat loss and fragmentation on arthropods in ancient forests.


Sign in / Sign up

Export Citation Format

Share Document