Patrick Norman

Dr. Patrick Norman

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Research Focus & Metrics

Academic Career Length

5Years (2022-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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19 December 2023 in Land
Verified
Journal Article
Open access
PDF file
Brendan MackeyBrendan Mackey
Brendan Mackey
CCCarly Campbell
Carly Campbell
PNPatrick Norman
Patrick Norman
SHSonia Hugh
Sonia Hugh
Dominick A DellaSalaDominick A DellaSala
Dominick A DellaSala
PDPierre Drapeau
Pierre Drapeau
The Canadian boreal forest biome has been subjected to a long history of management for wood production. Here, we examined the cumulative impacts of logging on older forests in terms of area, distribution and patch configuration in the managed forest zones of the Eastern Canadian provinces of Ontario and Quebec. We also examined the consequences of these cumulative impacts on a once widely distributed and now threatened species, the woodland caribou (Rangifer tarandus caribou). The cumulative area of recently logged forest (since ~1976) was 14,024,619 ha, with 8,210,617 ha in Quebec and 5,814,002 ha in Ontario. The total area of older forests was 21,249,341 ha, with 11,840,474 ha in Quebec and 9,408,867 ha in Ontario. Patch statistics revealed that there were 1,085,822 older forests with core patches < 0.25 ha and an additional 603,052 < 1.0 ha. There were 52 > 10,00–50,000 ha and 8 < 50,000 ha. Older forest patches (critical caribou habitat) in the 21 local population ranges totalled 6,103,534 ha, distributed among ~387,102 patches with 362,933 < 10 ha and 14 > 50,000 ha. The median percentage of local population ranges that was disturbed was 53.5%, with Charlevoix having the maximum (90.3%) and Basse Côte-Nord the least (34.9%). Woodland caribou local population ranges with disturbed suitable habitats >35% are considered unable to support self-sustaining populations. We found that for the 21 caribou local population ranges examined, 3 were at very high risk (>75% area disturbed), 16 at high risk (>45 ≤ 75% area disturbed), and 2 at low risk (≤35% area disturbed). Major changes are needed in boreal forest management in Ontario and Quebec for it to be ecologically sustainable, including a greater emphasis on protection and restoration for older forests, and to lower the risks for caribou populations.

19 May 2023 in Ecology and Evolution
Verified
Journal Article
Open access
GHGeoffrey W. Heard
Geoffrey W. Heard
LBLiam Bolitho
Liam Bolitho
DNDavid Newell
David Newell
HHHarry Hines
Harry Hines
PNPatrick Norman
Patrick Norman
BSBen C. Scheele
Ben C. Scheele
Deepening droughts and unprecedented wildfires are at the leading edge of climate change. Such events pose an emerging threat to species maladapted to these perturbations, with the potential for steeper declines than may be inferred from the gradual erosion of their climatic niche. This study focused on two species of amphibians—Philoria kundagungan and Philoria richmondensis (Limnodynastidae)—from the Gondwanan rainforests of eastern Australia that were extensively affected by the “Black Summer” megafires of 2019/2020 and the severe drought associated with them. We sought to assess the impact of these perturbations by quantifying the extent of habitat affected by fire, assessing patterns of occurrence and abundance of calling males post‐fire, and comparing post‐fire occurrence and abundance with that observed pre‐fire. Some 30% of potentially suitable habitat for P. kundagungan was fire affected, and 12% for P. richmondensis. Field surveys revealed persistence in some burnt rainforest; however, both species were detected at a higher proportion of unburnt sites. There was a clear negative effect of fire on the probability of site occupancy, abundance and the probability of persistence for P. kundagungan. For P. richmondensis, effects of fire were less evident due to the limited penetration of fire into core habitat; however, occupancy rates and abundance of calling males were depressed during the severe drought that prevailed just prior to the fires, with the reappearance of calling males linked to the degree of rehydration of breeding habitat post‐fire. Our results highlight the possibility that severe negative impacts of climate change for montane rainforest endemics may be felt much sooner than commonly anticipated under a scenario of gradual (decadal‐scale) changes in mean climatic conditions. Instead, the increased rate of severe stochastic events places these narrow range species at a heightened risk of extinction in the near‐term.

14 August 2023 in Pacific Conservation Biology
Verified
Journal Article
Open access
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PNPatrick Norman
Patrick Norman
Brendan MackeyBrendan Mackey
Brendan Mackey
Context The southern and central greater glider (Petauroides volans) is a nationally listed endangered species in Australia. The species depends upon mature native forest providing critical habitat resources including tree hollows. Aims This study aimed to map and evaluate the tenure of patches of potential high-quality (core) habitat and corridors for the southern greater glider in Queensland. Methods Within greater glider habitat, we mapped 10 ranked classes of relative forest maturity using a model comprising remotely sensed metrics of canopy height, above-ground living biomass and canopy cover at a 30 m resolution. We also modelled the optimum movement corridors within and between habitat patches. Key results Results showed that 35% (4.943 million ha) of habitat was found in the more mature classes (Classes 7–9), which represent a proxy for associated limiting habitat resources, especially tree hollows. Mean patch size above a 1.6 ha threshold was found to be 122 ha and most patches (71%) were ≤10 ha, with 14 patches ≥100 000 ha. Freehold and leasehold lands hold 63.4% of the more mature habitat, multiple-use public forest 21.4% and nature conservation areas 12.8%. About half of the potential habitat is located on formally recognised Indigenous lands that represent different categories of Aboriginal ownership, management and other special rights. Conclusions The protection of mature forest patches and movement corridors is necessary for the conservation of the greater glider, a nationally listed threatened species. Implications Conservation interventions are needed, using a whole-of-landscape approach to protect core habitat and corridors from inappropriate land use.

16 June 2023 in Australian Journal of Botany
Verified
Journal Article
Open access
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BVBrodie Verrall
Brodie Verrall
PNPatrick Norman
Patrick Norman
Brendan MackeyBrendan Mackey
Brendan Mackey
SFScout Fisher
Scout Fisher
JDJack Dodd
Jack Dodd
Context: Climate-induced changes of alpine vegetation diversity, cover and composition have been recorded globally, but most insights have been gleaned from field studies over small spatiotemporal scales. Aims: We assess dynamics in climate and vegetation of Australia’s highest and most biologically diverse alpine area that surrounds Mount Kosciuszko (~455 km2), as well as recovery following the 2003 wildfires. Methods: Climatic changes were analysed using gridded climate data for mean annual temperature (1910–2019) and seasonal precipitation (1900–2019), and changes in snow cover were assessed from snow course records (1954–2021). A vegetation cover time series (1990, 2000, 2010, 2020) was modelled with an optimised random forest classification using recursive feature selection, and the LandTrendr algorithm was used to detect areas burnt during wildfires. Key results: Over time, temperatures and summer precipitation increased, whereas snow cover and winter precipitation decreased. Subsequently, vegetation dynamics were dominated by the densification of subalpine woodlands at lower elevations, replacing dry and wet heathlands. There was treeline stasis but upslope advancement of dry and wet shrublines but grassland vegetation types were relatively stable. However, in burnt areas there was suppressed upslope advancement of shrublines, treeline recession and relatively less expansion of subalpine woodlands. Conclusions: Alpine vegetation may be impacted by climate change incrementally through relatively gradual changes in climatic conditions, and transformatively through landscape-level disturbance from wildfires. Implications: Higher temperatures and altered precipitation regimes increase the frequency and severity of wildfires, which may be amplified by increasing fuel loads and dryness from the proliferation and advance of woody vegetation in alpine areas.

9 October 2024 in Land
Verified
Journal Article
Open access
PDF file
Brendan MackeyBrendan Mackey
Brendan Mackey
SHSonia Hugh
Sonia Hugh
PNPatrick Norman
Patrick Norman
BRBrendan Rogers
Brendan Rogers
Dominick A DellaSalaDominick A DellaSala
Dominick A DellaSala
The world’s forests are being increasingly disturbed from exposure to the compounding impacts of land use and climate change, in addition to natural disturbance regimes. Boreal forests have a lower level of deforestation compared to tropical forests, and while they have higher levels of natural disturbances, the accumulated impact of forest management for commodity production coupled with worsening fire weather conditions and other climate-related stressors is resulting in ecosystem degradation and loss of biodiversity. We used satellite-based time-series analysis of two canopy indices—canopy photosynthesis and canopy water stress—to calculate an index that maps the relative stability of forest canopies in the Canadian provinces of Ontario and Quebec. By drawing upon available spatial time-series data on logging, wildfire, and insect infestation impacts, we were able to attribute the causal determinants of areas identified as having unstable forest canopy. The slope of the two indices that comprise the stability index also provided information as to where the forest is recovering from prior disturbances. The stability analyses and associated spatial datasets are available in an interactive web-based mapping app. that can be used to map disturbed forest canopies and the attribution of disturbances to human or natural causes. This information can assist decision-makers in identifying areas that are potentially ecologically degraded and in need of restoration and those stable areas that are a priority for protection.