Department Personnel

Lesley Rigg

    Lesley Rigg

       lrigg@niu.edu

       

 

Publications, Grants and Presentations 

Publications

Rigg, L.S. , S. McCarragher*, and A.J. Krmenec. (In press: 2013) Authorship, Collaboration, and Gender: fifteen years of publication productivity in selected geography journals."), Professional Geographer. Abstract

McCarragher*, S., D. Goldblum, and L.S. Rigg. (2011). Geographic variations in seed germination, seedling growth, and mortality of sugar maple (Acer saccharum) under different temperature and climatic regimes: results of common garden and reciprocal dispersal experiments. Physical Geography, 32: 1-21

Rigg, L.S., N.J. Enright, T. Jaffré, G.L.W. Perry and B.P. Miller (2010) Contrasting population dynamics of the endemic New Caledonian conifer, Araucaria laubenfelsii, in maquis and rainforest. Biotropica: 42:49-483 Abstract

Goldblum, D., L.S. Rigg, and J. Napoli. 2010. Environmental determinants of tree species distributions in central Ontario, Canada. Physical Geography. 31: 423-440. Abstract

Goldblum, D. and L.S. Rigg. 2010. The deciduous forest – boreal forest ecotone. Geography Compass. 4: 701-717. Abstract

Kwit, M.C., L.S. Rigg, and D. Goldblum. (2010). Sugar maple seedling carbon assimilation at the northern limits of its range: the importance of seasonal light. Canadian Journal of Forest Research. 40: 385-393. Abstract

Lenczewski, M., L.S. Rigg, N.J. Enright, T. Jaffre, and H. Kelly. (2009) Microbial Communities Associated with Shrubland and Rainforest in Ultramafic Soils, Mont Do, New Caledonia. Austral Ecology 34: 567-576 Abstract

Goldblum, D. and L. S. Rigg. (2009). Throughfall pH in a mixed deciduous-coniferous forest, Ontario, Canada: the effect of overstory species composition. Michigan Botanist. 48: 65-71. Abstract

Rigg, L.S. et al. (2008) Presidential Commission on the Status of Women: Report on the Status of Women at Northern Illinois University, 27 pg. Office of the President, NIU, December 2008. (Technical Report)
website: http://www.niu.edu/pcsw/reports/pcsw2008.pdf

Stan, A.B., L.S. Rigg, and L.S. Jones, (2006) Dynamics of a managed oak woodland in northeastern Illinois , USA . Natural Areas Journal 26 : 187-197 Abstract

Goldblum, D. and L.S. Rigg, (2005) Dominant tree species growth responses to climate at the deciduous/boreal ecotone. Canadian Journal of Forest Research 35 : 2709-2718. Abstract

Rigg, L.S. (2005) Disturbance processes in maquis and forest, and the resulting spatial patterns of two emergent maquis conifers, New Caledonia . Austral Ecology . 30 :363-373. Abstract

Rigg, L.S. and S. W. Beatty (2004) “The abundance and spatial distribution of herbaceous and woody vegetation along old field margins in three upstate New York fields” The Great Lakes Geographer. 11(1): 54-65. Abstract

Rigg, L.S. (2003) “Genetic Applications in Biogeography: An introduction.” Physical Geography, 24(5): 355-7. Refereed.

Diochon, A., L.S. Rigg, D. Goldblum, and N.O. Polans (2003) “The regeneration dynamics and genetic variability of sugar maple (Acer saccharum [Marsh.]) seedlings at the species’ northern growth limit, Lake Superior Provincial Park, Ontario, Canada.” Physical Geography, 24(5): 399-413. Abstract

Goldblum, D. and L.S. Rigg. (2002) Age structure and regeneration dynamics of sugar maple at the deciduous/boreal forest ecotone, Ontario, Canada. Physical Geography. 23(2): 115-129. Abstract - Poster

 Rigg, L.S., N.J. Enright, G.L.W. Perry and B.P. Miller. (2002) The role of fog in the transition of woodland to rainforest. Biotropica, 34(2): 199-210 Abstract

Stojanovic, B., L.S. Rigg, and M.E. Konen. (2001) Stand structure of shagbark hickory (Carya ovata) and soil properties in an extremely fragmented woodlot in northeastern Illinois. Great Lakes Geographer. 8 (2);66-76. Abstract

Enright, N.J., L.S. Rigg, and T. Jaffré (2001) Environmental controls on species composition along a (maquis) shrubland to forest gradient on ultramafics at Mont Do, New Caledonia. South African Journal of Science 97:573-80. Abstract

Enright, N. J., J. Ogden, and L.S. Rigg (1999) Dynamics of forests with Araucariaceae in the western Pacific. Journal of Vegetation Science. 10(6): 793-804. Abstract

Rigg, L.S., N.J. Enright, and T. Jaffré (1998) Stand structure of emergent conifer Araucaria laubenfelsii, in maquis and rain forest, Mont Do, New Caledonia. Australian Journal of Ecology. 23:528-38

Kellman, M. C., R. Tackaberry, and L.S. Rigg (1998) Structure and function in two tropical gallery forest communities: Implications for forest conservation in fragmented systems. Journal of Applied Ecology. 35: 195-206. Abstract

 

Grants

National Science Foundation, REU Site:”Operation ETank: Moving Toward a Sustainable World” (David Changnon and Lisa Reeman Co-PIs with L. Rigg, C. Mirman and J. Spears as Co-project managers). Funded 2012.

National Science Foundation, Geography and Regional Science, “Operation CRETE: fostering Collaborations, expanding Research horizons, and Establishing and Transforming networks for Early career Biogeographers. “ (Lesley Rigg, PI, as President of and representing, the Biogeography Specialty Group, AAG). Funded 2010-2012.

National Science Foundation, ADVANCE, IT Catalyst , “Navigate, Balance, and Retain: Developing Success in Mid-Career for Female STEM Faculty.” (with C. McCord, A. Levin, B. Collier, and J. Reynolds, NIU). Funded 2010-2012

Institute for the Study of Environment, Sustainability, and Energy, NIU. The tortoise and the hare: Competing dynamics of Araucaria laubenfelsii and angiosperms on ultramafic substrates, in New Caledonia. 2010-2011.

Institute for the Study of Environment, Sustainability, and Energy: Impact of Wastewater Injection on Mangroves and Coastal Forest Ecosystems in Yucatan Peninsula, Mexico: A preliminary examination 2010-2011.

National Science Foundation, Geography and Regional Science. “Study of microbial communities in Northern Ontario under simulated climate change”, 2009-2012. (with Drs. D. Goldblum and M. Lenczewski, NIU), Funded 2009-2012 Summary 

National Science Foundation, Geography and Regional Science, The Impact of Simulated Climate Change on Sugar Maple at the Hardwood/Boreal Forest Ecotone. (with. D. Goldblum). 2007-2010. Poster 

Argonne National Laboratory; Advanced Photon Source Beamtime (GSECARS Users). (With Drs. M. Lenczewski and M. R. Frank, Geology, NIU), 36 hours on APS,  

American Association of Geographers Research Grant, 2002-2003 

American Association for the Advancement of Science and the National Science Foundation: Program for Women in International Scientific Collaboration (with Dr. M. Lenczewski, Geology, NIU), 2002 

National Geographic Research and Exploration Grant, 2001-2002. 

American Association of Geographers, Anne U. White Fund, 2001. 

National Geographic Research and Exploration Grant, 2000-2001

Top 


Publications 

Rigg, L.S., N.J. Enright, T. Jaffré, G.L.W. Perry and B.P. Miller (2010) Contrasting population dynamics of the endemic New Caledonian conifer, Araucaria laubenfelsii, in maquis and rainforest. Biotropica: 42:49-483

Abstract
This study compares demographic parameters and population dynamics for high disturbance (maquis) and low disturbance (rain forest) environments of the montane conifer, Araucaria laubenfelsii, in New Caledonia. The establishment, growth, survival and reproduction of ca 2500 individuals were followed in permanent plots over 10 yr. Growth and survival rates for A. laubenfelsii show that it is a long-lived, slow growing tree, with evidence of suppression in the sapling size classes in mature rain forest. Growth rates for all size classes are generally faster in maquis than rain forest. Transition matrix analyses estimated positive rates of population increase (λ values>1), with populations expanding in maquis, and stable in mature forest. Araucaria laubenfelsii is able to regenerate continuously in maquis and early successional rain forest, but recruitment is limited in older stands. Life table response experiment analyses showed that reproduction, and transitions from sapling to mature tree stage, contributed positively to λ in maquis, but negatively in forest. Araucaria laubenfelsii on Mont Do can be considered a long-lived pioneer, with early maquis colonizers helping to drive succession from maquis to forest. While opportunities for recruitment decline with time as rain forest sites develop a closed canopy, occasional gap phase recruitment, combined with disturbance by cyclones, landslides and fire, provide opportunities to ensure species persistence. Understanding contrasting population dynamics of A. laubenfelsii in maquis and rain forest will better facilitate conservation management of this species, particularly given current high rates of land conversion and degradation in New Caledonia.
Top 


Goldblum, D., L.S. Rigg, and J. Napoli. 2010. Environmental determinants of tree species distributions in central Ontario, Canada. Physical Geography. 31: 423-440.

Abstract
The ability to model forest distributions in light of anthropogenic disturbance requires a thorough understanding of how trees respond to their physical and climatic environment. The primary objective of this study is to determine how four environmental variables (elevation, latitude, slope angle, and slope aspect) affect the distribution of seven common tree species (Acer saccharum, Betula alleghaniensis, Betula papyifera, Abies balsamea, Picea glauca, Thuja occidentalis, and Acer spicatum) using both regression tree analysis (RTA) and canonical correspondence analysis (CCA) techniques. In general, within the study area, Acer saccharum, Abies balsamea, and Thuja occidentalis abundance was controlled by elevation and latitude, whereas the other species showed limited response to the measured environmental variables. While CCA and RTA showed similar patterns, RTA allows for a more nuanced evaluation of species-environment interactions. Given that the study area encompasses Acer saccharum's northern limit, there were differences in the response of Abies balsamea to environmental conditions in the absence of Acer saccharum.
Top 


Goldblum, D. and L.S. Rigg. 2010. The deciduous forest – boreal forest ecotone. Geography Compass. 4: 701-717.

Abstract
Ecotones have been subject to significant attention over the past 25 years as a consensus emerged that they might be uniquely sensitive to the effects of climate change. Most ecotone field studies and modeling efforts have focused on transitions between forest and non-forest biomes (e.g. boreal forest to Arctic tundra, forest to prairie, subalpine forests to alpine tundra) while little effort has been made to evaluate or simply understand forest–forest ecotones, specifically the deciduous forest – boreal forest ecotone. Geographical shifts and changes at this ecotone because of anthropogenic factors are tied to the broader survival of both the boreal and deciduous forest communities as well as global factors such as biodiversity loss and dynamics of the carbon cycle. This review summarizes what is known about the location, controlling mechanisms, disturbance regimes, anthropogenic impacts, and sensitivity to climate change of the deciduous forest – boreal forest ecotone.
Top 


Kwit, M.C., L.S. Rigg, and D. Goldblum. (2010). Sugar maple seedling carbon assimilation at the northern limits of its range: the importance of seasonal light. Canadian Journal of Forest Research. 40: 385-393.

Abstract: Dendrochronological analysis is used to determine white oak’s (Quercus alba L.) sensitivity to mean monthly temperature and monthly precipitation for the entirety of its range in the United States. Throughout much of its range, white oak is sensitive to summer precipitation (positive), summer temperature (negative), and previous season latesummer and fall precipitation (positive). Spatially, populations of white oak in the western and central portion of its range are most highly correlated with these variables, while Appalachian and eastern populations show little sensitivity to monthly climate variables. White oak’s radial growth rate in light of anthropogenic climate change (based on regional and downscaled climate models) may be most reduced in the far western portion of its range (Illinois and Missouri), whereas eastern populations are less likely to be adversely affected.
Top 


Lenczewski, M., L.S. Rigg, N.J. Enright, T. Jaffre, and H. Kelly. (2009) Microbial Communities Associated with Shrubland and Rainforest in Ultramafic Soils, Mont Do, New Caledonia. Austral Ecology 34: 567-576

We analyzed variation in microbial community richness and function in soils associated with a fire-induced vegetation successional gradient from low maquis (shrubland) through tall maquis to rainforest on metal-rich ultramafic soils at Mt Do, New Caledonia. Random amplified polymorphic DNA fingerprinting was used to determine the extent of genetic relatedness among the microbial communities and indicated that the open and tall maquis microbial communities were more similar to each other than they were to the rainforest community. Sole-source carbon utilization indicated variation in the microbial communities, again with greater diversity in rainforest soils. Plate counts showed that both rainforest and maquis soils contained bacteria that can grow in the presence of up to 20 mmol L−1 nickel and 10 mmol L−1 chromium. Understanding microbial community composition and dynamics in these ultramafic soils may lead to a better understanding of the processes facilitating vegetation succession from shrubland to forest on these high-metal substrates, and of approaches to successful revegetation following mining for metals including nickel, chromium and cobalt.
Top 


Goldblum, D. and L. S. Rigg. (2009). Throughfall pH in a mixed deciduous-coniferous forest, Ontario, Canada: the effect of overstory species composition. Michigan Botanis. 48: 65-71.

Abstract: Throughfall and precipitation pH were observed for one growing season in an undisturbed mixed deciduous-conifer forest on the east shore of Lake Superior in Ontario. Rainfall and throughfall were collected for pH analysis from late-May through mid-August under the dominant tree species. From a total of 18 measureable rainfall events, pH of deciduous (sugar maple and paper birch) and coniferous (white spruce and balsam fir) throughfall was significantly less acidic than the incident rainfall for nine of the events; particularly for events following deciduous canopy leafout. Deciduous and coniferous throughfall pH differed significantly from each other for four of the 18 rain events throughout the middle of the growing season. Paper birch had the least acidic throughfall and sugar maple, white spruce, and balsam fir throughfall were generally similar and more acidic. The spatial heterogeneity of throughfall chemistry as controlled by overstory species composition, in addition to numerous other environmental factors that differ at fine spatial scales in forest understories, may play an important role in mediating germination, growth rates, carbon assimilation rates, and mortality of understory tree seedlings.
Top 


Stan, A.B., L.S. Rigg, and L.S. Jones, (2006) Dynamics of a managed oak woodland in northeastern Illinois , USA . Natural Areas Journal 26 : 187-197  

Abstract: We examined the current composition and structure of a woodland in northeastern Illinois and evaluated the early effect of two prescribed burns. In an effort to increase white oak ( Quercus alba L.) regeneration, managers are reintroducing fire into the woodland understory. We assessed canopy species and compared understory vegetation and light, along with soil nutrient characteristics, between a burned and an unburned area. In addition, we monitored transplanted white oak seedlings to better understand their growth and survivorship in the woodland. The canopy was dominated by white oak, but non-oak species, particularly slippery elm ( Ulmus rubra Muhl.), ash (Fraxinus spp. L), and black cherry ( Prunus serotina Ehrh.), dominated the smaller size classes. There were no differences in woody and herbaceous vegetation, soil, and light characteristics between the burned and unburned area. White oak regeneration was poor which appeared to be due to low understory light levels associated with high density of the shrub prickly ash ( Zanthoxylum americanum Mill.) and high numbers of non-oak saplings. Transplanted seedlings also performed poorly, with low survival rates throughout the woodland as a whole. Mammalian herbivory is a likely cause of additional stress to white oak regeneration. Evidence of browsing of transplanted white oak seedlings was apparent throughout the study area. If white oak is to be a component of the future woodland, managers should consider: (1) implementing a more intensive management program aimed at reducing competition from non-oak species and (2) increasing light in the understory.
Top   


Goldblum, D. and L.S. Rigg, (2005) Dominant tree species growth responses to climate at the deciduous/boreal ecotone . Canadian Journal of Forest Research 35 : 2709-2718.  

Abstract: We consider the implications of climate change on the future of the three dominant forest species, sugar maple (Acer saccharum), white spruce (Picea glauca), and balsam fir (Abies balsamea) at the deciduous/boreal forest ecotone, Ontario, Canada. Our analysis is based upon individual species responses to past monthly temperature and precipitation conditions in light of GCM modeled monthly temperature and precipitation conditions in the study area for the 2080s. We then consider the tree species sensitivity to past climate with predicted conditions for the 2080 period. Sugar maple, located at its northern limit in the study area, shows the greatest potential for increased growth rates under the predicted warming and altered precipitation regime. White spruce is likely to benefit less, while the understory dominant, balsam fir, is likely to experience a decrease in growth potential. These projected changes would enhance the future status of sugar maple at its northern limit and facilitate range expansion northward in response to global warming.
Top 


Rigg, L.S. (2005) “Disturbance processes in maquis and forest, and the resulting spatial patterns of two emergent maquis conifers, New Caledonia” (Austral Ecology)..  

Abstract: Araucaria laubenfelsii and Araucaria montana are emergent conifers in maquis and forest communities which are subjected to a combination of fire and cyclonic disturbances. Both species are able to survive fire once stems reach a critical size, but most seedlings and saplings are killed. Both species were found to be clumped at most spatial scales for both saplings and trees in maquis, resulting from a combination of patchy fire and a limited ability to disperse seeds. The high degree of clumping indicated that fire disturbances may occur relatively frequently in the field sites. Comparisons of burned and unburned Araucaria montana sites suggest that clumping increases only slightly after fire. Cyclonic disturbances are infrequent but may result in blow-down of large individuals within both maquis and forest. All of the individuals blown-down during the study had been previously fire scarred. Around tree blow-downs, seedling and sapling densities can be high. This likely reflects both the low dispersability of Araucaria seeds and enhanced moisture from the shading of the adult, when it was alive. Disturbance by fire and wind play an important role in the regeneration dynamics and spatial pattern of these species in maquis in New Caledonia.
Top    


Rigg, L.S. and S. W. Beatty (2004) “The abundance and spatial distribution of herbaceous and woody vegetation along old field margins in three upstate New York fields” The Great Lakes Geographer.
11(1): 54-65. 

Abstract: Abandoned agricultural fields are a prominent landscape feature of the Great Lakes region of North America. When fields are abandoned, species are influenced by the nature of the surrounding landscape. This study examined the abundance and spatial distribution of woody and herbaceous vegetation species along old field margins (within 25 m of field edge or hedgerow) and the structure and composition of adjacent hedgerows. Ordination and regression analysis examined the preference of certain species, both herbaceous and woody, for either edge or field interior environments. No herbaceous species were found to decrease significantly with distance from the field edge, although many species were found to occur with greater frequency in the "interior" 10 meters of the transects. A group of "edge" species was easily identified with many occurring more in the first 10 meters of transects. In general, total tree seedling densities significantly decreased with distance from the edge, but this study found no correlation between woody species establishment and species composition of hedgerows, except for sugar maple. Since this study was able to quantify an edge community for both herbaceous and woody species, given time, the edge communities may be used as a possible indicator of vegetation change for the old field community.
Top   


Diochon, A., L.S. Rigg, D. Goldblum, and N.O. Polans (2003) “The regeneration dynamics and genetic variability of sugar maple (Acer saccharum [Marsh.]) seedlings at the species’ northern growth limit, Lake Superior Provincial Park, Ontario, Canada.” Physical Geography, 24(5): 399-413. 

Abstract: The transition from deciduous forest to boreal forest is abrupt regionally and topographically in Lake Superior Provincial Park, Ontario, Canada. The northern range limit of Acer saccharum is coincident with the forest transition to boreal forest. The goal of our study was to characterize the distribution of A. saccharum seedlings at the transition zone to determine if variability in seedling demographics and genetics with topographic position and along a short north-south gradient was evident. Seedling density, size, age, and growth were evaluated in permanent plots across the regional transition zone, and at the south-facing, ridge top and north-facing limits across the topographic transition. Growth over five years was determined by measuring the distance between terminal bud scars, and compared with regional climate data. Genetic material was collected and analyzed from two of these sites. No significant differences were detected in density or growth of Acer saccharum across the regional transition, but mean age increased and height decreased as the limit was approached. Across the topographic transition, ridge top seedling densities were greater than south-facing or north-facing limits. Genetic variability was substantial with no cohort preference for topographic position detected. 
Top     

 


 

Goldblum, D. and L.S. Rigg. (2002) Age structure and regeneration dynamics of sugar maple at the deciduous/boreal forest ecotone, Ontario, Canada. Physical Geography. 23(2): 115-129 

Abstract: Sugar maple reaches its northern limit along the eastern shore of Lake Superior marking the transition from the deciduous forest of eastern North America to a predominantly boreal forest community. In light of regional warming trends over the past 100 years and projections for even warmer conditions in the future we sought to characterize the current age structure and regeneration status of both sugar maple and boreal tree species within this ecotone zone. Within Lake Superior Provincial Park (Ontario, Canada) a series of west-east trending hills create numerous deciduous-boreal transition zones as sugar maple occupy uplands and boreal species occupy valley bottoms, then once north of the sugar maple limit, boreal species dominate all topographic positions. Unlogged forest stands were sampled in the transition zone on ridges and slopes both north and south of the sugar maple limit. Overall tree density and basal area in sugar maple and boreal stands was similar across the ecotone, but seedling density was significantly higher in plots dominated by sugar maple. Moreover, sugar maple seedlings, but not saplings, were found slightly beyond the adult sugar maple tree limit indicating the potential for range expansion may be limited by microclimatic variables, namely cold air drainage.
Top   


Rigg, L.S., N.J. Enright, G.L.W. Perry and B.P. Miller. (2002) The role of fog in the transition of woodland to rainforest. Biotropica, 34(2): 199-210  

Abstract: This study examined the role of shading and cloud-combing of moisture by scattered trees of the emergent conifer, Araucaria laubenfelsii (Corbass.), in montane shrubland-maquis at Mt Do, New Caledonia, in facilitating the succession from shrubland to rainforest. Water collection experiments showed that these trees combed significant amounts of water from low clouds on days when no rainfall was recorded, and deposited this moisture on the ground beneath the tree canopy. Analysis of photosystem II function in Araucaria laubenfelsii and five other plant species using fluorometry revealed much lower photosystem stress in plants beneath scattered Araucaria laubenfelsii than for individuals exposed to full sunlight in the open maquis. Transition matrix analyses of vegetation change based on 'the most likely recruit to succeed' indicated that the transition from maquis to forest was markedly faster when emergent trees of Araucaria laubenfelsii acted as nuclei for forest species invasion of the maquis. On the basis of these lines of evidence it is argued that increased moisture and shading supplied to the area directly below the crown of isolated trees of Araucaria laubenfelsii in the maquis facilitates the establishment of both conifer seedlings and other rainforest tree and shrub species. In the absence of fire, rainforest can re-establish through spread in two ways; first, by expansion from remnant patches, and second, from coalescence of small rainforest patches formed around individual trees of Araucaria laubenfelsii.
Top    


Stojanovic, B., L.S. Rigg, and M.E. Konen. (2001) Stand structure of shagbark hickory (Carya ovata) and soil properties in an extremely fragmented woodlot in northeastern Illinois. Great Lakes Geographer. 8 (2);66-76.  

Abstract: The stand structure of shagbark hickory (Carya ovata) and soil properties in an extremely fragmented woodlot were examined in northeastern Illinois. The goal of this preliminary study was to examine the effect of extreme forest fragmentation (in a golf course environment) on the structure of oak-hickory remnants and the impact of golf course management on soil properties associated with the remnants. Seedling densities for shagbark hickory, density and basal area for all trees present, and soil samples (pH, bulk density, organic matter, and macronutrient concentrations) were obtained for each remnant and compared to a larger forest plot (11 hectares). Shagbark hickory seeds collected from the study site were germinated and grown under two different conditions: fertilized and non-fertilized to assess the effect of nutrient amendments on seedling growth and persistence. Seedling densities in woodlot remnants indicated shagbark hickory is capable of establishing within a fragmented environment, however, the stand structures indicated a lack of recent recruitment to the sub-canopy. Soil nutrient concentrations were highly variable with no clear trends among remnants. Fertilizer application to germinants indicated that shagbark hickory seedlings have a negative sensitivity to golf course levels of nutrient application. This research suggests that golf course management practices need to take into consideration the persistence of long-lived tree species within fragments to maintain a wooded course environment.
Top   


Enright, N.J., L.S. Rigg, and T. Jaffré (2001) Environmental controls on species composition along a (maquis) shrubland to forest gradient on ultramafics at Mont Do, New Caledonia. South African Journal of Science 97:573-80. 

Abstract: The landscape scale pattern of distribution of maquis, maquis with emergent conifers (Araucaria laubenfelsii), and rainforest, on ultramafic substrate at Mt Do, New Caledonia is investigated in relation to soil and plant chemistry, light and moisture. The structure and composition of these vegetation types reflects the impacts of disturbance on the one hand, and of physiological stresses on the other. Disturbance by fire is important in determining the presence and abundance of maquis and rainforest at the landscape level and is discussed in detail by Perry et al. elsewhere in this issue 1. The impacts of light environments, water availability and soil chemistry on the succession of vegetation from maquis to forest are also important. The chemistry of iron-crust and eroded oxisol soils does not vary greatly between vegetation types, and does not appear to define the distribution of species at the local scale. Nevertheless, low concentrations of macronutrients (such as P) and slow rates of biomass accumulation associated with this ultramafic landscape may be important in slowing the rate of progression of the vegetation from maquis to forest. Chlorophyll fluorescence studies of seedlings, saplings and trees in maquis and forest provide strong evidence for severe reductions in photosynthetic efficiency in photosystem II on clear days for seedlings growing in maquis. The importance of increased water supply to plants establishing beneath emergent araucarians in maquis through cloud-combing is also illustrated.
Top   


Enright, N. J., J. Ogden, and L.S. Rigg (1999) Dynamics of forests with Araucariaceae in the western Pacific. Journal of Vegetation Science. 10(6): 793-804. 

Abstract: Several species of Araucaria and Agathis (Araucariaceae) occur as canopy emergents in rain forests of the western pacific region, often representing major components of total stand biomass. New data from permanent forest plots (and other published work) for three species (Araucaria hunsteinii from New Guinea, A. laubenfelsii from New Caledonia, and Agathis australis from New Zealand) are used to test the validity of the temporal stand replacement model proposed by Ogden (1985) and Ogden & Stewart (1995) to explain the structural and compositional properties of New Zealand rain forests containing the conifer Agathis australis. Here we propose the model as a general one which explains the stand dynamics of rain forests with Araucariaceae across a range of sites and species in the western Pacific. Forest stands representing putative stages in the model were examined for changes through time in species recruitment, growth and survivorship, and stand richness, density and basal area. Support for the model was found on the basis of: 1. Evidence for a phase of massive conifer recruitment following landscape-scale disturbances (e.g. by fire at the Huapai site, New Zealand for Agathis australis); 2. Increasing species richness of angiosperm trees in the pole stage of forest stand development (i.e. as the initial cohort of conifers reach tree size; > 10 cm DBH); 3. A high turnover rate for angiosperms (< 100 yr), and low turnover for conifers (>> 100 yr) in the pole stage, but similar turnover rates for both components (50 - 100 yr) as forests enter the mature to senescent phase for the initial conifer cohort; 4. Very low rates of recruitment for conifers within mature stands, and projected forest compositions which show increasing dominance by angiosperm tree species; 5. A low probability of conifer recruitment in large canopy gaps created by conifer tree falls during the initial cohort senescent phase, which could produce a second generation low density stand in the absence of landscape scale disturbance; 6. Evidence that each of the three species examined required open canopy conditions (canopy openness > 10 %) for successful recruitment. The evidence presented here supports the temporal stand replacement model, but more long-term supporting data are needed, especially for the phase immediately following landscape level disturbance.
Top   


Kellman, M. C., R. Tackaberry, and L.S. Rigg (1998) Structure and function in two tropical gallery forest communities: Implications for forest conservation in fragmented systems. Journal of Applied Ecology. 35: 195-206. 

Abstract:
1. Composition, growth and turnover of trees in two species-rich tropical gallery forests were examined to evaluate what community reorganization may be needed to transform recently created tropical forest fragments into stable refugia for regional forest biotas.
2. Rates of tree growth and turnover over a 5-year interval were comparable to those recorded in continuous forests and in both communities there had been some tree species turnover in the measured stem size classes during the 5-year interval. 
Top  


Grants

National Science Foundation, Geography and Regional Science. “Study of microbial communities in Northern Ontario under simulated climate change”, 2009-2012. (with Drs. D. Goldblum and M. Lenczewski, NIU), Funded 2009-2012

Project Summary: Forest response to climate change is well documented and significant. During past warming and cooling espisodes associated with glaciation, the forests of North America have tracked climate by shifting there ranges north and south across the continent. However, projections of human-induced climate change over the next several hundred years suggest that warming may be much faster than tree species have experienced in the past 18,000 years – in fact, probably over the past two million years. This rapid rate of climate change may severely impact many species' ability to reproduce and persist in regions where they are currently found. This problem may result in altered forest communities dominated largely of species with wide ecological tolerances. Sugar maple, an ecologically and economically important species in the deciduous forests of North America, is likely to be affected by altered climates near its northen limit. These effects may include altered growth rates, changes in survivorship and changes in the plant/soil community dynamics including long term associations with soil microbial partners. This project will evaluate the impact of anthropogenic climate change on soil microbial communities associated with sugar maple seedlings under an artificial temperature and precipitation manipulation experiment. It is designed to complement an ongoing project (NSF 0724256; Rigg and Goldblum) examining growth of sugar maple seedlings in response to human-induced temperature and precipitation change the boreal-deciduous forest boundary located in Lake Superior Provincial Park, Canada.  Experimental plots, outfitted with rain-exclusion structures and infrared heat lamps, were established in May 2008. Since sugar maple is a dominant species in these forests it may drive much of the ecological change under modified climates. Soil microbial communities play a key role in geochemical processes including nutrient mineralization and soil organic matter transformation, but feedbacks between soil microorganisms and plant community composition/diversity are largely unknown. We will address two broad questions in habitats undergoing experimental climate change, 1) how will climate change alter soil microbial diversity and soil microbe community structure and 2) what role does the soil microbe community play in the feedback between climate change and soil respiration at the boreal-deciduous forest boundary where sugar maple is dominant. Microbial diversity will be evaluated in a three-fold manner: a) via polymerase chain reaction (PCR)-based product analysis, b) via cultivation of microbes, and c) via phospholipid fatty acid (PLFA) analysis.

There is no doubt that over long periods of time plant and microbial species respond to climate changes by range shifts, but using analogs from past climate change may not be entirely appropriate if forest ecologists wish to model biotic (both above- and belowground) response to climate change over the next century. Thus, field experiments that simulate the more pronounced and rapid temperature changes can provide constructive results identifying specific responses to alterations in temperature and atmospheric concentrations mimicking anthropogenic impacts. Thus, we aim to add to the growing knowledge base in forest ecology and microbiology that investigates the impact of climate change on natural ecosystems. Fully understanding and quantifying aspects of the carbon cycle in the plant-soil-atmosphere continuum will be critical in determining whether forest soils will become net sinks or sources of atmospheric carbon.  A detailed understanding of the largely unstudied impact of climate change on soil microbes and how soil microbes affect carbon sequestration may prove to be a vital component in the expanding field of ecological impacts of global climate change. Further, we expect that our results will provide information on whether ecological thresholds exist beyond which sugar maples and their associated microorganisms may not survive, so that forest managers, soil scientists, modelers, and policy makers can begin to consider when environmental changes may become irreparably detrimental and monitor the environment for indications that those changes are imminent.
Top

 


 

Presentations, Professional Meetings, and Invited Research Lectures

 


 

Professional Meetings

“Publication and Gender in 15 Geography Journals.” Presented at the Association of American Geographers Annual Meeting, 2011 (April), Seattle, WA. (with Shannon McCarragher* and Andrew Krmenec)

“Competition in the regeneration niche: balsam fir and sugar maple in the boreal/mixed forest ecotone, Ontario, Canada.” Presented at the Association of American Geographers annual meeting, April 16, 2010. Washington, D.C. (presented by J. Loesch*, with Rigg, L.S., and D. Goldblum)

“Sugar maple leaf phenology, light levels, carbon gain, and regeneration at and north of the current range limit.” Presented at the Association of American Geographers annual meeting, April 14, 2010. Washington, D.C. (presented by Kwit*, M.C. with D. Goldblum, and L.S Rigg).

“Modeling the Future of Sugar Maple at its Northern Limit: 2060 Here We Come.” Presented at the Association of American Geographers annual meeting, April 16, 2010. Washington, D.C. (Rigg, L.S., D. Goldblum, and M.C. Kwit*.)

“Demography of New Caledonian Araucariaceae: Doing better than expected?” Presented at the VI Southern Connection Congress, Bariloche, Argentina, February 2010. (Presented by N.J. Enright with L.S. Rigg)

“Simulating climate change (temperature and soil moisture) in a mixed-deciduous forest, Ontario, Canada.” Presented at the World Academy of Science, Engineering, and Technology annual meeting, September 24, 2009. Amsterdam, Netherlands. (Presented by D. Goldblum with L. Rigg).

“The impact of an experimental climate change simulation: Photosynthetic activity of sugar maples, Ontario, Canada.” Presented at the Annual Meeting of the Association of American Geographers, 2009, Las Vegas, NA, (Presented by L. Rigg, with D. Goldblum and M. Kwit*).

“Impacts of an experimental climate change simulation: respiration of root and soil organisms, Ontario, Canada." Presented at the Association of American Geographers annual meeting, March 26, 2009. Las Vegas, NV. (Presented by D. Goldblum with L. Rigg).

“Projected population transitions for sugar maple under different climate change scenarios” Presented at the Annual Meeting of the Association of American Geographers, 2007, San Francisco, CA, (Presented by L. Rigg, with D. Goldblum).

“Spatial distribution of benzene and microorganisms after simulated gasoline spill in loess”. Presented at the International Association of Hydrogeology Annual Meeting, Lisbon, Portugal. 2007. (Presented by Lenczewski, M., with R. M. Leal-Bautista, H. Kelly*, L. Rigg, and C. Stiles)

“Physiological Response of Sugar Maple to Forest Light Levels” Presented at the Annual Meeting of the Association of American Geographers, 2006, Chicago, IL, (Presented by Michelle Nyberg* with L. Rigg).

“Land use impacts on soil microbial community dynamics.” Presented at the Soil Science Society of America Annual Meeting, November 2006, Indianapolis, (Presented by H.R. Kelly*, with M. Lenczewski, and M.E. Konen). 

“Uptake, storage and influence of nickel and other metals in the wood of Araucaria laubenfelsii in both maquis and rainforest associated with ultramafic soils in New Caledonia”, Presented at the Annual Meeting of the Association of American Geographers, 2006, Chicago, IL, (with L. Jones*, M. Lenczewski)

“Stable isotope ratio from trees growing in ultramafic soils, New Caledonia.”, Presented at the Annual Meeting of the Association of American Geographers, 2006, Chicago, IL, (Presented by M. Lenczewski, with L. Rigg and L. Jones*).

“Use of dendroanalysis to study temporal changes in environmental chemistry along the deciduous forest / boreal forest ecotone in Lake Superior Provincial Park, Ontario, Canada" Presented at the Annual Meeting of the Association of American Geographers, 2006, Chicago, IL, (Presented by L. Jones*, with L. Rigg and M. Lenczewski).

“Distribution of metals in tree cores associated with ultramafic soils in New Caledonia.” Presented at the 6th annual PRWAC, Kyoto, Japan, (with L. Jones, M. Lenczewski, S. Sutton, and M. Newville.)

”Rarity and Endemism in a Biodiversity Hot Spot: The Importance of Research on the New Caledonian Flora” Presented at the Annual Meeting of the Association of American Geographers, 2005, Denver, CO. (with M. Lenczewski and L. Jones*)

“Pollution induced dieback and climate change interactions in the northern deciduous forest/boreal forest ecotone, Ontario, Canada.” Presented at the Annual Meeting of the Association of American Geographers, 2004, Philadelphia, PA.

“Dominant tree species growth responses to climate at the deciduous/boreal ecotone.” Presented at the Annual Meeting of the Association of American Geographers, 2004, Philadelphia, PA (presented by D. Goldblum)

“Growth rates and vegetation change in a New Caledonian conifer population using matrix analysis.” Presented at the Annual Meeting of the Association of American Geographers, 2002, Los Angeles, CA.

“Sugar maple population dynamics and environmental conditions at their northern limit.” Presented at the Annual Meeting of the Association of American Geographers, 2002, Los Angeles, CA. (presented by D. Goldblum)

“A demographic analysis of sugar maple seedlings at the species northern growth limit, Ontario, Canada.” Presented at the Annual Meeting of the Ecological Society of America, 2002, Tucson, AZ. (presented by A. Diochon*, with D. Goldblum and N. Polans)

“Growth rates of competing forest species at the deciduous/boreal ecotone, Ontario, Canada.”  Presented at the Annual Meeting of the Association of American Geographers, 2001, New York, NY. (with D. Goldblum).

“Age structure and regeneration dynamics of sugar maple in the deciduous/boreal forest ecotone, Ontario, Canada” Presented at the Annual Meeting of the Association of American Geographers, 2001, New York, NY. (presented by D. Goldblum).

“Composition, structure, and regeneration dynamics of an oak woodland in northeastern Illinois.” Presented at the Annual Meeting of the Association of American Geographers, 2001, New York, NY. (presented by L. Jones*).

“Factors affecting white oak seedling (Quercus alba) establishment in a northern Illinois woodland.” Presented at the Annual Meeting of the Association of American Geographers, 2001, New York, NY. (presented by A. Stan*).

“Sugar maple (Acer saccharum Marsh.) seedling demographics at the northern growth limit in Ontario, Canada.” Presented at the Annual Meeting of the West Lakes Division of the Association of American Geographers, 2001, Joleit, IL. (presented by A. Diochon*).

“Cloud-combing and the transition from woodland to rainforest.” Illustrated poster presented at the Annual Meetings of the Association of American Geographers, 2000, Pittsburgh, USA. 

“The role of disturbance on the spatial dynamics of high altitude tropical woodlands.” Presented at the 1999 West Lakes Meetings: Regional Division of the Association of American Geographers, DeKalb, USA. 

“Element uptake along a shrubland to forest gradient, Mont Do, New Caledonia.” Presented at The 3rd International Conference on Serpentine Ecology, 1999, South Africa. (with N.J. Enright and T. Jaffré).

“Conservation of Rare and Endangered Species in New Caledonia.”  Presented at the Association of American Geographers Annual Meeting, 1998, Boston, MA (with T.  Jaffré).

“Population Dynamics of Araucaria laubenfelsii, Mont Do, New Caledonia.”  Presented at the Association of American Geographers Annual Meeting, 1997, Fort Worth, TX (with N.J. Enright and T.  Jaffré).

“Regeneration Dynamics of Araucaria laubenfelsii, Mont Do, New Caledonia.”  Presented at the Institute of Australian Geographers Society Conference, 1997, Hobart, Australia (with N.J. Enright and T. Jaffré)

“Herbaceous and Woody Species Distributions and Associations along Old-field Margins.” Presented at the Association of American Geographers Annual Meeting, 1994, San Francisco, CA (with S.W. Beatty).

“The Effect of Field Margins on Old Field Heterogeneity in Three Upstate New York Fields.” Presented at the Ecological Society of America Annual Meeting, 1994, Madison, WI (with S.W. Beatty).

“An Observational Study of Old Field Succession in Relation to Different, Historical, Physical, and Environmental Factors.”  Presented at the Association of American Geographers Annual Meeting, 1993, Atlanta, GA (with S.W. Beatty).

Top


 

Invited Research Lectures

”Women in Science” Guest Lecture: WOMS/GEOL 430, February 2012.

” Preliminary Results: Navigate, Balance and Retain, ADVANCE, NIU. Vice President For Research STEM Retreat, NIU. February 2012.

“Women in Science: Tarring a Balance and Measuring Productivity” SigmaXi Brown Bag Talks, October 13, 2011, Northern Illinois University.

“Putting it all together” Invited Presentation at NIU New Faculty Day, August 2011

“Teaching Women in Science at Northern Illinois University: teaching a class, changing perceptions and assessing the outcomes” Invited Talk: Multicultural Transformation Institute, May 2011

“Teaching Women in Science at Northern Illinois University: teaching a class, changing perceptions and assessing the outcomes” Invited Talk: Teacher Enrichment Symposium, NIU, March 2011

“Women in Science and Geographic Productivity” Brown Bag lecture series, Department of Geography, University of Wisconsin, Madison, December 3, 2010.

“Teaching Successfully” Invited Presentation at NIU New Faculty Day, August 2010

“Graduate” Inductee Keynote Speaker: Phi kappa Phi, NIU Chapter, April 2011

“Northward Bound: The impact of experimental warming and precipitation manipulation on Sugar Maple seedlings in the Boreal/Deciduous Forest Ecotone in North America”. Yi Fu Tuan Lectures, Department of Geography, University of Wisconsin, Madison, December 3, 2010.

“Experimental warming and precipitation manipulation: Sugar Maples in the Boreal/Deciduous Forest Ecotone.” Ecology and Evolution Group Lecture Series, University of Illinois, Chicago, November 15, 2010.

“Northward Bound: Climate Change and the Boreal/Deciduous Forest Ecotone in North America” University of Iowa Department of Geography Lecture Series. March 5, 2010.

“Women in Environmental Science” Invited Talk, Women’s History Month, Brown-Bag Series, NIU, March 2009

“Women in Science at Northern Illinois University” Invited Speaker, NIU Mortar Board. March 2009.

“Women in Science at Northern Illinois University” Invited Speaker, Provost’s Retreat for Women in Science. 2009.

“A Sabbatical Does Not Mean Rest” Invited speaker at Board of Trustees meeting, Northern Illinois University. March 2009.

“Living and Working Green” Invited Speaker, Women’s Networking Lunch, NIU, September 2007.

“A Double Life, A Double Helix: A Brief History of Women in Science”, NIU Notable Lecture Series, Lifelong Learning Institute, July 2007.

“Climate change and ecosystems: impacts on plants”. NIU symposium on Climate Change, organized by the Geography Dept. April 12, 2007.

“History of Women in Science” Invited Speaker, Women’s Networking Lunch, NIU, November 2005.

“Transforming a Syllabus: Women in Science” Multicultural Transformation Institute, October 2005.

“Conservation in a Biodiversity Hotspot: New Caledonia”, Dept. of Geography and Environmental Sciences, DePaul University, Chicago, Fall 2000.

“Population Dynamics of the Endemic conifer, Araucaria laubenfelsii in New Caledonia”, Biological Sciences Colloquium. February 25, 1999.

Top