How resilient are northern hardwood forests to human disturbance? An evaluation using a plant functional group approach

ABSTRACT Evaluating forest ecological integrity remains a major challenge for ecologists. We analyzed understory vegetation using an approach that combined plant functional types and vertical stratification to evaluate the effects of human disturbances on the ecological integrity of sugar maple-dominated stands in southern Québec. Ecological integrity was evaluated by analyzing the divergence of understory species assemblages from those observed in comparable unmanaged forest. Multivariate analyses of biological traits revealed 13 emergent groups that share common traits associated with a similar life history strategy. Responses of these groups, of specific traits, and of understory structure to different human disturbances were tested. Nine of the 13 emergent groups varied in occurrence or diversity among disturbance types. Analyses also revealed a set of traits specifically associated with unmanaged old growth forest, indicating that species possessing these traits may be sensitive to human disturbance. Overall, the understory vegetation assemblage was found to be relatively stable among all human disturbances investigated. However, our results suggest some issues of possible long-term conservation concern given a continuation of human disturbances: (i) an increase of species associated with open environment, including exotic species; (ii) a decrease of spring geophytes; (iii) a decrease of certain shade-tolerant forbs; and (iv) a modification of understory structure by the development of a dense sapling stratum.

[1]  Thomas J. Givnish,et al.  COMPARATIVE STUDIES OF LEAF FORM: ASSESSING THE RELATIVE ROLES OF SELECTIVE PRESSURES AND PHYLOGENETIC CONSTRAINTS , 2008 .

[2]  G. Houle,et al.  Response of herbaceous plant diversity to reduced structural diversity in maple-dominated (Acer saccharum Marsh.) forests managed for sap extraction , 2006 .

[3]  Alejandro A. Royo,et al.  On the formation of dense understory layers in forests worldwide: consequences and implications for forest dynamics, biodiversity, and succession , 2006 .

[4]  O. Honnay,et al.  The relative importance of local, regional and historical factors determining the distribution of plants in fragmented riverine forests: an emergent group approach , 2005 .

[5]  Marilou Beaudet,et al.  Comparing composition and structure in old-growth and harvested (selection and diameter-limit cuts) northern hardwood stands in Quebec , 2005 .

[6]  David A. Wardle,et al.  Understory vegetation as a forest ecosystem driver: evidence from the northern Swedish boreal forest , 2005 .

[7]  A. Bouchard,et al.  Vegetation Composition and Succession of Abandoned Farmland: Effects of Ecological, Historical and Spatial Factors , 2005, Landscape Ecology.

[8]  M. Diekmann,et al.  Effects of Life‐History Traits on Responses of Plant Species to Forest Fragmentation , 2005 .

[9]  Mark Vellend,et al.  Recovery of forest plant communities in post‐agricultural landscapes , 2005 .

[10]  Sophie Gachet,et al.  BASECO: a floristic and ecological database of Mediterranean French flora , 2005, Biodiversity & Conservation.

[11]  G. Whitney,et al.  Sweet trees, sour circumstances: the long search for sustainability in the North American maple products industry. , 2004 .

[12]  L. Vasseur,et al.  Recovery of late-seral vascular plants in a chronosequence of post-clearcut forest stands in coastal Nova Scotia, Canada , 2004, Plant Ecology.

[13]  S. McLachlan,et al.  Understorey indicators of disturbance for riparian forests along an urban–rural gradient in Manitoba , 2004 .

[14]  L. Fahrig,et al.  Influence of canopy cover and amount of open habitat in the surrounding landscape on proportion of alien plant species in forest sites1 , 2004 .

[15]  André Bouchard,et al.  Environmental, historical, and contextual determinants of vegetation cover: a landscape perspective , 2001, Landscape Ecology.

[16]  André Bouchard,et al.  Temporal (1958–1993) and spatial patterns of land use changes in Haut-Saint-Laurent (Quebec, Canada) and their relation to landscape physical attributes , 1999, Landscape Ecology.

[17]  D. Hix,et al.  Influence of aspect and stand age on ground flora of southeastern Ohio forest ecosystems , 1998, Plant Ecology.

[18]  M. Willson,et al.  Dispersal mode, seed shadows, and colonization patterns , 1993, Vegetatio.

[19]  S. Bédard,et al.  Growth following single-tree selection cutting in Québec northern hardwoods , 2003 .

[20]  D. Foster,et al.  Response of forest plant species to land‐use change: a life‐history trait‐based approach , 2003 .

[21]  J. Brisson,et al.  Old-growth forests in the temperate deciduous zone of Quebec: Identification and evaluation for conservation and research purposes , 2003 .

[22]  A. Bouchard,et al.  In the past two centuries, human activities have caused major changes in the tree species composition of southern Québec, Canada , 2003 .

[23]  D. Mladenoff,et al.  UNDERSTORY SPECIES PATTERNS AND DIVERSITY IN OLD‐GROWTH AND MANAGED NORTHERN HARDWOOD FORESTS , 2002 .

[24]  D. Foster,et al.  Legacies of the agricultural past in the forested present: an assessment of historical land‐use effects on rich mesic forests , 2002 .

[25]  Alain Leduc,et al.  Silvicultural disturbance severity and plant communities of the southern Canadian boreal forest , 2002 .

[26]  J. Battles,et al.  The effects of forest management on plant species diversity in a Sierran conifer forest , 2001 .

[27]  S. McLachlan,et al.  Recovery Patterns of Understory Herbs and Their Use as Indicators of Deciduous Forest Regeneration , 2001 .

[28]  B. Graae,et al.  The impact of forest continuity and management on forest floor vegetation evaluated by species traits. , 2000 .

[29]  D. Ackerly,et al.  Landscape and species-level distribution of morphological and life history traits in a temperate woodland flora , 2000 .

[30]  Marilou Beaudet,et al.  Light extinction coefficients specific to the understory vegetation of the southern boreal forest, Quebec. , 2000 .

[31]  L. Firbank,et al.  An ecological comparison between ancient and other forest plant species of Europe, and the implications for forest conservation , 1999 .

[32]  S. Díaz,et al.  Plant functional traits, ecosystem structure and land-use history along a climatic gradient in central-western Argentina , 1999 .

[33]  D. Peart,et al.  Understory herb assemblages 25 and 60 years after clearcutting of a northern hardwood forest, USA , 1999 .

[34]  A. Perevolotsky,et al.  The effect of shrub clearing and grazing on the composition of a Mediterranean plant community: functional groups versus species , 1999 .

[35]  Michael Kleyer,et al.  Distribution of plant functional types along gradients of disturbance intensity and resource supply in an agricultural landscape , 1999 .

[36]  J. Deckers,et al.  Migration of herbaceous plant species across ancient–recent forest ecotones in central Belgium , 1999 .

[37]  M. Cain,et al.  SEED DISPERSAL AND THE HOLOCENE MIGRATION OF WOODLAND HERBS , 1998 .

[38]  Christian Messier,et al.  Comparison of various methods for estimating the mean growing season percent photosynthetic photon flux density in forests , 1998 .

[39]  Frédérik Doyon,et al.  Tree productivity and successional status in Québec northern hardwoods. , 1998 .

[40]  K. P. Reese,et al.  LANDSCAPE CHANGES WITHIN THE HISTORICAL DISTRIBUTION OF COLUMBIAN SHARP-TAILED GROUSE IN EASTERN WASHINGTON : IS THERE HOPE? , 1998 .

[41]  S. Lavorel,et al.  Plant functional classifications: from general groups to specific groups based on response to disturbance. , 1997, Trends in ecology & evolution.

[42]  Simon A. Levin,et al.  The Multifaceted Aspects of Ecosystem Integrity , 1997 .

[43]  André Bouchard,et al.  The transformations of the natural landscapes of the Haut-Saint-Laurent (Québec) and their implications on future resource management , 1997 .

[44]  O. Eriksson,et al.  Local colonization and extinction of field layer plants in a deciduous forest and their dependence upon life history features , 1997 .

[45]  Wayne T. Swank,et al.  Successional changes in plant species diversity and composition after clearcutting a Southern Appalachian watershed , 1997 .

[46]  D R Foster,et al.  Ecological and conservation insights from reconstructive studies of temperate old-growth forests. , 1996, Trends in ecology & evolution.

[47]  André Bouchard,et al.  The precolonial 19th century forest of the Upper St. Lawrence Region of Quebec; a record of its exploitation and transformation through notary deeds of wood sales , 1996 .

[48]  Daniel Gagnon,et al.  Population Viability Analysis of American Ginseng and Wild Leek Harvested in Stochastic Environments , 1996 .

[49]  S. Bratton,et al.  Possible Ecological Mechanisms for Loss of Vernal‐Herb Diversity in Logged Eastern Deciduous Forests , 1995 .

[50]  S. D. Blois,et al.  Dynamics of Thuja occidentalis in an agricultural landscape of southern Quebec , 1995 .

[51]  Roger del Moral,et al.  Species attributes in early primary succession on volcanoes , 1995 .

[52]  S. Lavorel,et al.  Plant life-history attributes: their relationship to disturbance response in herbaceous vegetation. , 1995 .

[53]  C. Messier,et al.  Spatial and temporal variation in the light environment of developing Scots pine stands: the basis for a quick and efficient method of characterizing light , 1995 .

[54]  G. Matlack.  PLANT SPECIES MIGRATION IN A MIXED-HISTORY FOREST LANDSCAPE IN EASTERN NORTH AMERICA' , 1994 .

[55]  S. Bratton.  Logging and Fragmentation of Broadleaved Deciduous Forests: Are We Asking the Right Ecological Questions? , 1994 .

[56]  R. Reader,et al.  Value of selectively cut deciduous forest for understory herb conservation: An experimental assessment , 1992 .

[57]  H. Hammond.  Corrections and Additions for and Errors Found in the Manual of Vascular Plants of Northeastern United States and Adjacent Canada, Second Edition, by Henry A. Gleason (Late) and Arthur Cronquist , 1992 .

[58]  Yves Bergeron,et al.  The use of notary deeds to estimate the changes in the composition of 19th century forests, in Haut-Saint-Laurent, Quebec , 1989 .

[59]  Charles B. Halpern,et al.  Early Successional Patterns of Forest Species: Interactions of Life History Traits and Disturbance , 1989 .

[60]  Roderick Hunt,et al.  Comparative Plant Ecology: A Functional Approach to Common British Species , 1989 .

[61]  Y. Bergeron,et al.  Les successions secondaires sur sites mésiques dans le Haut-Saint-Laurent, Québec, Canada , 1988 .

[62]  M. Moore,et al.  Responses of the Herb Layer to the Gap Dynamics of a Mature Beech-Maple Forest , 1986 .

[63]  S. Pickett,et al.  Chapter 12 – Responses of Forest Herbs to Canopy Gaps , 1985 .

[64]  R. Rogers.  Early Spring Herb Communities in Mesophytic Forests of the Great Lakes Region , 1982 .

[65]  P. Bierzychudek.  LIFE HISTORIES AND DEMOGRAPHY OF SHADE‐TOLERANT TEMPERATE FOREST HERBS: A REVIEW , 1982 .

[66]  James R. Karr,et al.  Ecological perspective on water quality goals , 1981 .

[67]  P. Harcombe,et al.  Understory Structure of a Mesic Forest in Southeast Texas , 1977 .

[68]  R. Whittaker.  Evolution and measurement of species diversity , 1972 .

[69]  Arthur Cronquist,et al.  Manual of Vascular Plants of Northeastern United States and Adjacent Canada , 2004 .