Effect of Habitat Deterioration on Population Dynamics and Extinction Risks in a Previously Common Perennial

Abstract:  Habitat deterioration affects population viability and persistence of both plant and animal species. For plants the effect of changes in environmental conditions on population dynamics and extinction risks largely depends on the life span of the species. We used transition matrix models, a life‐table response experiment, and stochastic simulations to investigate the overall effects of nitrogen enrichment (9, 6, 3, and 0 g N/m2/year) and grassland management (mowing and grazing) on vital rates, population growth rate (λ), and extinction risks of a previously common perennial herb ( Primula veris [L.]). We experimentally manipulated 32 permanent plots that were monitored during a 5‐year period. To study the effects of nitrogen addition and management on recruitment in more detail and to evaluate the role of seed availability, we experimentally sowed seeds at different densities. Nitrogen addition always resulted in negative population growth rates (range: 0.998 to 0.700), whereas mean population growth rates in the control situation were >1. Interaction effects indicated that the negative effect of increasing nitrogen addition decreased population growth rate more strongly when the vegetation was mown compared with grazing. Besides significantly increased mortality rates, especially in the youngest life stages, decreased population growth rates under nitrogen enrichment were mainly the result of reduced flowering probabilities, seed production rates per plant, recruitment, and establishment of seedlings. Mowing, however, encouraged growth of vegetative adults into a flowering stage and decreased germination and seedling establishment, whereas the reverse was observed under grazing. Under the highest nitrogen levels, mean times to extinction were much shorter than would be expected based on the longevity of the species, especially under mowing. These results demonstrate that even long‐lived and formerly common perennial species may quickly respond to habitat deterioration, especially when the deterioration takes place over a short period of time.

[1]  R. Brys,et al.  The effects of grassland management on plant performance and demography in the perennial herb Primula veris , 2004 .

[2]  Danny A. P. Hooftman,et al.  Genetic Effects of Habitat Fragmentation on Common Species of Swiss Fen Meadows , 2004 .

[3]  R. Brys,et al.  Reduced reproductive success in small populations of the self‐incompatible Primula vulgaris , 2004 .

[4]  R. Brys,et al.  The relationship between reproductive success and demographic structure in remnant populations of Primula veris , 2003 .

[5]  María B. García.  Demographic Viability of a Relict Population of the Critically Endangered Plant Borderea chouardii , 2003 .

[6]  J. Oostermeijer,et al.  Integrating demographic and genetic approaches in plant conservation , 2003 .

[7]  C. Thomas,et al.  Ecological dynamics of extinct species in empty habitat networks. 1. The role of habitat pattern and quantity, stochasticity and dispersal , 2003 .

[8]  M. Fischer,et al.  Habitat fragmentation affects the common wetland specialist Primula farinosa in north‐east Switzerland , 2003 .

[9]  N. J. Ouborg,et al.  Effects of population size and genetic variation on the response of Succisa pratensis to eutrophication and acidification , 2003 .

[10]  R. Brys,et al.  Short-term effects of different management regimes on the response of calcareous grassland vegetation to increased nitrogen , 2003 .

[11]  B. Jonsson,et al.  Edge Effects on Liverworts and Lichens in Forest Patches in a Mosaic of Boreal Forest and Wetland , 2003 .

[12]  J. Benítez‐Malvido,et al.  Impact of Forest Fragmentation on Understory Plant Species Richness in Amazonia , 2003 .

[13]  E. Bruna.  Are plant populations in fragmented habitats recruitment limited? Tests with an amazonian herb , 2003 .

[14]  A. Ellison,et al.  NITROGEN DEPOSITION AND EXTINCTION RISK IN THE NORTHERN PITCHER PLANT, SARRACENIA PURPUREA , 2002 .

[15]  O. Eriksson,et al.  Land-use history and fragmentation of traditionally managed grasslands in Scandinavia , 2002 .

[16]  J. Ehrlén,et al.  How perennial are perennial plants , 2002 .

[17]  María B. García,et al.  Reproductive effort and herbivory timing in a perennial herb: fitness components at the individual and population levels. , 2002, American journal of botany.

[18]  O. Ovaskainen,et al.  Extinction Debt at Extinction Threshold , 2002 .

[19]  R. Lindborg,et al.  Evaluating the Extinction Risk of a Perennial Herb: Demographic Data versus Historical Records , 2002 .

[20]  R. Brys,et al.  Temporal changes (1986–1999) in populations of primrose (Primula vulgaris Huds.) in an agricultural landscape and implications for conservation , 2002 .

[21]  J. Oostermeijer,et al.  Future prospects for the rare, late-flowering Gentianella germanica and Gentianopsis ciliata in Dutch nutrient-poor calcareous grasslands , 2002 .

[22]  D. O. Logofet.  Matrix Population Models: Construction, Analysis, and Interpretation , 2002 .

[23]  O. Eriksson,et al.  Size‐related deterioration of semi‐natural grassland fragments in Sweden , 2002 .

[24]  T. Lennartsson,et al.  Demographic variation and population viability in Gentianella campestris: effects of grassland management and environmental stochasticity , 2001 .

[25]  M. Kuitunen,et al.  Population Persistence and Offspring Fitness in the Rare Bellflower Campanula cervicaria in Relation to Population Size and Habitat Quality , 2000 .

[26]  R. Holt,et al.  A Survey and Overview of Habitat Fragmentation Experiments , 2000 .

[27]  E. Menges,et al.  Population viability analyses in plants: challenges and opportunities. , 2000, Trends in ecology & evolution.

[28]  M. Kéry,et al.  Reduced fecundity and offspring performance in small populations of the declining grassland plants Primula veris and Gentiana lutea , 2000 .

[29]  B. Rathcke,et al.  Mechanisms of Reduced Trillium Recruitment along Edges of Old‐Growth Forest Fragments , 1999 .

[30]  Emilio M. Bruna,et al.  Habitat fragmentation and large‐scale conservation: what do we know for sure? , 1999 .

[31]  J. Oostermeijer,et al.  Relationships between Population and Habitat Characteristics and Reproduction of the Rare Gentiana pneumonanthe L. , 1998 .

[32]  J. Aber,et al.  Nitrogen Excess in North American Ecosystems: Predisposing Factors, Ecosystem Responses, and Management Strategies , 1998 .

[33]  E. Jules.  HABITAT FRAGMENTATION AND DEMOGRAPHIC CHANGE FOR A COMMON PLANT: TRILLIUM IN OLD-GROWTH FOREST , 1998 .

[34]  M. Fischer,et al.  Local Extinctions of Plants in Remnants of Extensively Used Calcareous Grasslands 1950 –1985 , 1997 .

[35]  O. Eriksson.  Regional dynamics of plants : a review of evidence for remnant, source-sink and metapopulations , 1996 .

[36]  Carol C. Horvitz,et al.  Spatiotemporal Variation in Demographic Transitions of a Tropical Understory Herb: Projection Matrix Analysis , 1995 .

[37]  M. Nowak,et al.  Habitat destruction and the extinction debt , 1994, Nature.

[38]  J. Oostermeijer,et al.  Population structure of the rare, long-lived perennial Gentiana pneumonanthe in relation to vegetation and management in The Netherlands , 1994 .

[39]  Ingrid M. Parker,et al.  Evaluating approaches to the conservation of rare and endangered plants , 1994 .

[40]  R. Hobbs,et al.  Biological Consequences of Ecosystem Fragmentation: A Review , 1991 .

[41]  P. Klinkhamer,et al.  The importance of small-scale disturbance for seedling establishment in Cirsium vulgare and Cynoglossum officinale , 1988 .

[42]  D. Whale.  HABITAT REQUIREMENTS IN PRIMULA SPECIES , 1984 .

[43]  R. Brys,et al.  Does nectar reward affect rarity and extinction probabilities of orchid species? An assessment using historical records from Belgium and the Netherlands , 2005 .

[44]  R. Brys,et al.  EFFECTS OF AGRICULTURAL LAND USE AND FRAGMENTATION ON GENETICS, DEMOGRAPHY AND POPULATION PERSISTENCE OF THE RARE PRIMULA VULGARIS, AND IMPLICATIONS FOR CONSERVATION , 2003 .

[45]  K. Holsinger.  Genetics, Demography and Viability of Fragmented Populations: Demography and extinction in small populations , 2000 .

[46]  H. Caswell,et al.  The Relative 'Importance' of Life-History Stages to Population Growth: Prospective and Retrospective Analyses , 1997 .

[47]  M. Brugman,et al.  Temporal and spatial variation in the demography of Gentiana pneumonanthe, rare perennial herb , 1996 .