Tuesday, August 5, 2008 - 3:20 PM

COS 38-6: Ever since warming: Topical gradients in plant ecology textbooks

Daniel C. Laughlin, Northern Arizona University

Background/Question/Methods Since the emergence of the first plant ecology textbook by Eugenius Warming in 1895, at least 30 other plant ecology textbooks have been published worldwide. I compare the great diversity of these textbooks to quantify how books differ in their emphases of certain topics and to understand how the emphasis of topics has changed over time. The textbooks chosen for the analysis were focused on plants, were not restricted to a particular community type, and were directed toward use as a teaching resource. I generated a “textbook x topic” matrix by calculating the proportion of each book that is dedicated to 35 topics in plant ecology. The “beta diversity” of this matrix was 2.0, suggesting only moderate turnover of topics among textbooks. I used nonmetric multidimensional scaling (NMS) to represent the Bray-Curtis distance matrix calculated from the data matrix. The final ordination extracted three important topical gradients in plant ecology textbooks and was able to represent 84% of the variation in the distance matrix.
Results/Conclusions One gradient represented a contrast between an emphasis on the topics of plant populations, competition, reproduction and dispersal (e.g., Harper 1977, Crawley et al. 1997) with an emphasis on soil ecology (e.g., Braun-Blanquet 1932, Stalfelt 1972). Another gradient represented a contrast between emphasizing functional anatomy and resource capture (e.g., Clements 1907, Lambers et al. 2000) with emphasizing diversity and applied ecology (i.e., conservation and management) (e.g., van der Maarel 2004, Keddy 2007). The third gradient represented a contrast between an emphasis on ecosystem ecology (e.g., Larcher 2003, Schulze et al. 2005) with an emphasis on community types and succession (e.g., Warming 1909, Daubenmire 1968). Textbooks not located at ends of gradients were more general and emphasized topics relatively equally (e.g., Barber et al. 1998, Gurevitch et al. 2006). Additionally, there were several important temporal trends. Population ecology grew in importance over time, whereas communities and successional dynamics have been emphasized equally over time.  There has been a general shift of focus away from plant anatomy toward a focus on ecosystem ecology, applied ecology, and biodiversity. This important topical shift illustrates how ecology has expanded its scale of inference from individuals to ecosystems. Additionally, this illustrates how important the ecological sciences have become for providing information to guide natural resource management. This information can be useful to students and professors alike in their search for applicable syntheses of the widely varied topic of plant ecology.