Density-dependent dynamics of a dominant rain forest tree change with juvenile stage and time of masting

Although negative density dependence (NDD) can facilitate tree species coexistence in forests, the underlying mechanisms can differ, and rarely are the dynamics of seedlings and saplings studied together. Herein we present and discuss a novel mechanism based on our investigation of NDD predictions for the large, grove-forming ectomycorrhizal mast fruiting tree, Microberlinia bisulcata (Caesalpiniaceae), in an 82.5-ha plot at Korup, Cameroon. We tested whether juvenile density, size, growth and survival decreases with increasing conspecific adult basal area for 3245 ‘new’ seedlings and 540 ‘old’ seedlings (< 75-cm tall) during an approximately 4-year study period (2008–2012) and for 234 ‘saplings’ (≥ 75-cm tall) during an approximately 6-year study period (2008–2014). We found that the respective densities of new seedlings, old seedlings and saplings were positively, not and negatively related to increasing BA. Maximum leaf numbers and heights of old seedlings were negatively correlated with increasing basal areas, as were sapling heights and stem diameters. Whereas survivorship of new seedlings decreased by more than one-half with increasing basal area over its range in 2010–2012, that of old seedlings decreased by almost two-thirds, but only in 2008–2010, and was generally unrelated to conspecific seedling density. In 2010–2012 relative growth rates in new seedlings’ heights decreased with increasing basal area, as well as with increasing seedling density, together with increasing leaf numbers, whereas old seedlings’ growth was unrelated to either conspecific density or basal area. Saplings of below-average height had reduced survivorship with increasing basal area (probability decreasing from approx. 0.4 to 0.05 over the basal area range tested), but only sapling growth in terms of leaf numbers decreased with increasing basal area. These static and dynamic results indicate that NDD is operating within this system, possibly stabilizing the M. bisulcata population. However, these NDD patterns are unlikely to be caused by symmetric competition or by consumers. Instead, an alternative mechanism for conspecific adult–juvenile negative feedback is proposed, one which involves the interaction between tree phenology and ectomycorrhizal linkages.

Nochmals: Kult- und Kulturdenkmäler des Rheinischen Judentums [Rezension] : (s. S. 234 ff.)

Alex Lewin

Na 50 Nachlass Arthur Schopenhauer - 'Schopenhauer-Archiv', 234 - Dankesschreiben wegen Zusendung des Frankfurter Konversationsblattes

u.a.: Geburtstag Schopenhauers;

Na 50 Nachlass Arthur Schopenhauer - 'Schopenhauer-Archiv', 181 - Übersendung der Stadtlotterie von A. May

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Ms. Barth. 181 (Ausst. 67) - Evangelistarium

Vorbesitzer: Hartmann Becker; Margarethe von Appenheim; Bartholomaeusstift Frankfurt am Main

Ms. Praed. 181 - Expositio in Regulam beati Augustini

Vorbesitzer: Dominikanerkloster Frankfurt am Main

Ms.Ff.F.Stoltze 3. 234 - Brief von Georg Pingler an Friedrich Stoltze

Stoltze: Kur in Königstein

Ms.Ff.F.Stoltze 3. 181 - Brief von Georg Krumm an Friedrich Stoltze

Christine Retting, Ihr Tod, Stoltze, Georg Herwegh: "Einundzwanzig Bogen aus der Schweiz", Bruno Bauer, Ludwig Börne: "Menzel, der Franzosenfresser", Bitte um Beiträge für die Zeitschrift "Der Taunus", Didaskalia, Frankfurter Konversationsblatt, Samuel Zirndorfer, Vorschlag eines Briefwechsels

Na 1 Nachlass Max Horkheimer, 589 - Korrespondenzen mit Friedrich (Frederick) Pollock (p. VI 37, 181-431)

2 Briefe von Frederick Pollock an Theodor W. Adorno, Juni 1954; 1 Brief von Frederick Pollock an Rosenberg, 27.10.1954; 1 Brief von Lotte Steinberger an Frederick Pollock, 23.05.1954; 1 Brief von dem British Consulate General (Los Angeles) an Frederick Pollock, 27.03.1954; 1 Brief von Max Horkheimer an das British Consulate General (Los Angeles), 26.01.1954;

Ms. lat. oct. 181 - Magnum manuale rhetorum

Vorbesitzer: Antonius Fischer