Ingrid Kottke

Gradients in a Tropical Mountain Ecosystem of Ecuador

Part I Introduction 1 The Ecosystem (Reserva Biologica San Francisco) E. Beck, F. Makeschin, F. Haubrich, M. Richter, J. Bendix, C. Valerezo 2 Mountain rain forests in southern Ecuador as a hotspot of biodiversity - Limited knowledge and diverging patterns G. Brehm, J. Homeier, K. Fiedler, I. Kottke, J. Illig, N.M. Noske, F. Werner, S-W. Breckle 3 The people settled around Podocarpus National Park P. Pohle 4 Ecuador suffers the highest deforestation rate in South America R. Mosandl, S. Gunter, B. Stimm, M. Weber 5 Methodological challenges of a megadiverse ecosystem G. Brehm, K. Fiedler, Ch. Hauser, H. Dalitz Part II Gradients in ecosystem analysis 6 Why investigating gradients in ecosystem analysis K. Fiedler, E. Beck 7 The investigated gradients E. Beck, R. Mosandl, M. Richter, I. Kottke Part III The altitudinal gradient Part III.1 Gradual changes along the altitudinal gradient 8 Climate J. Bendix, R. Rollenbeck, M. Richter, P. Fabian, P. Emck 9 Soils along the altitudinal transect and in catchments W. Wilcke, S. Yasin, A Schmitt, C. Valarezo, W. Zech 10 Flora: Composition and function 10.1 Potential vegetation and floristic composition of Andean forests in South Ecuador, with a focus on the RBSF J. Homeier, F. A. Werner, S. R. Gradstein, S -W. Breckle, M. Richter 10.2 Past vegetation and fire dynamics H. Niemann & H. Behling 10.3 Forest structure along an altitudinal gradient in southern Ecuador A. Paulsch, D. Piechowski, K. Muller-Hohenstein 10.4 Vegetation structures and ecological features of the upper timberline ecotone M. Richter, K.-H. Diertl, Th. Peters, R. W. Bussman 10.5 Mycorrhizal state and new and special features of mycorrhizae of trees, ericads, orchids, ferns andliverworts I. Kottke, A. Beck, I. Haug, S. Setaro, V. Jeske, J.P. Suarez, L. Paxmino, M. Preussing, M, Nebel, F. Oberwinkler 11 Fauna: Composition and function 11.1 Bird species distribution along an altitudinal gradient in southern Ecuador and its functional relationships with vegetation structure D. Paulsch and K. Muller-Hohenstein 11.2 Seed dispersal by birds, bats and wind F. Matt, K. Almeida, A. Arguero, C. Reudenbach 11.3 Variation of diversity patterns across moth families along a tropical elevational gradient K. Fiedler, G. Brehm, N. Hilt, D. Sussenbach, and C.L. Hauser 11.4 Soil fauna M. Maraun, J. Illig , D. Sandman,V. Krashevskaya, R.A. Norton, S. Scheu Part III.2 Processes along and within the gradient 12 Water relations W. Wilcke, S. Yasin, K. Fleischbein, R. Goller, J. Boy, J. Knuth, C. Valarezo, W. Zech 13 Nutrient status and fluxes at the field and catchment scale W. Wilcke, S.Yasin, K. Fleischbein, R. Goller, J. Boy, J. Knuth, C. Valarezo, W. Zech 14 Biotic soil activities S. Iost, F. Makeschin, M. Abiy, F. Haubrich 15 Elevational changes in stand structure and biomass allocation of tropical mountain forests in relation to microclimate and soil chemistry G. Moser, M. Roderstein, N. Soethe, D. Hertel, C. Leuschner 16 Stand structure, transpiration responses in trees and vines and stand transpiration of different forest types within the mountain rainforest M. Kuppers, T. Motzer,D. Schmitt., C. Ohlemacher, R. Zimmermann, V. Horna, B.I.L. Kuppers, T. Mette 17 Plant growth along the altitudinal gradient-role of plant nutritional status, fine root activity, and soil properties N. Soethe, W. Wilcke, J. Homeier, J. Lehmann, C. Engels Part III.3 Gradient heterogeneities Part III.3.A Spatial heterogeneities 18 Spatial

An in vitro method for establishing mycorrhizae on coniferous tree seedlings

SummaryA method for in vitro synthesis of mycorrhizae on coniferous tree seedlings is described. Tree seedlings (Larix decidua Mill., Picea abies (L.) Karst, and Pinus sylvestris L.) and fungi Amanita muscaria (L. ex Fr.) Hooker, Piloderma croceum Erikss. et Hjorst., Pisolithus tinctorius (Pers.) Coker et Couch, and Suillus grevillei (Klotzsch) Singer were maintained under sterile conditions in petri dishes. Typical ectomycorrhizae were established within 2–3 weeks after inoculation and within 2 months after germination of seedlings. Eventually a high percentage of mycorrhizal root tips was obtained.

Mycorrhiza of forest trees — structure and function

Comprehensive surveys on mycorrhizae have recently been published by Harley and Smith (1983) and Strullu (1985). Harley (1984) has also briefly summarized mycorrhizal associations in general, whilst Moser and Haselwandter (1983) reported on the ecophysiology and Duddridge (1985) on the interface in mycorrhizae of Agaricales. France and Reid (1983) presented a compilation of the current knowledge regarding the nitrogen and carbon physiology of ectomycorrhizae. The main interest of the present paper lies in the interpretation of the morphology and ultrastructure of ectomycorrhizae of forest trees in respect of their function in the uptake and exchange of nutrients. The protectional ability of mycorrhizae is also considered briefly. Recent studies have shown the surprising similarity in the structure of the Hartig net and significant differences in the structure of the mantles of different mycorrhiza-forming fungal species, thus confirming the early report by Mangin (1910). This review article therefore deals firstly with more general aspects, that is the structure and function of the Hartig net in respect to nutrient exchange and transport, and secondly with the more specialized structures of the hyphal mantle, including hyphal strands and rhizomorphs and their function in nutrient uptake and storage. Finally, developmental changes of structure and function and those caused by environmental conditions are discussed.

Toxic element filtering in Rhizopogon roseolus/Pinus sylvestris mycorrhizas collected from calamine dumps

Rhizopogon roseolus/Pinus sylvestris mycorrhizas collected from calamine dumps (rich in Cd, Zn and Pb) were analysed by electron energy loss spectroscopy (EELS) connected to a transmission electron microscope. The distribution of potentially toxic elements within selected mycorrhizas was shown. Complementary data were obtained by cytochemical tests revealing the distribution of polysaccharides (PATAg) and cysteine-rich proteins (Gomori-Swift reaction). The mycorrhizas investigated were characterized by the accumulation of Cd and Al in the fungal mantle and a gradual decrease of these elements was observed along the Hartig net towards the inside of the root, suggesting a filtering effect. Both of these elements were detected in the electron-opaque deposition in the vacuoles, in periplasmic spaces as well as in the extracellular material. A comparatively high level of these elements was found in the phenolic material of dead cortical cells. This was probably an additional source of toxic elements for the mycelium which was colonizing the tannin cells.

Mycorrhizal status of indigenous trees in dry Afromontane forests of Ethiopia

Abstract The dry Afromontane forests in Ethiopia are composed of a number of indigenous tree species. Currently, indigenous trees are declining at an alarming rate in this ecosystem. The few reforestation programs, which have so far been undertaken, employ exotic tree species. This is mainly due to lack of knowledge on the environmental requirements of indigenous trees. Though there have been efforts to solve problems associated with the use of indigenous trees in the reforestation activities, information on the mycorrhizal symbiosis is still lacking. Investigation of roots of 11 indigenous trees, Albizia gummifera , Albizia schimperiana , Aningeria adolfi - friedericii , Croton machrostachyus , Ekebergia capensis , Hagenia abyssinica , Juniperus procera , Podocarpus falcatus , Prunus africana , Olea europaea ssp. cuspidata , and Syzygium guineense , revealed arbuscular mycorrhizal colonization. No evidence of ectomycorrhizal colonization was found. This is the first report on the mycorrhizal status of A. gummifera , A. schimperiana , A. adolfi - friedericii , E. capensis , H. abyssinica , P. africana and S. guineense. The mycorrhizas are characterized by dominantly intercellular hyphal growth, formation of arbuscules on intracellular hyphal branches and low frequency of hyphal coils which can be classified as an Arum -type of AM. The Arum -type of AM is reported for the first time in S. guineense (Myrtaceae), E. capensis (Meliaceae), A. adolfi - friedericii (Sapotaceae) and the gymnosperms J. procera and P. falcatus . Results established that arbuscular mycorrhizas (AM) are predominant in the dry Afromontane forests of Ethiopia. Therefore, AM should receive special attention in indigenous tree seedling production and restoration activities of the dry Afromontane ecosystems of the country.

Subcellular localization of cadmium in the root cells of Allium cepa by electron energy loss spectroscopy and cytochemistry.

The ultrastructural investigation of the root cells ofAllium cepa L. exposed to 1 mM and 10 mM cadmium (Cd) for 48 and 72 h was carried out. The results indicated that Cd induced several obvious ultrastructural changes such as increased vacuolation, condensed cytoplasm with increased density of the matrix, reduction of mitochondrial cristae, severe plasmolysis and highly condensed nuclear chromatin. Electron dense granules appeared between the cell wall and plasmalemma. In vacuoles, electron dense granules encircled by the membrane were aggregated and formed into larger precipitates, which increase in number and volume as a consequence of excessive Cd exposure. Data from electron energy loss spectroscopy (EELS) confirmed that these granules contained Cd and showed that significantly higher level of Cd in vacuoles existed in the vacuolar precipitates of meristematic or cortical parenchyma cells of the differentiating and mature roots treated with 1 mM and 10 mM Cd. High levels of Cd were also observed in the crowded electron dense granules of nucleoli. However, no Cd was found in cell walls or in cells of the vascular cylinder. A positive Gomori-Swift reaction showed that small metallic silver grains were abundantly localized in the vesicles, which were distributed in the cytoplasm along the cell wall.

Axenic mycorrhization of wild type and transgenic hybrid aspen expressing T-DNA indoleacetic acid-biosynthetic genes

Abstract We describe and document the in vitro synthesis of ectomycorrhiza between roots of wild type and transgenic aspen (Populus tremula × P. tremuloides), expressing Agrobacterium tumefaciens T-DNA indoleacetic acid (IAA)-biosynthetic genes, and Amanita muscaria. Plantlets were raised from tissue culture. The root system of approximately 4-week-old plantlets was transferred to Petri dishes and incubated together with fungal mycelia under sterile conditions. Ectomycorrhiza showing both a well developed hyphal mantle and Hartig net were established within 3 to 4 weeks. Formation and morphology of ectomycorrhiza were not affected by the transformation of aspen, expressing the IAA biosynthetic genes in roots. As both hybrid aspen and fungal cells can be genetically engineered, this system offers a new approach to the study of mycorrhizal symbioses.

Arbuscular endomycorrhizas are dominant in the organic soil of a neotropical montane cloud forest

The ecology and forest management of tropical montane cloud forests of the Neotropics have attracted little scientific attention so far, and understanding of the ecosystem is still fragmentary (Churchill et al . 1995). The montane forests of southern Ecuador are an outstanding biodiversity hotspot for vascular plants (Barthlott et al . 1996), including a multitude of tree species (Madsen & Ollgard 1994). However, identification of species, studies of phenology, productivity, seed production and growth of seedlings have only just begun (Homeier & Breckle 2002). None of the trees has been investigated with respect to their mycorrhizal status, although it is well established that mycorrhizal symbioses are not only important for survival of trees in nutrient-poor habitats (Read 1991) and play a key role for nutrient cycling and nutrient retention in the humus layers (Medina & Cuevas 1993, Rilling et al . 2001), but also have an important impact on the composition of plant communities (Allen et al . 1995, Kottke 2002, van der Heijden et al . 1998).

Aluminium polyphosphate complexes in the mycorrhizal basidiomycete Laccaria bicolor: A 27Al-nuclear magnetic resonance study

The techniques of 27Al- and 31P-nuclear magnetic resonance (NMR) spectroscopy were used to investigate the interactions of aluminium with intracellular ligands within the mycelium of the ectomycorrhizal basidiomycete Laccaria bicolor (Maire) Orton (S238). The vegetative mycelium was grown on medium containing 0.5 mM AlCl3 for 0.5 to 3 d. The 27Al-NMR spectra showed that aluminium was rapidly taken up and accumulated into polyphosphate complexes in the vacuole. Comparison with Al-polyphosphate complexes obtained in vitro on model systems indicated that Al forms at least three mixed-solvation complexes with Pi and polyphosphates, that there is more than one complex present under any set of conditions, and that the equilibrium between these complexes shifts dramatically with Al concentration in the medium. The high phosphate concentrations in the growth medium favoured the accumulation of the Al-polyphosphate complexes. When mycelium containing Al-polyphosphate complexes was transferred to Al-free nutrient solution for 9 d, the Alpolyphosphate complexes were not remobilized. The sequestration of Al in the polyphosphate complexes could therefore make a significant contribution to the protection of mycorrhizal plants against aluminium toxicity.

Phenolics of mycorrhizas and non-mycorrhizal roots of Norway spruce

The occurrence and amount of soluble and insoluble phenolics in mycorrhizal and non-mycorrhizal roots of Picea abies (L.) Karst, were investigated, p-Hydroxybenzoic acid glucoside, picein, piceatannol and its glucoside, isorhapontin, catechin and ferulic acid could be identified by high-performance liquid chromatography in mycorrhizas of Picea abies-Lactarius deterrimus and Picea abies-Laccaria amethystea. Both types were collected from axenic cultures and the latter also from a spruce stand. The same phenolics occurred in non-mycorrhizal short roots from sterile cultures. However, the amounts of p-hydroxybenzoic acid glucoside, picein, catechin and cell wall-bound ferulic acid were considerably reduced in mycorrhizas from axenic culture, whereas the hydroxystilbenes piceatannol, its glucoside and worhapontin were not significantly reduced. Pure mycelia of Laccaria amethystea (Bull.) Murr, and Lactarius deterrimus Gröger were also analysed for phenolic compounds. Both fungal species contained none of the identified phenolics. The results are discussed with respect to mycorrhization in different mycorrhizal types.