Erfolgreiche Bekämpfung des Apfelschorfs mit Kalziumhydroxid

Zusammenfassung In einer 12-jährigen Apfelanlage mit den Sorten Elstar, Fiesta, Golden Delicious, Jonagold und Kent wurde im Jahre 2004 die Schorfbekämpfung durch Überkronenberegnung mit Suspensionen von Kalziumhydroxid (5 g/l) durchgeführt. Im Zeitraum 7. April bis 30. September 2004 wurde insgesamt 62-mal für 15 min beregnet. Drei verschiedene Zeitpunkte der Behandlungen wurden getestet. Bei Behandlung A wurde mit der Beregnung begonnen, wenn nach Mills 100% Infektion erreicht waren. Bei den Behandlungen B und C wurde die Beregnung 6 bzw. 20 h später gestartet. Bei den nicht behandelten Kontrollen waren zum Zeitpunkt der Ernte bei Golden Delicious 30% und bei Jonagold 23% der Früchte mit Schorf befallen. Die Kontrollbäume der anderen Sorten hatten keinen Fruchtschorf. Die Früchte der drei Behandlungen waren bei der Ernte und nach einer 7,5-monatigen Lagerung im Kühllager oder im ULO-Lager frei von Schorf. Die Bonitur auf Schorfbefall der Blätter erfolgte zum Zeitpunkt der Ernte an 3 Langtrieben pro Baum mit je etwa 20–25 Blättern. Bei der Ernte im September/Oktober wurden bei allen Kontrollen Schorfflecken gefunden. Die Extreme reichten von 20 bis fast 60% befallene Blätter. Die Blätter der Langtriebe aller Behandlungen waren schorffrei. Bei den Behandlungen hatten die Blattunterseiten im Mittel bis zu 15% Schorfläsionen. Das liegt vermutlich daran, dass bei der Überkronenberegnung die Blattunterseiten nicht vollständig benetzt wurden. Die Ergebnisse zeigen, dass Schorfbekämpfung mit Überkronenberegnung von Kalziumhydroxid möglich ist.     

Für eine Verdopplung der Ca-Gehalte der Äpfel sind auch unter günstigen Bedingungen mindestens 12 Spritzungen mit Kalziumchlorid erforderlich

Zusammenfassung Siebenjährige Apfelbäume der Sorten Elstar, Gala, Karmijn de Sonnaville, Pinova und Pilot wurden 2003 von Juni bis September 12-mal mit 400 l/ha CaCl₂-Lösungen gesprüht. Kontrollen (Fu) waren Bäume, die nur mit Fungiziden (Discus, Dithane Ultra oder Kumulus) behandelt wurden. Bei den Behandlungen FuCa wurde den Fungiziden CaCl₂ (ansteigend von 5–25 g/l) zugegeben. Die Behandlungen FuCaTe enthielten zusätzlich das Netzmittel Plantacare 1200 UP, um die Benetzung der Früchte (Oberflächenspannung 29–30 mN/m) zu verbessern. Die Ca-Konzentrationen in den Kontrollfrüchten (Schale plus 5 mm Fruchtfleisch) variierten von 3,6 (Elstar) bis 9,0 mg/100 mg Frischsubstanz (Pilot). Durch die Fruchtdüngung (FuCa) stiegen die Konzentrationen auf 6,3 bzw. 13,3 mg/100 g Frischsubstanz (FS). Zugabe des Netzmittels (FuCaTe) erhöhte die Ca-Gehalte weiter auf 6,8 bzw. 14,9 mg/100 g FS. Bezogen auf die Behandlung Fu entspricht das einer Erhöhung der Ca-Konzentrationen der Früchte auf 163 bzw. 193%. Der Tensideffekt auf die Ca-Konzentrationen der Früchte wird auf die schnellere Penetration des CaCl₂ infolge besserer Benetzung zurückgeführt, da ein Einfluss auf die Retention der Spritzbrühe ausscheidet. Von der applizierten Ca-Dosis in Höhe von 26 kg/ha wurden nur 2,3 kg in den Früchten (50 t/ha) wieder gefunden, was einer Wiederfindungsrate von 8,8% entspricht. Die beobachtete Erhöhung der Ca-Konzentrationen der Früchte durch 12 Spritzungen dürfte in der Nähe des maximal Möglichen liegen, da die Witterungsbedingungen günstig und die Ca-Konzentrationen der Spritzbrühen hoch waren.     

Scale dependence of tree abundance and richness in a tropical rain forest,Malaysia

Abundance and richness are the two fundamental components of speciesdiversity. They represent two distinct types of variables of which the formerisadditive when aggregated across scales while the latter is nonadditive. Thisstudy investigated the changes in the spatial patterns of abundance andrichnessof tree species across multiple scales in a tropical rain forest of Malaysiaandtheir variations in different regions of the study area. The results showedthatfrom fine to coarse scales abundance had a gradual and systematic change inpattern, whereas the change in richness was much less predictable and ahotspot in richness at one scale may become acoldspot at another. The study also demonstrated that differentmeasures of diversity variation (e.g., variance and coefficient of variation)can result in different or even contradictory results which further complicatedthe interpretation of diversity patterns. Because of scale effect the commonlyused measure of species diversity in terms of unit area (e.g.,species/m²) is misleading and of little use in comparing speciesdiversitybetween different ecosystems. Extra care must be taken if management andconservation of species diversity have to be based on information gathered at asingle scale.This revised version was published online in May 2005 with corrections to the Cover Date.     

Eintritt für Selbstpflücke, ein Kontinent ohne Frigopflanzen und ‘Elsanta‘

Zusammenfassung Die im Wachstum begriffene australische Erdbeerindustrie ist geprägt durch optimale Klimabedingungen und einfachen Zugang zu den Ressourcen, hohe Intensivierung und — wie in Kalifornien — hohe Erträge über 30 t/ha. Der Markt ist fast autark, Im- und Exporte frischer Erdbeeren spielen keine Rolle. Mit einem derzeitigen Produktionsvolumen von 40.000 t/Jahr auf ca. 1.300 ha wird eine Ausweitung auf 71.000 t bis zum Jahre 2008 angestrebt. Dies entspricht — bei ca. 20 Mio. Einwohnern Australiens — einer Steigerung des Erdbeerkonsums von 2,0 kg auf ca. 2,7 kg/Kopf und Jahr im Jahr 2008. Der gegenwärtige Erdbeerkonsum in Deutschland liegt bereits bei ca. 2,7 kg/Kopf und Jahr, wobei die Erdbeerimporte von ca. 120.000 t die Eigenproduktion von ca. 100.000 t auf 10.420 ha Anbaufläche — im Gegensatz zu Australien — übersteigen. Die drei australischen Hauptanbaugebiete konzentrieren sich auf Queensland im Nordosten, Perth im Westen und Victoria im Südosten Australiens. Der überwiegend einjährige Anbau erfolgt mit 45.000–66.000 Grünpflanzen/ha als Einzel- oder Doppelreihe in Dammkultur und Mulchfolie mit integriertem Fertigationsschlauch. Nach telefonischem Verkauf erfolgt die Lieferung im Kühl-LKW direkt an die Supermärkte oft weit entfernter Großstädte. Als tagneutrale Erdbeersorten dominieren mit 90% amerikanische Sorten wie Selva, Camarosa und Camino Real aus Kalifornien sowie Sweet Charlie und Festival aus Florida. Interessante Neuzüchtungen aus dem Jahre 2003 sind Rubygem, Sugarbaby, Brighteyes und Harmony aus Queensland als Kurztagssorten. Zusammen mit tagneutralen Sorten aus dem südlichen Züchtungsprogramm in Victoria stieg ihr Marktanteil in den letzten drei Jahren von 8% auf 10%. Primäre Zuchtziele des nördlichen Züchtungsprogramms in Queensland sind Kurztagssorten mit frühem Reifebeginn und hohem Ertrag über 1,2 kg/Pflanze. Das südliche Züchtungsprogramm um Victoria zielt dagegen sowohl auf Kurztagssorten als auch Tagneutralität sowie eine zusätzlich lange Ernteperiode über mindestens 10 Wochen. Während die Zuchtziele der äußeren Fruchtqualität wie Fruchtgröße, Fruchtfestigkeit und Glanz mit denen Deutschlands übereinstimmen, unterscheiden sich die der inneren Fruchtqualität wie süßer Geschmack bei gleichzeitiger Säurearmut und hoher Fruchtfleischfestigkeit.     

Introduction

The realization of strategies for sustainable land use assumes specificresearch concepts from the local to the global scale (micro-, meso- andmacroscale). Therefore, landscape ecological science has to provideinvestigation methods for all these different scales. By combiningtop-down and bottom-up approaches in addition tocoupled GIS-model applications and traditional methods, the investigation oflandscape ecological structures and processes seems to be possible. Thepresented studies show this approach on examples of two study areas in EasternGermany: A watershed of 400 km² and an administrativedistrict of about 4000 km². The scale-specificapplicability of several models and methods were tested for theseinvestigations, and the validation of the calculated results are presented. Animportant outcome of the project should be the prevention of conflicts betweenagriculture, water management and soil, and water and nature conservation;based onrecommendations for land use variants with decreased pollutant loading withinagricultural areas. The scale specific investigations can be considered as abase for establishing sustainable land use.This revised version was published online in May 2005 with corrections to the Cover Date.     

Gap analysis: concepts,methods, and recent results*

Rapid progress is being made in the conceptual, technical, and organizational requirements for generating synoptic multi-scale views of the earth's surface and its biological content. Using the spatially comprehensive data that are now available, researchers, land managers, and land-use planners can, for the first time, quantitatively place landscape units – from general categories such as Forests or Cold-Deciduous Shrubland Formation to more categories such as Picea glauca-Abies balsamea-Populus spp. Forest Alliance – in their large-area contexts. The National Gap Analysis Program (GAP) has developed the technical and organizational capabilities necessary for the regular production and analysis of such information. This paper provides a brief overview of concepts and methods as well as some recent results from the GAP projects. Clearly, new frameworks for biogeographic information and organizational cooperation are needed if we are to have any hope of documenting the full range of species occurrences and ecological processes in ways meaningful to their management. The GAP experience provides one model for achieving these new frameworks.     

A case study of forest change in the Swiss lowlands

This paper presents a regional case study of forest development and the history of forest use and management in the north-eastern lowlands of Switzerland during the 19th and 20th centuries. The analysis draws on historical documents related to forestry to consider the following aspects of forest change: forest types, growing stock, trees species composition and non-timber forest uses. Based on the data presented, three overlapping periods of forest use and management can be discerned. The period of traditional multiple use lasted until the second half of the 19th century. From the mid 19th to the mid 20th century, a period of primacy of timber production occurred. During the 20th century, the period of modern multi-impact management has developed. For these three periods, groups of main actors, their needs and interests, and how they were causing the changes in the aspects under study were defined. This procedure of defining periods and the respective groups of main actors is a critical link between landscape ecology and history, as changes in demands of the society can be directly linked with changes in land-use and land-cover.     

Spatial theory in early conservation design: examples from Aldo Leopold’s work

Aldo Leo­pold is well known in North America as a conservationist, author, and promoter of the Land Ethic. Although Leo­polds work is rarely included in the realm of landscape ecology, he left several illustrations of an early spatial theory for conservation. While European geographer Troll published the term landscape ecology in 1939, Leo­pold was discovering the role of spatial configuration in European working landscapes, and began to apply the landscape ecology concepts to wildlife management and cooperative conservation in the US. With his own spatial language he wrote, mapped, and applied elements of pattern, process, and connectedness in the landscape. In this perspective piece I use three examples from Leo­polds work to demonstrate his contribution to spatial theory in early conservation design. First, this paper deciphers spatial elements conveyed through Leo­polds writing, drawing, and teaching in the early 1930s. Second, I re-interpret Leo­polds observations of the spatial design of remises from his visit to Silesia, Europe. Third, I show how the lessons from Silesia were applied to a landscape in Wisconsin, USA, involving both farmers and townspeople in cooperative implementation of a remise system. Collectively, a new perspective emerges on the early dialogue of landscape ecology and conservation across continents.This revised version was published online in May 2005 with corrections to the Cover Date.     

Using spatial analysis to drive reserve design: a case study of a national wildlife refuge in Indiana and Illinois (USA)

Our refuge design strategy involves a landscape approach formulated to complement existing management efforts and employ restoration in the heavily degraded Kankakee River watershed in northeastern Indiana and northwestern Illinois. The watershed historically contained an approximately 400,000 ha wetland (Grand Marsh), a diverse riverine system, oak savanna, and prairie. Today only fragments of these habitats remain. The U.S. Fish and Wildlife Service developed a preliminary project proposal (PPP) during the summer of 1996 to protect and restore habitat within the watershed by establishing the Grand Kankakee Marsh National Wildlife Refuge. The Indiana and Illinois Gap Analysis projects provided the resources to move beyond the expert workshop approach to a data-driven method for initial reserve design. Using visual analysis of various Gap Analysis data layers, we established Focus Areas that formed the basis for the Environmental Assessment and the Economic Impact Study required under the National Environmental Policy Act (NEPA). We have initiated Phase II of the reserve design analysis using preliminary results of the Indiana Gap Analysis project and C-Plan software in conjunction with the New South Wales National Parks and Wildlife Service.     

The ocean ‘landscape’

The ocean has a complex physical structure at all scales in space and time, with peaks at certain wave numbers and frequencies. Pelagic ecosystems show regular progressions in size of organisms, life cycle, spatial ambit, and trophic status. Thus, physiological and ecological parameters are closely coupled to spatial and temporal physical scales.     

Pseudoreplication: a sine qua non for regional ecology

We question whether classical experimentation is adequate for real progress in landscape or regional ecology. One cannot do classical experimentation unless one can replicate the treatment. There is conflict between the need to replicate and the need to study processes at appropriately large scales.Because of the difficulties in doing controlled field experiments at regional scales, we propose that landscape ecologists take greater advantage of natural field experiments. Natural experiments must be coordinated, standardized, and synchronized over space and through time, and will require the cooperation of multiple investigators. Distributed computer networks can help provide the automated region-wide monitoring which will supply natural experiments with pre-treatment data.Regions or landscapes need not be replicated, and indeed, cannot be. One can achieve a relational understanding between a system's response and environmental characteristics. This understanding is not definitive, but allows for the development of testable hypotheses, in the classical sense. The confounding of space, time, and/or other environmental factors in pseudoreplicated natural experiments only allows for the development of hypotheses - how-possibly explanations. Discrimination among competing hypotheses can be done at smaller scales and used to infer processes occurring at larger scales. Use of natural and controlled field experiments in complementary roles is a more promising approach than views of one or the other as methodologically inferior.     

Allochthonous ecosystems

In extreme deserts with precipitation of less than 10–20 mm/yr, biocoenoses occur which are void of producers but show ecosystem functions such as food chains and energy flow. Since they are fed by the importation of allochthonous organic material the term allochthonous ecosystems is proposed to designate these systems. The application of this term to other incomplete ecosystems without producers is discussed.     

Landscape changes and breeding bird assemblages in northwestern Portugal: the role of fire

Fire is a major driving force of landscape change in the Mediterranean region. The objectives of this paper were to explore the implications of landscape change and wildfires in a region of northwestern Portugal for the diversity of breeding birds. Land use cover for the years 1958, 1968, 1983 and 1995 was obtained from aerial photography for a study area of 3700 ha. Breeding bird assemblages in each of six land use categories were characterized in 1998 using point counts. The main landscape changes in the study area across the 40 years were a decrease in the area of agricultural land and low shrublands (respectively 29% and 48%) and an increase in forests and tall shrublands (both over 95%). Bird assemblages showed increased richness and diversity across the gradient: low shrublands tall shrublands conifer mixed deciduous agricultural areas. Many of the species with narrow niche breadth (specialists) were associated with agricultural areas and deciduous forests. In spite of the low diversity of burned areas (mostly shrublands) a few specialist species depend on this habitat. Thus, the current fire regime probably contributes to maintaining bird diversity at the landscape level. There was an inverse relationship between landscape diversity and estimated bird diversity across the last 40 years. Landscape management actions to preserve bird diversity should focus on the maintenance of agricultural land and deciduous forests. In parallel, a wider use of prescribed burning and grazing is suggested. This would contribute to maintaining low shrublands in the landscape, useful both as an habitat for some bird species and as fuel breaks for preventing the occurrence of large wildfires.     

Effects of patch shape on the number of organisms

This study examined effects of habitat patch shape on the abundance of organisms. The effects of patch shape were considered in terms of (1) immigration and emigration of organisms. (2) the amount of available resources in a patch and (3) spatial and temporal heterogeneity of the organisms and environment. I hypothesized that (1) the number of organisms would increase as patch shape elongates because organisms are more likely to encounter an elongated patch, (2) the number of organisms in a patch would remain constant for all patch shapes where the number of organisms in a patch was limited by the amount of resources, because patch shape does not change the patch area that is directly associated with the amount of patch resources, and (3) spatial and temporal variation of the abundance of organisms would increase as patch shape elongates because an elongated patch is more likely to interact with the variable surrounding matrix.Common millipedes,Oxidus gracilis, and their habitat, plywood boards of five shapes (width:length ratio; 11, 14, 19, 136, 1144) with an area of 900 cm² were placed in forest and old field and the number of millipedes appearing under the boards was monitored. Significantly higher mean number of millipedes under the boards was observed at a patch with an elongated shape in the forest and the old field. A significant positive correlation was observed between perimeter length of a patch and the number of millipedes in the old field. The temporal and spatial variation of the number of millipedes was high in the old field. The spatial and temporal variation was higher for boards with elongated shape.     

Bestimmung der S-Allele in Brennkirschensorten (Prunus avium L.)

Zusammenfassung Brennkirschen sind Süßkirschensorten, welche spezielle Eigenschaften für die Branntweinproduktion und die industrielle Verarbeitung besitzen. Ihr Hauptanbaugebiet in Deutschland befindet sich in Baden-Württemberg und in Teilen Bayerns. In den letzten Jahren wurde über einen geringen Fruchtbehang in neu gepflanzten Brennkirschenanlagen berichtet. Süßkirschen sind selbstinkompatibel und benötigen deshalb eine Bestäubersorte. Ursache ist ein gametophytischer Selbstinkompatibilitätsmechanismus, bedingt durch einen S-Lokus. Mit Hilfe molekularer Marker wurden deshalb Untersuchungen zu den S-Allel-Kombinationen in 62 Brennkirschensorten bzw. -herkünften aus dem Raum Oberkirch, Mittelbaden, durchgeführt. Im Ergebnis konnten zwei bisher noch nicht beschriebene S-Allele und 14 neue Inkompatibilitätsgruppen ermittelt werden. Ursache für den schlechten Fruchtansatz in neuen Kirschenanlagen mit den Hauptsorten Dolleseppler und Benjaminer sind die gleichen S-Allel-Kombinationen (S₁S₇) in beiden Sorten. Als mögliche Befruchtersorten werden die Sorten Schwarze Schüttler (S₆S₇), Hartwälder (S₄S₇), Feuerkirsche (S₄S₁₄) und die ehemalige Sorte Dolleseppler der Baumschule Kiefer (S₁S₄) empfohlen.     

The use of herders’ accounts to map livestock activities across agropastoral landscapes in Semi-Arid Africa

Improved understandings of the agricultural and range ecologies ofsemi-arid Africa require better information on the spatiotemporal distributionof domestic livestock across agropastoral landscapes. An empirical GIS-basedapproach was developed for estimating distributions of herded livestock acrossthree agropastoral territories (around 100 km² each)over a two-year period. Algorithms developed from regression analyses of herdtracking data (with R²s 0.67) are used to transform a morecomprehensive but incomplete set of data generated from herders accounts oftheir herds grazing itineraries (400 herds following 6500 itineraries). Theresulting characterization registers 40 000 days of livestock activitiesacross694 land units (averaging 70 ha) over the study period. This studydemonstrates that rural producers knowledge of their daily extractionpracticescan be translated to fine-grained characterizations of extraction densitiesacross mixed landscapes. The spatiotemporal distribution of livestock that isrevealed by this approach diverges strongly from that predicted bycommonly-usedpoint-diffusion estimation procedures. Instead, the distribution reflects localpatterns of land use, topography, vegetation, settlements, and water points.Grazing and nongrazing times spent in land units are not spatially correlatedand the seasonality of grazing pressure is spatially variable. Therefore, theecological impacts of livestock grazing are spatially variable at fine scalesand there is a significant potential for livestock-mediated nutrient transfersacross agropastoral landscapes. The georeferenced data produced by thisapproachnot only will help evaluate the impact and sustainability of differentmanagement practices but also provides a strong empirical base for improvedspatial modeling of herded livestock.This revised version was published online in May 2005 with corrections to the Cover Date.     

A model of arctic tundra vegetation derived from topographic gradients

We present a topographically-derived vegetation model (TVM) that predicts the landscape patterns of arctic vegetation types in the foothills of the Brooks Range in northern Alaska. In the Arctic there is a strong relationship between water and plant structure and function and TVM is based on the relationships between vegetation types and slope (tan ) and discharge (), two independent variables that can be easily derived from digital terrain data. Both slope and discharge relate to hydrological similarity within a landscape: slope determines the gravitational hydrological gradient and hence influences flow velocity, whereas discharge patterns are computed based on upslope area and quantify lateral flow amount. TVM was developed and parameterized based on vegetation data from a small 2.2 km² watershed and its application was tested in a larger 22km² region. For the watershed, TVM performed quite well, having a high spatial resolution and a goodness-of-fit ranging from 71–78%, depending on the functions used. For the larger region, the strength of the vegetation types predictions drops somewhat to between 56–59%. We discuss the various sources of error and limitations of the model for purposes of extrapolation.     

Die Zukunft: krankheitsresistente Apfelsorten

Zusammenfassung Integrierte und biologische Anbauverfahren gewinnen zunehmend an Bedeutung. Die Anwendung von Pflanzenschutzmitteln gestaltet sich zunehmend schwieriger bezüglich ihrer Bereitstellung als auch im Hinblick auf zunehmende Umweltsensibilität der Bevölkerung. Im Obstbau ist eine der Alternativen der Anbau resistenter Sorten, die mit weit weniger Pflanzenschutzaufwand produziert werden können. Eines der Ziele der Pillnitzer Obstzüchtung war die Kombination von hoher Fruchtqualität mit guter Ertragsleistung und Resistenz gegenüber Krankheiten und Schädlingen. Resistente früh, mittel und spät reifende Sorten, die Re-Sorten^®, konnten ausgelesen werden. Sie garantieren einen hohen Resistenzgrad unter Feldbedingungen, sie sind aber nicht immun. Dreifachresistente Sorten mit Widerstandsfähigkeit gegenüber Schorf, Mehltau und Feuerbrand sind: Remo, Regia, Rewena und Rebella. Rebella besitzt weiterhin Resistenz gegenüber Rindenbrand, Rote Spinne und abiotische Stressfaktoren. Obwohl in Mitteleuropa seit 1984 verschiedentlich Resistenzdurchbrüche an schorfresistenten Sorten mit M.-floribunda-Resistenz (V_f) beobachtet wurden, blieben die Sorten mit anderer genetischer Basis befallsfrei, so u. a. Reglindis (V_A), Reka (V_r) oder Regia (V_r). Als künftiges Ausgangsmaterial für die Züchtung wurde in der Genbank Obst nach weiteren Resistenzträgern unter den Malusarten und alten Apfelsorten gesucht, das in Zukunft durch Pyramidisierung von Resistenzgenen bei der Züchtung neuer Sorten zu mehr Stabilität unter Feldbedingungen beitragen kann.     

Coincidences between different landscape ecological zones and growth forms of Cembran pine (Pinus cembra L.) in subalpine habitats of the Central Alps

The forgotten depots of the European Nutcracker (Nucifraga c. caryocatactes) often lead to the development of tufts of Pinus cembra. In many cases the other individuals of such tufts are not suppressed by the fittest one, rather there is an intraspecific coexistence up to the senescent stage of the trees. There are fusions of separate trunks, and so frequently the individual history of older trees can only be reconstructed by studying sutures, crown structures or trunk cross sections. Different types of trunk fusions are worked out. By means of transect counting the occurrence of these multiple trunk trees is documented quantitatively in different landscape ecological zones of the Engadin region (the Grisons, Switzerland). The data base is 3024 counted microsites of Pinus cembra individuals arising from seeds, including 5272 living individuals. These multiple trunk trees significantly play an important role in the landscape ecological zones of recent glacier recession and at the alpine timberline. Their growth forms have a higher biomechanical stability.