Forest-grassland transitions : How livestock and fire shape grassy biomes
Bernardi, Rafael E. - \ 2017
Wageningen University. Promotor(en): M. Scheffer, co-promotor(en): M. Holmgren; Matías Arim. - Wageningen : Wageningen University - ISBN 9789463436212 - 129
forests - grasslands - fire - cattle - livestock - subtropics - south america - trees - bossen - graslanden - brand - rundvee - vee - subtropen - zuid-amerika - bomen
Plant associations are determined by complex interactions with their environment depending on resource availability, landscape features, and periodic disturbances that shape the structure and functions of these communities. Forests, savannas and grasslands extend across the global land surface, contribute to planetary processes and provide ecosystems services sustaining local production. However, the factors that explain the distribution of trees and determine these biomes are still not well understood. In this thesis, long-standing questions about the origins and distribution of these ecosystems are discussed in light of new evidence suggesting that a feedback of fire and grasses may maintain forests, savannas and grasslands as alternative tree cover states. I also address how anthropogenic land use, including the introduction of livestock, may be affecting these dynamics, particularly in the neotropics, with consequences in terms of potential transitions in tree cover regimes.
I analyze the distribution of trees in the grasslands of subtropical South America, looking at what may determine current tree cover and change dynamics (Chapters 2 & 3). The results suggest that, in non-cultivated areas, the expansion of trees into grasslands is likely limited by fire, livestock and precipitation, and that livestock likely reduces fire frequency (Chapter 2). The analyses also suggest that in the Uruguayan Campos of southeastern South America, where fire frequency is low and livestock densities are high, a release in livestock density may cause a moderate expansion of forests into grasslands (Chapter 3). To understand the consequences of a potential transition to higher tree cover by increasing precipitation, I looked at the effects of tree cover in subtropical rangelands (Chapter 5). The results indicated that isolated trees can improve the forage quality and abundance of these rangelands, with potential benefits in terms of biodiversity and ecosystem services. Lastly, I analyzed correlational patterns relating livestock density to vegetation structure across the global tropics and subtropics (Chapter 4), in an attempt to generalize the findings of Chapter 2. The results indicate that extensive livestock systems reduce fire frequency and impact vegetation structure, maintaining savannas and grasslands with low tree cover, low fire frequency and a higher presence of shrubs and dwarf trees.
Manure management in the (Sub-)Tropics : training manual for extension workers
Teenstra, E.D. ; Buisonjé, F.E. de; Ndambi, A. ; Pelster, D. - \ 2015
Lelystad : Wageningen UR Livestock Research (Livestock Research report 919) - 41
dierlijke meststoffen - bedrijfsvoering - opleiding - voorlichters - veehouderij - verontreiniging - duurzame ontwikkeling - subtropen - handboeken - animal manures - management - training - extension agents - livestock farming - pollution - sustainable development - subtropics - handbooks
Having identified a general lack of knowledge about the value of livestock manure and integrated manure management at multiple levels in government and society, a concerted action led to the compilation of a training manual for extension workers on manure management in the (sub-)tropics. Covering the whole manure chain, from animal excretion to the final application, the manual describes the basic principles of integrated manure management. Although much information originates from more temperate regions, the manual focusses on farm practices in the tropics and subtropics.
Sustainable potato production: guidelines for developing countries
Lutaladio, N. ; Ortiz, O. ; Haverkort, A.J. ; Caldiz, D.O. - \ 2009
Rome : FAO - ISBN 9789251064092 - 94
solanum tuberosum - aardappelen - gewasproductie - agronomie - landbouwplantenteelt - plantenziektekunde - duurzaamheid (sustainability) - ontwikkelingslanden - tropen - subtropen - solanum tuberosum - potatoes - crop production - agronomy - crop husbandry - plant pathology - sustainability - developing countries - tropics - subtropics
During the International Year of the Potato, celebrated in 2008, FAO and CIP helped forge partnerships worldwide to address critical aspects of sustainable potato production. This technical guide collates that experience to review technical, socio-economic, policy and institutional factors that currently constrain increased potato production and productivity in tropical and subtropical countries. It presents Good Agriculture Practices relevant to potato production, and indicators and recommendations for action in key areas, from the utilization of potato biodiversity and improvements in seed systems, to soil management, insect pest and disease control and opportunities for value addition. It outlines a new policy and research agenda for the potato subsector that aims at making a real contribution to the eradication of hunger and poverty.
Application of biotechnology and molecular biology and breeding : General breeding and breeding and evaluation of temperate zone fruits for the tropics and subtropics
Plas, L.H.W. van der; Bockstaele, E. van - \ 2000
In: Proceedings of the XXV International Horticultural Congress International Society for Horticultural Sciences (ISHS) (Acta Horticulturae 522) - ISBN 9789066058637 - p. 253 - 253.
biotechnologie - moleculaire biologie - plantenveredeling - fruitgewassen - tropen - subtropen - biotechnology - molecular biology - plant breeding - fruit crops - tropics - subtropics
Bridging the gap between plant physiology and breeding : identifying traits to increase wheat yield potential using systems approaches
Bindraban, P.S. - \ 1997
Agricultural University. Promotor(en): R. Rabbinge; H. van Keulen. - S.l. : Bindraban - ISBN 9789054857525 - 135
triticum aestivum - tarwe - hexaploïdie - oogsttoename - oogstverliezen - opbrengsten - groei - plantenontwikkeling - bladeren - milieufactoren - genetische variatie - modellen - onderzoek - tropen - subtropen - triticum aestivum - wheat - hexaploidy - yield increases - yield losses - yields - growth - plant development - leaves - environmental factors - genetic variation - models - research - tropics - subtropics
Part of the required increase in wheat production in currently high yielding wheat producing regions, like in the (sub-)tropics (ME1), will have to be obtained primarily by increased genetic wheat yield potential. Progress obtained by breeding to increase yield potential was substantial in the past, but is currently declining. Support from other disciplines to improve breeding efficiency is urgently needed. A systems approach was applied to identify processes that determine wheat growth and yield, and traits that need to be adapted to increase genetic yield potential for ME1 conditions. Increasing biomass through leaf nitrogen affords little opportunity to obtain gains under optimum management conditions. Growth analysis suggested the source capacity of wheat to exceed yield at higher yield levels, while remobilization of stem reserves was needed to supplement grain demand at lower yield levels. The latter aspect was confirmed in an analysis of stem reserve dynamics. Despite sufficient assimilate production, remobilization also occurred at higher yield levels, suggesting other processes, like wasteful respiration and negative feedback on photosynthesis, to become important. Also, higher amounts of residual reserves were found under higher than under lower yield levels. These results indicate that wheat yields under optimum conditions in ME1 are limited by sink capacity, as source capacity is abundant. Sink capacity can be increased by increasing kernel number or weight. Kernel number is determined between early booting and final anthesis, and depends on the duration and the crop growth rate of this period and on the allocation to the spike. Required adjustments to increase kernel number depend on enviromnental conditions. Competition among kernels for carbohydrates limited their growth, in particular those positioned further away from the rachis. This may be due to an inadequate transport system. Without competition, yields were assessed to increase at least one ton per hectare over a wide range of enviromnental conditions. It is concluded that increase in wheat yield potential under ME1 conditions should be obtained by increased sink capacity, which may be realized through the adaptation of the spike morphology. Sufficient genetic variation of this trait is at hand to be incorporated in a breeding program.
|Livestock and the environment : finding a balance
Verheijen, L.A.H.M. ; Wiersema, D. ; Hulshoff Pol, L.W. ; Brandjes, P.J. ; Wit, J. de; Meer, H.G. van der; Bos, J.J.F. ; Westra, P.T. ; Nell, A.J. ; Jansen, J.C.M. - \ 1996
Wageningen : IAC
azië - agrarische bedrijfsvoering - agrarische bedrijfsplanning - kunstmeststoffen - irrigatie - mest - gemengde landbouw - natuurlijke hulpbronnen - voedingsstoffen - bescherming - herstel - hulpbronnengebruik - subtropen - duurzaamheid (sustainability) - tropen - asia - farm management - farm planning - fertilizers - irrigation - manures - mixed farming - natural resources - nutrients - protection - rehabilitation - resource utilization - subtropics - sustainability - tropics
Comprehensive study on interactions between livestock production systems and the environment. Management of waste from animal product processing is the main subject
|Modelling effects of water conservation tillage in the semi arid tropics.
Stroosnijder, L. ; Hoogmoed, W.B. ; Berkhout, J.A.A. - \ 1994
In: Bilan hydrique agricole et secheresse en Afrique tropicale : vers une gestion des flux hydriques par le systeme de cultures : seminaire international, Bamako, 9 - 13 decembre 1991 / Reyniers, F.N., Netoyo, L., - p. 235 - 251.
erosiebestrijding - modellen - onderzoek - zaaibedbereiding - bodembescherming - subtropen - grondbewerking - tropen - waterbescherming - erosion control - models - research - seedbed preparation - soil conservation - subtropics - tillage - tropics - water conservation
Integrated crop management of hot pepper (Capsicum spp.) in tropical lowlands
Vos, J.G.M. - \ 1994
Agricultural University. Promotor(en): J.C. Zadoks; H.D. Frinking. - S.l. : Vos - ISBN 9789054853176 - 188
bestrijdingsmethoden - plantenplagen - plantenziekten - geïntegreerde plagenbestrijding - geïntegreerde bestrijding - capsicum annuum - capsicum frutescens - spaanse pepers - tropen - subtropen - paprika - control methods - plant pests - plant diseases - integrated pest management - integrated control - capsicum annuum - capsicum frutescens - chillies - tropics - subtropics - sweet peppers
Hot pepper ( Capsicum spp.) is the most important low elevation vegetable commodity in Indonesia. Yields are low, in part due to crop health problems. Farmers' practices were surveyed by means of exploratory surveys. Hot pepper pests and diseases were identified and described. Components of integrated crop management (ICM) of hot pepper were investigated, such as plant raising practices during the nursery phase, and mulching and nitrogen fertilizing during the field phase. Experiments were carried out in the field at various locations in Indonesia and Malaysia and in growth chambers and greenhouses in the Netherlands. During the nursery phase, screen-covered nurseries protected plants from aphids and aphid-transmitted viruses. In the field phase, after transplanting, potted transplants showed better crop establishment than bare-root transplants and earlier harvesting. When plantlets were raised in screen-covered nurseries, a plant raising period of 1½ months appeared best for plant growth and earliness of harvesting after transplanting. In the field phase, white and silvery plastic mulches improved plant growth and earliness of fruiting, reduced virus infection and thrips injury, and improved crop production. Nitrogen fertilizing improved plant growth. Increasing nitrogen application rates aggravated anthracnose fruit rot and Cercospora leaf spot. Best yields were attained with nitrogen fertilization of 150 kg N/ha. The investigated components of ICM benefited crop production through, among others, improvement of crop health. The effects of the ICM components on yield were irrespective of cultivar or location.
Old tree root channels in acid soils in the humid tropics: Important for crop root penetration, water infiltration and nitrogen management
Noordwijk, M. van; Widianto, ; Heinen, M. - \ 1991
In: Plant-soil interactions at low pH - p. 423 - 430.
bacteriën - bosbouw - uitspoelen - stikstof - stikstofkringloop - plantenontwikkeling - plantenfysiologie - wortels - bodem - bodemaciditeit - bodem ph - subtropen - tropen - bacteria - forestry - leaching - nitrogen - nitrogen cycle - plant development - plant physiology - roots - soil - soil acidity - soil ph - subtropics - tropics
Land evaluation and farming systems analysis for Land Use Planning.
Fresco, L.O. ; Huizing, H. ; Keulen, H. van; Luning, H. ; Schipper, R. - \ 1990
Rome : FAO (FAO Working Document ) - 207
ontwikkelingslanden - bedrijfssystemen - grondvermogen - landevaluatie - bodemgeschiktheid - subtropen - tropen - studieboeken - developing countries - farming systems - land capability - land evaluation - soil suitability - subtropics - tropics - textbooks
|N-management in the humid tropics : report of field visits to Ketapang (Lampung, Sumatera, Indonesia) in August 1988 and January 1989, including observations on roots and water infiltration
Noordwijk, M. van - \ 1989
Haren (Gr.) : IB (Nota / Instituut voor Bodemvruchtbaarheid 208) - 28
bacteriën - indonesië - stikstof - stikstofkringloop - rizosfeer - bodem - bodemwater - subtropen - tropen - sumatra - bacteria - indonesia - nitrogen - nitrogen cycle - rhizosphere - soil - soil water - subtropics - tropics
|Land evaluation and farming systems analysis for land use planning.
Fresco, L. ; Huizing, H. ; Keulen, H. van; Luning, H. ; Schipper, R.A. - \ 1989
Rome [etc.] : FAO - 201
bedrijfssystemen - landevaluatie - grondvermogen - bodemgeschiktheid - ontwikkelingslanden - tropen - subtropen - farming systems - land evaluation - land capability - soil suitability - developing countries - tropics - subtropics
Tropische plantenteelt, Wageningen en de wereld.
Wessel, M. - \ 1988
Wageningen : Landbouwuniversiteit Wageningen - 31
veldgewassen - akkerbouw - tropen - subtropen - onderzoek - nederland - openbare redes - field crops - arable farming - tropics - subtropics - research - netherlands - public speeches
|Storage of potatoes in the tropics and sub-tropics
Wustman, R. - \ 1987
Wageningen : IBVL (Publikatie / Institute for Storage and Processing of Agricultural Produce 373B) - 8
aardappelen - solanum tuberosum - opslag - subtropen - tropen - potatoes - storage - subtropics - tropics
|Conservation de pommes de terre dans les regions tropique et subtropique
Wustman, R. - \ 1987
Wageningen : IBVL (Publikatie / Institute pour la Conservation et la Transformation de Produits 373A) - 8
kortdurende tussenteelt (double cropping) - intensieve teelt - aardappelen - solanum tuberosum - subtropen - tropen - double cropping - intensive cropping - potatoes - subtropics - tropics
Medicinal and poisonous plants of the tropics : proceedings of symposium 5-35 of the 14th International Botanical Congress, Berlin 24 July-1 August 1987
Leeuwenberg, A.J.M. - \ 1987
Wageningen : Pudoc - ISBN 9789022009215 - 152
geneesmiddelen - medicinale planten - fytotoxinen - giftige planten - stimulerende middelen - subtropen - toxische stoffen - tropen - wilde planten - plantkunde - natuurlijke producten - economische botanie - drugs - medicinal plants - phytotoxins - poisonous plants - stimulants - subtropics - toxic substances - tropics - wild plants - botany - natural products - economic botany
Root studies on a tropical ultisol in relation to nitrogen management : report of field work at IITA's high rainfall substation at Onne (Port Harcourt, Nigeria) in 1985
Hairiah, K. ; Noordwijk, M. van - \ 1986
Haren (Gr.) : I.B. (Rapport / Instituut voor Bodemvruchtbaarheid no. 7-86) - 121
akkerbouw - bacteriën - veldgewassen - stikstof - stikstofkringloop - stikstofmeststoffen - plantenontwikkeling - plantenfysiologie - wortels - bodem - subtropen - tropen - ultisols - arable farming - bacteria - field crops - nitrogen - nitrogen cycle - nitrogen fertilizers - plant development - plant physiology - roots - soil - subtropics - tropics - ultisols
The relation between nitrogen fertilization and root development is studied for several crop types. Also the root development in intercropping of maize and cassave is studied
|Veldmethodiek tropische bodemkunde
Andriesse, W. - \ 1986
Wageningen : STIBOKA (Interne mededeling / Stichting voor Bodemkartering no. 76)
bemonsteren - grondanalyse - bodemclassificatie - bodemtaxonomie - bodemtypen - subtropen - tropen - sampling - soil analysis - soil classification - soil taxonomy - soil types - subtropics - tropics
Progress and future plans of the project "management of nitrogen in acid low activity clay soils in the humid tropics for food crop production"
Kang, B.T. ; Kruijs, A. van der; Heide, J. van der - \ 1986
Haren : IB (Rapport / Instituut voor Bodemvruchtbaarheid 14-86)
akkerbouw - bacteriën - zware kleigronden - veldgewassen - voedselproductie - humide klimaatzones - uitspoelen - stikstof - stikstofkringloop - stikstofmeststoffen - onderzoek - bodem - bodemvruchtbaarheid - subtropen - tropen - toekomst - arable farming - bacteria - clay soils - field crops - food production - humid zones - leaching - nitrogen - nitrogen cycle - nitrogen fertilizers - research - soil - soil fertility - subtropics - tropics - future
|Distribution, mapping, classification and use of acid sulphate soils in the tropics : a literature study
Langenhoff, R. - \ 1986
Wageningen : Soil Survey Institute (Interne mededeling / Soil Survey Institute nr. 74) - 133
zure gronden - kattekleigronden - bodemtaxonomie - bodemclassificatie - bodemtypen - bibliografieën - tropen - subtropen - acid soils - acid sulfate soils - soil taxonomy - soil classification - soil types - bibliographies - tropics - subtropics
Bodemkundige informatie zure gronden Stiboka