Rainforestation farming on Leyte island, Philippines - aspects of soil fertility and carbon sequestration potential

This study aimed at investigating rainforestation systems in Leyte, Philippines, under different aspects: Characterisation of typical soils in Leyte with respect to physical, chemical and biological parameters relevant for tree growth, possible contributions of rainforestation to restoring soil fertility, performance of a recently planted rainforestation system under different microclimatic and soil conditions, potential of the rainforestation approach for projects under the umbrella of the Clean Development Mechanism (CDM). Soils in Leyte can be grouped into a volcanic and a calcareous category. The latter were formed on coralline limestone and are high in pH and Ca2+ and Mg2+. Contents of organic matter are high while concentrations of plant available PBray are low. Volcanic soils are characterised by low pH and CEC as well as extremely low PBray contents. Organic matter levels are below those of the calcareous soils but still moderate. In any analysed soil, N would not limit tree growth. Pore volume and water infiltration were propitious for all sites, which is relevant in the context of erosion. For calcareous soils, drought and reduced rootability due to clayey subsoil posed the most relevant constraints. The frequently claimed role of rainforestation in the rehabilitation of degraded soils was assessed in a paired plot approach. Chemical and biological soil parameters under 10 year old rainforestation were contrasted with adjacent fallow or Gmelina sp. Clear tendencies across all seven sampled sites were lower available Mg2+ and pH under rainforestation. Other differences were less distinct. Generally, a depletion of soil reserves e.g. in basic cations can be explained by uptake into the plants. A feed-back of these elements to the topsoil via leaf litter, however, could be observed only for available P. In conclusion, plant uptake of single elements can reach orders of magnitudethat reduce soil stocks. At the same time, generally lower pH under rainforestation may have contributed to elevated losses, especially of basic cations. A general improvement of the sampled soils in terms of chemical or biological characteristics through rainforestation could not be observed. To evaluate plant performance six timber and four fruit species, most native, were interplanted on a 1ha plot. Rainforestation, commonly understood as high-density closed canopy system was modified to a less dense 5x5m grid, interplanted with Musa textilis. The plot varied strongly on a small scale due to heterogeneous canopy closure and relief. Methodologically, the entire area was divided into 10 subplots in representative positions to be sampled. Soil physical and chemical properties, microbial activity, PAR and root length density were determined and correlated to plant survival and growth at consecutive inventories. For Musa textilis, the most sensitive species, which was used as an indicator, logistic regressions were calculated to determine the influence of all relevant parameters on survival rates. The most important predictors for survival were organic matter contents, parameters related to biological activity and leaf litter production, which resembled canopy closure and thus indirectly light intensity and soil moisture. To assess growth, multiple regressions were formulated for biomass at five inventories. Corg and NLOM were the most relevant variables determining the regressions used for biomass and growth of abaca. Assessing the potential of rainforestation for Clean Development Mechanism (CDM) measures, amounts of sequestered CO2 during 10 and 20 years, respectively, were estimated under different management options using the WaNuLCAS model. Despite all given uncertainty associated with modelling, one very obvious finding was the dominant role of soil carbon for the plot balance: Appropriate soil management, especially during land preparation (e.g. clearing vs. enrichment planting) is of paramount importance. Looking at the modelled contribution of various tree species to the carbon balance, Musa textilis had a significant influence only during the very first years; later on, the principal share of carbon was bound in the tree component. Here, exotic Gmelina arborea built up biomass more quickly than a rainforestation plot composed of native Shorea contorta and Durio zibethinus, but was then overtaken. In absolute quantities of CO2 sequestration, magnitudes matched inventory and modelled data given in various literature sources for Leyte and the Philippines. Relative to earlier inventory data from two rainforestation sites, modelled values overestimated growth.Auf Leyte, Philippinen, wurde in den 1990er Jahren der Rainforestation-Ansatz zur Inwertsetzung degradierter Flächen durch Aufforstung mit einheimischen Baumarten entwickelt. Im Rahmen der vorliegenden Arbeit wurden auf bestehenden Rainforestation-Flächen folgende Aspekte untersucht: Standortskundliche Charakterisierung typischer Böden in Hanglagen im Hinblick auf physikalische, chemische und biologische Parameter; Beitrag der Rainforestation-Systeme zur Bodenrehabilitation im Vergleich mit traditionellen Landnutzungen; Identifizierung geeigneter Wuchsbedingungen einer Neupflanzung unter kleinräumig unterschiedlichen Boden- und Klimabedingungen; mittel- bis langfristige Potenziale zur CO2-Sequestrierung einer Rainforestation-Pflanzung im Rahmen von Projekten des Clean Development Mechanism (CDM) mit Hilfe eines Wachstumsmodells. Böden an Waldstandorten Leytes können nach ihrer Entstehung aus Korallenkalk oder Vulkangestein unterschieden werden. Die Kalkböden (Cambisol und Leptosol) sind neben hohen pH-Werten und Gehalten an Ca2+- und Mg2+-Ionen durch niedrige Gehalte an pflanzenverfügbarem Phosphor gekennzeichnet. Die Vulkanböden (Luvisols, Cambisols, Nitisol) weisen pH-Werte zwischen 4 und 5, geringe effektive KAK und extrem geringe P-Gehalte auf. Die meisten untersuchten Standorten waren hinsichtlich ihrer Humus- und Stickstoffgehalte nicht unterversorgt. Auch Porenvolumen und Wasserinfiltration, beide relevant für Bodenerosion, wurden durchgehend als günstig eingestuft. Allerdings kann Hangzugwasser über BT-Tonhorizonten wechselfeuchte Bedingungen hervorrufen. Besonders auf den Kalkböden kann das Pflanzenwachstum zudem durch temporäre Trockenheit und Verhärtung der tonreichen Unterböden eingeschränkt werden. Im Zusammenhang mit der Durchführung von Rainforestation-Projekten wurde in der Vergangenheit oft die Rolle dieser Systeme bei der Rehabilitation übernutzter bzw. erodierter Hanglböden herausgestellt. Diese Aussage wurde mittels eines Vergleichs mindestens 10-jähriger Rainforestationflächen an 7 verschiedenen Standorten zu jeweils direkt benachbarten Brachen bzw. Aufforstungen mit Gmelina arborea untersucht. Statistisch signifikante Unterschiede zwischen den Landnutzungen bestanden bei den pH-Werten und Gehalten an austauschbarem Mg2+, welche in Rainforestation-Böden unter denjenigen der jeweiligen Referenzflächen lagen. Eine generelle Verarmung von Böden an basischen Kationen durch Festlegung in Pflanzen erscheint plausibel (Nykvist 1997). Anzeichen für eine erneute Freisetzung von Elementen aus Bäumen über den Laubfall wurden hinsichtlich PBray an zwei Standorten deutlich. Verbesserte Bodenfruchtbarkeit bzgl. chemischer oder biologischer Parameter durch Rainforestation konnte mit dem verwendeten Ansatz nicht festgestellt werden. 2004 wurde eine neue Rainforestation-Pflanzung, bestehend aus einheimischen Wertholzarten, Obstbäumen und Musa textilis angelegt. Hier wurde die Entwicklung der Pflanzen wiederholter Inventuren erfasst. Bodenphysikalische und -chemische Parameter sowie mikrobielle Aktivität und Biomasse, photosynthetisch aktive Einstrahlung sowie Streuproduktion und Wurzellängendichte der vorhandenen Vegetation wurden auf zehn Teilflächen bestimmt. Diese Parameter wurden zu Überlebens- und Zuwachsraten von Musa textilis in der Neupflanzung mit Hilfe von Logit-Funktionen in Beziehung gesetzt. Dabei waren die wichtigsten Standortfaktoren bzgl. der Überlebensraten Humusgehalt, biologische Aktivität im Boden und Streuproduktion. Alle drei Größen hängen wesentlich mit der Bodenfeuchte zusammen. Zur Bewertung von Einflussgrößen auf Pflanzenbiomasse und -wachstum wurden multiple Regressionen erstellt. Organischer Kohlenstoff und N in der leicht abbaubaren organischen Bodensubstanz waren die bedeutendsten Steuergrößen für Biomasse und Zuwachs. Zur Bewertung des Potenzials kleinbäuerlicher Agroforstpflanzungen für CDM-Projekte wurde ein Modellansatz gewählt. Mit Hilfe des Modells WaNuLCAS (Water, Nutrients, Light and Carbon in Agroforestry Systems) wurden Wachstumsverläufe von Pflanzen auf Grundlage gemessener Standorteigenschaften und Pflanzenparameter unter verschiedenen Landnutzunsszenarien während 10 bzw 20 Jahren simuliert. In allen Modellläufen war der C-Haushalt des Bodens von herausragender Bedeutung für die CO2-Bilanz der gesamten Parzelle. Ein nennenswerter Beitrag der schnellwachsenden M. textilis zur CO2-Sequestrierung ergab sich in den Simulationen nur während der Anfangsphase. Im Vergleich verschiedener Pflanzsysteme zeichnete sich Gmelina arborea als Pionierart durch schnellen Aufbau von Biomasse, verbunden mit hoher CO2-Fixierung, aus. Dieses System wird gewöhnlich im Aufforstungsansatz staatlicher Programme favorisiert. Eine dem Rainforestation-Ansatz entsprechende Kombination einheimischer Nutzholz- und Obstbaumarten benötigte dagegen längere Zeit zur Entwicklung, nahm aber insgesamt über knapp 20 Jahre größere Mengen an CO2 auf

Rainforestation farming on Leyte island, Philippines - aspects of soil fertility and carbon sequestration potential

This study aimed at investigating rainforestation systems in Leyte, Philippines, under different aspects: Characterisation of typical soils in Leyte with respect to physical, chemical and biological parameters relevant for tree growth, possible contributions of rainforestation to restoring soil fertility, performance of a recently planted rainforestation system under different microclimatic and soil conditions, potential of the rainforestation approach for projects under the umbrella of the Clean Development Mechanism (CDM). Soils in Leyte can be grouped into a volcanic and a calcareous category. The latter were formed on coralline limestone and are high in pH and Ca2+ and Mg2+. Contents of organic matter are high while concentrations of plant available PBray are low. Volcanic soils are characterised by low pH and CEC as well as extremely low PBray contents. Organic matter levels are below those of the calcareous soils but still moderate. In any analysed soil, N would not limit tree growth. Pore volume and water infiltration were propitious for all sites, which is relevant in the context of erosion. For calcareous soils, drought and reduced rootability due to clayey subsoil posed the most relevant constraints. The frequently claimed role of rainforestation in the rehabilitation of degraded soils was assessed in a paired plot approach. Chemical and biological soil parameters under 10 year old rainforestation were contrasted with adjacent fallow or Gmelina sp. Clear tendencies across all seven sampled sites were lower available Mg2+ and pH under rainforestation. Other differences were less distinct. Generally, a depletion of soil reserves e.g. in basic cations can be explained by uptake into the plants. A feed-back of these elements to the topsoil via leaf litter, however, could be observed only for available P. In conclusion, plant uptake of single elements can reach orders of magnitudethat reduce soil stocks. At the same time, generally lower pH under rainforestation may have contributed to elevated losses, especially of basic cations. A general improvement of the sampled soils in terms of chemical or biological characteristics through rainforestation could not be observed. To evaluate plant performance six timber and four fruit species, most native, were interplanted on a 1ha plot. Rainforestation, commonly understood as high-density closed canopy system was modified to a less dense 5x5m grid, interplanted with Musa textilis. The plot varied strongly on a small scale due to heterogeneous canopy closure and relief. Methodologically, the entire area was divided into 10 subplots in representative positions to be sampled. Soil physical and chemical properties, microbial activity, PAR and root length density were determined and correlated to plant survival and growth at consecutive inventories. For Musa textilis, the most sensitive species, which was used as an indicator, logistic regressions were calculated to determine the influence of all relevant parameters on survival rates. The most important predictors for survival were organic matter contents, parameters related to biological activity and leaf litter production, which resembled canopy closure and thus indirectly light intensity and soil moisture. To assess growth, multiple regressions were formulated for biomass at five inventories. Corg and NLOM were the most relevant variables determining the regressions used for biomass and growth of abaca. Assessing the potential of rainforestation for Clean Development Mechanism (CDM) measures, amounts of sequestered CO2 during 10 and 20 years, respectively, were estimated under different management options using the WaNuLCAS model. Despite all given uncertainty associated with modelling, one very obvious finding was the dominant role of soil carbon for the plot balance: Appropriate soil management, especially during land preparation (e.g. clearing vs. enrichment planting) is of paramount importance. Looking at the modelled contribution of various tree species to the carbon balance, Musa textilis had a significant influence only during the very first years; later on, the principal share of carbon was bound in the tree component. Here, exotic Gmelina arborea built up biomass more quickly than a rainforestation plot composed of native Shorea contorta and Durio zibethinus, but was then overtaken. In absolute quantities of CO2 sequestration, magnitudes matched inventory and modelled data given in various literature sources for Leyte and the Philippines. Relative to earlier inventory data from two rainforestation sites, modelled values overestimated growth.Auf Leyte, Philippinen, wurde in den 1990er Jahren der Rainforestation-Ansatz zur Inwertsetzung degradierter Flächen durch Aufforstung mit einheimischen Baumarten entwickelt. Im Rahmen der vorliegenden Arbeit wurden auf bestehenden Rainforestation-Flächen folgende Aspekte untersucht: Standortskundliche Charakterisierung typischer Böden in Hanglagen im Hinblick auf physikalische, chemische und biologische Parameter; Beitrag der Rainforestation-Systeme zur Bodenrehabilitation im Vergleich mit traditionellen Landnutzungen; Identifizierung geeigneter Wuchsbedingungen einer Neupflanzung unter kleinräumig unterschiedlichen Boden- und Klimabedingungen; mittel- bis langfristige Potenziale zur CO2-Sequestrierung einer Rainforestation-Pflanzung im Rahmen von Projekten des Clean Development Mechanism (CDM) mit Hilfe eines Wachstumsmodells. Böden an Waldstandorten Leytes können nach ihrer Entstehung aus Korallenkalk oder Vulkangestein unterschieden werden. Die Kalkböden (Cambisol und Leptosol) sind neben hohen pH-Werten und Gehalten an Ca2+- und Mg2+-Ionen durch niedrige Gehalte an pflanzenverfügbarem Phosphor gekennzeichnet. Die Vulkanböden (Luvisols, Cambisols, Nitisol) weisen pH-Werte zwischen 4 und 5, geringe effektive KAK und extrem geringe P-Gehalte auf. Die meisten untersuchten Standorten waren hinsichtlich ihrer Humus- und Stickstoffgehalte nicht unterversorgt. Auch Porenvolumen und Wasserinfiltration, beide relevant für Bodenerosion, wurden durchgehend als günstig eingestuft. Allerdings kann Hangzugwasser über BT-Tonhorizonten wechselfeuchte Bedingungen hervorrufen. Besonders auf den Kalkböden kann das Pflanzenwachstum zudem durch temporäre Trockenheit und Verhärtung der tonreichen Unterböden eingeschränkt werden. Im Zusammenhang mit der Durchführung von Rainforestation-Projekten wurde in der Vergangenheit oft die Rolle dieser Systeme bei der Rehabilitation übernutzter bzw. erodierter Hanglböden herausgestellt. Diese Aussage wurde mittels eines Vergleichs mindestens 10-jähriger Rainforestationflächen an 7 verschiedenen Standorten zu jeweils direkt benachbarten Brachen bzw. Aufforstungen mit Gmelina arborea untersucht. Statistisch signifikante Unterschiede zwischen den Landnutzungen bestanden bei den pH-Werten und Gehalten an austauschbarem Mg2+, welche in Rainforestation-Böden unter denjenigen der jeweiligen Referenzflächen lagen. Eine generelle Verarmung von Böden an basischen Kationen durch Festlegung in Pflanzen erscheint plausibel (Nykvist 1997). Anzeichen für eine erneute Freisetzung von Elementen aus Bäumen über den Laubfall wurden hinsichtlich PBray an zwei Standorten deutlich. Verbesserte Bodenfruchtbarkeit bzgl. chemischer oder biologischer Parameter durch Rainforestation konnte mit dem verwendeten Ansatz nicht festgestellt werden. 2004 wurde eine neue Rainforestation-Pflanzung, bestehend aus einheimischen Wertholzarten, Obstbäumen und Musa textilis angelegt. Hier wurde die Entwicklung der Pflanzen wiederholter Inventuren erfasst. Bodenphysikalische und -chemische Parameter sowie mikrobielle Aktivität und Biomasse, photosynthetisch aktive Einstrahlung sowie Streuproduktion und Wurzellängendichte der vorhandenen Vegetation wurden auf zehn Teilflächen bestimmt. Diese Parameter wurden zu Überlebens- und Zuwachsraten von Musa textilis in der Neupflanzung mit Hilfe von Logit-Funktionen in Beziehung gesetzt. Dabei waren die wichtigsten Standortfaktoren bzgl. der Überlebensraten Humusgehalt, biologische Aktivität im Boden und Streuproduktion. Alle drei Größen hängen wesentlich mit der Bodenfeuchte zusammen. Zur Bewertung von Einflussgrößen auf Pflanzenbiomasse und -wachstum wurden multiple Regressionen erstellt. Organischer Kohlenstoff und N in der leicht abbaubaren organischen Bodensubstanz waren die bedeutendsten Steuergrößen für Biomasse und Zuwachs. Zur Bewertung des Potenzials kleinbäuerlicher Agroforstpflanzungen für CDM-Projekte wurde ein Modellansatz gewählt. Mit Hilfe des Modells WaNuLCAS (Water, Nutrients, Light and Carbon in Agroforestry Systems) wurden Wachstumsverläufe von Pflanzen auf Grundlage gemessener Standorteigenschaften und Pflanzenparameter unter verschiedenen Landnutzunsszenarien während 10 bzw 20 Jahren simuliert. In allen Modellläufen war der C-Haushalt des Bodens von herausragender Bedeutung für die CO2-Bilanz der gesamten Parzelle. Ein nennenswerter Beitrag der schnellwachsenden M. textilis zur CO2-Sequestrierung ergab sich in den Simulationen nur während der Anfangsphase. Im Vergleich verschiedener Pflanzsysteme zeichnete sich Gmelina arborea als Pionierart durch schnellen Aufbau von Biomasse, verbunden mit hoher CO2-Fixierung, aus. Dieses System wird gewöhnlich im Aufforstungsansatz staatlicher Programme favorisiert. Eine dem Rainforestation-Ansatz entsprechende Kombination einheimischer Nutzholz- und Obstbaumarten benötigte dagegen längere Zeit zur Entwicklung, nahm aber insgesamt über knapp 20 Jahre größere Mengen an CO2 auf

Legume CHOICE - a participatory tool to fit multi-purpose legumes to appropriate niches in mixed crop-livestock farming systems

German Federal Ministry for Economic Cooperation and DevelopmentDeutsche Gesellschaft für Internationale Zusammenarbei

What is the State of Resilience of Today’s Global Food System? Looking back to 1816

The eruption of the Indonesian volcano Tambora in 1815, in conjunction with other circumstances, caused a severe and global climate anomaly. The year following turned out to be extremely cold and brought heavy rain to some and draught to other parts of the world. “The year without summer”, as it was nicknamed in Europe and North America, saw very poor plant growth and poor harvests which, in combination with other factors, led to hardship, extreme food crisis and starvation in various regions of the world, including China, Germany, India and the US. Undoubtedly, advances in research and development in agriculture, transportation and other fields as well as globalization have changed the global food system tremendously since then. Nevertheless, regional specialisation and reliance on global availability of food supply and trade put into question whether today’s global food system would also be resilient against such climate shocks which are of global nature: How resilient is today’s global food system with respect to such extreme climate events? To what extent would it be capable of compensating the widespread harvest failures? How fragile is national food security with respect to protectionist trade policy reactions? To shed light on these questions, we combine global crop yield and computable general equilibrium (CGE) models for simulating the impact of a climate anomaly comparable to 1816

What is the State of Resilience of Today’s Global Food System? Looking back to 1816

The eruption of the Indonesian volcano Tambora in 1815, in conjunction with other circumstances, caused a severe and global climate anomaly. The year following turned out to be extremely cold and brought heavy rain to some and draught to other parts of the world. “The year without summer”, as it was nicknamed in Europe and North America, saw very poor plant growth and poor harvests which, in combination with other factors, led to hardship, extreme food crisis and starvation in various regions of the world, including China, Germany, India and the US. Undoubtedly, advances in research and development in agriculture, transportation and other fields as well as globalization have changed the global food system tremendously since then. Nevertheless, regional specialisation and reliance on global availability of food supply and trade put into question whether today’s global food system would also be resilient against such climate shocks which are of global nature: How resilient is today’s global food system with respect to such extreme climate events? To what extent would it be capable of compensating the widespread harvest failures? How fragile is national food security with respect to protectionist trade policy reactions? To shed light on these questions, we combine global crop yield and computable general equilibrium (CGE) models for simulating the impact of a climate anomaly comparable to 1816

Market access and resource endowment define the soil fertility status of smallholder farming systems of South‐Kivu, DR Congo

This study verified the inter‐related effect of ‘market distance’, defined as walking time, ‘farm typology’, defined as resource endowment, and ‘site’, defined as geographic location with contrasting agro‐ecologies, as well as farmers’ indigenous knowledge on soil fertility variability in smallholder farming systems in two distinct regions (Bushumba, Mushinga) of South‐Kivu, DR Congo. A total of 384 soil samples were selected from representative farmers’ fields and analysed for soil pH, soil organic carbon (SOC) content and quality, as well as nutrient contents, using midDRIFTS (mid‐infrared diffuse reflectance Fourier transform spectroscopy) and wet chemistry analyses. MidDRIFTS was also used to calculate SOC stability indexes as SOC quality proxies. ‘Market distance’ and ‘farm typology’ were key determinants of soil fertility variability, both with contrasting trends in Bushumba and Mushinga. Decreasing soil fertility with increasing market distance was noted across all farm typologies. ‘Farm typology’ was related to exchangeable calcium and magnesium, while ‘site’ resulted in a difference of plant available phosphorus. SOC quality indexes were related to ‘site’, interacting with ‘market distance’. A ‘market distance’ effect became obvious in the medium wealthy and poor farms of Mushinga, where a lower SOC quality in remote fields plots was noted with increasing market distance. In agreement with farmers’ indigenous knowledge, soil fertility levels were higher in deep than shallow soils, which were reflected in higher nutrient stocks in deep soils receiving organic amendments. Our results inferred that soil fertility variability across smallholder farms must consider various inter‐related determinants as basis for site‐specific fertility management interventions.German Federal Ministry for Economic Cooperation and Development (BMZ

Agro‐ecology, resource endowment and indigenous knowledge interactions modulate soil fertility in mixed farming systems in Central and Western Ethiopia

Site‐specific soil fertility management requires a fundamental understanding of factors that modulate soil fertility variability in the local context. To verify this assumption, this study hypothesized that soil fertility variability across two regions in Central and Western Ethiopia is determined by inter‐related effects of agro‐ecological zones and farmers’ resource endowment (‘wealthy’ versus ‘poor’ farmers). Mid‐infrared spectroscopy coupled to partial least squares regression (midDRIFTS‐PLSR) and wet‐laboratory analyses were used to assess the soil fertility (soil pH, total soil carbon [TC] and nitrogen [TN], plant‐available phosphorous [Pav] and potassium [Kav]) across four agro‐ecological zones: ‘High‐Dega’ (HD), ‘Dega’ (D), ‘Weina‐Dega’ (WD) and ‘Kola’ (K). MidDRIFTS peak area analysis of spectral frequencies (2,930 [aliphatic C‐H], 1,620 [aromatic C = C], 1,159 [C‐O poly‐alcoholic and ether groups] cm‐1) was applied to characterize soil organic carbon (SOC) quality and to calculate the SOC stability index (1,620:2,930). Higher TC in HD, as well as higher TN and Kav contents in K were found in fields of wealthy compared with poor farmers. Resource endowment dependent soil fertility management options revealed SOC of higher quality in wealthy compared with poor farms in D. Agro‐ecological zones distinctions contributed to these soil fertility differences. Farmers distinguished visually fertile and less fertile fields based on soil colour. Higher pH in K and WD as well as Pav in K and HD were found in fertile (brown/black) than less fertile (red) soils. To conclude, tailor‐made soil fertility management in the local context must consider agro‐ecological zones and resource endowment interactions along with farmers’ indigenous knowledge.German Federal Ministry for Economic Cooperation and Development (BMZ) through the International Institute for Tropical Agricultural (IITA) with its LegumeCHOICE projec

Coupled biophysical and decision-making processes in grassland systems in East African savannahs – A modelling framework

<p>Increasing livestock densities on limited grazing areas in African savannahs lead to resource degradation through overgrazing, aggravated by drought. Assessing herd management strategies over longer periods at landscape scale is important to propose options for sustainable land use. This requires an understanding of processes related to hydrology, nutrient cycling, herd movement, pasture degradation, and animal resilience that involve dynamic soil-plant-animal interactions and human decisions about stocking rates, livestock purchases and sales.</p><p>We present the coupled model system MPMAS-LUCIA-LIVSIM (MLL), the combination of a spatially explicit agent-based model for human decision-making (MPMAS), a spatially distributed landscape model for water flows, nutrient cycles and plant growth (LUCIA), and a herd model (LIVSIM) representing grazing, body weight, nutrition and excreta of individual animals. MLL represents daily vegetation growth in response to grazing and organic inputs, monthly animal performance influenced by forage availability and quality, and herders' management in response to resource status. New modules for selective grazing, resprouting of pasture, herd movement and model coupling were developed for MLL.</p><p>The test case of a pastoral system in the Ethiopian Borana region demonstrates the capabilities of MLL to simulate key soil-plant-animal-human interactions under climate-related management scenarios with varying access to grazing land, changing cattle prices and different spending / saving behaviour of herders. 20-year simulations showed the negative impact of consecutive drought years on vegetation biomass, on herd development and movement and how reserving grazing areas for dry seasons could mitigate overgrazing and improve income. Seasonality and drought response of vegetation growth, selective grazing of different plant parts, resprouting after grazing, calving intervals, milk yields and lactation in response to forage supply and quality as well as herder reactions to shocks were plausibly represented.</p><p>Building upon this successful proof-of-concept, MLL can be used to identify robust management options for improved grazing systems in savannahs in follow-up research.</p&gt