The intensive silvopastoral systems in Latin America sustainable alternative to face climatic change in animal husbandry

Los Sistemas silvopastoriles intensivos en América Latina alternativa sostenible para enfrentar el cambio climático en la ganadería

E. Murgueitio,^I R. Barahona,^II J. D., Chará,^I M. X. Flores,^III R.M. Mauricio,^IV J. J. Molina,^I,V

^ICentro para la Investigación en Sistemas Sostenibles de Producción Agropecuaria, CIPAV, Cali, Colombia.
^IIUniversidad Nacional de Colombia, Medellín, Colombia. ]]> ^IIIFundación Produce Michoacán. Morelia, México.
^IVProfesor Investigador Universidad Federal Sao Joao del-Rei. Minas Gerais, Brasil.
^VReserva Natural El Hatico, Valle del Cauca, Colombia.

ABSTRACT

The challenge of facing the climatic change in the Latin America animal husbandry is a global priority especially in tropical and subtropical regions. Although the expressions rate of this global phenomenon forces to work quickly in adaptation agendas, it also advances in reducing the main causes (mitigation). In recently way the research and innovation look for productive models that combine mixed attributes of adaptation and mitigation in simultaneous way. One of these is the Intensive Silvopastoral System (ISPS) that has positive results which is already promoted in programs and alliance projects between governments, farmer institutions and institutions of international cooperation. These initiatives contribute to the environmental management of the territory occupied by animal husbandry (in many regions they occupy more than a third of the territory) and can be a tool to reduce deforestation; they are good to rehabilitate degraded lands; increase the production of animal husbandry benefits with low demand of agrochemical and forest at the time that are generator of ecosystem services such as quality and quantity of water, biodiversity conservation and the greenhouse gas reduction. The Intensive Silvopastoral Systems (ISPS) are a use of land within the Livestock Agricultural Forestry Systems (LAFS) characterized by simultaneous applying several agro-ecological principles. They combine forage shrubs in high density for direct browsing; they use several tropical or subtropical grasses and wood tress species, palms or fruit trees. The ISPS uses rotational grazing with electric fences and tapes, and guarantees good water in mobile water trough and mineralized salt for cattle (milk, meat, dual purpose) and sheeps. This article provides an update synthesis on research conducted mostly in Latin America, which show an increase in meat and milk production with obvious attributes of sustainability.

Key words: Intensive silvopastoral systems, sustainable animal husbandry, climatic change.

RESUMEN

El reto de enfrentar al cambio climático en la ganadería de América Latina es una prioridad mundial especialmente en regiones tropicales y subtropicales. Aunque la velocidad de las expresiones de este fenómeno global obliga a trabajar con rapidez en agendas de adaptación, también se avanza en la reducción de las causas principales (mitigación). En forma reciente la investigación y la innovación buscan modelos productivos que combinen atributos mixtos de adaptación y mitigación en forma simultánea. Uno de estos es el Sistema Silvopastoril Intensivo (SSPi) que tiene resultados positivos que ya es promovido en programas y proyectos de alianzas entre gobiernos, organizaciones de productores e instituciones de cooperación internacional. Estas iniciativas contribuyen al ordenamiento ambiental del territorio ocupado por la ganadería (en muchas regiones ocupan más de la tercera parte del territorio) y pueden ser una herramienta para reducir la deforestación; sirven para rehabilitar tierras degradadas; incrementan la producción de bienes pecuarios con baja demanda de agroquímicos y forestales al tiempo que son generadoras de servicios ecosistémicos tales como la calidad y cantidad de agua, la conservación de la biodiversidad y la reducción de gases con efecto de invernadero. Los Sistemas Silvopastoriles Intensivos (SSPi) son un uso de la tierra dentro de la modalidad de los Sistemas Agroforestales Pecuarios (SAFP) caracterizados por aplicar simultáneamente varios principios agroecológicos. Combinan arbustos forrajeros en alta densidad para el ramoneo directo; emplean varios pastos tropicales o subtropicales y especies de árboles maderables, palmas o árboles frutales. El SSPi emplea el pastoreo rotacional con cercas y cintas eléctricas, y garantiza agua de buena calidad en bebederos móviles y sal mineralizada para bovinos (leche, carne, doble propósito) y ovinos. Este artículo ofrece una síntesis actualizada de trabajos de investigación en su mayoría realizados en América Latina, que evidencian el incremento de la producción de carne y leche con evidentes atributos de sustentabilidad.

INTRODUCTION

Most of the animal husbandry in tropical and subtropical America is carried out in native meadows and/ or selected with tendency towards monoculture uses. Compared with the used diets in industrial production systems (fattening in pen, intensive dairies), the feeding on grazing is of low cost as minimum inputs are used at the time that large extensions of land are used with low investment and poor human labor demand. However, this type of production is not stable since, it is subjected to the climatic seasonality which in turn generates great variations in forage production; as well as the low nutritional quality of the grasses used for grazing (Barahona et al. 2014).

Tropical grasses are characterized for low to medium energy availability (Wilkins 2000) which is associated with high content of structural carbohydrates, low indicators of soluble carbohydrates, protein values lower than 7% and lower digestibility to 55% (Barahona et al. 2014). During the dry season, that varies from two to six months according to regions (sub-humid tropic to dry tropic), the dry matter availability dramatically decreased. Moreover, the low levels of crude protein, minerals and some vitamins, in tropical grasses, tend to rapidly decrease during the dry season. As a result, cattle loss weight and milk production decreases. Thus for decades is seeks through research in forage species and cattle production systems, to modify the supply of feed strategic components (Ku Vera et al. 2011, Ayala-Burgos and Aguilar Pérez 2011 and Barahona et al. 2014).

Moreover, it is recognized that in Latin America and the Caribbean animal husbandry registers low productivity and competitiveness levels in most of the tropical cattle systems as a result of natural resources depletion and the environmental impacts (Acosta 2010). The negative effects of animal husbandry grazing on the environment continues researching, while the international community is pushing for the cattle sector of the region reduces the greenhouse gas emissions(GGE) such as carbon dioxide(CO₂),methane(CH₄) and nitrogen dioxide (NO₂) (Peters et al. 2013). For this it has proposed an integrated intervention including reducing deforestation and the use of fire; the improvement and diversification of the animals diet, the use of natural sources of nutrients (atmospheric nitrogen fixation and nutrients recycling); encouraging biological processes in place of agrochemicals (Chará and Giraldo 2011) and the transformation of grasses monocultures toward the agro-silvopastoral systems (Montagnini 2011).

The silvopastoral systems are a type of agricultural forestry system in which interacts in a simultaneous way perennial woody plant (trees or shrubs), herbaceous or twining plants (grasses, herbaceous legumes and weeds) and domestic animals mainly cattle, horses, sheep and caprine (Montagnini 2011).It combines in the same space several plants strata dedicated to animal feeding, forages as grasses and creeping legumes, with shrubs and trees.

The trees can be selected in groups that differ in their function and supply of goods and services. A group of them is considered valuable because they produce wood for joinery and constructions as mahogany tree (Swietenia macrophylla King) and the tropical cedar (Cedrela odorata L. from Meliaceae family). Others for cellulose or dendroenergetic production as pine tree (Pinus ssp., Pinacea family) and the eucalyptus (Eucalyptus spp., Myrtaceae family); (Calle et al. 2012 and Colcombet et al. 2015). Another group of trees are dedicated to give direct benefit to the cattle with foliage, shade and eatable fruits; for example carobs or mesquites (Prosopis ssp., Leguminosae: Mimosoideae family) or the saman, or janissary (Samanea saman [Jacq.] Merril) and the quick stick tree (Gliricidia sepium [Jacq.] Kunth ex Walp Fabaceae family) (Murgueitio et al. 2015). Finally a third group is that of fruit trees, used as human and animal food among those are the guava (Psidium guajaba L., Myrtaceae family) and the mango(Mangifera indica L., Anacardiaceae family) (Patiño 2002 and Cardozo 2007).

The cattle intensification with adaptation to the climatic change requires applying agro-ecological principles that allow raising the efficiency of several essential biophysical process as the photosynthesis in three or four plant strata; the nitrogen fixation and nutrient recycling with the purpose of to increase the production and the biomass quality and to increase the content of the soil organic matter (Murgueitio et al. 2015).

The ISPS are a modality of the livestock agricultural forestry system dedicated to meat and milk production as well as wood, fruits and other associated goods. In the ISPS interacts in the same space and time one or more species from different strata. In the herbaceous stratum are the native forage grasses from America Axonopus, Paspalum genus and others) or introduced (Cynodon, Megathyrsus, Brachiaria, Urochloa, Pennisetum,Dichanthium, Cenchrus, Bothriochloa genus and  others); as well as legumes herbaceous plants(Desmodium, Centrosema, Calopogonium, Pueraria, Stylosanthes, Clitoria, Arachis, Teramnus, Macroptilium, Zornia, Trifolium, Lotus  genus and  others). It fallows an stratum of shrubs in high density (between ten and more than 40 thousand plants ha^-1) dedicated to cattle browsing with species as Leucaena leucocephala (Lam.) of Wit., from the  Mimosoidae subfamily; Tithonia diversifolia (Hemsl.) A. Gray, from Asteracea family; or Guazuma ulmifolia Lam., from Malvaceae family. Also the system includes trees of all types in the periphery and paddock  divisions as well as dispersed trees or in lines (between 25 and 200 mature trees ha^-1) for wood or fruits and palms production  (Murgueitio et al. 2015). This system requires the permanent offer of good water for animal intake in mobile water trough and balance mineralized salt. The paddocks periphery are established with  live fences and cattle are managed by electrical fences fixed or mobile according to the rotation rate and the physiology of forage plants involved (Murgueitio et al. 2013a).

Unlike conventional intensive agricultural systems, the ISPS are supported in agro-ecological processes, not in fossil energy and products of industrial synthesis (agrochemicals). So shrubs planted in high density, which differentiate ISPS from other silvopastoral systems (scattered trees in paddocks), perform functions of high atmospheric nitrogen fixation, protect the soil from water and wind erosion while avoided compaction by cattle trampling, improve nutrient recycling, particularly phosphorus (often insoluble in tropical and subtropical soils), and provide habitat for biological control organisms of grasses pests,  cattle ectoparasites and also for several functional groups of biodiversity as birds, small mammals, ants, dung beetles, earthworms and other (Fajardo et al. 2010, Giraldo et al. 2011, Murgueitio et al. 2011 and Rivera et al. 2013).

HIGHER MEAT AND MILK PRODUCTION

The ISPS stand to reduce the seasonality crisis of reproduction because cattle have better food at critical drought times (Molina et al. 2011 and Broom et al. 2013) and throughout the time are able to increase meat and milk production to lower financial costs (Reyes 2015). The highest effect occurs with increasing stocking rate (up to four times against extensive grazing) and consequently the meat and milk production per hectare per year (Murgueitio et al. 2015 and Reyes 2015) with evidence of being products of high nutritional quality (Mahecha et al. 2011 and Corral-Flores et al. 2012).

The ISPS is mainly used by cattle (Murgueitio et al. 2015) and to a lesser scale by sheep (Uribe et al. 2013) that benefit from abundant forage supply in an environment of low heat stress with high welfare (Broom et al. 2013). They are managed with fences and electrical tapes by rotational grazing with high stocking rates (between 800 and 2000 kg of live weight ha^-1) for very short periods, from 12 at 36 hours, and longer rest periods, between 35 up to 50 days or more (Murgueitio et al. 2015).

The forage shrub with more research and dissemination between farmers is the Leucaena leucocephala cultivar Cunningham, offers higher advantages for browsing by its flexibility in the branches, high nitrogen fixation, lower mimosime contents, drought tolerance, high regrowth capacity, total acceptance by ruminants and persistence after planting (Uribe et al. 2011). Used with high initial densities (planting 8 at 10 kg seed ha^-1) is inoculated with specific fixatives bacteria (Rhizobium), is sown by machine on flat land or with gently declivity and cultivated associated  to tropical grasses chosen for their high biomass production, shade adaptation and positive response to nitrogen (Molina et al. 2011).

Leucaena leucocephala forage is three times richer in protein 22.3 at 30% (Rivera et al. 2015) than tropical grasses, also has low fiber with maximum values not exceeding 41% neutral detergent fiber (NDF) and 30% of acid detergent fiber (ADF) (Barahona et al. 2014). Researches from the ISPS of this shrub with tropical grasses (Cynodon plectostachyus and Megathyrsus maximus) in Colombia have recorded forage biomass productions (leucaena and grasses) in a range of 15.6 to 19.2 tons of dry matter ha^-1 year^-1. In these studies it was concluded that legume contributes 25% of the total intake diet, which favors in the animal's diet increased 25% CP and 15% decrease in the NDF and 16% in the ADF, as well as 30% increase in the calcium (Rivera et al. 2015). Similar data were published in Mexican studies (Ayala- Burgos and Aguilar-Pérez 2011 and Ku Vera et al. 2011). This allows achieving stocking rates ranging by region and climate between 2.0 and 4.5 AU (animal unit = AU = 450 kg live weight) higher to  continuous grazing in savannas (5 times) or in selected grasses without fertilization (two to three times) and close or equal to those achieved with irrigation and fertilization of tropical grasses (Murgueitio et al. 2015).

Thanks to the high biomass production in the rainy seasons and the lowest reduction of it and their quality and in the dry seasons, the trees and the interaction between forage grasses and legumes also favor the bovine milk production in dual-purpose systems or specialized in milk production. The load per unit area is the main supporting of milk production per hectare to less cost and reducing the falling production under adverse climatic conditions (Rivera et al. 2011 and Paciullo et al. 2014). It has also been researched the metabolic balance in tropical dairy cows in the fifth s thirds of lactation, and the results show that there was not high mobilization of adipose tissue in animals. This means that the forage basal diet, supplied supplementation and cow comfort, favored energy-protein balance of the animals which were found under balance metabolic conditions with normal indicators, clearing the doubts of a supposed high amount of protein in the ISPS diet (Molina et al. 2013).

To improve the habitats biodiversity, provide fruits and more comfort with shade for cattle, the design is enriched with trees in a third and fourth stratum of wood trees or fruits and palms species. In addition to these innovations, the animals management techniques are also improved for a grazing lead to the rapid rotation of animals, where they only intake fresh biomass. In that way high stocking rates are get, during short periods, in an environment with dim shadow that allows the immediate intake of the shrubs and grasses biomass, followed by long periods of rest and recovery (Bacab-Pérez and Solorio-Sánchez 2011 and Murgueitio et al. 2015).

OTHER SHRUBS FOR BROWSING AT HIGH DENSITIES

Another researched species and increasingly widespread in recent years in the ISPS is Tithonia diversifolia known as tithonia, Mexican sunflower or the marigold. It is a herbaceous plant that reaches heights up to five meters, which is distributed naturally from the central and southern of Mexico, Central America and northern of South America, although today is found in several regions of the world including the Caribbean islands (Peters et al. 2002 and Maina et al. 2012). It is considered as a strategy in the assembly of ISPS for their ability to adapt to various environmental conditions such as humid subtropical and tropical agro-ecosystems, sub-humid and mountainous. In equatorial areas it is adapted from sea level up to 2500 m o.s.l and from 800 up to 5000 mm of annual precipitation (Calle and Murgueitio 2008). It adapts to multiple edaphic conditions as sandy soil, loam, clay with wide spectrum of fertility, although it emphasizes especially its adaptation to soils from acid to very acid with high presence of iron and aluminum ions which are limiting for good Leucaena leucocephala performance (Rivera et al. 2011 and Mauricio et al. 2014).

The regrowth capacity and rapid growth, the high protein value, calcium (Ca) and phosphorus (P) in the foliage (leaves and green stems) and their tolerance to browsing and trampling by cattle have favored the research papers and technology adaptation of Botón de Oro  as the main shrub in ISPS especially for milk production where it  is recorded that the quality of milk can improve (Mahecha et al. 2007, Pérez et al. 2009 and Mauricio et al. 2014) or not alters milk composition when is used as partial replacement of soybeans and corn in diets for cows of high milk production (Ribeiro et al. 2015).

The multipurpose tree Guazuma ulmifolia (common name Guacimo or Caulote) is also of importance for the ISPS as forage source in browsing, besides that its fruits are edible by domestic animals and traditionally is used as shade for cattle, firewood and charcoal. At present research studies are performed in Mexico (Villa-Herrera et al. 2009 and Manriquez-Mendoza et al. 2011), Panama and Colombia management it with pruning as  forage shrub for browsing and high-density planting. This tree grows in flat lands and gently rolling from 27° north latitude in Mexico up to 28° South latitude in Paraguay and northern Argentina, and also in the Caribbean islands. It adapts to warm climates, as wet and dry, from the tropics and subtropics. It is found from sea level to 1200 meters altitude in premontane areas. Its optimum range of annual rainfall is between 700 and 1500 mm. Most of the natural range of guacimo is characterized by a dry season lasting from two to seven months (Cordero and Boshier 2003).

The protein content of guacimo varies between 13and17 % on leaves and 7-10% on fruits; in the young leaves crude protein varies between 16 and 23% in young stems and between 7 and 8%.A research carried out in Venezuela recorded crude protein level of 22.25%, gross energy of 15.96 kJ per gram of dry matter, 9.25% ash and low tannin content on guacimo leaves (Calle and Murgueitio 2011). Guazuma ulmifolia is important in the ISPS because it adapts to marginal areas restricted for Leucaena leucocephala as those with high groundwater level, flooded or subjected to periodic flooding. The researches focus on propagation systems more financial, in tropical cattle diets (Creole Dairy Mexican), dual purpose systems or tropical hair sheep for farmers as well as direct sowing with mechanization (Villa-Herrera et al.2009 Galindo et al. 2010 and Manriquez-Mendoza et al. 2011).

For areas of high tropical mountains between forage of shrub plants with potential for ISPS is the Sambucus peruviana Kunth (syn S. nigra), which in equatorial regions has a range of altitudinal adaptation from 2000-3500 m o.s.l. Its foliage is avidly intake by cattle, it is frost tolerant with rapid regrowth after the heavy falls in temperature and rapid recovery if it is compared with forage grown in these environments. The hedges or sambucus or linden barriers are useful to counteract the wind effects and promote the biological control of pests which affects grasses, especially the Kikuyu (Pennistum clandestinum). The sambucus performance in browsing conditions by cattle is still proven. (Murgueitio et al. 2013a).

ADAPTING TO CLIMATIC CHANGE WITH ISPS

Rehabilitation of strategic functions in soils.The agricultural forestry systems and silvopastoral systems, acts through several complementary mechanisms to protect the soil from the direct solar radiation thanks to the canopy cover and litter contribution (McNeely and Schroth 2006);  the increase of atmospheric nitrogen entry in the presence of shrubs and trees associated with specialized bacteria in fixing this element; the increase in nutrients availability as a result of the higher production and decomposition of trees biomass with higher recovery of nutrients from deeper soil layers thanks to the longest roots of trees (Nair 2011) and improvement in the soil physical properties and increase in microbial activity due to the penetration of tree roots (Nair et al. 2008 and Vallejo et al. 2012).

Some of these factors in turn reduce the vulnerability of these systems to extremes climatic phenomenon when conserve soil moisture and reduce the drying effect of high temperatures and wind on the productive stratum. In the highlands and temperate climates, trees and shrubs also help to reduce the impact of frost on the grasses (Murgueitio et al. 2013b).

The best conditions to soil level in turn favor the edaphic biota that can fulfill important functions. It has been possible to research the work of dung beetles and earthworms in the ISPS, to recover environmental services that are related with soil fertility and improvement in cattle productive systems. The mulch, shade and the particular microclimate conditions of the ISPS helps to restore the edaphic macrofauna, which, during mating and feeding process of beetles, it directly participates in the soil removal process which increases aeration and porosity, prevents compaction and improves the permeability and the water retention capacity (Giraldo et al. 2011).

Among the factors concerning the ISPS management that contribute to the conservation of the organisms diversity in the soil and biota in general, it is worth mentioning short occupation periods with instantaneous stocking rates (2 to 4 AU = 900 to 1800) kg, alternates with long rest periods (40 to 60 days) during which happens very little disturbance and soil and plants recover from grazing (Chará et al. 2015).

Increased product diversity in the system. A factor that significantly contributes to reducing vulnerability and increasing production within the system is the greatest diversity of animal and plant species. The inclusion of trees and shrubs in the silvopastoral system allows the generation of additional products such as firewood, wood for fences and construction, fruits and fibers, among others that contribute to diversify the incomes or reduce costs within the system, while increased the farmer economic alternatives. The higher diversity also promotes the provision of environmental services related to the biological control of grasses pests or the cattle ectoparasites, pollination and water regulation already mentioned (Murgueitio et al. 2015). Additionally many trees species produce fruits rich in sugars and protein that provides important nutrients to the animals in the most critical periods of the year (Cardozo 2007).

CLIMATIC CHANGE MITIGATION WITH ISPS

The meadows with good management, appropriate stocking rate according to the climatic season and the requirements of each forage species, without compaction, erosion and overgrazing; have valuable potential for storing organic carbon in the soil, due to the exchange dynamic of this element for the production and death of fine roots in the upper layers (Moreno and Lara 2003). Also the trees and shrubs of the SPS contribute to the high carbon capture per unit area (Montagnini et al. 2013). Research studies carried out in the Andean region (Valle del Cauca) in Colombia concluded that the soil at half a meter deep is the system component that stores more carbon with 94.6% of the total, equivalent to 555.43 Mg CO₂ ha^-1 in dry season and 559.27 Mg CO₂ ha^-1 in rainy season. This contribution is in addition to the carbon fixation in biomass is a test to the mitigation of climatic change (Arias-Giraldo et al. 2009).

DIFFUSION OF THE ISPS

The ISPS are promoted through alliances between governments, farmer organizations and institutions of cooperation for the sustainable rural development because they facilitate the ordering of the territory occupied by animal husbandry  and can be a tool to reduce pressure for deforestation (Calle et al. 2012), in the same way that favor the fight against  the climatic change when  having attributes for mitigation as lower gas emissions and higher carbon capture than conventional systems (Naranjo et al. 2012, Montagnini et al. 2013 and Harvey et al. 2013 ).

In the last years and partly by the reaction to the effects of climatic change and higher demand of livestock products in the regional and global market, it is active works in efforts to scale the benefits of agricultural forestry and silvopastoral systems to landscapes and regions. The processes are complex because they include elements of cultural change, state policies, technological development, farmer participation and hihger knowledge (Calle et al. 2013).

In many Latin American countries it is required to modify the weak in the institutional sustainability. For example in Central America, experts agree on the need of generate knowledge in an integrated way between researchers, professionals, technicians, extension workers and farmers while successful results and innovations require communication schemes aimed to public policy makers. For these, between the instruments that can be used, are the strengthening of the capacities of the technical equipments on the establishment and management of the SPS - ISPS, in the development of rural schools, the design of financial support instruments and payment for environmental services. It is stated that the success of these processes depends on the simultaneous and coordinated implementation of various incentives to reach social and economic synergies (Acosta et al. 2014).

Globally are consider major challenges in the livestock subsector due to the increase in world population and  the demand of animal protein, pressing  a rapid growth in the immediate future, especially in low-income economies and emerging. This growth must be done without affecting the base of natural resources, ensuring the animals welfare, generation of diversified products and safer food with better quality. The challenges require a concerted and shared action by governments and all sectors of society. For this reason since 2010 the Global Agenda for Sustainable Livestock exits, an initiative that seeks to perform the challenge of increasing the production of animal origin food as well as its impact on natural resources is reduced, the efficiency increased and the farmers livelihoods are protected in different parts of the world.

The agenda has more than fifty members recognized worldwide, including multilateral organizations such as FAO and the World Bank, as well as international research institutes, aid agencies, farmer organizations, private companies, universities and agencies of government research among others. The agenda hope to influence on the policies and initiatives that affect the animal protein production in the world and their social, environmental, ethical and health effects.

During the fifth international meeting had in Cali (Colombia) in October 2014, in recognition of progress in Latin America and the Caribbean, a global network of silvopastoral systems was proposed, with the strategic vision of becoming a knowledge platform and international exchanges on the integration of animal husbandry with forests and trees, and the communication link between the different actors involved with sustainable animal husbandry. Surely, the Intensive Silvopastoral Systems played an important role in this new initiative that will benefit other parts of the continent and the world.

After more than two decades of research and practical experience, the ISPS show evidence of having high efficiency to transform solar energy into plant biomass and this in meat, milk and other goods (wood, fruits) without resorting to fossil energy and agrochemicals products. There are also of interest in public policies and projects that seek the land and environmental management of lands and livestock systems because they help to the sustainable use of land and recover the economic potential and the generation of environmental services of agro ecosystems.

The Leucaena leucocephala and Tithonia diversifolia species are those with higher scientific support and practical application, as components of forage shrub stratum of high density that identifies the Intensive Silvopastoral System. Moreover, the Megathyrsus and Cynodon grasses genus are the most studied in ISPS, but it progress in the knowledge of other species cultivars (Urochloa, Brachiaria, Axonopus and Pennisetum).

REFERENCES

Acosta, A. 2010. “Cambio Climático y Desarrollo Pecuario: Desafíos Institucionales para el Desarrollo Sostenible de Sistemas Silvopastoriles en Centroamérica”. In: Ibrahim M. & Murgueitio E. (eds.), VI Congreso Latinoamericano de Agroforestería para la Producción Pecuaria Sostenible, (ser. Serie técnica, no.15), Turrialba, Costa Rica: CATIE, p. 160.

Acosta, A., Murgueitio, E., Zapata, C. & Solarte, A. 2014. “Establecimiento de sistemas agrosilvopastoriles institucionalmente sostenibles”. In: Acosta A. & Díaz T. (eds.), Lineamientos de Política para el desarrollo sostenible del sector ganadero, Organización Mundial de las Naciones Unidas para la Alimentación y la Agricultura (FAO), p. 112.

Arias-Giraldo, L. M., Camargo, J. C., Dossman, M. A., Echeverry, M. A., Rodríguez, J. A., Molina, C. H., Molina, E. J. & Melo, I. D. 2009. “Estimación de biomasa aérea y desarrollo de modelos alométricos para Leucaena leucocephala en sistemas silvopastoriles de alta densidad en el valle del Cauca, Colombia”. Recursos Naturales y Ambiente, 58: 32–39.

Ayala-Burgos, A. & Aguilar-Pérez, C. 2011. “Balance energético/proteico para intensificar la producción animal en los sistemas silvopastoriles”. In: III Congreso sobre Sistemas Silvopastoriles Intensivos para la ganadería sostenible del siglo XXI, Morelia, Michoacán, México.

Bacab-Pérez, H. M. & Solorio-Sánchez, F. J. 2011. “Oferta y consumo de forraje y producción de leche en ganado de doble propósito manejado en sistemas silvopastoriles en Tepalcatepec, Michoacán”. Tropical and Subtropical Agroecosystems, 13 (3): 271–278.

Broom, D. M., Galindo, F. A. & Murgueitio, E. 2013. “Sustainable, efficient livestock production with high biodiversity and good welfare for animals”. Proceedings of the Royal Society of London B: Biological Sciences, 280 (1771): 20132025.

Calle, D. Z. & Murgueitio, E. 2008. “El botón de oro: arbusto de gran utilidad para sistemas ganaderos de tierra caliente y de montana”. Carta Fedegan, 108: 54–63.

Calle, Z. & Murgueitio, E. 2011. “El guasimo: uno de los árboles más adaptables a los sistemas silvopastoriles del trópico americano”. Carta Fedegan, 121: 88–94.

Calle, Z., Murgueitio, E. & Chará, J. 2012. “Integrating forestry, sustainable cattle-ranching and landscape restoration”. Unasylva, 63 (1): 31–40.

Calle, Z., Murgueitio, E., Chará, J., Molina, C. H., Zuluaga, A. F. & Calle, A. 2013. “A strategy for scaling-up Intensive Silvopastoral Systems in Colombia”. Journal of sustainable forestry, 32 (7): 677–693.

Cardozo, A. 2007. “Los Frutos de Árboles Forrajeros en la Alimentación Animal”. In: II Seminario Nacional de Investigación Agroforestal en Venezuela, San Javier, Yaracuy, Venezuela: Fundación Polar.

Chará, J., Camargo, J. C., Calle, Z., Bueno, L., Murgueitio, E., Arias, L., Dossman, M. & Molina, C. H. 2015. “Servicios ambientales de Sistemas Silvopastoriles Intensivos: mejora en propiedades del suelo y restauración ecológica”. In: Montagnini F., Somarriba E., Murgueitio E., Fassola H. & Eibl B. (eds.), Sistemas Agroforestales. Funciones productivas, socioeconómicas y ambientales, (ser. Técnica, no. ser. 402), Turrialba, Costa Rica: CATIE, p. 454.

Chará, J. & Giraldo, C. 2011. Servicios Ambientales de la Biodiversidad en Paisajes Agropecuarios. Cali: Fundación CIPAV, 76 p.

Cordero, J. & Boshier, D. H. 2003. Árboles de Centroamérica. Un manual para extensionistas. Oxford Forestry Institute, Centro Agronómico Tropical de Investigación y Enseñanza (CATIE), 1080 p.

Corral-Flores, G., Rodríguez-Echavarría, M. E., Solorio-Sánchez, B., Alarcón-Rojo, A. D., Grado-Ahuir, J. A., Rodríguez-Muela, C., Cortés-Palacios, L., Segovia-Beltrán, V. E. & Solorio-Sánchez, F. J. 2012. “Calidad de la carne de bovinos engordados en un sistema silvopastoril intensivo en dos épocas del año”. In: IV Congreso Internacional Sobre Sistemas Silvopastoriles Intensivos en la Ganadería con Ciencia, Morelia, México, pp. 113–122.

Corral-Flores, G., Solorio-Sánchez, B., Rodríguez, C. & Ramírez, J. 2011. “La calidad de la carne producida en el sistema silvopastoril intensivo y su diferenciación en el mercado”. In: III Congreso sobre Sistemas Silvopastoriles Intensivos, para la ganadería sostenible del siglo XXI, Morelia y Tepalcatepec, México.

Fajardo, D., Johnston, R., Neira, L., Chará, J. & Murgueitio, E. 2010. “Influencia de los sistemas silvopastoriles en la diversidad de aves en la cuenca del río La Vieja, Colombia”. Recursos Naturales y Ambiente, 58: 9–16.

Galindo, W., Naranjo, J. F., Murgueitio, M., Galindo, V. A. & Tatis, R. 2010. “Producción de carne bovina con sistemas silvopastoriles intensivos basados en Guazuma ulmifolia y otras especies en la región del Caribe seco de Colombia”. In: Ibrahim M. & Murgueitio E. (eds.), VI Congreso Latinoamericano Agroforestería para la Producción Agropecuaria Sostenible, Panamá, Available: <http://www.cipav.org.co/red_de_agro/Panama2010.html>.

Gaviria, X., Sossa, C. P., Montoya, C., Chará, J., Lopera, J. J., Córdoba, C. P. & Barahona, R. 2012. “Producción de Carne Bovina en Sistemas Silvopastoriles Intensivos en el Trópico Bajo Colombiano”. In: Martins R. (ed.), VII Congreso Latinoamericano de Sistemas Agroforestales para la Producción Animal Sostenible Belén, Pará, Brasil, Versión digital.

Giraldo, C., Escobar, F., Chara, J. D. & Calle, Z. 2011. “The adoption of silvopastoral systems promotes the recovery of ecological processes regulated by dung beetles in the Colombian Andes”. Insect Conservation and Diversity, 4 (2): 115–122.

Harvey, C. A., Chacón, M., Donatti, C. I., Garen, E., Hannah, L., Andrade, A., Bede, L., Brown, D., Calle, A., Chará, J., Clement, C., Gray, E., Hoang, M. H., Minang, P., Rodríguez, A. M., Seeberg-Elverfeldt, C., Semroc, B., Shames, S., Smukler, S., Somarriba, E., Torquebiau, E., van Etten, J. & Wollenberg, E. 2013. “Climate-Smart Landscapes: Opportunities and Challenges for Integrating Adaptation and Mitigation in Tropical Agriculture”. Conservation Letters, 7 (2): 77–90, ISSN: 1755-263X, DOI: 10.1111/conl.12066.

Mahecha, L., Escobar, J. P., Suárez, J. F. & Restrepo, L. F. 2007. “Tithonia diversifolia (hemsl.) Gray (botón de oro) como suplemento forrajero de vacas F1 (Holstein por Cebú)”. Livestock Research for Rural Development, 19 (2): 1–6.

Mahecha, L., Murgueitio, M. M., Angulo, J., Olivera, M., Zapata, A., Cuartas, C. A., Naranjo, J. F. & Murgueitio, E. 2011. “Desempeño animal y características de la canal de dos grupos raciales de bovinos doble propósito pastoreando en Sistemas Silvopastoriles Intensivos”. Revista Colombiana de Ciencias Pecuarias, 24 (3): 470.

Maina, O. I., Abdulrazak, S. A., Muleke, C. I. & Fujihara, T. 2012. “Potential nutritive value of various parts of wild sunflower (Tithonia diversifolia) as source of feed for ruminants in Kenya”. Journal of Food, Agriculture and Environment, 10 (2): 632–635.

Manríquez-Mendoza, L. Y., López-Ortíz, S., Pérez-Hernández, P., Ortega-Jiménez, E., López-Tecpoyotl, Z. G. & Villarruel-Fuentes, M. 2011. “Agronomic and forage characteristics of Guazuma ulmifolia Lam”. Tropical and Subtropical Agroecosystems, 14: 453–463.

Mauricio, R. M., Ribeiro, R. S., Silveira, S. R., Silva, P. L., Calsavara, L., Pereira, L. G. & Paciullo, D. S. 2014. “Tithonia diversifolia for ruminant nutrition”. Tropical Grasslands-Forrajes Tropicales, 2 (1): 82–84.

McNeely, J. A. & Schroth, G. 2006. “Agroforestry and biodiversity conservation–traditional practices, present dynamics, and lessons for the future”. Biodiversity & Conservation, 15 (2): 549–554.

Molina, C. H., Molina, E. J., Giraldo, C., Calle, Z. & Murgueitio, E. 2011. “Resiliencia de los sistemas silvopastoriles intensivos a los efectos de cambio climático en el Valle del Cauca, Colombia”. In: III Congreso sobre Sistemas Silvopastoriles Intensivos para la ganadería sostenible del siglo XXI, Morelia, Michoacán, México, pp. 208–214.

Molina, I. C., Lemos, G. D., Montoya, S., Angarita, E., Rivera, J. E., Villegas, G., Cantet, J. M., Correa, G., Mayorga, O., Chará, J. & Barahona, R. 2015. “Emisiones de metano en sistemas de producción con y sin inclusión de Leucaena leucocephala”. In: Peri P. L. (ed.), IIICongreso Nacional de Sistemas Silvopastoriles: VII Congreso Internacional Sistemas Agroforestales, Argentina: INTA, pp. 611 – 615.

Molina, J. J., Ceballos, A., Murgueitio, E., Campos, R., Rosero, R., Molina, E. J., Molina, C. H. & Suárez, J. F. 2013. “Suplementación energética: clave para vacas en SSPi”. Revista Carta Fedegán, 138: 20–26.

Montagnini, F., Ibrahim, I. & Murgueitio, E. 2013. “Silvopastoral systems and climate change mitigation in Latin America”. Bois et Forêts des Tropiques, 316 (2): 3–16.

Moreno, F. H. & Lara, W. 2003. “Variación del carbono orgánico del suelo en bosques primarios intervenidos y secundarios”. In: Orrego S. A., del Valle J. I. & Moreno F. H. (eds.), Medición de la captura de carbono en ecosistemas forestales tropicales de Colombia: contribuciones para la mitigación del cambio climático, Bogotá, Colombia: Universidad Nacional de Colombia, Departamento de Ciencias Forestales, Centro Andino para la Economía en el Medio Ambiente.

Murgueitio, E., Calle, Z., Uribe, F., Calle, A. & Solorio, B. 2011. “Native trees and shrubs for the productive rehabilitation of tropical cattle ranching lands”. Forest Ecology and Management, 261 (10): 1654–1663.

Murgueitio, E., Chará, D., Uribe, F. & Galindo, W. 2013a. “Los Sistemas Silvopastoriles en regiones con heladas. Experiencias en Colombia”. In: I Simpósio Internacional de Arborização de Pastagens em Regiões Subtropicais, Curitiba, Paraná, Brasil.

Murgueitio, E., Chará, J. D., Solarte, A. J., Uribe, F., Zapata, C. & Rivera, J. E. 2013b. “Agroforestería Pecuaria y Sistemas Silvopastoriles Intensivos (SSPi) para la adaptación ganadera al cambio climático con sostenibilidad”. Revista Colombiana de Ciencias Pecuarias, 26: 313–316.

Murgueitio, E., Flores, M., Calle, Z., Chará, J., Barahona, R., Molina, C. & Uribe, F. 2015. “Productividad en sistemas silvopastoriles intensivos en América Latina”. In: Montagnini F., Somarriba E., Murgueitio E., Fassola H. & Eibl B. (eds.), Sistemas Agroforestales. Funciones productiva, socioeconómica y ambientales, (ser. Técnica, no. ser. 402), Turrialba, Costa Rica: CATIE-Fundación CIPAV, pp. 59–101.

Nair, P. K. 2011. “Agroforestry systems and environmental quality: introduction”. Journal of environmental quality, 40 (3): 784–790.

Nair, P. K. R., Gordon, A. M. & Mosquera-Losada, M. R. 2008. “Agro-forestry”. In: Jorgensen S. E. & Fath B. D. (eds.), Ecological Engineering. Encyclopedia of Ecology, vol. 1, Oxford, Elsevier, pp. 101–110.

Naranjo, J. F., Cuartas, C. A., Murgueitio, E., Chará, J. & Barahona, R. 2012. “Balance de gases de efecto invernadero en sistemas silvopastoriles intensivos con Leucaena leucocephala en Colombia”. Livestock Research for Rural Development, 24: 8.

Patiño, V. M. 2002. Historia y distribución de los Frutales Nativos del Neotrópico. (no. ser. 326), Cali, Colombia: Centro Internacional de Agricultura Tropical (CIAT), Asociación Hortofrutícola de Colombia (ASOHOFRUCOL), Fondo Nacional de Fomento Hortofrutícola, 655 p.

Pérez, A., Montejo, I., Iglesias, J., López, O., Martín, G., García, D., Milián, Y. & Hernández, A. 2009. “Tithonia diversifolia (Helms.) A. Gray”. Pastos y Forrajes, 32 (1): 1–15.

Peters, M., Franco, L. H., Schmidt, A. & Hincapié, B. 2002. Especies forrajeras multipropósito: Opciones para productores de Centroamérica. CIAT, 124 p., ISBN: 978-958-694-048-1.

Peters, M., Herrero, M., Fisher, M., Erb, K.-H., Rao, I., Subbarao, G. V., Castro, A., Arango, J., Chará, J., Murgueitio, E. & others 2013. “Challenges and opportunities for improving eco-efficiency of tropical forage-based systems to mitigate greenhouse gas emissions”. Tropical Grasslands-Forrajes Tropicales, 1 (2): 156–167.

Reyes, E. 2015. “Análisis de los benefícios de la adopción de sistemas silvopastoriles en la Producción de carne y leche en Colombia. (Estudios de caso)”. In: Peri P. L. (ed.), III Congreso Nacional de Sistemas Silvopastoriles: VII Congreso Internacional Sistemas Agroforestales, Argentina: INTA, pp. 459–462.

Ribeiro, R. S., Chaves, A. V., Silveira, S. R., Sacramento, J. P., Delarota, G. D., Freitas, D. S., Tomich, T. R., Pereira, L. G. R. & Mauricio, R. M. 2015. “The effects of Tithonia diversifolia on dairy cow performance”. In: XXIII International grassland congress, India.

Rivera Herrera, J. E., Molina Botero, I. C., Donney´s Lemos, G., Villegas Sánchez, G. & Barahona Rosales, R. 2015. “Análisis de los benefícios de la adopción de sistemas silvopastoriles en la Producción de carne y leche en Colombia. (Estudios de caso)”. In: Peri P. L. (ed.), III Congreso Nacional de Sistemas Silvopastoriles: VII Congreso Internacional Sistemas Agroforestales, Argentina: INTA, pp. 176–181.

Rivera, L. F., Armbrecht, I. & Calle, Z. 2013. “Silvopastoral systems and ant diversity conservation in a cattle-dominated landscape of the Colombian Andes”. Agriculture, ecosystems & environment, 181: 188–194.

Uribe, F., Zuluaga, A. F., Valencia, L., Murgueitio, E., Zapata, A. & Solarte, L. 2011. Establecimiento y manejo de sistemas silvopastoriles. Proyecto Ganadería Colombiana Sostenible, no. 1, Bogotá, Colombia: GEF, The World Bank, FEDEGAN, CIPAV, Fondo Acción, TNC, p. 78, Available: <http://www.cipav.org.co/pdf/1.Establecimiento.y.manejo. de.SSP.pdf> .

Uribe, P., Castaño, K., Murgueitio, E., Uribe, F., Xóchitl, M., Valencia, L., Molina, E. J., Molina, C. H., Molina, J. J. & Suarez, J. F. 2013. “Sistemas silvopastoriles intensivos para producir carne ovina”. Revista de Carne, 5: 56–59.

Vallejo, V. E., Arbeli, Z., Terán, W., Lorenz, N., Dick, R. P. & Roldan, F. 2012. “Effect of land management and Prosopis juliflora (Sw.) DC trees on soil microbial community and enzymatic activities in intensive silvopastoral systems of Colombia”. Agriculture, ecosystems & environment, 150: 139–148.

Villa-Herrera, A., Nava-Tablada, M. E., López-Ortiz, S., Vargas-López, S., Ortega-Jiménez, E. & López, F. G. 2009. “Utilización del Guácimo (Guazuma ulmifolia Lam) como Fuente de forraje en la ganadería bovina extensive del trópico mexicano”. Tropical and Subtropical Agroecosystems, 10 (2): 253–261.

Wilkins, R. J. 2000. “Forages and their Role in Animal Systems”. In: Givens D. I., Owen E., Axford R. F. E. & Omed H. D. (eds.), Forage Evaluation in Ruminant Nutrition, Wallingford, UK: CAB International, pp. 1–14.

E. Murgueitio, Centro para la Investigación en Sistemas Sostenibles de Producción Agropecuaria, CIPAV, Cali, Colombia. Email: enriquem@fun.cipav.org.co