Diversity In Agroforestry Systems Research Articles

Plant Diversity and Conservation Role of Three Indigenous Agroforestry Systems of Southeastern Rift-Valley Landscapes, Ethiopia

Woody and non-woody plant species conservation is one of the ecosystem services provided by agroforestry (AF) systems across the agricultural landscapes. Little attention has been paid to assessing the conservation of plant diversity in AF systems. This study was, thus, aimed at investigating plant species diversity, structure, and composition of three AF systems in Gedeo zone of south-eastern rift–valley agricultural landscape of Ethiopia. The study was conducted in three agroforestry systems, namely, enset based, coffee–enset based (C–E based AF), and coffee–fruit trees–enset based (C–Ft–E based AF) agroforestry systems. Twenty farms representative of each AF system were randomly selected, and inventory of the floristic diversity was employed in a 10 m × 10 m sample plot per farm. A total of 52 perennial woody and non-woody plant species belonging to 30 families were recorded. Of all species identified, 33 (63.5%) were native, of which two species, namely Millettia ferruginea (Hochst.) Baker and Erythrina brucei Schweinf., were registered as endemic. The highest proportion of native species was recorded in enset based AF (93.3%), and the least were in C–Ft–E based AF (59%). According to the IUCN Red List and local criteria, 13 species were recorded as being of interest for conservation in all AF systems. The woody species Prunus africana was identified as both vulnerable by IUCN Red List and rare for 25% of species that least occur. The Shannon diversity index and richness showed that C–Ft–E based AF systems were significantly different from the two remaining AF systems. However, the species abundance and evenness did not show significant differences between the three AF systems. In general, retaining such numbers of woody and non-woody perennial plant species richness under the AF systems of the present study underlines their potential for biodiversity conservation.

Seasonal variation of arthropod diversity in agroforestry systems in the humid tropics of Mexico

Seasonal variation of arthropod diversity in agroforestry systems in the humid tropics of Mexico

Floristic diversity in agroforestry systems in the state of Rio de Janeiro

The present article brings together existing plant diversity in agroforestry systems (AFS) in the state of Rio de Janeiro. The survey was carried out with digital databases, using terms in Portuguese and English, such as: ‘‘sistemas agroflorestais RJ’’, ‘‘agrofloresta RJ’’, ‘‘agroforestry RJ’’, and ‘‘agroforestry systems RJ’’, with fourteen AFSs being verified. The species present in the agroforests of Rio de Janeiro were listed when present in at least five of the fourteen AFSs found (35.71%). Fifteen species (8.82%) were among the most common, out of a total of 170 different species found, demonstrating the diversity of AFSs. Plant species are located in the following cities in the state of Rio de Janeiro: Seropédica, Rio de Janeiro, Três Rios, Paraty and Nova Friburgo. The most mentioned species were papaya (Carica papaya L.) and annatto (Bixa orellana L.). More AFSs were analyzed in the Metropolitan Region within the state of Rio de Janeiro, highlighting the municipality of Seropédica. Agroforests can contribute to the conservation or restoration of plant diversity, while promoting food and nutritional sovereignty and security, community subsistence, and local commercialization, among other benefits.

Species ethnobotanical values rather than regional species pool determine plant diversity in agroforestry systems

The conversion of natural systems into farms and agroecosystems is the main cause of biodiversity loss. In human-dominated landscapes, understanding the interactions between agroforestry systems and adjacent natural vegetation is fundamental to developing sustainable agricultural systems. Species can move between these two systems with natural systems providing the regional pool of species that shape the agricultural values and conservation value of the agroforestry systems. We investigated the influence of neighboring natural habitats on traditional agroforestry systems in the buffer zone of Pendjari Biosphere Reserve in Benin to understand the contribution of regional processes on the quality of agroforestry systems. We expected that agroforestry parklands adjacent to natural vegetation with high species diversity will also have higher plant species diversity. We found no similarity in plant species composition between agroforestry systems and adjacent natural habitats. A small proportion of species in adjacent natural habitats were found in agroforestry systems. The proportion of shared species was not significantly influenced by plant diversity in adjacent natural habitats or the distance from the agroforestry systems to the natural adjacent habitat. However, plant diversity in agroforestry systems was strongly associated with site ethnobotanical values indicating that farmers act as a supplemental but severe environmental filter of the regional species pool. Our study suggests that promoting the plantation of plants with high ethnobotanical use-value is a potentially viable strategy for sustainable agriculture and ecological restoration in Biosphere reserves.

Conservation of Plant Diversity in Agroforestry Systems in a Biodiversity Hotspot Region of Northeast India

In Assam, a north-eastern state of India, most of the traditional agroforestry systems are still practised. The plant species composition of three agroforestry systems namely homegardens tea gardens and agrisilvicultural systems, were assessed using quadrat method. A total of 516 plant species belonging to 241 genera under 91 families were recorded, which consisted of 134 trees, 143 shrubs (67 shrub species and 76 species of saplings) and 239 herbs (93 herb species, 33 climber species and 113 species of seedlings). Homegardens had the highest species richness (475 plant species) belonging to 234 genera under 90 families. This was followed by agrisilvicultural systems (101 spp., 43 genera, 29 families), and the least was in tea gardens (79 spp., 41 genera, 25 families). The highest average number of plant species per system was recorded in homegarden (108.96 ± 5.96, range 23–207 spp.). A negative correlation was found between the agroforestry system plot size and plant species richness. Sorenson’s similarity index showed a very low degree of similarity in the plant species recorded among the three selected systems. Out of 516 plant species recorded across the different agroforestry systems, 1.0% species (n = 3) were vulnerable (Aquilaria malaccensis, Saraca asoca and Santalum album), 8.9% species (n = 46) were least concerned, 1.6% species (n = 8) were data deficient and 88.6% species (n = 457) were not assessed. Only homegarden recorded all the three plant species under the vulnerable category of IUCN Red List. It can be concluded that the agroforestry systems, specially the homegardens harbour rich plant diversity and act as miniature versions of natural forests by conserving rare, threatened and data-deficient plant species. The results suggest that the agroforestry systems with some management interventions need to be promoted as conservation models in areas with high pressure on tropical forests.

Local biodiversity conservation in Sigi, Central Sulawesi, Indonesia: Analysis of the effect of elevation, land accessibility, and farmers’ income and perception on vegetation diversity in agroforestry systems

Lestari ND, Suprayogo D, Rachmansyah A. 2018. Local biodiversity conservation in Sigi, Central Sulawesi, Indonesia: Analysis of the effect of elevation, land accessibility, and farmers’ income and perception on vegetation diversity in agroforestry systems. Biodiversitas 19: 283-291. The objectives of the research were to evaluate the level of landscape vegetation diversity in agroforestry systems and to determine the effect of elevation, accessibility, and farmer's income and perception on vegetation diversity in agroforestry systems. The research was conducted in Sigi District, Central Sulawesi, Indonesia. The method used was the Multidisciplinary Landscape Assessment approach. The research sites were located in 3 districts and 6 representative villages i.e. Padende and Sibedi in the lower landscape (23-75 m asl.), Balane and Doda in the middle landscape (148-504 m asl.), Dombu and Ongulero in the upper landscape (1163-1404 m asl.), with 5 replications in each village. The total area of the six villages was 3772.13 ha that consisted of 1217.13 ha of agroforestry systems (32.3%). The research covered a population of 392 households who had landed with agroforestry systems. A total of 30 agroforestry farmers and their land (minimum 0.25 ha, homogeneous land system) were selected as samples. Research activities like observation, survey, and analysis were divided into two aspects, namely biophysical and socioeconomic aspects. The results revealed that at landscape level agroforestry systems had relatively high plant species diversity (H'= 3.1) and needed to be optimized to enhance its role as buffering zone for biodiversity conservation and for supporting sustainable livelihood. Efforts to improve vegetation diversity must be adjusted to habitat conditions (elevation and soil health), where vegetation can grow and produce well. The regional development such as accessibility improvement is still needed and it will not threaten the vegetation diversity as long as there is a harmony between human activities and the environment. An increase in the level of income with a positive perception of farmers on the benefits of vegetation diversity in the future will have a main role in vegetation diversity conservation as fundamental asset in sustainable development.

DIVERSIDADE E ESTRUTURA HORIZONTAL DE SISTEMAS AGROFLORESTAIS EM MONTE ALEGRE, PARÁ

RESUMO: O estudo da fitossociologia é importante para a avaliação de sistemas agroflorestais, pois fornece dados que possibilitam manejo mais adequado do sistema. O objetivo desse trabalho foi identificar espécies e caracterizar a estrutura horizontal e diversidade de sistemas agroflorestais no município de Monte Alegre, PA. Foram instaladas parcelas amostrais de 30 x 30 metros, onde coletou-se dados de diâmetro a altura do peito, número de espécies e altura total dos indivíduos. O sistema estudado possui seis arranjos com diferentes idades, no qual sua estrutura horizontal foi analisada através da abundância, dominância, frequência absoluta e relativa, obtidas a partir dos dados de indivíduos com DAP ? 5 cm. Para obter a diversidade de espécies foi usado o índice de Shannon-Weaver (H’). Os SAFs avaliados obtiveram um total de 253 indivíduos, em 12 famílias botânicas e 14 espécies. O índice de Shannon-Weaver (H') foi de 2,28, o que denota diversidade intermediária de espécies nos SAFs. A análise estrutural constatou que o mogno brasileiro (Swietenia macrophylla) foi a espécie com maior índice de importância, enquanto o mogno africano (Khaya ivorensis) obteve o maior índice de cobertura e dominância absoluta. Já o café (Coffea arabica) foi a espécie com maior densidade absoluta e a teca (Tectona grandis) a espécie com maior frequência absoluta.PALAVRAS-CHAVE: Agrossilvicultura, Arranjos florestais, Fitossociologia.

Impact of tree species on barley rhizosphere-associated fungi in an agroforestry ecosystem as revealed by 18S rDNA PCR-DGGE

Agroforestry systems have been considered a form of sustainable land use. Woody species in agroforestry systems can improve soil physicochemical properties by supplying leaf or stem litter. However, little is known about fungal community structure and diversity in agroforestry systems. In the present study, the culture-independent 18S rDNA-based polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) method was used to investigate fungal community structure in rhizosphere and bulk soil in Populus euramevicana-barley and Taxodium distichum-barley agroforestry systems. DGGE profiling and cluster analysis revealed that the fungal community structure in the rhizosphere was more complex than that of bulk soil. Our results also indicated that the rhizosphere fungal community in barley was less affected by T. distichum than by P. euramevicana. In addition, an increase in the relative abundance of certain rhizosphere fungal populations was detected in this agroforestry system. Sequencing of prominent DGGE bands revealed an increase in the rhizosphere of a fungal species belonging to the genera Chaetomium, which includes potential biocontrol agents. A rare cellulolytic fungus, Acremonium alcalophilum, was found in the bulk soil from P. euramevicana and barley grown under P. euramevicana. Taken together, our findings may provide new insights into agroforestry practices.

Status of microbial diversity in agroforestry systems in Tamil Nadu, India.

Soil is a complex and dynamic biological system. Agroforestry systems are considered to be an alternative land use option to help and prevent soil degradation, improve soil fertility, microbial diversity, and organic matter status. An increasing interest has emerged with respect to the importance of microbial diversity in soil habitats. The present study deals with the status of microbial diversity in agroforestry systems in Tamil Nadu. Eight soil samples were collected from different fields in agroforestry systems in Cuddalore, Villupuram, Tiruvanamalai, and Erode districts, Tamil Nadu. The number of microorganisms and physico-chemical parameters of soils were quantified. Among different microbial population, the bacterial population was recorded maximum (64%), followed by actinomycetes (23%) and fungi (13%) in different samples screened. It is interesting to note that the microbial population was positively correlated with the physico-chemical properties of different soil samples screened. Total bacterial count had positive correlation with soil organic carbon (C), moisture content, pH, nitrogen (N), and micronutrients such as Iron (Fe), copper (Cu), and zinc (Zn). Similarly, the total actinomycete count also showed positive correlations with bulk density, moisture content, pH, C, N, phosphorus (P), potassium (K), calcium (Ca), copper (Cu), magnesium (Mg), manganese (Mn), and zinc (Zn). It was also noticed that the soil organic matter, vegetation, and soil nutrients altered the microbial community under agroforestry systems.

Environmental filtering of agroforestry systems reduces the risk of biological invasion

Prevention is the most effective way of mitigating the negative impacts of exotic species invasions on biodiversity. Preventative measures include inhibiting the further dispersal and recruitment of established invasive species. We expect coffee production in agroforestry systems to reduce the recruitment of exotic species relative to monoculture stands because intercropped trees function as environmental filters that select for individuals with traits such as shade tolerance. If ecologically similar species are also closely related phylogenetically, such environmental filters should reduce phylogenetic diversity, supporting the coexistence of closely related species. Here, we test whether the taxonomic and phylogenetic diversity of native and exotic species in agroforestry systems is lower than in monocultures. We sampled the understory in 180 plots distributed in both habitats in three study sites within the Araponga municipality, Brazil, and measured understory light availability. Phylogenetic diversity was calculated as the net relatedness index (NRI) and the nearest taxon index (NTI). Understory light availability was lower in agroforestry systems. Of the 48 species found, 25 occurred in agroforestry systems, three of which were exotics. Forty-two species were found in monoculture stands (including 13 exotics). As expected, NRI and NTI indicated lower phylogenetic diversity in agroforestry systems than in monoculture stands. Agroforestry systems provide less favorable habitats for exotic species, filtering them from the understory. The mechanisms that select against exotic species remain unknown; however, shading might exclude predominantly heliophytic exotic species from the agricultural matrix. Therefore, agroforestry systems may function as buffer zones preventing invasion into sensitive ecosystems.

Traditional Knowledge of Homegarden-Dry Field Agroforestry as a Tool for Revitalization Management of Smallholder Land Use in Kulon Progo, Java, Indonesia

Agroforestry homegarden-dry field are the last biodiversity resort of land management which synergizes the production and the conservation as well. Market orientation changes will encourage dry field homegarden monoculturization to be a threat. Based on these considerations homegarden-dry field has a degree of urgency for management revitalization to do. This study aims to determine the traditional knowledge of homegarden-dry field agroforestry management and its developer’s revitalization scheme. This research was conducted in Kulonprogo Regency, Java, Indonesia with three agroecological zones of the Kulon Progo Coastal Plain (cluster 1); Kulon Progo Plain (cluster 2) and Kulon Progo Hills-Mountains zone (cluster 3). The traditional practices that are developed in the agroforestry management can be seen from the space arrangement in the homegarden-dry fields that seems to be perfunctory. On its function connectivity there is an overlap among the cultivated species -trees and seasonal crops- but its productivity is low. However, crop and tree species diversity in agroforestry systems is higher compared to agriculture and forest crops. Based on these considerations then revitalization management of agroforestry homegarden-dry field (RMA-HD) is made by integrating in a single management unit. Through RMA-HD schemes, agroforestry in the outside part of the forest will have a new management approach, and may be promising for agroforestry reference in Indonesia, particularly for the pro-poor program which is compatible with the intensive smallholder management.

Comparing genetic diversity in agroforestry systems with natural forest: a case study of the important timber tree Vitex fischeri in central Kenya

It is possible that current tree domestication practices undertaken by farmers reduce the genetic base of tree resources on farms, raising concerns regarding the productivity, sustainability and conservation value of agroforestry ecosystems. Here, we assessed possible changes in genetic variation during domestication in the important and heavily utilised timber species, Vitex fischeri Gurke (syn. Vitex keniensis), by comparing geographically proximate forest and farm material in central Kenya. Employing RAPD analysis, a total of 104 polymorphic markers revealed by five arbitrary primers were scored in a total of 65 individuals, 32 from forest and 33 from farmland. Despite concerns of possible genetic erosion, forest and farm stands did not differ significantly in levels of genetic variation, with H values of 0.278 and 0.269, respectively. However, Mantel tests did reveal greater geographically related associative genetic structure among individuals in farm rather than forest material, with r M values of 0.217 and 0.114, respectively. A more detailed analysis of structure suggested this could be due to local variation in origin of some on-farm trees. Implications of data for the genetic management of V. fischeri stands during farmer-led tree domestication activities are discussed. At present, there appears little reason to reject on-farm V. fischeri as a source of germplasm for future on-farm planting or for conservation purposes, although this situation may change and will require monitoring.

Managing biological and genetic diversity in tropical agroforestry

The issues of biological and genetic diversity management in agroforestry are extremely complex. This paper focuses on genetic diversity management and its implications for sustainable agroforestry systems in the tropics, and presents an analysis of the role and importance of inter- and intra-specific diversity in agroforestry. Diversity within and between tree species in traditional agroforestry systems and modern agroforestry technologies in the tropics is assessed, with a view to understanding the functional elements within them and assessing the role and place of diversity. The assessment shows that although the practice of agroforestry has been a diversity management and conservation system, research in agroforestry over time has de-emphasized the diversity element; nevertheless farmers do value diversity and do manage agroforestry from that perspective. Based on a profiling of various traditional agroforestry systems and research-developed technologies, a strong case is made for increased species-and genetic diversity, at both inter- and intra-specific levels. The review and analysis point to the need for increased awareness, training/education, partnerships and collaborative efforts in support of genetic diversity in agroforestry systems; of special importance is increased cross-disciplinary research.