Tree and litter composition influences soil macrofauna in multi-strata agroforestry systems of Talamanca, Costa Rica

Humanity is facing a rapid decline in global biodiversity, caused mainly by tropical forest deforestation for industrial and smallholder agriculture. However, smallholder agriculture landscapes host areas of home gardens and other agroforestry systems (AFS) that have proven highly relevant for soil and biodiversity conservation. The positive interactions between aboveground and below-ground biodiversity is probably a key element to understand and promote the efficiency of these agro-ecosystems. To determine whether a relation exists between tree and soil macrofauna diversity and composition, we compared cacao AFS with contrasted tree diversity along a topography and forest cover gradient in Talamanca, Costa Rica. To determine which components of the tree cover composition (species), structure (density, richness, Shannon, Pielou) and agroforest floor (litter more ground cover) best explain the composition (orders and families) and structure (density, richness, Shannon, Pielou) of the macrofauna community we performed two separate redundancy analyses (composition and structure) and constructed the “best models” based on the tree composition, tree structure and agroforest floor as explanatory matrices. Macrofauna composition was best explained by a mix of tree species and litter composition variables (R2=26.5%) and macrofauna and vegetation share a low but significant co-variation with topography (R2=12%). Conversely, macrofauna structure is best explained by a selection of seven tree species (R2=10.9%). Tree evenness (Pielou index) only explained 7% of macrofauna community structure while other diversity indices were not correlated with macrofauna composition or structure. The soil macrofauna is therefore more influenced by tree and litter composition than by the overall diversity or evenness of the tree community. This information is important to design the optimal combinations of species for the intensification of production and ecosystem services provision in cacao-based AFS

Cocoa-based agroforestry vs fallow: what option for soil quality regeneration in the Peruvian amazon?

In the Peruvian Amazon, a significant amount of the agricultural landscape is cultivated with cocoa (Theobroma cacao) mostly grown under the shade of Musacea and timber trees. There, deforestation and its control are one of the main environmental issues for the Peruvian government and further, for the international community. In these landscapes, farmers who want to establish new plantations have the choice between tropical forest and degraded lands. Most of the latest are abandoned pastures or annual crops with mostly red ferralitic soils heavily unsaturated. As a response to the loss of fertility, farmers have currently two alternatives: entering illegally into the natural forest or practicing shifting cultivation on a long term basis that can reach more than 15 years. In this last case, the fallow lands, locally called “Purma”, are named under three categories according to the height of the pioneer vegetation: (i) low (10 years). Our study has been conducted with former coca farmers moved 20 years ago by the Peruvian government to the Ucayali department to produce cocoa. There, we compared soil quality, cadmium content and plant biomass including fine roots at 0-20 and 20-50 cm depth, among three land uses: (i) 31 agroforestry cocoa plantations at different ages, (ii) 24 low, 24 medium and 22 high “purmas”, and finally (iii) 22 forest patches as a control. Our results provide an interesting basis to discuss the ability of cocoa-based agroforestry systems to maintain and even restore soil fertility in degraded landscape at the Amazonian forest margin. The evolution of Cadmium content depending on land use and fallow period gives interesting indications for further investigations. (Résumé d'auteur

Impacto de la degradación de bosques ribereños en la riqueza y abundancia en Isoptera y Formicidae en la Amazonia Oriental

Formicidae e Isoptera han sido comúnmente usados en estudios de caracterización forestal. En el presente estudio se determinó el efecto de cuatro niveles de degradación de los bosques Pepital y Grande (Alcântara-Maranhão-Brasil) en la riqueza de hormigas y termitas, muestreados en los períodos seco y lluvioso con el método TSBF modificado. Para Formicidae fueron identificadas 85 especies, cuya riqueza fue mayor en el período seco, con diferencia significativa entre los bosques de sucesión secundaria comparadas con áreas de uso antrópico. Isoptera con 38 especies, mostró una riqueza mayor en los bosques secundarios en el periodo seco y en el río Grande en ambos periodos. Concluimos que la degradación tiene un fuerte efecto en la riqueza de termitas y de hormigas, con valores mínimos en el sistema de uso antrópico. Se destaca la potencialidad de los dos grupos como bioindicadores de degradación de los bosques ribereños.Formicidae and Isoptera have been commonly used in forest characterization studies. The objective in this study was determined the effect of four levels of degradation of Pepital and Grande forests (Alcantara-Maranhao-Brazil) on the Formicidae and Isoptera richness. Sampling was realized during dry and wet seasons, using the TSBF modified method. For Formicidae, 85 species were identified, its richness was higher in the dry season, also showed significant difference for secondary forests compared to anthropic use areas. For Isoptera, 38 species were identified, significant differences were observed in richness of secondary forests during the dry season and Grande forest for both season. We concluded that the degradation has a strong effect on the richness of ants and termites, with minimum values in the anthropic areas. We highlight the potential of the two groups as bioindicators of riparian forests degradation.Eje A4: Ambiente, Naturaleza y AgroecologíaFacultad de Ciencias Agrarias y Forestale

Impacto de la degradación de bosques ribereños en la riqueza y abundancia en Isoptera y Formicidae en la Amazonia Oriental

Formicidae e Isoptera han sido comúnmente usados en estudios de caracterización forestal. En el presente estudio se determinó el efecto de cuatro niveles de degradación de los bosques Pepital y Grande (Alcântara-Maranhão-Brasil) en la riqueza de hormigas y termitas, muestreados en los períodos seco y lluvioso con el método TSBF modificado. Para Formicidae fueron identificadas 85 especies, cuya riqueza fue mayor en el período seco, con diferencia significativa entre los bosques de sucesión secundaria comparadas con áreas de uso antrópico. Isoptera con 38 especies, mostró una riqueza mayor en los bosques secundarios en el periodo seco y en el río Grande en ambos periodos. Concluimos que la degradación tiene un fuerte efecto en la riqueza de termitas y de hormigas, con valores mínimos en el sistema de uso antrópico. Se destaca la potencialidad de los dos grupos como bioindicadores de degradación de los bosques ribereños.Formicidae and Isoptera have been commonly used in forest characterization studies. The objective in this study was determined the effect of four levels of degradation of Pepital and Grande forests (Alcantara-Maranhao-Brazil) on the Formicidae and Isoptera richness. Sampling was realized during dry and wet seasons, using the TSBF modified method. For Formicidae, 85 species were identified, its richness was higher in the dry season, also showed significant difference for secondary forests compared to anthropic use areas. For Isoptera, 38 species were identified, significant differences were observed in richness of secondary forests during the dry season and Grande forest for both season. We concluded that the degradation has a strong effect on the richness of ants and termites, with minimum values in the anthropic areas. We highlight the potential of the two groups as bioindicators of riparian forests degradation.Eje A4: Ambiente, Naturaleza y AgroecologíaFacultad de Ciencias Agrarias y Forestale

Impacto de la degradación de bosques ribereños en la riqueza y abundancia en Isoptera y Formicidae en la Amazonia Oriental

Formicidae e Isoptera han sido comúnmente usados en estudios de caracterización forestal. En el presente estudio se determinó el efecto de cuatro niveles de degradación de los bosques Pepital y Grande (Alcântara-Maranhão-Brasil) en la riqueza de hormigas y termitas, muestreados en los períodos seco y lluvioso con el método TSBF modificado. Para Formicidae fueron identificadas 85 especies, cuya riqueza fue mayor en el período seco, con diferencia significativa entre los bosques de sucesión secundaria comparadas con áreas de uso antrópico. Isoptera con 38 especies, mostró una riqueza mayor en los bosques secundarios en el periodo seco y en el río Grande en ambos periodos. Concluimos que la degradación tiene un fuerte efecto en la riqueza de termitas y de hormigas, con valores mínimos en el sistema de uso antrópico. Se destaca la potencialidad de los dos grupos como bioindicadores de degradación de los bosques ribereños.Formicidae and Isoptera have been commonly used in forest characterization studies. The objective in this study was determined the effect of four levels of degradation of Pepital and Grande forests (Alcantara-Maranhao-Brazil) on the Formicidae and Isoptera richness. Sampling was realized during dry and wet seasons, using the TSBF modified method. For Formicidae, 85 species were identified, its richness was higher in the dry season, also showed significant difference for secondary forests compared to anthropic use areas. For Isoptera, 38 species were identified, significant differences were observed in richness of secondary forests during the dry season and Grande forest for both season. We concluded that the degradation has a strong effect on the richness of ants and termites, with minimum values in the anthropic areas. We highlight the potential of the two groups as bioindicators of riparian forests degradation.Eje A4: Ambiente, Naturaleza y AgroecologíaFacultad de Ciencias Agrarias y Forestale

Sazonalidade da comunidade de macrofauna do solo em florestas ripárias da Amazônia Oriental

A pluviosidade é apontada como um dos principais fatores que alteram a composição, estrutura e atividade da macrofauna do solo nas regiões tropicais. O objetivo deste estudo foi avaliar a sazonalidade da macrofauna do solo em florestas ripárias localizadas na Amazônia Oriental. O estudo foi conduzido nas bacias hidrográficas dos rios Pepital e Grande, em Alcântara (MA), que apresenta as estações seca e chuvosa bem definidas. A amostragem de macrofauna foi realizada coletando-se monólitos de solo a 0,10 m de profundidade. A estação explicou 5,0% da variância total da comunidade de macrofauna (P=0,004), observando-se diferenças significativas na abundância de oito dos 30 grupos identificados. A abundância e atividade da macrofauna do solo são profundamente influenciadas pela sazonalidade do regime de chuvas, onde a condição de saturação periódica do solo nas florestas ripárias desfavorece a abundância de alguns grupos que compõem esta comunidade.Rainfall is considered as main factors that alter the composition, structure and activity of soil macrofauna in the tropical regions. This study aims to evaluate the seasonality of soil macrofauna in riparian forest located in the eastern Amazon. Our study was conducted in the riparian forest of Pepital and Grande rivers, Alcântara (MA). The climatic conditions are characterized by a well-defined dry and rainy seasons. The macrofauna sampling was performed collecting soil monoliths to 0.10 m depth. The season explained 5,0% of the total variability of the macrofauna community (P=0.004), observing significant differences in the abundance of eight of the 30 identified groups. The abundance and activity of soil macrofauna are highly influenced by the seasonality of rainfall, where the condition of periodic soil saturation in riparian forests disfavors the abundance of some groups that make up this community.Eje A4: Ambiente, Naturaleza y AgroecologíaFacultad de Ciencias Agrarias y Forestale

Sazonalidade da comunidade de macrofauna do solo em florestas ripárias da Amazônia Oriental

A pluviosidade é apontada como um dos principais fatores que alteram a composição, estrutura e atividade da macrofauna do solo nas regiões tropicais. O objetivo deste estudo foi avaliar a sazonalidade da macrofauna do solo em florestas ripárias localizadas na Amazônia Oriental. O estudo foi conduzido nas bacias hidrográficas dos rios Pepital e Grande, em Alcântara (MA), que apresenta as estações seca e chuvosa bem definidas. A amostragem de macrofauna foi realizada coletando-se monólitos de solo a 0,10 m de profundidade. A estação explicou 5,0% da variância total da comunidade de macrofauna (P=0,004), observando-se diferenças significativas na abundância de oito dos 30 grupos identificados. A abundância e atividade da macrofauna do solo são profundamente influenciadas pela sazonalidade do regime de chuvas, onde a condição de saturação periódica do solo nas florestas ripárias desfavorece a abundância de alguns grupos que compõem esta comunidade.Rainfall is considered as main factors that alter the composition, structure and activity of soil macrofauna in the tropical regions. This study aims to evaluate the seasonality of soil macrofauna in riparian forest located in the eastern Amazon. Our study was conducted in the riparian forest of Pepital and Grande rivers, Alcântara (MA). The climatic conditions are characterized by a well-defined dry and rainy seasons. The macrofauna sampling was performed collecting soil monoliths to 0.10 m depth. The season explained 5,0% of the total variability of the macrofauna community (P=0.004), observing significant differences in the abundance of eight of the 30 identified groups. The abundance and activity of soil macrofauna are highly influenced by the seasonality of rainfall, where the condition of periodic soil saturation in riparian forests disfavors the abundance of some groups that make up this community.Eje A4: Ambiente, Naturaleza y AgroecologíaFacultad de Ciencias Agrarias y Forestale

Sazonalidade da comunidade de macrofauna do solo em florestas ripárias da Amazônia Oriental

A pluviosidade é apontada como um dos principais fatores que alteram a composição, estrutura e atividade da macrofauna do solo nas regiões tropicais. O objetivo deste estudo foi avaliar a sazonalidade da macrofauna do solo em florestas ripárias localizadas na Amazônia Oriental. O estudo foi conduzido nas bacias hidrográficas dos rios Pepital e Grande, em Alcântara (MA), que apresenta as estações seca e chuvosa bem definidas. A amostragem de macrofauna foi realizada coletando-se monólitos de solo a 0,10 m de profundidade. A estação explicou 5,0% da variância total da comunidade de macrofauna (P=0,004), observando-se diferenças significativas na abundância de oito dos 30 grupos identificados. A abundância e atividade da macrofauna do solo são profundamente influenciadas pela sazonalidade do regime de chuvas, onde a condição de saturação periódica do solo nas florestas ripárias desfavorece a abundância de alguns grupos que compõem esta comunidade.Rainfall is considered as main factors that alter the composition, structure and activity of soil macrofauna in the tropical regions. This study aims to evaluate the seasonality of soil macrofauna in riparian forest located in the eastern Amazon. Our study was conducted in the riparian forest of Pepital and Grande rivers, Alcântara (MA). The climatic conditions are characterized by a well-defined dry and rainy seasons. The macrofauna sampling was performed collecting soil monoliths to 0.10 m depth. The season explained 5,0% of the total variability of the macrofauna community (P=0.004), observing significant differences in the abundance of eight of the 30 identified groups. The abundance and activity of soil macrofauna are highly influenced by the seasonality of rainfall, where the condition of periodic soil saturation in riparian forests disfavors the abundance of some groups that make up this community.Eje A4: Ambiente, Naturaleza y AgroecologíaFacultad de Ciencias Agrarias y Forestale

Macrofauna as Indicator of Riparian Forests Degradation in the Eastern Brazilian Amazonia

La macrofauna del suelo es ampliamente usada como bioindicadora de calidad ambiental. En este trabajo se estudió el efecto de la degradación forestal de bosques ribereños sobre la abundancia y composición de grupos taxonómicos y funcionales de macroinvertebrados en las cuencas Pepital y Grande, Alcântara, Maranhão - Brasil. Se tomaron muestras en la estación seca en zonas con cuatro niveles de degradación forestal utilizando el método TSBF modificado. Los organismos fueron clasificados en grandes grupos taxonómicos y funcionales. Se calculó la densidad media por grupo, densidad total y riqueza media, índices de Shannon, Simpson y Pielou. Patrones de distribución fueron observados a través del Análisis de Componentes Principales entre Clases (ACP-C). Los resultados indicaron que la degradación forestal tiene influencia directa sobre la abundancia y la diversidad de la macrofauna del suelo. La mayor riqueza y densidad total fueron observadas en las áreas conservadas (vegetación secundaria >7m y bosques maduros >15m). Los grupos de hormigas (Formicidae, Latreille) y termitas (Isoptera, Brullé) fueron dominantes con 80,5% de la abundancia total. El análisis de componentes principales fue altamente significativo (p=0.0001) e indicó que el 45,6% de la comunidad total de la macrofauna responde negativamente a la degradación forestal. Los grupos de opiliones (Opilionida, Sundevall), caracoles (Gastropoda, Cuvier), lombrices (Oligochaeta, Lamarck) y cochinillas (Isopoda, Latreille) se relacionan estrechamente con las áreas conservadas, al igual que los grupos saprófagos y herbívoros, los cuales mostraron preferencia por los bosques maduros (>15m). La ausencia de estos grupos indica el fuerte efecto causado por la eliminación de bosques ribereñosSoil macrofauna is widely used as bioindicator of environmental quality. The objective of this study was to evaluate the effect of the forest degradation on the abundance and composition of soil macrofauna groups for the selection of potential bioindicators in two micro-basins, Pepital and Grande, in the municipality of Alcântara, Maranhão-Brazil. We selected four levels of degradation. The sampling of macrofauna was held in the dry season using the modified method TSBF. Individuals collected were counted and classified in major taxonomic and functional groups. Total density and average richness by taxonomic group, richness, Shannon’s, Simpson's and Pielou’s indices were calculated. Patterns in macrofaunal distribution were observed through Between Class Principal Component Analysis (PCA-C). Results revealed the diversity of soil macrofauna were influenced by the level of degradation. The highest species richness and total density were observed in the conserved areas (secondary forest >7m and mature forests >15m). Ants (Formicidae, Latreille) and termites (Isoptera, Brullé)were dominant (80.5% of total abundance). The PCA-C was highly significant (p=0.0001) and showed 45.6% of total community of macrofauna respond negatively to degradation. Groups as Opilionida (Sundevall), Gastropoda (Cuvier), Oligochaeta (Lamarck) and Isopoda (Latreille) and functional groups as saprophagous and herbivores are related most strongly with mature forest (>15m), their absent can to indicate the high effect caused by the elimination of riparian forest.Facultad de Ciencias Agrarias y Forestale