Abstract

Conservation and development practitioners increasingly promote community forestry as a way to conserve ecosystem services, consolidate resource rights, and reduce poverty. However, outcomes of community forestry have been mixed, with many initiatives failing to achieve intended objectives. There is a rich literature on community forestry institutional arrangements, but fewer efforts to examine the role of socioeconomic, market, and biophysical factors in shaping both land cover change dynamics, and individual and collective livelihood outcomes. We systematically reviewed the peer-reviewed literature on community forestry to examine and quantify existing knowledge gaps about these factors in the community forestry literature. In examining 697 cases of community forest management, extracted from 267 peer-reviewed publications, we find three key trends that limit our understanding of community forestry. First, there are substantial data gaps linking population dynamics, market forces, and biophysical characteristics to both environmental and livelihood outcomes. Second, most studies focus on environmental outcomes, and the majority of studies that do assess socio-economic outcomes rely on qualitative data, making it difficult to make comparisons across cases. Finally, we find a heavy bias towards studies on South Asian forests, indicating that the literature on community forestry might not be representative of decentralization policies and community forest management globally.

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Abstract

Approaches to prioritize conservation actions are gaining popularity. However, limited empirical evidence exists on which species might benefit most from threat mitigation and on what combination of threats, if mitigated simultaneously, would result in the best outcomes for biodiversity. We devised a way to prioritize threat mitigation at a regional scale with empirical evidence based on predicted changes to population dynamics—information that is lacking in most threat-management prioritization frameworks that rely on expert elicitation. We used dynamic occupancy models to investigate the effects of multiple threats (tree cover, grazing, and presence of an hyperaggressive competitor, the Noisy Miner (Manorina melanocephala) on bird-population dynamics in an endangered woodland community in southeastern Australia. The 3 threatening processes had different effects on different species. We used predicted patch-colonization probabilities to estimate the benefit to each species of removing one or more threats. We then determined the complementary set of threat-mitigation strategies that maximized colonization of all species while ensuring that redundant actions with little benefit were avoided. The single action that resulted in the highest colonization was increasing tree cover, which increased patch colonization by 5% and 11% on average across all species and for declining species, respectively. Combining Noisy Miner control with increasing tree cover increased species colonization by 10% and 19% on average for all species and for declining species respectively, and was a higher priority than changing grazing regimes. Guidance for prioritizing threat mitigation is critical in the face of cumulative threatening processes. By incorporating population dynamics in prioritization of threat management, our approach helps ensure funding is not wasted on ineffective management programs that target the wrong threats or species.

El Uso de Modelos Empíricos de la Colonización de Especies bajo Procesos Múltiples de Amenazas para Identificar Estrategias Complementarias de Mitigación de Amenazas

Resumen

Las estrategias para priorizar las acciones de conservación están ganando popularidad. Sin embargo, existe evidencia empírica limitada sobre cuáles especies pueden beneficiarse más de la mitigación de amenazas y sobre cuál combinación de amenazas, si son mitigadas simultáneamente, tendría mejores resultados para la biodiversidad. Diseñamos una forma de priorizar la mitigación de amenazas a escala regional con evidencia empírica basada en los cambios pronosticados para las dinámicas poblacionales – información faltante en la mayoría de los marcos de trabajo de priorización que dependen de la obtención de información de expertos. Usamos modelos de ocupación dinámica para investigar los efectos de las amenazas múltiples (cobertura de árboles, pastoreo y presencia de un competidor hiperagresivo, Manorina melanocephala) sobre las dinámicas poblacionales de las aves de una comunidad boscosa en peligro de extinción en el sureste de Australia. Los tres procesos amenazantes tuvieron diferentes efectos sobre diferentes especies. Usamos probabilidades de colonización de fragmentos para estimar el beneficio de remover una o más amenazas para cada especie. Después determinamos el conjunto complementario de estrategias de mitigación de amenazas que maximizaron la colonización de todas las especies, a la vez que aseguraban que se evitaran las acciones redundantes y con pocos beneficios. La única acción que resultó en la mayor colonización fue el incremento de la cobertura de árboles, lo que aumentó la colonización del fragmento en un 5 % y 11 % en promedio para todas las especies y para las especies en declive, respectivamente. Combinar el control de Manorina melanocephala con el incremento de la cobertura de árboles aumentó la colonización de especies en un 10 % y 19 % en promedio para todas las especies y para las especies en declive, respectivamente, y fue una mayor prioridad que cambiar los regímenes de pastoreo. La guía es crítica para la priorización de mitigación de amenazas de frente a los procesos amenazantes acumulativos. Si incorporamos las dinámicas poblacionales en la priorización del manejo de amenazas, nuestra estrategia ayuda a asegurar que el financiamiento no se desperdicie en programas de manejo poco efectivos que enfoquen las amenazas o las especies incorrectas.

Abstract

Multibillion dollar investments in land restoration make it critical that conservation goals are achieved cost-effectively. Approaches developed for systematic conservation planning offer opportunities to evaluate landscape-scale, temporally dynamic biodiversity outcomes from restoration and improve on traditional approaches that focus on the most species-rich plantings. We investigated whether it is possible to apply a complementarity-based approach to evaluate the extent to which an existing network of restoration plantings meets representation targets. Using a case study of woodland birds of conservation concern in southeastern Australia, we compared complementarity-based selections of plantings based on temporally dynamic species occurrences with selections based on static species occurrences and selections based on ranking plantings by species richness. The dynamic complementarity approach, which incorporated species occurrences over 5 years, resulted in higher species occurrences and proportion of targets met compared with the static complementarity approach, in which species occurrences were taken at a single point in time. For equivalent cost, the dynamic complementarity approach also always resulted in higher average minimum percent occurrence of species maintained through time and a higher proportion of the bird community meeting representation targets compared with the species-richness approach. Plantings selected under the complementarity approaches represented the full range of planting attributes, whereas those selected under the species-richness approach were larger in size. Our results suggest future restoration policy should not attempt to achieve all conservation goals within individual plantings, but should instead capitalize on restoration opportunities as they arise to achieve collective value of multiple plantings across the landscape. Networks of restoration plantings with complementary attributes of age, size, vegetation structure, and landscape context lead to considerably better outcomes than conventional restoration objectives of site-scale species richness and are crucial for allocating restoration investment wisely to reach desired conservation goals.

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Abstract

Fruit selection, i.e., the consumption of fruits disproportionately to their availability, results from the interaction between diet preferences and ecological factors that modify them. We assessed the importance of functional fruit traits to explain fruit selection by birds in Andean subtropical forests, taking into account temporal variation in trait distribution in the assembly of available fruits. During 2 yr, we measured the abundance of ripe fruits and their consumption by birds in a 6-ha plot during 11 bimonthly samplings, and we used 17 phenological, morphological, and nutritional traits to characterize fruits selected by four bird species. Fruit selection was pervasive year-round, highly variable over time and across bird species. Fruit species were selected over time periods shorter than their ripening phenology, and the selection of fruits with particular traits was specific to the fruit-eating species. Maximization in pulp reward per consumed fruit seems to be the main driving force behind fruit selection, indicating that birds select fruits with traits that directly affect net energy gain. Our results can be interpreted in a framework of a hierarchy of foraging decisions, under which the spatiotemporal context of the fruiting environment modifies the relative intake rates of a particular fruit, while the ability to discriminate fruit contents becomes increasingly important on a smaller dimension. We show that fruit-selection properties are contingent on specific fruit traits and particular spatiotemporal conditions, which modify the structure of mutualistic interactions.

Resumen

La selección de frutos es el resultado de la interacción entre las preferencias de dieta de las aves y los factores ecológicos que las modifican. En este estudio, evaluamos la importancia de rasgos funcionales de frutos para explicar la selección de frutos por aves, teniendo en cuenta la variación temporal en la distribución de los rasgos en el ensamblaje de frutos disponibles en el ambiente. Medimos la abundancia de frutos maduros y su consumo por aves en 11 muestreos bimensuales en una parcela de 6 hectáreas. Utilizamos 17 rasgos fenológicos, morfológicos y nutricionales para caracterizar funcionalmente los frutos seleccionados por las cuatro especies de frugívoros más abundantes. La selección de frutos fue generalizada a lo largo del año, y muy variable en el tiempo y entre especies de aves. Las especies de frutos fueron seleccionadas por períodos de tiempo más cortos que el de su fenología de maduración, y la selección de frutos con rasgos particulares fue específica de cada especie de ave. La principal fuerza detrás de la selección de frutos parece ser la maximización de la recompensa en pulpa por fruto consumido, sugiriendo que las aves seleccionan frutos con rasgos que afectan directamente su ganancia neta de energía. Nuestros resultados pueden entenderse en una jerarquía de decisiones de forrajeo, según la cual el contexto espaciotemporal del ambiente fructificante modifica la tasa relativa de ingesta de una especie de fruto, y en una dimensión menor, prevalece la capacidad de discriminar el contenido de los frutos. Mostramos que las propiedades del proceso de selección de frutos son contingentes de determinados caracteres de los frutos y de condiciones particulares tales como la presencia de otras especies en fruto, las cuales modifican la estructura de las interacciones mutualistas.

Abstract

By harvesting scattered large trees, selective logging increases light availability and thereby stimulates growth and crown expansion at early-life stage among remnant trees. We assessed the effects of logging on total and merchantable bole (i.e., lowest branch at crown base) heights on 952 tropical canopy trees in French Guiana. We observed reductions in both total (mean, −2.3 m) and bole (mean, −2.0 m) heights more than a decade after selective logging. Depending on local logging intensity, height reductions resulted in 2–13 percent decreases in aboveground tree biomass and 3–17 percent decreases in bole volume. These results highlight the adverse effects of logging at both tree and stand levels. This decrease in height is a further threat to future provision of key environmental services, such as timber production and carbon sequestration.

Resume

L'abattage commercial de grands arbres en forêts tropicales crée des ouvertures dans la canopée. L'augmentation de lumière qui en résulte a pour effet de stimuler la croissance et l'expansion de la couronne des arbres sous-jacents. Dans cette étude, nous avons mesuré l'effet de l'intensité d'exploitation (i.e. biomasse perdue) sur la hauteur totale et du tronc (jusqu’à la base de la couronne) de 952 arbres de canopée en Guyane Française. Nous avons observés une réduction significative de la hauteur totale (moyenne : -2.3 m) et du tronc (moyenne : -2.0) plus d'une décennie après exploitation. En fonction de l'intensité d'exploitation, la réduction en hauteur observée induit une diminution de 2-13% de la biomasse épigée et 3-17% du volume du tronc. Ces résultats illustrent les conséquences néfastes de l'exploitation intensive à l’échelle de l'arbre et du peuplement. Une diminution de la hauteur des arbres en forêts tropicales exploitées est une menace supplémentaire sur la production future de services écosystemiques, tels que la production de bois ou la séquestration de carbone.

Abstract

Trichostrongylids nematodes are capilliform worms that parasitize the gastrointestinal tract of ruminants that frequently cause serious injuries such as severe gastroenteritis and acute anemia. Sheep breeds are highly susceptible to these parasites, including adult animals as well. In sheep herds, this parasitic disease is traditionally controlled through the use of antihelminthics; however, some possible auxiliary methods of control have been suggested, and among them is the adoption of the integration livestock–forest system. The aim of the present study was to evaluate comparatively the recovery of trichostrongylid nematode larvae (L3) from sheep in a integration livestock–forest system and in grass monoculture, also analyzing the climatic influence in the four seasons of the year. The study was carried out from December 2013 to September 2014 in the experimental field of Embrapa Agrosilvopastoral located in the municipality of Sinop/MT, Brazil. In each season of the year, each treatment received thirty samples of feces weighing 20 g and containing approximately 60,000 eggs of trichostrongylid nematodes. At the end of 14 days, the remaining feces from the soil surface, as well as soil below the deposition area, and the adjacent forage near the feces were collected and taken to the laboratory where the number of infective larvae per kilogram of dry matter (L3/kg DM) in each collected material was determined. The recovery of L3 larvae was possible in all seasons and in all samples collected. There was a significant interaction between treatments and seasons of the year (p < 0.05). The silvopastoral system showed greater counts of L3/kg DM in the forage during the spring, summer, and winter collections. The feces collected in the winter were the material with highest counts of L3/kg DM in the study, with 30,199 in silvopastoral area, and 22,020 in grass monoculture, which differed significantly (p < 0.05). The soil also showed the same response, with 6112.74 L3/kg DM in silvopastoral system and 4847.56 L3/kg DM in grass monoculture, which were also significantly different (p < 0.05).

Abstract

Terminalia chebula is very important herbal drug in Ayurvedic pharmacopeia and called “king of medicines” due to its vast therapeutic use. Variability study is prerequisite for any tree improvement programme. Magnitude of variability within and between population suggest proper domestication and improvement tool for enhancement of productivity of the species. In present study, five populations of T. chebula from its distribution zone in H.P., India were selected and fruit and pulp characters of 20 trees from each population studied to reveal within and between population variations. Result showed that there was highly significant variation for all the parameters studied (p ≤ 0.001). Overall, PRR was superior in all the fruit, pulp and endocarp characters except fruit length and kernel length where it was next to BCW. In most of traits, different tree were superior for different traits. Further, very high tree to tree variation within population indicates existence of different races within population. Further, very high tree to tree variation within population indicates existence of different races within population. All the traits were having low co-efficient of variation, higher mother tree within population variance and higher mother tree repeatability co-efficient. Within source variation was very high for all the traits, thus suggesting individual selection within natural population or clonal propagation will be more effective for further domestication and improvement of this medicinally important agroforestry tree species.

Abstract

Santalum album L. is an economically important tropical tree species. Sandalwood trees are the source of highly priced and fragrant heartwood, the ‘East Indian Sandalwood’ that on steam distillation yields on an average 5–7 % oil of high perfumery value. Owing to extensive logging, changes in land-use patterns and poor natural regeneration, the natural sandal populations are rapidly dwindling. An efficient protocol of plant regeneration from node explant has been developed for S. album. Optimal callus was developed from nodal segments on woody plant medium (WPM) supplemented with 0.6 mg 1−1 TDZ and 1.5 mg 1−1 2,4-D. Fresh weight (132.3 mg) and dry weight (41.0 mg) of node derived callus were highest in medium supplemented with 0.6 mg l−1 TDZ. Shoot bud initiation was achieved from the surface of callus when transferred on shoot induction medium supplemented with BA and NAA in combination. Highest number of shoot buds (16.0) per callus was observed in medium containing 2.5 mg l−1BA + 0.4 mg 1−1 NAA. Shoot proliferation (number of shoots/callus) (21.5) and shoot length (4.7) was highest in media containing 3.0 mg 1−1 Kn. Plantlets were rooted on WPM medium with different concentrations of indole-3-butyric acid (IBA). Highest rooting percentage (82.37) and survival was achieved on WPM media with 1.5 mg 1−1 IBA. The in vitro raised plantlets with properly developed shoot and roots were acclimatized successfully and grew well in the greenhouse. All the regenerated plants appeared normal with respect to morphology and growth characteristics.

Abstract

The main objective of this study was to determine how the conversions of home gardens to mono-crop fields affect soil organic carbon (SOC) and total nitrogen (TN) stocks. The study compared SOC and soil TN stocks in 7 paired sites of home gardens and converted mono-crop fields (khat and sugar cane; cultivated for 1–20 years after conversion) in Wondo Genet, Southern Ethiopia. Except two recently converted mono-crop fields (1 and 4 years after conversion), most of converted mono-crop fields had significantly lower contents of SOC (18.3–47.1 %) and soil TN (14.9–45 %) compared to home gardens. Converted mono-crop fields over 10–20 years old showed significantly lower SOC stocks (18.2–30.2 %) and soil TN stocks (16.7–28.7 %) compared to home gardens. There was no significant relationship between the periods after conversion and the rate of decrease of SOC and TN stocks in the mono-crop fields. Study results show that conversion of home gardens to mono-crop fields decreases SOC and TN stocks. Further studies are needed to identify the major mechanisms causing the decrease and quantify the change of SOC and TN in different environment and climate conditions.

Graphical Abstract

Abstract

Agroforestry is an integrated self-sustainable land use management system that is not only capable of producing food from marginal agricultural land but also capable of maintaining and improving the quality of environment. It plays a vital role in achieving integrated rural and urban development. But reliable data on area under agroforestry is not available as methodology for estimation of area under agroforestry is not yet standardized. In this paper, we propose to use remote sensing techniques for estimation of area under agroforestry using high resolution satellite data. Area under agroforestry in Ludhiana district of Punjab State, India has been estimated using the proposed methodology. Land use/land cover map of the district has also been generated using ERDAS IMAGINE software. It has been observed from the accuracy assessment that the estimate of area under agroforestry obtained using the proposed methodology under this study is reliable. Further, area under agroforestry has been classified into detailed classes within agroforestry.

Abstract

This paper quantifies roots down to 1 m depth in two study-sites of a short-fallow multi-cycle shifting-cultivation system in eastern Amazonia. Root biomass was 38.7 Mg ha−1 in the 3-year-old fallow-site and 12.7 Mg ha−1 in the 1.5-year-old cultivation-site, corresponding to 55.9 % (fallow-site) and 65.1 % (cultivation-site) of total ecosystem biomass. Root distribution was shallow, with 33–41 % of all roots and 47–55 % of fine roots concentrated in the top 10 cm. Cultivation caused large reduction of topsoil fine-root biomass. We specially focus on roots of the ruderal babassu palm, very widespread and increasingly dominant in degraded lands throughout deforested Amazonia. Whereas babassu-shares in total root biomass (14.9–25.2 %) were similar to aboveground biomass-shares, fine-root shares were substantially higher (29.0–44.1 %), pointing to great competitive strength of this palm. Fine roots of babassu and of all other vegetation were closely correlated, suggesting that both occupy the same space within the study sites and throughout the soil profile, contrary to hypotheses of babassu vertical resource complementarity or deepsoil nutrient-pumping. Babassu coarse-roots were markedly deeper than those of remaining vegetation, a serious obstacle for density-control efforts. This study indicates that intensification of shifting-cultivation strongly increases the role of roots, with high coarse root biomass and root:shoot-ratios, and strong plasticity of the fine-root component to environmental changes associated with slash & burn, cultivation- and fallow-phases. Roots are key for the environmental success of ruderal babassu. We find (i) a high biomass-share in fine roots which guarantees high competitivity in soil resource acquisition, and (ii) significant coarse root stocks in the subsoil, well protected reserves which guarantee vigorous resprouting in multi-cycle slash & burn.

Abstract

The arbuscular mycorrhizal fungal diversity in Mexico has not been intensively studied. Although some studies have reported the presence of 29 % of the reported species in the world, the knowledge regarding their functional diversity is poor. The aim of this study was to evaluate the impact of the disturbance on arbuscular mycorrhizal fungi (AMF) functional diversity. Three sites at the Biosphere Reserve Los Tuxtlas in the state of Veracruz were selected for this study, according to the disturbance gradient and the land use: López Mateos (LM), San Fernando (SF), and Venustiano Carranza (VC) (with low, medium and high disturbance, respectively). The land use in each site includes milpa and pasture. High percentages of root colonization, spore abundance and spore viability were found on LM soils. Additionally, 100 % of the pasture soils have a high mycorrhizal infective potential (MIP). In addition, the fungi consortiums coming from that site promote the highest mycorrhizal growth response (MGR), with increases ranging from 74.1 to 194.6 % over the control treatment. SF soils had high percentages of root colonization and spore viability, whereas only 20 % of these soils had a high MIP, and their MGR promoted increases ranged from 14.6 to 120.4 % over the control. Soils from VC had the lowest percentages of root colonization and spore viability. Only 10 % of the soils had high MIP, and their MGR was not better than the control. These results indicate that the soil disturbance or use changes negatively affect the functionality of AMF.