•Amazonian trees show intraspecific variation in responses to environmental conditions.•We document intraspecific variation in wood density in relation to forest hydrology.•Amazon unflooded trees ...store more mass per unit volume than floodplain conspecifics.
For tropical tree species, wood density can vary greatly both within and between species depending on environmental conditions. In Amazonian seasonally flooded forests, yearly flood pulses influence tree growth and floodplain trees have developed specialised strategies to cope with prolonged submersion during flooding. We therefore hypothesised that seasonal floods significantly affect the capacity of trees to store carbon as woody biomass per unit volume and that forest hydrology would be an important factor in determining above-ground woody biomass and carbon stocks across the Amazon Basin. To test these hypotheses, we collected and analysed wood cores from 44 species occurring in both seasonally flooded (várzea) forests and adjacent unflooded (terra firme) forests along the Juruá River, western Brazilian Amazon. We used wood specific gravity (WSG) as a proxy of woody biomass and carbon. We compared WSG values within species, genera and families and found higher WSG in unflooded forest trees compared to their conspecifics in seasonally flooded várzea. Moreover, the effect of forest type on WSG was strongest at the family level and weakest at the species level. We further assessed the implications of WSG accuracy on above-ground woody tree biomass and found significant differences in AGWB as a function of WSG. Again, the differences became greater with lower taxonomic specificity, but also increased with lower site-specificity and greater tree dimensions. In conclusion, habitat specific WSG is important to quantify and map the spatial distribution of above-ground woody biomass and carbon in Amazonian forests.
Rural populations in the tropics frequently rely on game vertebrates and fish to supply their daily protein requirements. However, few studies have quantified the environmental and socioeconomic ...drivers of hunting and fishing effort and the potential compensatory relationship between these extractive activities. Here, we assessed game and fish extraction by 222 semi-subsistence households from 28 villages along a major white-water tributary of Brazilian Amazonia. During the 44months study, a total of 32,114kg of game and 261,752kg of fish were harvested, amounting to an average extraction rate of 30.5±109.9gperson−1day−1 and 1519.4±1037.6gperson−1day−1 for game and fish, respectively. While 97.93±0.03% of all fishing trips resulted in fish catches, only 77.12±27.02% of the hunting forays successfully obtained at least one forest vertebrate. The flood pulse had a strong effect on both fishing and hunting activities. However, the seasonally rising floodwaters had a negative effect on fish yield and catch per unit effort (CPUE), but had a positive effect on game yields. Game yield was also an important variable explaining fish yield, indicating a strong compensatory interaction between these two forms of protein acquisition. Our results highlight the importance of considering different modes of animal protein harvesting in conservation planning and management of both forest vertebrates and aquatic organisms.
•We assessed the drivers of fish and game acquisition by semi-subsistence Amazonians.•The flood pulse had a strong effect on both fishing and hunting activities.•Fish yield and catch per unit effort were negatively influenced by the seasonal floodwaters.•Game yield was also a strong predictor of fishing effort and yield.•The seasonal dynamics of wild protein offtake should be considered in conservation planning.
The domestic cat (Felis catus) is among the most popular companion animals and most abundant carnivores globally. It is also a pet with an immense ecological footprint because even non-feral and ...food-subsidized cats can be prolific predators. Whereas knowledge about the spatial behavior of individual domestic cats is growing, we still know little about how a local population of free-ranging pet cats occupies the landscape. Using a citizen science approach, we GPS-tagged 92 pet cats with outdoor access living in a residential area in southern Norway. The resulting position data allowed us to construct both individual home range kernels and a population-level utilization distribution. Our results reveal a dense predatory blanket that outdoor cats drape over and beyond the urban landscape. It is this population-level intensity surface-the "catscape"-that potential prey have to navigate. There were few gaps in the catscape within our residential study area and therefore few terrestrial refuges from potential cat predation. However, cats spent on average 79% of their outdoor time within 50 m to their owner's home, which suggests that the primary impact is local and most acute for wildlife in the vicinity to homes with cats. We discuss the catscape as a conceptual and quantitative tool for better understanding and mitigating the environmental impact of domestic cats.
Secondary forests are promoted as having pivotal roles in reversing the tropical extinction crisis. While secondary forests recover carbon and species over time, a key question is whether ...phylogenetic diversity—the total evolutionary history across all species within a community—also recovers. Conserving phylogenetic diversity protects unique phenotypic and ecological traits, and benefits ecosystem functioning and stability. We examined the extent to which avian phylogenetic diversity recovers in secondary forests in the Colombian Chocó-Andes. sesPD, a measure of phylogenetic richness corrected for species richness, recovered to old-growth forest levels after ~30years, while sesMPD, a measure of the phylogenetic distance between individuals in a community, recovered to old-growth levels even within young secondary forest. Mean evolutionary distinctiveness also recovered rapidly in secondary forest communities. Our results suggest that secondary forests can play a vital role in conserving distinct evolutionary lineages and high levels of evolutionary history. Focusing conservation and carbon-based payments for ecosystem services on secondary forest recovery and their subsequent protection thus represent a good use of scarce conservation resources.
The Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES) regulates international legal trade to prevent the detrimental harvest of wildlife. We assess the volumes ...of threatened and non-threatened bird, mammal, amphibian, and reptile species in the CITES-managed trade and how this trade responded to category changes of species in the IUCN Red List between 2000 and 2018. In this period, over a thousand wild-sourced vertebrate species were commercially traded. Species of least conservation concern had the highest yearly trade volumes (excluding birds), whereas species in most Red List categories showed an overall decrease in trade reoccurrence and volume through time, with most species unlikely to reoccur in recent trade. Charismatic species with populations split-listed between Appendices I and II were traded in substantially lower yearly volumes when sourced from the more-threatened Appendix I populations. Species trade volumes did not systematically respond to changes in the Red List category, with 31.0% of species disappearing from trade before changing category and the majority of species revealing no difference in trade volumes from pre- to post-change. Just 2.7% (12/432) of species volumes declined and 2.1% (9/432) of volumes increased after a category change. Our findings highlight that non-threatened species dominate trade but reveal small numbers of highly threatened species in trade and a disconnect between species trade volumes and changing extinction risk. We highlight potential drawbacks in the current regulation of trade in listed species and urgently call for open and accessible assessments—non-detriment findings—robustly evidencing the sustainable use of threatened and non-threatened species alike.
•Non-threatened species dominate trade richness and volume•Generally, volumes are declining across threatened and non-threatened species•CITES split-listing greatly reduces trade in the threatened Appendix I populations•Changing threat status had little correlation with changing trade volume
Morton et al. report that non-threatened species dominate CITES-listed wildlife trade presence and volume, with declining volume trends across most categories of threat. However, there is little evidence that becoming more or less threatened correlates with the changes in species trade volumes.
Large-scale conversion of natural habitats to agriculture reduces species richness and functional diversity, with important implications for the provision of many ecosystem services. We investigated ...possible solutions to minimise loss of functional diversity: retaining forest fragments to enhance functional diversity within agricultural lands, and restricting future expansion of tropical crops to degraded lands or low-productivity farmlands to conserve functional diversity at a landscape level. We focused on birds, which play key functional roles and have well-known functional ecology, and oil palm, a rapidly expanding tropical crop. We did so in the Colombian Llanos, a region highlighted for the planting of sustainable oil palm, where plantations are currently replacing two main habitat types: forest remnants and improved cattle pasture. We found that levels of functional diversity (FD) and richness (FRic) were highest in remnant forests. Furthermore, levels of functional diversity and richness in oil palm and improved pasture were positively related to the proportion of forest in a 250m radius surrounding each sample point. Frugivorous and canopy foraging species were particularly associated with remnant forests, while aquatic and terrestrial foragers were associated with pasture. This suggests that retaining forest remnants in agricultural landscapes is important in preventing large losses of functional diversity, and might also play a role in maintaining avifaunal functional richness within farmland.
The ecological impacts of meeting rising demands for food production can potentially be mitigated by two competing land‐use strategies: off‐setting natural habitats through intensification of ...existing farmland (land sparing), or elevating biodiversity within the agricultural matrix via the integration of “wildlife‐friendly” habitat features (land sharing). However, a key unanswered question is whether sparing or sharing farming would best conserve functional diversity, which can promote ecosystem stability and resilience to future land‐use change. Focusing on bird communities in tropical cloud forests of the Colombian Andes, we test the performance of each strategy in conserving functional diversity. We show that multiple components of avian functional diversity in farmland are positively related to the proximity and extent of natural forest. Using landscape and community simulations, we also show that land‐sparing agriculture conserves greater functional diversity and predicts higher abundance of species supplying key ecological functions than land sharing, with sharing becoming progressively inferior with increasing isolation from remnant forest. These results suggest low‐intensity agriculture is likely to conserve little functional diversity unless large blocks of adjacent natural habitat are protected, consistent with land sparing. To ensure the retention of functionally diverse ecosystems, we urgently need to implement mechanisms for increasing farmland productivity whilst protecting spared land.
Using landscape and community simulations, we test the performance of land‐sparing and land‐sharing cattle pasture in conserving avian functional diversity of the Colombian Andes. We show that land‐sparing agriculture conserves greater functional diversity and predicts higher abundance of species supplying key ecological functions than land sharing. To ensure the retention of functionally diverse ecosystems, we urgently need to implement mechanisms for increasing farmland productivity whilst protecting spared land.
•Illegal logging had a minor effect on the vertebrate assemblage in a protected area.•Illegally logged forests can retain much conservation value if protected from further impacts.•Findings represent ...a best-case scenario, as the study area is protected.
Selective logging is a major form of land use in tropical rainforests, with more than half of the world’s tropical forest already explored. In the Brazilian Amazon, most logging operations are illegal and highly damaging to forests. However, the effects of illegal logging on wildlife are poorly studied. Here we investigate the effects of illegal logging on the assemblage of medium- to large-bodied terrestrial vertebrates at the Gurupi Biological Reserve, a protected area in extreme eastern Amazonia that has been subjected to three decades of illegal logging. We used camera traps to survey the terrestrial vertebrate assemblage and visual interpretation of Landsat time series data (1984–2016) to assess the history of illegal logging (number of logging bouts and recovery time) for each camera trap site. Hierarchical Modelling of Species Communities (HMSC) indicates that logging had a minor effect on both the assemblage composition and individual species abundance. At the local level, the study demonstrates that the reserve effectively safeguards a significant portion of the regional biodiversity even though it suffered degradation by illegal logging. At a wider scale, the results suggest that illegally logged forests can retain much of their conservation value, if they are protected from further anthropogenic impacts such as hunting, fragmentation and fires. However, our study represents a best-case scenario, unlikely to be met in most other illegally logged areas in the tropics, where logging is usually followed by secondary effects that amplify its impacts.
The wildlife trade is a billion‐dollar global business, involving millions of people, thousands of species, and hundreds of millions of individual organisms. Unravelling whether trade targets ...reproductively distinct species and whether this preference varies between captive‐ and wild‐sourced species is a crucial question. We used a comprehensive list of all bird species traded, trade listings and records kept in compliance with the Convention on International Trade in Endangered Species (CITES), and a suite of avian reproductive parameters to examine whether wildlife trade is associated with particular facets of life history and to examine the association between life‐history traits and captive‐ and wild‐sourced traded volumes over time. Across all trade, CITES listing, and CITES trade, large birds were more likely to be traded and listed, but their longevity and age at maturity were not associated with CITES listing or trade. We found species across almost the full range of trait values in both captive and wild trade between 2000 and 2020. Captive trade volumes clearly associated with relatively longer lived and early‐maturing species; these associations remained stable and largely unchanged over time. Trait–volume associations in wild‐sourced trade were more uncertain. Only body mass had a clear association, and it varied from negative to positive over time. Although reproductive traits were important in captive‐sourced trade, species‐level variation dominated trade, with even congeneric species varying greatly in volume despite similar traits. The collection and incorporation of trait data into sustainability assessments of captive breeding facilities are crucial to ensure accurate quotas and guard against laundering.
Asociación entre los rasgos reproductivos de aves en cautiverio versus las de origen silvestre comercializadas
Resumen
El mercado de fauna es un negocio mundial de miles de millones de dólares que involucra a millares de personas, miles de especies y cientos de millones de organismos individuales. Por ello es necesario resolver la cuestión de si el mercado se enfoca en especies con distinciones reproductivas y si esta preferencia varía entre las especies de origen silvestre y en cautiverio. Usamos una lista completa de todas las especies de aves comercializadas, listados y registros comerciales conforme a la Convención sobre el Comercio Internacional de Especies Amenazadas (CITES) y un conjunto de parámetros de reproducción de aves para analizar si el mercado de fauna está asociado con facetas particulares de la historia de vida. También analizamos la asociación entre los rasgos de la historia de vida y el volumen comercializado de origen silvestre y de cautiverio a lo largo del tiempo. En todos los mercados, listas de CITES y mercados CITES, las aves de mayor tamaño tuvieron mayor probabilidad de ser comercializadas y estar enlistadas, pero su longevidad y edad a la madurez no se asoció con el mercado o la lista e CITES. Detectamos especies en casi toda la gama de rasgos tanto en el comercio de cautiverio como el silvestre entre 2000 y 2020. El volumen comercial de cautiverio mostró una asociación clara con las especies relativamente más longevas y de madurez temprana; esta relación fue estable y casi no cambió con el tiempo. La asociación del volumen en las especies de origen silvestre fue más incierta; sólo la masa corporal tuvo una relación clara y ésta varió entre positiva y negativa con el tiempo. Aunque los rasgos reproductivos fueron importantes para el mercado con origen en cautiverio, la variación a nivel de especies dominó el mercado, incluso mostrando una enorme variación del volumen entre las especies congéneres a pesar de tener rasgos similares. La recolección e incorporación de datos sobre los rasgos dentro de los análisis de sustentabilidad de las instalaciones para la cría en cautiverio es crucial para asegurar las cuotas adecuadas y prevenir blanqueo de capitales.
圈养及野生来源鸟类的贸易与繁殖性状的关系
【摘要】 野生动物贸易是一项价值数十亿美元的全球业务, 涉及数百万人、数千个物种和数亿生物个体。了解作为贸易目标的物种是否在繁殖性状上有所不同, 以及贸易上的偏好是否在圈养和野生来源的物种之间存在差异是十分重要的。本研究利用贸易涉及的所有鸟类物种、贸易清单、符合《濒危物种国际贸易公约》(CITES)的贸易记录, 以及一系列鸟类繁殖参数的综合数据, 研究了野生动物贸易是否与特定的生活史性状有关, 并分析了生活史特征与圈养和野生来源鸟类的贸易量之间随时间推移的关系。我们发现在所有贸易、CITES附录和符合CITES的贸易中, 大型鸟类更有可能被贸易和被列入附录, 但它们的寿命和性成熟时间与是否被贸易或被列入CITES附录没有关系。在2000‐2020年间, 被贸易的圈养及野生鸟类的性状几乎涵盖了物种性状的所有数值范围。圈养物种的贸易量与相对较长的寿命和较早的性成熟时间显著有关;这些关联随时间推移保持稳定且基本没有变化。在野生来源鸟类的贸易中, 物种性状与贸易量的关联更不明确。只有体重与贸易量存在明显的关联, 且随时间推移从负相关变为正相关。尽管繁殖性状在圈养鸟类的贸易中很重要, 但物种水平的变异在贸易中仍占主导地位, 即使是同属性状相近的物种在贸易量上也有很大差异。收集性状数据并将其纳入鸟类圈养繁殖的可持续发展评估, 对于确保准确的配额和反洗钱至关重要。【翻译:胡怡思;审校:聂永刚】
Oil palm agriculture is rapidly expanding in the Neotropics, at the expense of a range of natural and seminatural habitats. A key question is how this expansion should be managed to reduce negative ...impacts on biodiversity. Focusing on the Llanos of Colombia, a mixed grassland–forest system identified as a priority zone for future oil palm development, we survey communities of ants, dung beetles, birds and herpetofauna occurring in oil palm plantations and the other principal form of agriculture in the region – improved cattle pasture – together with those of surrounding natural forests. We show that oil palm plantations have similar or higher species richness across all four taxonomic groups than improved pasture. For dung beetles, species richness in oil palm was equal to that of forest, whereas the other three taxa had highest species richness in forests. Hierarchical modelling of species occupancy probabilities indicated that oil palm plantations supported a higher proportion of species characteristic of forests than did cattle pastures. Across the bird community, occupancy probabilities within oil palm were positively influenced by increasing forest cover in a surrounding 250 m radius, whereas surrounding forest cover did not strongly influence the occurrence of other taxonomic groups in oil palm. Overall, our results suggest that the conversion of existing improved pastures to oil palm has limited negative impacts on biodiversity. As such, existing cattle pastures of the Colombian Llanos could offer a key opportunity to meet governmental targets for oil palm development without incurring significant biodiversity costs. Our results also highlight the value of preserving remnant forests within these agricultural landscapes, protecting high biodiversity and exporting avian ‘spill‐over’ effects into oil palm plantations.
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