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Summary Infrastructure must become more resilient as the global climate changes and also more affordable in the economic and political context of a post-COVID world. We can solve this dual challenge and drive global infrastructure investment into a more sustainable direction by taking our cues from Nature.

The Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) pandemic reveals a major gap in global biosecurity infrastructure: a lack of publicly available biological samples representative across space, time, and taxonomic diversity. The shortfall, in this case for vertebrates, prevents accurate and rapid identification and monitoring of emerging pathogens and their reservoir host(s) and precludes extended investigation of ecological, evolutionary, and environmental associations that lead to human infection or spillover. Natural history museum biorepositories form the backbone of a critically needed, decentralized, global network for zoonotic pathogen surveillance, yet this infrastructure remains marginally developed, underutilized, underfunded, and disconnected from public health initiatives. Proactive detection and mitigation for emerging infectious diseases (EIDs) requires expanded biodiversity infrastructure and training (particularly in biodiverse and lower income countries) and new communication pipelines that connect biorepositories and biomedical communities. To this end, we highlight a novel adaptation of Project ECHO’s virtual community of practice model: Museums and Emerging Pathogens in the Americas (MEPA). MEPA is a virtual network aimed at fostering communication, coordination, and collaborative problem-solving among pathogen researchers, public health officials, and biorepositories in the Americas. MEPA now acts as a model of effective international, interdisciplinary collaboration that can and should be replicated in other biodiversity hotspots. We encourage deposition of wildlife specimens and associated data with public biorepositories, regardless of original collection purpose, and urge biorepositories to embrace new specimen sources, types, and uses to maximize strategic growth and utility for EID research. Taxonomically, geographically, and temporally deep biorepository archives serve as the foundation of a proactive and increasingly predictive approach to zoonotic spillover, risk assessment, and threat mitigation.

The Belt and Road Initiative, due to its diverse and extensive infrastructure investments, poses a wide range of environmental risks. Some projects have easily identifiable and measurable impacts, such as energy projects' greenhouse gas emissions. Others, such as transportation infrastructure, due to their vast geographic reach, generate more complex and potentially more extensive environmental risks. The proposed Belt and Road Initiative rail and road investments have stimulated concerns because of the history of significant negative environmental impacts from large-scale transportation projects across the globe. This paper studies environmental risks -- direct and indirect -- from Belt and Road Initiative transportation projects and the mitigation strategies and policies to address them. The paper concludes with a recommendation on how to take advantage of the scale of the Belt and Road Initiative to address these concerns in a way not typically available to stand-alone projects. In short, this scale motivates and permits early integrated development and conservation planning.

At a time of great global change, and as the world begins to implement a redefined global development agenda, is timely to consider the importance of the tropical region and its role in our global future. The ‘International Day of the Tropics’, inaugurated in early June this year and celebrated for the first time on June 29, 2016, shines a light on the significant challenges and opportunities faced by nations of the Tropics and the global implications of the rapid changes the region is experiencing. This paper summarises discussions held at the United Nations in New York on that inaugural International Day of the Tropics.

Tropical forests vary substantially in the densities of trees of different sizes and thus in above-ground biomass and carbon stores. However, these tree size distributions show fundamental similarities suggestive of underlying general principles. The theory of metabolic ecology predicts that tree abundances will scale as the -2 power of diameter. Demographic equilibrium theory explains tree abundances in terms of the scaling of growth and mortality. We use demographic equilibrium theory to derive analytic predictions for tree size distributions corresponding to different growth and mortality functions. We test both sets of predictions using data from 14 large-scale tropical forest plots encompassing censuses of 473 ha and > 2 million trees. The data are uniformly inconsistent with the predictions of metabolic ecology. In most forests, size distributions are much closer to the predictions of demographic equilibrium, and thus, intersite variation in size distributions is explained partly by intersite variation in growth and mortality.

Summary 1 We mapped and identified all trees ≥ 10 mm in diameter in 25 ha of lowland wet forest in Amazonian Ecuador, and found 1104 morphospecies among 152 353 individuals. The largest number of species was mid-sized canopy trees with maximum height 10‐20 m and understorey treelets with maximum height of 5‐10 m. 2 Several species of understorey treelets in the genera Matisia and Rinorea dominated the forest numerically, while important canopy species were Iriartea deltoidea and Eschweilera coriacea . 3 We examined how species partition local topographic variation into niches, and how much this partitioning contributes to forest diversity. Evidence in favour of topographic niche-partitioning was found: similarity in species composition between ridge and valley quadrats was lower than similarity between two valley (or two ridge) quadrats, and 25% of the species had large abundance differences between valley and ridge-top. On the other hand, 25% of the species were generalists, with similar abundance on both valley and ridges, and half the species had only moderate abundance differences between valley and ridge. 4 Topographic niche-partitioning was not finely grained. There were no more than three distinct vegetation zones: valley, mid-slope, and upper-ridge, and the latter two differed only slightly in species composition. 5 Similarity in species composition declined with distance even within a topographic habitat, to about the same degree as it declined between habitats. This suggests patchiness not related to topographic variation, and possibly due to dispersal limitation. 6 We conclude that partitioning of topographic niches does make a contribution to the α -diversity of Amazonian trees, but only a minor one. It provides no explanation for the co-occurrence of hundreds of topographic generalists, nor for the hundreds of species with similar life-form appearing on a single ridge-top.

The high alpha-diversity of tropical forests has been amply documented, but beta-diversity—how species composition changes with distance—has seldom been studied. We present quantitative estimates of beta-diversity for tropical trees by comparing species composition of plots in lowland terra firme forest in Panama, Ecuador, and Peru. We compare observations with predictions derived from a neutral model in which habitat is uniform and only dispersal and speciation influence species turnover. We find that beta-diversity is higher in Panama than in western Amazonia and that patterns in both areas are inconsistent with the neutral model. In Panama, habitat variation appears to increase species turnover relative to Amazonia, where unexpectedly low turnover over great distances suggests that population densities of some species are bounded by as yet unidentified processes. At intermediate scales in both regions, observations can be matched by theory, suggesting that dispersal limitation, with speciation, influences species turnover.

This paper examines the impact of early market integration on the extraction of forest resources by traditional forest-based households, with emphasis on the commercial-subsistence dichotomy. Empirical analysis of resource use transition among the Huaorani People of the Ecuadorian Amazon shows that as markets become more accessible production patterns change but do not seem to affect subsistence production. Huaoranis increase the production of animal resources from forests. However, the extraction of harvested and primarily of farmed commodities seems not to be affected. Data also suggest that trade relies on limited specialization. Trade among the Huaorani communities studied depends on raising the production of some of the same commodities that are found in the subsistence basket. These changes are clearly explained if a flexible-labor theory of early market integration is used. This period is characterized by labor and land abundance and a relative ease to move labor from low return to more productive activities. Under these conditions, market participation need not be accompanied by a reduction in the production of subsistence commodities or commodity specialization. High risks and uncertainty and high transportation costs keep poor forest households from shifting completely to commercial activities. This contrasts with a long presumption that production of individual commodities responds quickly to price changes, based on demand shifts between products, but that total output is slow to respond. Only after all the surplus labor has been allocated to productive activities total output becomes less flexible. At this point increased production requires commodity or technological specialization.

Biologists are nearly unanimous in their belief that humanity is in the process of extirpating a significant portion of the earth's spe­ cies. The ways in which we are doing so reflect the magnitude and scale of human enterprise. Everything from highway construction to cattle ranch­ ing to leaky bait buckets has been implicated in the demise or endan­ germent of particular species. Ac­ cording to Wilson (1992), most of these activities fall into four major categories, which he terms "the mind­ less horsemen of the environmental apocalypse": overexploitation, habi­ tat destruction, the introduction of non-native (alien) species, and the spread of diseases carried by alien species. To these categories may be added a fifth, pollution, although it can also be considered a form of habitat destruction. Surprisingly, there have been reIa­ tively few analyses of the extent to which each of these factors-much less the more specific deeds encomDavid S. Wilcove is a senior ecologist at the Environmental Defense Fund, Wash­ ington, DC 20009. David Rothstein re­ ceived his J.D. in 1997 from Northeastern

Large-seeded plant species tend to be restricted to late-seral and mature forests, yet the reason for this habitat specificity is often not understood. The typical absence of these species from younger forests may be due to either their ineffective seed dispersal to early-seral habitats or postdispersal factors such as life history traits and physical and biotic variables, or both. Two large-seeded palm species, Iriartea deltoidea and Astrocaryum murumuru var. javarense, were used to experimentally evaluate the role of postdispersal limitation by testing whether the species exhibit differential seedling survivorship in forest stands of different ages. Under natural conditions, both palm species are largely absent from early- and mid-seral floodplain forest but are common in late-seral and mature forest. Iriartea seedlings and juveniles are found occasionally in early- and mid-seral forest, whereas Astrocaryum are almost never found there. To assess the degree to which postdispersal factors could account for these patterns, seeds of the two palm species were transplanted into four zones in the successional floodplain forest of Manu National Park, Peru. Three experiments quantifying seedling establishment and survivorship were carried out : a 3-yr experiment using Iriartea, in which flooding during the 1st yr was lower than average (Iriartea Dry Experiment) ; a 1-yr experiment using Iriartea, in which flooding during the 1st yr was higher than average (Iriartea Wet Experiment) ; and a 2-yr experiment using Astrocaryum, in which flooding during the 1st yr was also higher than average (Astrocaryum Wet Experiment). For each experiment, four or five plots, each containing 75 seeds, were placed in each of four zones from early to late succession. The entire design was replicated in two successional transects that were separated by 6 km. Seedling survivorship of Astrocayum was highest in the late-seral zones of both transects, which corresponded closely to its restricted natural distribution. Hence, postdispersal limitations, perhaps in conjunction with restricted seed dispersal, apparently contributed heavily to the general absence of Astrocaryum from the early- and mid-seral floodplain forests. Flooding did not appear to influence Astrocaryum seedling survivorship. Postdispersal factors also seemed to influence strongly Iriartea establishment, as evidenced by the significant variation in seedling survivorship across seral zones and between transects. Moreover, in the Iriartea Dry Experiment, seedling survivorship was negatively correlated with level of flooding. During the Iriartea Wet Experiment, survivorship was substantially lower in all seral zones, probably due to the heavy flooding. Thus, flooding, as a postdispersal factor, appeared to play a major role in shaping the natural distribution of Iriartea in the successional floodplain forests. Because seedling survivorship in one mid-seral zone was substantially higher than would be predicted from the natural Iriartea seedling density, results from transplant experiments also suggest that limited seed dispersal may contribute to this palm's early-seral distribution. For Iriartea, seed dispersal limitation may play a role complementary to that of flooding. In Amazonian primary-successional floodplain forest, the habitat specificity of at least one, and perhaps two, large-seeded species appears to result from both dispersal limitation and postdispersal limitation factors.

cit has brought about closer scrutiny of a number of federally subsidized programs. Among them are subsidies for natural resource extraction-particularly hard-rock mining, logging, and livestock grazing-on federal lands and for federal water development projects. The US government's own figures reveal the magnitude of the subsidies. For example, according to the US Department of Agriculture's Forest Service (USFS), timber sale programs in most national forests lose money every year; in 1992 alone, 95 of the 120 national forests operated at a loss-totaling $174.9 million-because the agency spent more money preparing and administering timber sales than it received in revenue from those sales (USFS 1993). The losses are even higher when transfer payments to

The rapid disruption of tropical forests probably imperils global biodiversity more than any other contemporary phenomenon(1-3). With deforestation advancing quickly, protected areas are increasingly becoming final refuges for threatened species and natural ecosystem processes. However, many protected areas in the tropics are themselves vulnerable to human encroachment and other environmental stresses(4-9). As pressures mount, it is vital to know whether existing reserves can sustain their biodiversity. A critical constraint in addressing this question has been that data describing a broad array of biodiversity groups have been unavailable for a sufficiently large and representative sample of reserves. Here we present a uniquely comprehensive data set on changes over the past 20 to 30 years in 31 functional groups of species and 21 potential drivers of environmental change, for 60 protected areas stratified across the world's major tropical regions. Our analysis reveals great variation in reserve `health': about half of all reserves have been effective or performed passably, but the rest are experiencing an erosion of biodiversity that is often alarmingly widespread taxonomically and functionally. Habitat disruption, hunting and forest-product exploitation were the strongest predictors of declining reserve health. Crucially, environmental changes immediately outside reserves seemed nearly as important as those inside in determining their ecological fate, with changes inside reserves strongly mirroring those occurring around them. These findings suggest that tropical protected areas are often intimately linked ecologically to their surrounding habitats, and that a failure to stem broad-scale loss and degradation of such habitats could sharply increase the likelihood of serious biodiversity declines.

The United States Endangered Species Act of J973 (ESA) is the strongest tool for protecting plants and animals in the US and has served as a model of species protection for many other nations. Because the goals of the Act — to conserve all endangered and threatened species in the US and the ecosystems upon which they depend - are widely supported among US environmentalists and biologists, it is commonly believed that these groups offer united support for the legislation. Within the US, however, vigorous debate ensues among conservation biologists as to the effectiveness of the species-oriented approach of the Act.

Much current controversy exists about the role that foreign debt plays in deforestation in Latin America. In an attempt to familiarize concerned biologists with this issue, we present an overview of the proposed positive and negative effects that foreign debt has had on neotropical forest loss. From the literature, we identify three main hypotheses as to how the large external debts of developing Latin American countries may contribute to deforestation. We find that (1) countries have not increased exports of tropical timber and beef in response to rising debt; (2) external debts have contributed to economic stagnation and an associated increase in poverty in Latin America, which in turn has caused the degradation of marginal lands, but the role of debt in this process cannot be isolated from other important contributing factors; and (3) while debt payments have probably led to governmental budget cutbacks in environmental spending, historically spending in these areas has not been high. On the positive side, we found that (1) innovative debt-for-nature swaps have traded devalued debt for a commitment and funds to create and protect nature reserves; and (2) debt could be exchanged for forestry and agricultural sectoral reform, which would have very large positive effects on the conservation and management of forests. En el presente existe mucha controversia sobre el rol que la deuda externa juega en la deforestacion de America Latina. En un intento de familiarizar a biologos interesados en este tema nosotros presentamos una resena sobre los efectos positivos y negativos que la deuda externa ha tenido en la perdida de selvas Neotropicales. A partir de la literatura sobre el tema, nosotros identificamos tres hopotesis principales sobre como las grandes deudas externas de los paises en vias de dasarrollo de America Latina contribuirian a la deforestacion. Encontramos que (1) los paises no han incrementado las exportaciones de madera tropical y carne como respuesta a la creciente deuda, (2) las deudas externas han contribuido al estancamiento economico y al asociado incremento de la pobreza en America Latina, lo que a su vez ha causado la degradacion de las tierras marginales; sin embargo, el rol de la deuda en este proceso no puede ser aislado de otros importantes factores cotribuyentes, y (3) si bien los pagos de la deuda probablemente han producido recortes en el presupuesto de gastos relativos a medio ambiente, historicamente los gastos en estas areas no han sido altos. Desde un punto de vista positivo, (1) el innovativo troque de deuda por naturaleza ha intercambiado deuda devaluada por un compromiso y fondos para crear y proteger reservas naturales y (2) la deuda puede ser intercambiada por una reforma en los sectores de bosques y agricultura, la cual puede tener un gran efecto positivo en la conservacion manejo de los bosques.

In Amazonian tropical forests, recent studies have reported increases in aboveground biomass and in primary productivity, as well as shifts in plant species composition favouring fast-growing species over slow-growing ones. This pervasive alteration of mature tropical forests was attributed to global environmental change, such as an increase in atmospheric CO2 concentration, nutrient deposition, temperature, drought frequency, and/or irradiance. We used standardized, repeated measurements of over 2 million trees in ten large (16–52 ha each) forest plots on three continents to evaluate the generality of these findings across tropical forests. Aboveground biomass increased at seven of our ten plots, significantly so at four plots, and showed a large decrease at a single plot. Carbon accumulation pooled across sites was significant (+0.24 MgC ha−1 y−1, 95% confidence intervals [0.07, 0.39] MgC ha−1 y−1), but lower than reported previously for Amazonia. At three sites for which we had data for multiple census intervals, we found no concerted increase in biomass gain, in conflict with the increased productivity hypothesis. Over all ten plots, the fastest-growing quartile of species gained biomass (+0.33 [0.09, 0.55] % y−1) compared with the tree community as a whole (+0.15 % y−1); however, this significant trend was due to a single plot. Biomass of slow-growing species increased significantly when calculated over all plots (+0.21 [0.02, 0.37] % y−1), and in half of our plots when calculated individually. Our results do not support the hypothesis that fast-growing species are consistently increasing in dominance in tropical tree communities. Instead, they suggest that our plots may be simultaneously recovering from past disturbances and affected by changes in resource availability. More long-term studies are necessary to clarify the contribution of global change to the functioning of tropical forests., Author Summary Recent studies have reported major changes in mature tropical forests, with increases in both forest biomass and net primary productivity, as well as shifts in plant species composition that favour fast-growing species over slow-growing ones. These pervasive alterations were attributed to global environmental change, and may result in dramatic shifts in the functioning of tropical forest ecosystems. We reassessed these findings using a dataset of large permanent forest plots on three continents. We found that tree biomass increased at seven of our ten plots, and showed a large decrease at a single plot. Overall, this increase was significant, albeit lower than reported previously for Amazonian forests. At three sites for which we had data for multiple census intervals, we found no concerted increase in biomass gain, in conflict with the increased productivity hypothesis. With the exception of one plot, slow-growing species gained more biomass than either fast-growing species or the tree community as a whole. Hence, our results do not support the hypothesis that fast-growing species are consistently increasing in dominance in tropical tree communities. Overall, our results suggest that our plots may be simultaneously recovering from past disturbances and affected by changes in resource availability., An analysis of changes in biomass and primary productivity across ten large tropical forest plots revealed that aboveground biomass increased significantly, fast-growing species increased significantly in dominance at a single site, and slow-growing species increased significantly at half of our sites.

The theory of metabolic ecology predicts specific relationships among tree stem diameter, biomass, height, growth and mortality. As demographic rates are important to estimates of carbon fluxes in forests, this theory might offer important insights into the global carbon budget, and deserves careful assessment. We assembled data from 10 oldgrowth tropical forests encompassing censuses of 367 ha and > 1.7 million trees to test the theory’s predictions. We also developed a set of alternative predictions that retained some assumptions of metabolic ecology while also considering how availability of a key limiting resource, light, changes with tree size. Our results show that there are no universal scaling relationships of growth or mortality with size among trees in tropical forests. Observed patterns were consistent with our alternative model in the one site where we had the data necessary to evaluate it, and were inconsistent with the predictions of metabolic ecology in all forests.

An ecological community's species diversity tends to erode through time as a result of stochastic extinction, competitive exclusion, and unstable host-enemy dynamics. This erosion of diversity can be prevented over the short term if recruits are highly diverse as a result of preferential recruitment of rare species or, alternatively, if rare species survive preferentially, which increases diversity as the ages of the individuals increase. Here, we present census data from seven New and Old World tropical forest dynamics plots that all show the latter pattern. Within local areas, the trees that survived were as a group more diverse than those that were recruited or those that died. The larger (and therefore on average older) survivors were more diverse within local areas than the smaller survivors. When species were rare in a local area, they had a higher survival rate than when they were common, resulting in enrichment for rare species and increasing diversity with age and size class in these complex ecosystems.

Fully mapped tree census plots of large area, 25 to 52 hectares, have now been completed at six different sites in tropical forests, including dry deciduous to wet evergreen forest on two continents. One of the main goals of these plots has been to evaluate spatial patterns in tropical tree populations. Here the degree of aggregation in the distribution of 1768 tree species is examined based on the average density of conspecific trees in circular neighborhoods around each tree. When all individuals larger than 1 centimeter in stem diameter were included, nearly every species was more aggregated than a random distribution. Considering only larger trees (≥ 10 centimeters in diameter), the pattern persisted, with most species being more aggregated than random. Rare species were more aggregated than common species. All six forests were very similar in all the particulars of these results.

We studied the pre-germination loss of seeds to invertebrate and vertebrate seed predators of 5 species of Amazonian trees (Astrocaryum macrocalyx — Palmae; Bertholletia excelsa — Lecithydaceae; Calatola venezuelana — Icacinaceae; Dipteryx micrantha — Leguminosae (Papilionoidae); Hymenaea courbaril — Leguminosae (Caesalpinoidae)). These five species were selected from a large tree flora on several criteria. All possess large (3–10 cm) well-protected seeds that might plausibly be attractive to mammalian seed predators. The reproductive biology of three of the species, or close congeners, had been studied elsewhere in the Neotropics (Astrocaryum, Dipteryx, Hymenaea); one is important to the economy of southeastern Peru (Bertholletia); and one, despite large and apparently edible seeds, appeared to suffer no pre-germination loss to predators (Calatola). We conducted the research in mature forests in the Manu National Park of southeastern Peru where mammal densities are unperturbed by human activities. Densities of adult trees of the five species in our area range from very high (> 30 per ha: Astrocaryum) to very low («1 per ha: Hymenaea).