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Missouri Botanical Garden

archiveSt Louis, Missouri, United States

Research output, citation impact, and the most-cited recent papers from Missouri Botanical Garden (United States). Aggregated across the NobleBlocks index of 300M+ scholarly works.

Total works
15.5K
Citations
343.4K
h-index
256
i10-index
4.2K
Also known as
Missouri Botanical GardenShaw's Garden

Top-cited papers from Missouri Botanical Garden

The biodiversity of species and their rates of extinction, distribution, and protection
Stuart L. Pimm, Clinton N. Jenkins, Robin Abell, Thomas M. Brooks +4 more
2014· Science3.5Kdoi:10.1126/science.1246752

Background A principal function of the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES) is to “perform regular and timely assessments of knowledge on biodiversity.” In December 2013, its second plenary session approved a program to begin a global assessment in 2015. The Convention on Biological Diversity (CBD) and five other biodiversity-related conventions have adopted IPBES as their science-policy interface, so these assessments will be important in evaluating progress toward the CBD’s Aichi Targets of the Strategic Plan for Biodiversity 2011–2020. As a contribution toward such assessment, we review the biodiversity of eukaryote species and their extinction rates, distributions, and protection. We document what we know, how it likely differs from what we do not, and how these differences affect biodiversity statistics. Interestingly, several targets explicitly mention “known species”—a strong, if implicit, statement of incomplete knowledge. We start by asking how many species are known and how many remain undescribed. We then consider by how much human actions inflate extinction rates. Much depends on where species are, because different biomes contain different numbers of species of different susceptibilities. Biomes also suffer different levels of damage and have unequal levels of protection. How extinction rates will change depends on how and where threats expand and whether greater protection counters them. Advances Recent studies have clarified where the most vulnerable species live, where and how humanity changes the planet, and how this drives extinctions. These data are increasingly accessible, bringing greater transparency to science and governance. Taxonomic catalogs of plants, terrestrial vertebrates, freshwater fish, and some marine taxa are sufficient to assess their status and the limitations of our knowledge. Most species are undescribed, however. The species we know best have large geographical ranges and are often common within them. Most known species have small ranges, however, and such species are typically newer discoveries. The numbers of known species with very small ranges are increasing quickly, even in well-known taxa. They are geographically concentrated and are disproportionately likely to be threatened or already extinct. We expect unknown species to share these characteristics. Current rates of extinction are about 1000 times the background rate of extinction. These are higher than previously estimated and likely still underestimated. Future rates will depend on many factors and are poised to increase. Finally, although there has been rapid progress in developing protected areas, such efforts are not ecologically representative, nor do they optimally protect biodiversity. Outlook Progress on assessing biodiversity will emerge from continued expansion of the many recently created online databases, combining them with new global data sources on changing land and ocean use and with increasingly crowdsourced data on species’ distributions. Examples of practical conservation that follow from using combined data in Colombia and Brazil can be found at www.savingspecies.org and www.youtube.com/watch?v=R3zjeJW2NVk .

Drought Sensitivity of the Amazon Rainforest
Oliver L. Phillips, Luiz E. O. C. Aragão, Simon L. Lewis, Joshua B. Fisher +4 more
2009· Science1.9Kdoi:10.1126/science.1164033

Amazon forests are a key but poorly understood component of the global carbon cycle. If, as anticipated, they dry this century, they might accelerate climate change through carbon losses and changed surface energy balances. We used records from multiple long-term monitoring plots across Amazonia to assess forest responses to the intense 2005 drought, a possible analog of future events. Affected forest lost biomass, reversing a large long-term carbon sink, with the greatest impacts observed where the dry season was unusually intense. Relative to pre-2005 conditions, forest subjected to a 100-millimeter increase in water deficit lost 5.3 megagrams of aboveground biomass of carbon per hectare. The drought had a total biomass carbon impact of 1.2 to 1.6 petagrams (1.2 x 10(15) to 1.6 x 10(15) grams). Amazon forests therefore appear vulnerable to increasing moisture stress, with the potential for large carbon losses to exert feedback on climate change.

A comparative ethnobotany of Khevsureti, Samtskhe-Javakheti, Tusheti, Svaneti, and Racha-Lechkhumi, Republic of Georgia (Sakartvelo), Caucasus
Rainer W. Bussmann, Narel Y. Paniagua-Zambrana, Shalva Sikharulidze, Zaal Kikvidze +4 more
2016· Journal of Ethnobiology and Ethnomedicine1.6Kdoi:10.1186/s13002-016-0110-2

BACKGROUND: The Republic of Georgia (Sakartvelo in Georgian language) is part of the Caucasus biodiversity hotspot, and human agricultural plant use dates bat at least 6000 years. However, little ethnobiological research has been published from the region since the 1940s. Given the lack of recent research in the region, the present study we report on plant uses in Skartvelo (Republic of Georgia), Caucasus. We hypothesized that, (1) given the long tradition of plant use, and the isolation under Soviet rule, plant use both based on homegardens and wild harvesting would be more pronounced in Georgia than in the wiser region, (2) the Soviet occupation would have had broad influence on plant use, and (3) there would still be incidence of knowledge loss despite wide plant use. METHODS: Fieldwork was conducted in Khevsureti, Samtskhe-Javakheti, Tusheti, Svaneti, and Racha in July-August 2013, July-August 2014, and September-October 2015. Interviews using semi-structured questionnaires were conducted with 170 participants (80 women and 90 men) after obtaining their oral prior informed consent. All interviews were carried out in the participants' homes and gardens by native speakers of Georgian and its local dialects (Svan, Tush, Khevsur, Psav), or, where participants spoke these as their native language, Armenian, Russian, or Greek. RESULTS: In the present study we encountered 480 plant species belonging to 249 genera of 95 families being used in the research region. The highest number of species and of unique species were reported from the remote Tusheti-Khevsureti region. Informant consensus and number of use reports were highest for each region in the food and medicinal use categories. Of the 480 plants being used in the research region 282 species were exclusively wild-harvested, 103 were grown in homegardens, and 84 were both grown in gardens and sourced in the wild. CONCLUSIONS: Plant species, and uses, found in our study, both for Georgia in general, as well as for its regions, showed clear relations to the wider Caucasus - Asia Minor - Balkans cultural complex. However, plant use in Georgia was much more diverse than reported in other studies from Eurasia.

Starch Gel Electrophoresis of Ferns: A Compilation of Grinding Buffers, Gel and Electrode Buffers, and Staining Schedules
Pamela S. Soltis, Christopher H. Haufler, David C. Darrow, Gerald J. Gastony
1983· American Fern Journal1.4Kdoi:10.2307/1546611

Douglas E. Soltis, Christopher H. Haufler, David C. Darrow, Gerald J. Gastony, Starch Gel Electrophoresis of Ferns: A Compilation of Grinding Buffers, Gel and Electrode Buffers, and Staining Schedules, American Fern Journal, Vol. 73, No. 1 (Jan. - Mar., 1983), pp. 9-27

Hyperdominance in the Amazonian Tree Flora
Hans ter Steege, Nigel C. A. Pitman, Daniel Sabatier, Christopher Baraloto +4 more
2013· Science1.4Kdoi:10.1126/science.1243092

Introduction Recent decades have seen a major international effort to inventory tree communities in the Amazon Basin and Guiana Shield (Amazonia), but the vast extent and record diversity of these forests have hampered an understanding of basinwide patterns. To overcome this obstacle, we compiled and standardized species-level data on more than half a million trees in 1170 plots sampling all major lowland forest types to explore patterns of commonness, rarity, and richness. Methods The ~6-million-km 2 Amazonian lowlands were divided into 1° cells, and mean tree density was estimated for each cell by using a loess regression model that included no environmental data but had its basis exclusively in the geographic location of tree plots. A similar model, allied with a bootstrapping exercise to quantify sampling error, was used to generate estimated Amazon-wide abundances of the 4962 valid species in the data set. We estimated the total number of tree species in the Amazon by fitting the mean rank-abundance data to Fisher’s log-series distribution. Results Our analyses suggest that lowland Amazonia harbors 3.9 × 10 11 trees and ~16,000 tree species. We found 227 “hyperdominant” species (1.4% of the total) to be so common that together they account for half of all trees in Amazonia, whereas the rarest 11,000 species account for just 0.12% of trees. Most hyperdominants are habitat specialists that have large geographic ranges but are only dominant in one or two regions of the basin, and a median of 41% of trees in individual plots belong to hyperdominants. A disproportionate number of hyperdominants are palms, Myristicaceae, and Lecythidaceae. Discussion The finding that Amazonia is dominated by just 227 tree species implies that most biogeochemical cycling in the world’s largest tropical forest is performed by a tiny sliver of its diversity. The causes underlying hyperdominance in these species remain unknown. Both competitive superiority and widespread pre-1492 cultivation by humans are compelling hypotheses that deserve testing. Although the data suggest that spatial models can effectively forecast tree community composition and structure of unstudied sites in Amazonia, incorporating environmental data may yield substantial improvements. An appreciation of how thoroughly common species dominate the basin has the potential to simplify research in Amazonian biogeochemistry, ecology, and vegetation mapping. Such advances are urgently needed in light of the >10,000 rare, poorly known, and potentially threatened tree species in the Amazon.

International principles and standards for the practice of ecological restoration. Second edition
George D. Gann, Tein McDonald, Bethanie Walder, James Aronson +4 more
2019· Restoration Ecology1.4Kdoi:10.1111/rec.13035

The Society for Ecological Restoration (SER) is an international non-profit organization with members in 70 countries. SER advances the science, practice and policy of ecological restoration to sustain biodiversity, improve resilience in a changing climate, and re-establish an ecologically healthy relationship between nature and culture. SER is a dynamic global network, linking researchers, practitioners, land managers, community leaders and decision-makers to restore ecosystems and the human communities that depend on them. Via its members, publications, conferences, policy work, and outreach, SER defines and delivers excellence in the field of ecological restoration.

Global State of Biodiversity and Loss
Rodolfo Dirzo, Peter H. Raven
2003· Annual Review of Environment and Resources1.3Kdoi:10.1146/annurev.energy.28.050302.105532

Biodiversity, a central component of Earth's life support systems, is directly relevant to human societies. We examine the dimensions and nature of the Earth's terrestrial biodiversity and review the scientific facts concerning the rate of loss of biodiversity and the drivers of this loss. The estimate for the total number of species of eukaryotic organisms possible lies in the 5–15 million range, with a best guess of ∼7 million. Species diversity is unevenly distributed; the highest concentrations are in tropical ecosystems. Endemisms are concentrated in a few hotspots, which are in turn seriously threatened by habitat destruction—the most prominent driver of biodiversity loss. For the past 300 years, recorded extinctions for a few groups of organisms reveal rates of extinction at least several hundred times the rate expected on the basis of the geological record. The loss of biodiversity is the only truly irreversible global environmental change the Earth faces today.

ORIGIN OF EUKARYOTIC CELLS
Peter H. Raven
1971· Evolution1.2Kdoi:10.1111/j.1558-5646.1971.tb01930.x

Journal Article ORIGIN OF EUKARYOTIC CELLS Get access Peter H. Raven Peter H. Raven Missouri Botanical Garden and Washington University St. Louis Missouri Search for other works by this author on: Oxford Academic Google Scholar Evolution, Volume 25, Issue 4, 1 December 1971, Page 737, https://doi.org/10.1111/j.1558-5646.1971.tb01930.x Published: 01 December 1971 Article history Received: 29 March 1971 Published: 01 December 1971

A new subfamily classification of the Leguminosae based on a taxonomically comprehensive phylogeny: The Legume Phylogeny Working Group (LPWG)
Nasim Azani, Marielle Babineau, C. Donovan Bailey, Hannah Banks +4 more
2017· Taxon1.1Kdoi:10.12705/661.3

Abstract The classification of the legume family proposed here addresses the long‐known non‐monophyly of the traditionally recognised subfamily Caesalpinioideae, by recognising six robustly supported monophyletic subfamilies. This new classification uses as its framework the most comprehensive phylogenetic analyses of legumes to date, based on plastid matK gene sequences, and including near‐complete sampling of genera (698 of the currently recognised 765 genera) and ca. 20% (3696) of known species. The matK gene region has been the most widely sequenced across the legumes, and in most legume lineages, this gene region is sufficiently variable to yield well‐supported clades. This analysis resolves the same major clades as in other phylogenies of whole plastid and nuclear gene sets (with much sparser taxon sampling). Our analysis improves upon previous studies that have used large phylogenies of the Leguminosae for addressing evolutionary questions, because it maximises generic sampling and provides a phylogenetic tree that is based on a fully curated set of sequences that are vouchered and taxonomically validated. The phylogenetic trees obtained and the underlying data are available to browse and download, facilitating subsequent analyses that require evolutionary trees. Here we propose a new community‐endorsed classification of the family that reflects the phylogenetic structure that is consistently resolved and recognises six subfamilies in Leguminosae: a recircumscribed Caesalpinioideae DC., Cercidoideae Legume Phylogeny Working Group (stat. nov.), Detarioideae Burmeist., Dialioideae Legume Phylogeny Working Group (stat. nov.), Duparquetioideae Legume Phylogeny Working Group (stat. nov.), and Papilionoideae DC. The traditionally recognised subfamily Mimosoideae is a distinct clade nested within the recircumscribed Caesalpinioideae and is referred to informally as the mimosoid clade pending a forthcoming formal tribal and/or clade‐based classification of the new Caesalpinioideae. We provide a key for subfamily identification, descriptions with diagnostic charactertistics for the subfamilies, figures illustrating their floral and fruit diversity, and lists of genera by subfamily. This new classification of Leguminosae represents a consensus view of the international legume systematics community; it invokes both compromise and practicality of use.

General Principles of Classification and Nomenclature in Folk Biology
Brent Berlin, Dennis E. Breedlove, Peter H. Raven
1973· American Anthropologist952doi:10.1525/aa.1973.75.1.02a00140

Since about 1954, modern field research has been carried out by a number of ethnographers and biologists in an effort to understand more fully the nature of folk biological classification. Much of this work has been devoted to studies dealing with the naming and classification of plants and animals in non‐Western societies. It has now become apparent that several important and far reaching generalizations can be formulated which promise to throw considerable light on prescientific man's understanding of his biological universe.

Neotropical Floristic Diversity: Phytogeographical Connections Between Central and South America, Pleistocene Climatic Fluctuations, or an Accident of the Andean Orogeny?
Alwyn H. Gentry
1982· Annals of the Missouri Botanical Garden922doi:10.2307/2399084

Alwyn H. Gentry, Neotropical Floristic Diversity: Phytogeographical Connections Between Central and South America, Pleistocene Climatic Fluctuations, or an Accident of the Andean Orogeny?, Annals of the Missouri Botanical Garden, Vol. 69, No. 3 (1982), pp. 557-593

Vertebrates on the brink as indicators of biological annihilation and the sixth mass extinction
Gerardo Ceballos, Paul R. Ehrlich, Peter H. Raven
2020· Proceedings of the National Academy of Sciences907doi:10.1073/pnas.1922686117

The ongoing sixth mass species extinction is the result of the destruction of component populations leading to eventual extirpation of entire species. Populations and species extinctions have severe implications for society through the degradation of ecosystem services. Here we assess the extinction crisis from a different perspective. We examine 29,400 species of terrestrial vertebrates, and determine which are on the brink of extinction because they have fewer than 1,000 individuals. There are 515 species on the brink (1.7% of the evaluated vertebrates). Around 94% of the populations of 77 mammal and bird species on the brink have been lost in the last century. Assuming all species on the brink have similar trends, more than 237,000 populations of those species have vanished since 1900. We conclude the human-caused sixth mass extinction is likely accelerating for several reasons. First, many of the species that have been driven to the brink will likely become extinct soon. Second, the distribution of those species highly coincides with hundreds of other endangered species, surviving in regions with high human impacts, suggesting ongoing regional biodiversity collapses. Third, close ecological interactions of species on the brink tend to move other species toward annihilation when they disappear-extinction breeds extinctions. Finally, human pressures on the biosphere are growing rapidly, and a recent example is the current coronavirus disease 2019 (Covid-19) pandemic, linked to wildlife trade. Our results reemphasize the extreme urgency of taking much-expanded worldwide actions to save wild species and humanity's crucial life-support systems from this existential threat.

Benefits of restoring ecosystem services in urban areas
Thomas Elmqvist, Heikki Setälä, SN Handel, S. van der Ploeg +4 more
2015· Current Opinion in Environmental Sustainability848doi:10.1016/j.cosust.2015.05.001

Cities are a key nexus of the relationship between people and nature and are huge centers of demand for ecosystem services and also generate extremely large environmental impacts. Current projections of rapid expansion of urban areas present fundamental challenges and also opportunities to design more livable, healthy and resilient cities (e.g. adaptation to climate change effects). We present the results of an analysis of benefits of ecosystem services in urban areas. Empirical analyses included estimates of monetary benefits from urban ecosystem services based on data from 25 urban areas in the USA, Canada, and China. Our results show that investing in ecological infrastructure in cities, and the ecological restoration and rehabilitation of ecosystems such as rivers, lakes, and woodlands occurring in urban areas, may not only be ecologically and socially desirable, but also quite often, economically advantageous, even based on the most traditional economic approaches.

Introgressive hybridization
Edgar Anderson
1949830doi:10.5962/bhl.title.4553

This little book is concerned with hybridization under those circumstances which we so glibh^refer to as "natural conditions," that is, with the results of hybridization outside the laboratorj nd the breeding plot. It passes no judgments on the importance of hybridization in evolution but attempts to take this whole problem outside the area of argument and opinion and into the zone of measurement and analysis. It is verj^largely concerned with how the effects of hybridization can best be measured in natural populations and with a discussion of the forces at work in such populations.

Variation in wood density determines spatial patterns inAmazonian forest biomass
Timothy R. Baker, Oliver L. Phillips, Yadvinder Malhi, Samuel Almeida +4 more
2004· Global Change Biology807doi:10.1111/j.1365-2486.2004.00751.x

Abstract Uncertainty in biomass estimates is one of the greatest limitations to models of carbon flux in tropical forests. Previous comparisons of field‐based estimates of the aboveground biomass (AGB) of trees greater than 10 cm diameter within Amazonia have been limited by the paucity of data for western Amazon forests, and the use of site‐specific methods to estimate biomass from inventory data. In addition, the role of regional variation in stand‐level wood specific gravity has not previously been considered. Using data from 56 mature forest plots across Amazonia, we consider the relative roles of species composition (wood specific gravity) and forest structure (basal area) in determining variation in AGB. Mean stand‐level wood specific gravity, on a per stem basis, is 15.8% higher in forests in central and eastern, compared with northwestern Amazonia. This pattern is due to the higher diversity and abundance of taxa with high specific gravity values in central and eastern Amazonia, and the greater diversity and abundance of taxa with low specific gravity values in western Amazonia. For two estimates of AGB derived using different allometric equations, basal area explains 51.7% and 63.4%, and stand‐level specific gravity 45.4% and 29.7%, of the total variation in AGB. The variation in specific gravity is important because it determines the regional scale, spatial pattern of AGB. When weighting by specific gravity is included, central and eastern Amazon forests have significantly higher AGB than stands in northwest or southwest Amazonia. The regional‐scale pattern of species composition therefore defines a broad gradient of AGB across Amazonia.

Computational thinking for youth in practice
Irene Lee, Fred Martin, Jill Denner, Bob Coulter +4 more
2011· ACM Inroads774doi:10.1145/1929887.1929902

Computational thinking (CT) has been described as the use of abstraction, automation, and analysis in problem-solving [3]. We examine how these ways of thinking take shape for middle and high school youth in a set of NSF-supported programs. We discuss opportunities and challenges in both in-school and after-school contexts. Based on these observations, we present a "use-modify-create" framework, representing three phases of students' cognitive and practical activity in computational thinking. We recommend continued investment in the development of CT-rich learning environments, in educators who can facilitate their use, and in research on the broader value of computational thinking.

Agricultural intensification and climate change are rapidly decreasing insect biodiversity
Peter H. Raven, David L. Wagner
2021· Proceedings of the National Academy of Sciences762doi:10.1073/pnas.2002548117

Major declines in insect biomass and diversity, reviewed here, have become obvious and well documented since the end of World War II. Here, we conclude that the spread and intensification of agriculture during the past half century is directly related to these losses. In addition, many areas, including tropical mountains, are suffering serious losses because of climate change as well. Crops currently occupy about 11% of the world's land surface, with active grazing taking place over an additional 30%. The industrialization of agriculture during the second half of the 20th century involved farming on greatly expanded scales, monoculturing, the application of increasing amounts of pesticides and fertilizers, and the elimination of interspersed hedgerows and other wildlife habitat fragments, all practices that are destructive to insect and other biodiversity in and near the fields. Some of the insects that we are destroying, including pollinators and predators of crop pests, are directly beneficial to the crops. In the tropics generally, natural vegetation is being destroyed rapidly and often replaced with export crops such as oil palm and soybeans. To mitigate the effects of the Sixth Mass Extinction event that we have caused and are experiencing now, the following will be necessary: a stable (and almost certainly lower) human population, sustainable levels of consumption, and social justice that empowers the less wealthy people and nations of the world, where the vast majority of us live, will be necessary.

Ecological status and traditional knowledge of medicinal plants in Kedarnath Wildlife Sanctuary of Garhwal Himalaya, India
Jahangeer A. Bhat, Munesh Kumar, Rainer W. Bussmann
2013· Journal of Ethnobiology and Ethnomedicine741doi:10.1186/1746-4269-9-1

BACKGROUND: Himalayan forests are the most important source of medicinal plants and with useful species for the local people. Kedarnath Wildlife Sanctuary (KWLS) is situated in the interior part of the Garhwal Himalayan region. The presented study was carried out in Madhmeshwar area of KWLS for the ecological status of medicinal plants and further focused on the ethnomedicinal uses of these plants in the study area. METHODS: Ecological information about ethnomedicinal plants were collected using random quadrats in a random sampling technique along an altitudinal gradient in the KWLS. Information on medicinal properties of plants encountered in the present study was generated by questionnaire survey and was also compared with relevant literature. RESULTS: A total of 152 medicinally important plant species were reported, in which 103 were found herbs, 32 shrubs and 17 were tree species which represented 123 genera of 61 families. A total of 18 plant species fell into the rare, endangered (critically endangered) and vulnerable status categories. CONCLUSION: The present study documented the traditional uses of medicinal plants, their ecological status and importance of these plants in the largest protected area of Garhwal Himalaya. This study can serve as baseline information on medicinal plants and could be helpful to further strengthen the conservation of this important resource.

Plant and fungal use in Tusheti, Khevsureti, and Pshavi, Sakartvelo (Republic of Georgia), Caucasus
Rainer W. Bussmann, Narel Y. Paniagua-Zambrana, Shalva Sikharulidze, Zaal Kikvidze +4 more
2016· Acta Societatis Botanicorum Poloniae729doi:10.5586/asbp.3517

In this study, we documented traditional plant use in Tusheti, Khevsureti, and Pshavi and hypothesized that (i) plant use knowledge in general would be higher in isolated high elevation communities, and that (ii) use of home gardens would be much more restricted to lower elevation settings. Fieldwork was conducted in Khevsureti, Pshavi, and Tusheti. Interviews using semi-structured questionnaires were conducted with 74 participants. In the present study, we encountered 317 plant species belonging to 203 genera of 80 families being used in the research region. Of these, 197 species were exclusively wild-harvested, 73 were grown in homegardens, and 47 were both grown in gardens and sourced in the wild. The ordinations in plant-space and in use-space were significantly fit by elevation of informant community, and community itself. Age and gender did not significantly fit the distribution of informants across either plant-space or use-space, respectively. Number of use-reports was highest across all communities in the food and medicinal use-categories, and informant consensus. Species with especially high use-diversity (UD) tended to be woody species although. Species with high use-value (UV) were mostly managed/domesticated species from home orchards, gardens, or farms. Plant species, and uses, found in our study, showed clear relations to the wider Eurasian cultural complex. The species number found was, however, far higher than in any published study from either the region or the wiser Mediterranean and Eurasia. The maintenance of home gardens in Georgia serves as socio-ecological memory. While the great variety of plant species used in the Georgian Caucasus might provide a reservoir for food security climate change is starting to affect both natural floristic diversity and gardens both in the Caucasus as well as continent wide.

Effects of isolation on the water status of forest patches in the Brazilian Amazon
Valerie Kapos
1989· Journal of Tropical Ecology699doi:10.1017/s0266467400003448

ABSTRACT Patterns of edge-related environmental changes and plant water relations were investigated in the isolated forest reserves of the INPA-WWF Minimum Critical Size of Eco-systems project near Manaus, Brazil early in the wet season. Air temperature was elevated and humidity reduced in the understorey within 40 m of the reserve margins, and air temperature and vapour pressure deficit (VPD) were higher in the interiors of 1 ha reserves than in 100 ha reserves. There was increased photosynthetically active radiation penetration to understorey level up to 40 m into a 100 ha reserve. Soil moisture was depleted in the outer 20 m of both small and large reserves, and surface soil water potentials fell below – 1.5 MPa at the margin of a 1 ha reserve. Studies of leaf relative water contents (RWCs) in understorey shrubs revealed no appreciable saturation deficits, though RWCs were sometimes lower at the reserve margins. Studies of leaf conductances revealed no evidence of restriction of water loss in these plants, and conductances of plants near the edges were significantly higher and higher for longer. The implications of these results for reserve design and for local and regional water budgets, as well as the possible role of water stress in increased tree mortality in isolated reserves are discussed. Padrōes de mudanças ambientais e hídricos de plantas relacionados a bordas de matas isoladas foram investigadas no início da estação seca nas reservas de floresta do Projeto Dinâmica Biológica de Fragmentos Florestais do INPA-WWF, proximo de Manaus, Brasil. No sub-bosque, até 40 m da borda da mata, a temperatura ambiental estava elevada e a umidade reduzida, e a temperatura do ar e o DPV estavam maiores nas reservas de 1 ha do que nas reservas de 100 ha. A penetração de radiaçao fotosintéticamente ativa no sub-bosque estava aumentada até 40 m da borda em reservas de 100 ha. A umidade do solo baixou consideravelmente nos 20 m periféricos de reservas grandes a pequenas, e o potencial hídrico na superficie do solo baixou para menos de −1.5 MPa na margem de uma reserva de 1 ha. Estudos do teor relativo de água (TRA) em folhas de arbustos de sub-bosque nӑo revelaram deficits de saturação apreciaveis apesar de que TRAs foram menores nas bordas das reservas. Estudos da conductancia foliar não revelaram evidência de restrições de perdas hídricas nessas plantas, e as conductancias de plantas próximas a bordas foram significativamente maiores durante um período mais longo. As impliçõtes desses resultados para o planejamento de reservas e para o balanço hídrico local e regional, assim como as possiveis funçoes de ‘stress’ hídrico na alta mortalidade de árvores em reservas isoladas são discutidas.