Tree Diversity In Forests Research Articles

Tree Species Richness Promotes Invertebrate Herbivory on Congeneric Native and Exotic Tree Saplings in a Young Diversity Experiment.

Tree diversity in forests is an important driver of ecological processes including herbivory. Empirical evidence suggests both negative and positive effects of tree diversity on herbivory, which can be, respectively, attributed to associational resistance or associational susceptibility. Tree diversity experiments allow testing for associational effects, but evidence regarding which pattern predominates is mixed. Furthermore, it is unknown if herbivory on tree species of native vs. exotic origin is influenced by changing tree diversity in a similar way, or if exotic tree species escape natural enemies, resulting in lower damage that is unrelated to tree diversity. To address these questions, we established a young tree diversity experiment in temperate southwestern Germany that uses high planting density (49 trees per plot; plot size 13 m2). The species pool consists of six congeneric species pairs of European and North American origin (12 species in total) planted in monocultures and mixtures (1, 2, 4, 6 species). We assessed leaf damage by leaf-chewing insects on more than 5,000 saplings of six broadleaved tree species. Plot-level tree species richness increased leaf damage, which more than doubled from monocultures to six-species mixtures, strongly supporting associational susceptibility. However, leaf damage among congeneric native and exotic species pairs was similar. There were marked differences in patterns of leaf damage across tree genera, and only the genera likely having a predominately generalist herbivore community showed associational susceptibility, irrespective of the geographical origin of a tree species. In conclusion, an increase in tree species richness in young temperate forests may result in associational susceptibility to feeding by generalist herbivores.

Partitioning the effect of composition and diversity of tree communities on leaf litter decomposition and soil respiration

The decomposition of plant material is an important ecosystem process influencing both carbon cycling and soil nutrient availability. Quantifying how plant diversity affects decomposition is thus crucial for predicting the effect of the global decline in plant diversity on ecosystem functioning. Plant diversity could affect the decomposition process both directly through the diversity of the litter, and/or indirectly through the diversity of the host plant community and its affect on the decomposition environment. Using a biodiversity experiment with trees in which both functional and taxonomic diversity were explicitly manipulated independently, we tested the effects of the functional diversity and identity of the living trees separately and in combination with the functional diversity and identity of the decomposing litter on rates of litter decomposition and soil respiration. Plant traits, predominantly leaf chemical and physical traits, were correlated with both litter decomposition and soil respiration rates. Surface litter decomposition, quantified by mass loss in litterbags, was best explained by abundance‐weighted mean trait values of tree species from which the litter was assembled (functional identity). In contrast, soil respiration, which includes decomposition of dissolved organic carbon and root respiration, was best explained by the variance in trait values of the host trees (functional diversity). This research provides insight into the effect of loss of tree diversity in forests on soil processes. Such understanding is essential to predicting changes in the global carbon budget brought on by biodiversity loss.

Fungi help trees hunt for food

Symbiosis![Figure][1] Symbiotic root fungi help trees access nutrient “patches” in soil PHOTO: EYE OF SCIENCE/SCIENCE SOURCE Trees face a difficult paradox: how to access nutrients that are not uniformly spread throughout the soil while remaining stationary. Nearly all plant roots associate with symbiotic soil-dwelling fungi (either intracellular arbuscular mycorrhizal or extracellular ectomycorrhizal fungi), which aid in nutrient uptake. Chen et al. now report that mycorrhizae help trees forage. Tree species with finer roots that associate with arbuscular mycorrhizal fungi produce more roots when they encounter a nutrient patch, and those that associate with ectomycorrhizal fungi produce more fungal hyphae. Moreover, trees in mixed woodlands probably have complementary foraging strategies by virtue of their differing symbionts, likely contributing to tree diversity in temperate forests. Proc. Natl. Acad. Sci. U.S.A. 10.1073/pnas.1601006113 (2016). [1]: pending:yes

Managing for diversity: harvest gap size drives complex light, vegetation, and deer herbivory impacts on tree seedlings

AbstractMany managed northern hardwood forests are characterized by low‐diversity tree regeneration. Small harvest gaps, competition from shrub–herb vegetation, and browsing by white‐tailed deer (Odocoileus virginianus) contribute to this pattern, but we know little about how these factors interact. With a stand‐scale experiment, we examined the effects of gap size (0–3234 m2), vegetation (weeded:unweeded), and deer (fenced:unfenced) on seedling growth and survival for 18 tree species. With increasing gap size and light, shrub–herb vegetation density increased, while deer browsing on seedlings in unweeded plots decreased. Fenced:weeded seedlings of all species increased in height up to 35–45% light, with optimal growth in large‐group selection and patch cut harvest gaps. Height growth rank order among tree species changed between gap sizes, but growth varied little in small, low‐light gaps. Instead, a low‐light survival (i.e., shade tolerance) vs. high‐light growth tradeoff we observed is likely more important for species sorting of gap sizes. Shrub–herb vegetation decreased seedling survival and growth, especially in larger harvest gaps, shifting gap size optima to smaller gaps, but had little effect on growth/survival rank order among species. In contrast, deer had strong impacts on growth rank order, especially in larger gaps where species differences in growth potential were trumped by differences in deer browsing pressure responses. However, contrary to their consistently negative main effects, vegetation and deer had two positive interacting effects: dense shrub–herb vegetation in large gaps protected seedlings of faster‐growing species from browsing and deer browsing of shrub–herb vegetation modestly increased light and growth of short, suppressed, browsing‐avoided species. In summary, harvest gap size‐mediated light availability, shrub–herb vegetation, and deer herbivory had strong interacting effects on tree seedling interspecific performance ranks and intraspecific optimal gap sizes. For management, a broad range of harvest gap sizes and rapid establishment of tree regeneration (naturally or planted) to minimize shrub–herb competition should increase tree diversity in forests with few deer. However, with deer browsing pressure, a more limited set of lesser‐browsed species are likely to recruit successfully regardless of gap size, except in large patch cut gaps, where recruitment of faster‐growing, shade‐intolerant species is possible.

Assessment of Urban Forest Tree Species Population and Diversity in Ibadan, Nigeria

This research focuses on the urban tree species population and diversity within Ibadan metropolis as a means of creating biodiversity database for the urban centre in South west, Nigeria. This was determined by assessing urban forest tree abundance, species diversity and growth yield. All trees with diameter at breast height (dbh) ≥ 10 cm were identified, dbh measured and their frequencies taken in all the area enumerated within Ibadan. There are 155 tree stems belonging to 26 families and 54 tree species within Ibadan built-up areas and 101 tree stems belonging to 16 families and 19 tree species in peri-urban centre of Ibadan. The two most abundant species and families were Delonix regia of Fabaceae family and Terminalia ivorensis of Combretaceae family (18 and 17 stems) respectively while Fabaceae family has (7 species). The value of the Shannon's max diversity index (Hmax) of (3.99 and 2.94), Shannon-Wiener diversity index (3.35 and 2.48) and species evenness 0.84 were the same for peri-urban centre, while the growth variable were basal area and volume of (22.8m2 and 18.5m2) and (284.8m3 and 275.3m3) respectively. This study provide information on the level of tree species biodiversity due to infrastructure development that has reduced forest cover within the built-up areas of Ibadan which can expose the city to lot of environmental hazard.

Vegetation patch dynamics and tree diversity in a diverse conifer and oak forest in central Mexico

Mexican conifer and oak forests are very diverse, and represent the vegetation type with the highest timber production in Mexico. Yet, there is little knowledge about the relationship of forest recovery and tree diversity in this type of vegetation. In this study, we analyzed the dynamics of vegetation patches over three time periods covering five decades, within an area in central Mexico dominated by conifer and oak forest. We identified vegetation patches, and evaluated their number and changes in patch size and vegetation cover. We also evaluated the composition and structure of the plant canopy in vegetation plots representing different canopy cover classes. Over the three periods studied, the number and total area of patches remained relatively constant, but an increase in canopy vegetation cover occurred in most vegetation patches. Patch canopies were dominated by the long-lived pioneer tree species Juniperus deppeana and the shrub Arctostaphylos pungens . We suggest that forest management in our study region should focus on facilitating the dominance of pines and oaks in sites that have recovered their canopy cover, and to identify the factors inhibiting succession in patches with less than 10 % vegetation cover.

How Do Urban Forests Compare? Tree Diversity in Urban and Periurban Forests of the Southeastern US

There is a need to understand how anthropogenic influences affect urban and periurban forest diversity at the regional scale. This study aims to compare urban and periurban tree composition along a geographic gradient, and test hypotheses about species composition and ecological homogeneity. We paired urban forest (UF) data from eight cities across the southeastern US with periurban forest (PF) data from the USDA Forest Service Forest Inventory and Analysis program. We found that tree diversity, as well as both observed and estimated species richness values were greater in UF versus PF. Community size structure analysis also indicated a greater proportion of large trees and greater numbers of non-native, invasive, and unclassified tree species in the UF versus the PF, regardless of location. Both forest type and ecological province had a significant effect on community species composition, with forests closer together in space being more similar to each other than those more distant. While land use change and management has been associated with ecological homogenization in human dominated landscapes, we found that species composition was more dissimilar along latitudinal lines than compared to between forest types, refuting this hypothesis, at least in terms of tree diversity.

Vielfältige Anwendungen genetischer Methoden im Wald

Diverse applications of genetic methods in forest ecosystems Swiss forests are managed in a close-to-nature way, and they mainly get naturally rejuvenated. This leads to a forest situation most beneficial for the conservation of the genetic diversity of forest trees. If tree breeding and artificial planting are not main targets in Switzerland, why then using genetics in Swiss forests? In fact, the applications of genetic methods in forests are manifold. They can be used for the identification of connectivity and the evaluation of the success of connectivity measures, e.g., among total reserves, old-growth stands and habitat trees. With genetic methods, one may also study how native tree species and their genetic varieties can best be used for adaptation to climate change. Other applications comprise the investigation of biodiversity and ecology, e.g., the influence of forest management on soil biodiversity, or the diagnosis of invasive pests and pathogens and the search for agents of biological control. In the framework of multifunctional forest management, genetic applications can play an important role, if used in a sensible way.

Tree Diversity Changes over a Decade (2003-2013) in Four Inland Tropical Dry Evergreen Forest Sites on the Coromandel Coast of India

Forest tree diversity inventory and its periodical monitoring are important to understand changes in tree population structure and to provide information useful for biodiversity conservation and reserve management. In a long-term forest dynamics program in Indian tropical dry evergreen forest, this communication deals with tree diversity changes at decadal interval. The initial inventory of tree diversity was carried out in 2003, in four tropical dry evergreen forest sites - (much disturbed sites Shanmuganathapuram - SP and Araiyapatti - AP and moderately disturbed sites - Karisakkadu - KR and Maramadakki - MM) on the Coromandel Coast of peninsular India, by establishing four 1ha permanent plots, one in each site. In 2013, the four plots were re-inventoried for tree diversity (≥10 cm gbh) changes which yielded 56 species from 46 genera and 26 families. The studied forest sites are threatened by disturbance due to multiple reasons; cutting of trees inside of the forest, grazing by goats, construction of temple approach road, and some aspects cultural attachment of local people like constructing new, additional strctures of temple by denuding a portion of forest etc.. Tree species richness over a decade increased by four species in site SP, two species in site AP, and one species in site KR, but decreased by one species in site MM. Tree density decreased drastically by 480 (28.92%) and 102 (12.63%) stems ha -1 respectively in sites SP and AP, but moderately increased by 82 (12.09%) stems ha -1 in site KR and 26

Comparison of forest regeneration in two sites with different primate abundances in Northwestern Ecuador

There is increasing evidence that large-bodied primates play important roles as seed dispersers and in the maintenance of tree diversity in forest ecosystems. In this study we compared forest regeneration at two sites with differing primate abundances in the Ecuadorian Chocoan rainforest. We predicted: (1) significant differences in primate abundance between the two sites; (2) higher understory tree species richness and density at the site with greater primate abundance; (3) the site with lower primate abundance characterized by tree species dispersed by non-primate biotic agents and/or abiotic factors. We compared two sites, Tesoro Escondido (TE) a campesino cooperative, and the El Pambilar (EP) wildlife refuge that both maintain populations of mantled howler monkey (Alouatta palliata), the brown-headed spider monkey (Ateles fusciceps fusciceps) and the capuchin monkey (Cebus capucinus). We characterized canopy structure by point-quadrant sampling, determined primate abundance and sampled seedlings/saplings in 1 m2 plots, classifying tree species based on three dispersal syndromes: adapted for primate dispersal, dispersed by other biological agents, and abiotic dispersal. We compared sites in terms of primate abundance (groups and individuals observed per day) and regeneration characteristics (overall density, species richness, and dispersal syndrome). We carried out within site comparisons and constructed understory tree species accumulation curves. Overall the forests were structurally similar - with significantly higher densities of A. f. fusciceps at TE. Encounter rates for the other two primate species were similar at both sites. Understory tree density and species richness was significantly higher in TE with no stabilization of tree species accumulation curves. The species accumulation curve for understory trees at EP stabilized. Higher densities and species richness of primate dispersed tree species were observed at TE, with non-primate biotically dispersed tree species the dominant dispersal syndrome at both sites. Our observations are consistent with those from other studies investigating the role of large-bodied frugivorous primates in forest regeneration, and point to a general pattern: future lowland tropical forest tree diversity depends on maintaining robust populations of large primate species in these systems. It is highly probable that the maintenance of high levels of tree diversity in Chocoan rainforests is dependent on the conservation of its largest resident primate, the critically endangered brown-headed spider monkey (A. f. fusciceps).

The role of cocoa agroforestry systems in conserving forest tree diversity in the Central region of Cameroon

This paper seeks to examine the contribution of cocoa-based agroforestry systems (CAFS) in the conservation of native tree species of nearby forests. The study was conducted in two sites in Mbankomo sub-division of Cameroon, where a field inventory was carried out in both land use systems in 26 sample plots of 30 × 30 m2 each, in 20 cocoa agroforest plots and six adjacent secondary forests plots. Tree diversity, composition and structure in the cocoa agroforests and secondary forests were characterized, α-diversity was evaluated and similarity/dissimilarity of species composition assessed using non-metric multidimensional scaling (NMDS). The results reveal that all the CAFS appear to conserve 46 % of forest tree species found in nearby forests. This may be justified by the multipurpose use of forest tree species during the implementation and the evolution of the CAFS on a spatial–temporal scale. CAFS harbored lower forest tree species diversity at the plot level compared to nearby forest stands meanwhile the non-parametric estimator suggested that both land uses conserve approximately the same species richness. Mean values for species richness, the Shannon and reciprocal Simpsons indices diversity, stem density and basal area were significantly higher in forests than in CAFS (p < 0.001). The NMDS showed a clear dissimilarity which was confirmed by the Rstatistic = 0.998 and p value = 0.009 of the analysis of similarities test between cocoa agroforests and forest stands. In conclusion, the results show that CAFS can serve as reservoirs for the conservation of forest tree species; this can be expanded if the issue of ownership of timber forest trees is addressed in the forest law.

Effects of fragmentation and landscape variation on tree diversity in post-logging regrowth forests of the Southern Philippines

The conservation value of forest fragments remains controversial. An extensive inventory of rainforest trees in post-logging regrowth forest in the southern Philippines provided a rare opportunity to compare stem density, species richness, diversity and biotic similarity between two types of post-logging forests: broken-canopy forest fragments and adjacent tracts of closed-canopy ‘contiguous’ forest. Tree density was much lower in the fragments, but rarefied species richness was higher. ‘Hill’ numbers, computed as the exponential of Shannon’s diversity index and the inverse of Simpson’s diversity index, indicated that fragments have higher numbers of typical and dominant species compared to contiguous forest. Beta diversity (based on species incidence) and the exponential of Shannon’s diversity index was higher in fragmented forest, indicating higher spatial species turnover than in contiguous forest samples. Lower mean values of the Chao-Jaccard index in fragmented forest compared to contiguous forest also indicated a lower probability of shared species across fragments. The high species richness of contiguous forest showed that an earlier single logging event had not caused biodiversity to be degraded leaving mostly generalist species. Fragmentation and further low-level utilisation by local farmers has also not caused acute degradation. Post-logging regrowth forest fragments present a window of opportunity for conservation that may disappear in a few years as edge effects become more apparent. For the conservation of trees in forests in south-east Asia generally, our findings also suggest that while conservation of remaining primary forest may be preferable, the conservation value of post-logging regrowth forests can also be high.

Region effects influence local tree species diversity

Global patterns of biodiversity reflect both regional and local processes, but the relative importance of local ecological limits to species coexistence, as influenced by the physical environment, in contrast to regional processes including species production, dispersal, and extinction, is poorly understood. Failure to distinguish regional influences from local effects has been due, in part, to sampling limitations at small scales, environmental heterogeneity within local or regional samples, and incomplete geographic sampling of species. Here, we use a global dataset comprising 47 forest plots to demonstrate significant region effects on diversity, beyond the influence of local climate, which together explain more than 92% of the global variation in local forest tree species richness. Significant region effects imply that large-scale processes shaping the regional diversity of forest trees exert influence down to the local scale, where they interact with local processes to determine the number of coexisting species.

Interacting effects of forest stratum, edge and tree diversity on beetles

Edge effects are an important component of forest fragmentation, altering microclimatic conditions and species composition within forest remnants. Yet, major factors affecting strength and extent to which edge effects might penetrate into fragments have remained elusive. Here, we study for the first time how tree diversity and forest stratum alter edge effects and how these factors affect beetle communities.We sampled beetles over 7months using 92 flight interception traps in the canopy and near the ground in the Hainich National Park; Germany’s largest connected deciduous forest. Traps were exposed along 10 transects (0–500m) from the forest edge into the forest interior, comparing transects with high or low abundance of beech (low or high tree diversity).Tree diversity had no influence on the range or strength of edge effects. In the understory, edge effects extended up to maximal transect length of 500m into the forest interior. Edge effects were weaker in the canopy than in the understory, likely because of higher, edge-like microclimatic variability and harshness in the canopy. The edge response of beetle species richness was driven by habitat generalists while forest and saproxylic species responded less strongly.The richness of forest and saproxylic beetles peaked in the canopy, whereas habitat generalists and non-saproxylic beetles strongly dominated the understory. Pathways driving beetle species richness differed across forest strata. Structural equation modelling showed that tree diversity (+, positive effect) and overall dead wood volume (+) were the most important factors driving beetle species richness in the canopy. In contrast, tree diversity effects (+) were less strong and canopy openness (+) and distance from the forest edge (−) were more important in the understory.

The advantage of the extremes: tree seedlings at intermediate abundance in a tropical forest have the highest richness of above‐ground enemies and suffer the most damage

Summary Tropical forest tree diversity has been hypothesized to be maintained via the attraction of density responsive and species‐specific enemies. Tests of this hypothesis usually assume a linear relationship between enemy pressure (amount of damage and enemy richness) and seedling or tree density. However, enemy pressure is likely to change nonlinearly with local seedling abundance and community scale tree abundance if enemies are characterized by nonlinear functional responses. We examined the abiotic and biotic factors associated with richness of above‐ground enemies and foliar damage found in tree seedlings in a tropical forest in Puerto Rico. Rather than identify specific enemies targeting these seedlings, we used damage morphotypes, a paleo‐ecological method, to derive a proxy for enemy species richness. We found that the relationships between local and (conspecific seedling density) community scale (conspecific basal area of adult trees) abundance and both richness of above‐ground enemies and foliar damage were hump‐shaped. Seedlings of tree species existing at intermediate levels of abundance, at both local and community scales, suffered more damage and experienced pressure from a greater diversity of enemies than those existing at high or low densities. We hypothesized that greater damage at intermediate abundance level could arise from a rich mixture of generalist and specialist enemies targeting seedlings of intermediate abundance tree species. Consistent with this hypothesis, we found that generalist enemies were more diverse on species at rare or intermediate abundance relative to common tree species. However, specialist enemies showed no significant trend across tree species abundance at either the local or community scales. Synthesis. Our results suggest that interspecific variation in tree species abundance leads to differences in the magnitude and type of damage tropical tree seedlings suffer. This variation leads to a nonlinear, hump‐shaped relationship between species abundance and enemy damage, highlighting fruitful directions for further development of species coexistence theory.

Distance-responsive predation is not necessary for the Janzen–Connell hypothesis

The Janzen–Connell hypothesis states that tree diversity in tropical forests is maintained by specialist predators that are distance- or density-responsive (i.e. predators that reduce seed or seedling survival near adults of their hosts). Many empirical studies have investigated whether predators are distance-responsive; however, few studies have examined whether distance-responsiveness matters for how predators maintain tree diversity. Using a site-occupancy model, we show analytically that distance-responsive predators are actually less able to maintain diversity than specialist predators that are not distance-responsive. Generally, specialist predators maintain diversity because they become rare when their host’s densities are low, reducing predation risk. However, if predators are distance-responsive, and most seeds cannot disperse away from these predators, then seed predation rates will remain high, even if predator density is low across the landscape. Consequently, a reduction in a host’s population density may not lead to a significant reduction in seed and seedling predation. We show that habitat partitioning can cause recruitment to be highest near conspecific adults, even in the presence of distance-responsive predators, without any change in the effect that the predators have on coexistence (a result contrary to predictions of the Janzen–Connell hypothesis). Rather, specialist predators and habitat partitioning have additive effects on species coexistence in our model, i.e., neither mechanism alters the effect of the other one.

Bacterial diversity indicates dietary overlap among bats of different feeding habits

Bats are among the most conspicuous mammals with extraordinary adaptations. They play a key role in the ecosystem. Frugivorous bats are important seed dispersing agents that help in maintaining forest tree diversity, while insectivorous bats are natural insect pest control agents. Several previous reports suggest that bats are reservoir of viruses; nonetheless their bacterial counterparts are relatively less explored. The present study describes the microbial diversity associated with the intestine of bats from different regions of India. Our observations stipulate that there is substantial sharing of bacterial communities between the insectivorous and frugivorous bats, which signifies fairly large dietary overlap. We also observed the presence of higher abundance of Mycoplasma in Cynopterus species of bats, indicating possible Mycoplasma infection. Considering the scarcity of literature related to microbial communities of bat intestinal tract, this study can direct future microbial diversity studies in bats with reference to their dietary habits, host-bacteria interaction and zoonosis.

Rapid Liana Colonization along a Secondary Forest Chronosequence

AbstractLianas (woody vines) can have profound effects on tree recruitment, growth, survival, and diversity in tropical forests. However, the dynamics of liana colonization soon after land abandonment are poorly understood, and thus it is unknown whether lianas alter tree regeneration early in succession. We examined the liana community in 43 forests that ranged from 1 to 31 yr old in central Panama to determine how fast lianas colonize young forests and how the liana community changes with forest succession. We found that lianas reached high densities early in succession, commonly exceeding 1000 stems/ha within the first 5 yr of forest regeneration. Lianas also increased rapidly during early succession in terms of basal area but did not show evidence of saturation within the 30 yr of our chronosequence. The relative contribution of lianas to total woody plant community in terms of basal area and density increased rapidly and reached a saturation point within 5 yr (basal area) to 15 yr (density) after land abandonment. Our data demonstrate that lianas recruit early and in high density in tropical forest regeneration, and thus lianas may have a large effect on the way in which secondary forests develop both early and throughout succession.

Where did all the trees come from? A novel multispecies approach reveals the impacts of biogeographical history and functional diversity on rain forest assembly

AbstractAimWe take advantage of next generation sequencing‐based technology to assess how landscape‐level dynamics, biogeographical history and functional factors shape the distribution of genetic diversity in rain forest trees. To achieve this, we explore chloroplast genomic diversity and divergence patterns across multiple, co‐distributed species from three major centres of rain forest diversity.LocationSubtropical rain forests in south‐eastern Australia: Nightcap–Border Ranges, Dorrigo and Washpool.MethodsWe assembled chloroplast genomic data from whole‐genome shotgun libraries for 71 species collected across three major centres of rain forest diversity. Chloroplast single nucleotide polymorphisms were used to measure genetic variation within and between multiple populations, species and locations, and we used this information to identify patterns related to landscape‐level processes, biogeographical origins and functional characteristics.ResultsWe identified Nightcap–Border Ranges and Dorrigo as containing multiple refugia and Washpool as primarily a recolonized area. We found that rapidly expanding lineages of Indo‐Malesian origin exhibit significantly lower levels of genetic diversity than Gondwanan lineages with longer local histories. Functional traits related to persistence and dispersal were the most important in regulating the distribution of genetic diversity.Main conclusionsThe distribution and assembly of species reflect interactions and competition between different floristic elements at different stages of continental occupation. Additionally, given the multiple evolutionary origins and histories of the Australian rain forest flora, it is important to avoid treating rain forest communities as single management units.

Shifts in indigenous culture relate to forest tree diversity: A case study from the Tsimane’, Bolivian Amazon

Understanding how indigenous peoples’ management practices relate to biological diversity requires addressing contemporary changes in indigenous peoples’ way of life. This study explores the association between cultural change among a Bolivian Amazonian indigenous group, the Tsimane’, and tree diversity in forests surrounding their villages. We interviewed 86 informants in six villages about their level of attachment to traditional Tsimane’ values, our proxy for cultural change. We estimated tree diversity (Fisher’s Alpha index) by inventorying trees in 48 0.1-ha plots in old-growth forests distributed in the territory of the same villages. We used multivariate models to assess the relation between cultural change and alpha tree diversity. Cultural change was associated with alpha tree diversity and the relation showed an inverted U-shape, thus suggesting that tree alpha diversity peaked in villages undergoing intermediate cultural change. Although the results do not allow for testing the direction of the relation, we propose that cultural change relates to tree diversity through the changes in practices and behaviors that affect the traditional ecological knowledge of Tsimane’ communities; further research is needed to determine the causality. Our results also find support in the intermediate disturbance hypothesis, and suggest that indigenous management can be seen as an intermediate form of anthropogenic disturbance affecting forest communities in a subtle, non-destructive way.