Interactive effects of landscape-wide intensity of farming practices and landscape complexity on wild bee diversity

Context

The local intensity of farming practices is considered as an important driver of biodiversity in agricultural landscapes and its effect on biodiversity has been shown to interact with landscape complexity. But the influence of landscape-wide intensity of farming practices on biodiversity and its combined effect with landscape complexity have been little explored.

Objective

In this study, we tested the interactive effect of the landscape-wide intensity of farming practices and landscape complexity on the local species richness and abundance of farmland wild bee communities.

Methods

We captured wild bees in 96 crop fields and explored the effect of landscape-wide intensity of various farming practices along a gradient of landscape complexity (proportion of semi-natural habitats).

Results

We found that species richness and abundance of wild bees were more positively influenced by landscape complexity in highly insecticide-sprayed landscapes than in less intensively managed landscapes. In contrast, we found that the positive effect of landscape complexity on bee species richness only occurred in landscapes with low nitrogen inputs.

Conclusions

Our study demonstrates the interactive effects of landscape-wide farming intensity and landscape complexity in shaping the diversity of farmland wild bee communities. We conclude that the management of farming intensity at the landscape-scale could mitigate the effects of habitat loss on wild bee decline and would help to maintain pollination services in agricultural landscapes.

     

Butterfly assemblages in residential gardens are driven by species’ habitat preference and mobility

Context

Understanding the factors contributing to maintaining biodiversity is crucial to mitigate the impact of anthropogenic disturbances. Representing large proportions of green area in highly modified landscapes, residential gardens are often seen as local habitats that can contribute to larger networks of suitable environments at the landscape scale.

Objectives

We investigated the impact of the landscape context on butterfly communities observed in residential gardens, taking into account garden characteristics, land-use types and presence of linear features in the surrounding landscape. We examined how species traits affected butterflies’ response to landscape context and habitat quality.

Methods

We performed a cross-scale study, based on citizen science data documenting butterfly species composition and abundance in 920 gardens across France. We examined the effect of garden quality, the area of different land-use types and the length of linear elements measured at three scales within the surrounding landscape. Species were grouped according to their habitat preference and mobility.

Results

Urbanization negatively affected total species richness and the abundance of butterfly in each group. This was related to declining habitat quality and reduced area of suitable habitat in the surrounding landscape. The magnitude of this effect, however, was negatively correlated with mobility, a trait related to habitat preference. The spatial scale at which landscape context best explained variation in butterfly abundance changed with species’ habitat preference.

Conclusions

This study highlights the importance of preserving high quality habitats in altered landscapes and considering species’ mobility and habitat preference when assessing the impact of landscapes on butterfly communities.

     

Small-scale agricultural landscapes promote spider and ground beetle densities by offering suitable overwintering sites

Context

Intensive agricultural management practices and landscape homogenisation are the main drivers of biodiversity loss in agricultural landscapes. Agricultural fields are regularly disturbed and provide unstable habitats due to crop management regimes. This may lead to movement of arthropods into neighbouring non-arable habitats, as natural and semi-natural habitats provide suitable overwintering sites.

Objectives

Here we assessed the effect of landscape composition and configuration on the overwintering spider and carabid fauna of grassy field margins and hedgerows.

Methods

We sampled ground-dwelling arthropods at field edges of different types (grassy field margin and hedgerows), landscape composition (diverse and simple) and configuration (mosaic and large-scale agricultural landscapes).

Results

We detected larger spiders in hedgerows than in grassy field margins and in complex landscapes rather than in simple landscapes. We found a significant effect of interaction between landscape composition and edge type on ballooning propensity of spiders. Agrobiont carabids were more abundant in field edges of compositionally simple and large-scale agricultural landscapes. Furthermore, we showed an effect of interaction between landscape composition and edge type on agrobiont spiders. We collected larger carabids in grassy field margins than in hedgerows and carabids were smaller in simple landscapes than in diverse landscapes. The spider community was affected by edge type, and landscape composition had a significant effect on the carabid community.

Conclusions

Small-scale agricultural landscapes may have higher overall densities of ground-dwelling spiders and carabids than large scale landscapes due to the relatively high edge density and the higher quantity of available overwintering sites.

     

Anuran responses to spatial patterns of agricultural landscapes in Argentina

Context

Amphibians are declining worldwide and land use change to agriculture is recognized as a leading cause. Argentina is undergoing an agriculturalization process with rapid changes in landscape structure.

Objectives

We evaluated anuran response to landscape composition and configuration in two landscapes of east-central Argentina with different degrees of agriculturalization. We identified sensitive species and evaluated landscape influence on communities and individual species at two spatial scales.

Methods

We compared anuran richness, frequency of occurrence, and activity between landscapes using call surveys data from 120 sampling points from 2007 to 2009. We evaluated anuran responses to landscape structure variables estimated within 250 and 500-m radius buffers using canonical correspondence analysis and multimodel inference from a set of candidate models.

Results

Anuran richness was lower in the landscape with greater level of agriculturalization with reduced amount of forest cover and stream length. This pattern was driven by the lower occurrence and calling activity of seven out of the sixteen recorded species. Four species responded positively to the amount of forest cover and stream habitat. Three species responded positively to forest cohesion and negatively to rural housing. Two responded negatively to crop area and diversity of cover classes.

Conclusions

Anurans within agricultural landscapes of east-central Argentina are responding to landscape structure. Responses varied depending on species and study scale. Life-history traits contribute to responses differences. Our study offers a better understanding of landscape effects on anurans and can be used for land management in other areas experiencing a similar agriculturalization process.

     

Spatiotemporal variability in resources affects herbivore home range formation in structurally contrasting and unpredictable agricultural landscapes

Context

Movement is one of the key mechanisms for animals to deal with changes within their habitats. Therefore, resource variability can impact animals’ home range formation, especially in spatially and temporally highly dynamic landscapes, such as farmland. However, the movement response to resource variability might depend on the underlying landscape structure.

Objectives

We investigated whether a given landscape structure affects the level of home range size adaptation in response to resource variability. We tested whether increasing resource variability forces herbivorous mammals to increase their home ranges.

Methods

In 2014 and 2015 we collared 40 European brown hares (Lepus europaeus) with GPS-tags to record hare movements in two regions in Germany with differing landscape structures. We examined hare home range sizes in relation to resource availability and variability by using the normalized difference vegetation index as a proxy.

Results

Hares in simple landscapes showed increasing home range sizes with increasing resource variability, whereas hares in complex landscapes did not enlarge their home range.

Conclusions

Animals in complex landscapes have the possibility to include various landscape elements within their home ranges and are more resilient against resource variability. But animals in simple landscapes with few elements experience shortcomings when resource variability becomes high. The increase in home range size, the movement related increase in energy expenditure, and a decrease in hare abundances can have severe implications for conservation of mammals in anthropogenic landscapes. Hence, conservation management could benefit from a better knowledge about fine-scaled effects of resource variability on movement behaviour.

     

Landscape context affects site occupancy of pond-breeding anurans across a disturbance gradient in the Brazilian Cerrado

Context

The Brazilian Cerrado, a global biodiversity hotspot, is being converted to agricultural production. Amphibians in particular are susceptible to agricultural practices that threaten both their wetland and upland habitats. Although local site variables are important for determining species occurrence, site occupancy is also mediated by the broader landscape and management context in which the site occurs.

Objectives

Investigate the relative effects of broad-, intermediate-, and local-scale factors on species occurrence for pond-breeding anurans within different landscapes across an agricultural-disturbance gradient in the Cerrado.

Methods

Ponds were surveyed for adult anurans over 3 years within 18 landscapes (each 625 km²) that varied in their degree of agricultural land use (landscape context). We analyzed species distribution models for eight pond-breeding anurans, using hierarchical binomial generalized linear models.

Results

The broader landscape context had a significant effect on the incidence of pond-breeding anurans, even after accounting for variation in other environmental factors at more local (pond) or intermediate (1-km²) scales. The top-ranked models for most species included some combination of broad-, intermediate- and local-scale factors, however. These covariates influenced species occurrence in different ways, with the response to agricultural disturbance varying among species. Although some species were negatively affected, others appeared to benefit from agricultural activities that increased breeding habitat (e.g., impoundments to provide water for cattle).

Conclusions

Landscape context, the degree to which landscapes have been transformed by agricultural land use, has a major influence on the distribution of pond-breeding anurans in the Brazilian Cerrado.

     

Thinking outside the patch: a multi-species comparison of conceptual models from real-world landscapes

Context

When modeling a species’ distribution, landscapes can alternatively be conceptualized following patch- or gradient-based approaches. However, choosing the most suitable conceptualization is difficult and methods for empirical validation are still lacking.

Objectives

To address the conditions under which a given conceptual model is more suitable, taking into account landscape context and species trait dependency effects. Patch- and gradient-based conceptualizations were built based on two structurally different landscapes: variegated and mosaic. We hypothesize that: (H1) gradient-based models better describe variegated landscapes while patch-based models perform better in mosaic landscapes; and (H2) gradient-based models will fit generalist species better while patch-based models will suit specialists better.

Methods

We modeled the distribution of eleven bird species in each landscape using each conceptualization. We determined the suitability of each conceptual model to fit statistical models by looking for cross-species responses and deviations from best models.

Results

We found no clear support for our hypotheses. Although patch-based models performed better in mosaic landscapes (H1), they also provided useful conceptualizations in variegated landscapes. However, when patches showed high heterogeneity, gradient-based approaches better fit specialist species (H2).

Conclusions

The suitability of a given conceptual model depends on the interaction between species habitat specialization, and the intrinsic spatial heterogeneity of the landscape and the ability of each conceptualization to capture it. Gradient-based models provide better information on resource allocation, while patch-based models offer a simplified perspective on landscape attributes. Future research should consider the nature of both species and landscapes in order to avoid bias from inadequate landscape conceptualizations.

     

Issues and challenges in landscape models for agriculture: from the representation of agroecosystems to the design of management strategies

Context

Agroecosystems produce food and many other services that are crucial for human well-being. Given the scales at which the processes underlying these services take place, agricultural landscapes appear as appropriate spatial units for their evaluation and management. The design of sustainable agricultural landscapes that value these services has thus become a pressing issue but faces major challenges stemming from the diversity of processes, their interactions and the number of scales at stake. Agricultural landscape modelling can provide a key contribution to this design but must still overcome several difficulties to offer reliable tools for decision makers.

Objectives

Our study aimed at shedding light on the main scientific and technical difficulties that make the building of landscape models that may efficiently inform decision-makers a complex task, as well as translating them in terms of challenges that can be further investigated and discussed.

Methods

We examine current issues and challenges and indicate future research needs to overcome the scientific and technical obstacles in the development of useful agricultural landscape models.

Results

We highlight research perspectives to better couple landscape patterns and process models and account for feedbacks, integrate the decisions of multiple stakeholders, consider the spatial and temporal heterogeneity of data and processes, explore alternative landscape organisations and assess multiobjective performance.

Conclusion

Coping with the issues and challenges discussed in this paper should improve our understanding of agroecosystems and give rise to new hypotheses, thereby informing future research.

     

Behavioral and social mechanisms behind pattern formation: an experimental study of animal movement

Context

Although animal movement behaviors are influenced by spatial heterogeneity, such behaviors can also generate spatial heterogeneity via interactions with the emergent spatial structure and other individuals (i.e., the social landscape).

Objective

Elucidate the behavioral and ecological mechanisms of pattern formation in a homogeneous resource landscape.

Methods

We analyzed the movement pathways and space-use patterns of the lesser grain borer (Rhyzopertha dominica) within homogeneous resource landscapes (wheat kernels). Experimental trials consisted of individual beetles foraging alone or paired with a member of the same or different sex.

Results

We identified two sources of pattern formation: (1) beetles were attracted to areas where they or another beetle had previously fed, leading to increased patchiness via positive reinforcement; and (2) the presence of conspecifics affected whether and at what scales patchiness occurred. Solitary males had lower rates of movement and less tortuous pathways than solitary females, but both sexes generated fine-scale patchiness in the resource distribution. Patchy resource landscapes were also generated by male–female pairs, but not by same-sex pairings. Paired females in particular exhibited significantly greater daily net displacements and more random space use than solitary females.

Conclusions

Pattern formation is a complex process, even in a relatively simple, homogeneous resource landscape. In particular, patterns created by individuals when foraging alone versus in pairs underscores how social interactions can fundamentally alter the resultant pattern of heterogeneity that emerges in resource landscapes.

     

Diverse landscapes have a higher abundance and species richness of spring wild bees by providing complementary floral resources over bees’ foraging periods

Context

Anthropogenic landscape simplification and natural habitat loss can negatively affect wild bees. Alternatively, anthropogenic land-use change may diversify landscapes, creating complementary habitats that maintain overall resource continuity and diversity.

Objectives

We examined the effects of landscape composition, including land-cover diversity and percent semi-natural habitat, on wild bee abundance and species richness within apples, a pollinator-dependent crop. We also explored whether different habitats within diverse landscapes can provide complementary floral resources for bees across space and time.

Methods

We sampled bees during apple bloom over 2 years within 35 orchards varying in surrounding landscape diversity and percent woodland (the dominant semi-natural habitat) at 1 km radii. To assess habitat complementarity in resource diversity and temporal continuity, we sampled flowers and bees within four unique habitats, including orchards, woodlands, semi-natural grasslands, and annual croplands, over three periods from April–June.

Results

Surrounding landscape diversity positively affected both wild bee abundance and richness within orchards during bloom. Habitats in diverse landscapes had different flower communities with varying phenologies; flowers were most abundant within orchards and woodlands in mid-spring, but then declined over time, while flowers within grasslands marginally increased throughout spring. Furthermore, bee communities were significantly different between the closed-canopy habitats, orchards and woodlands, and the open habitats, grasslands and annual croplands.

Conclusions

Our results suggest that diverse landscapes, such as ones with both open (grassland) and closed (woodland) semi-natural habitats, support spring wild bees by providing flowers throughout the entire foraging period and diverse niches to meet different species’ requirements.

     

Ecologies as a complement to ecosystem services? Exploring how landscape planners might advance understanding about human–nature relationships in changing landscapes

Context

One of the key challenges for landscape planners is to reframe the meaning of ecosystem services. In this context, alternative concepts such as ecologies have potential to complement ecosystem services when applied to human–nature relationships in changing landscapes.

Objectives

The objectives of this article are: (1) to review how landscape planners use major critical approaches to translate the meaning of ecosystem services and (2) to introduce why ecologies provides helpful insights to complement ecosystem services.

Methods

A conceptual framework examines how landscape planners use critique to reframe the meaning of ecosystem services. This framework is then revised as a scenario to reframe the meanings of ecologies and ecosystem services.

Results

Landscape planners use three critical approaches to reframe the meaning of ecosystem services to advance the understanding of human–nature relationships in changing landscapes. Yet, they identify some important issues and gaps that emerge when it is applied. These issues and gaps are part of the rationale for why landscape planning is at a crossroads with ecosystem services. This rationale is then extended to create a scenario for why a revised conceptual framework is needed for landscape planners to reframe the meanings of ecologies and ecosystem services.

Conclusion

The translational challenge of ecologies and ecosystem services is an example of the key role that landscape planners play in developing a deeper understanding of human–nature relationships.

     

Interactions of landscape disturbances and climate change dictate ecological pattern and process: spatial modeling of wildfire,insect, and disease dynamics under future climates

Context

Interactions among disturbances, climate, and vegetation influence landscape patterns and ecosystem processes. Climate changes, exotic invasions, beetle outbreaks, altered fire regimes, and human activities may interact to produce landscapes that appear and function beyond historical analogs.

Objectives

We used the mechanistic ecosystem-fire process model FireBGCv2 to model interactions of wildland fire, mountain pine beetle (Dendroctonus ponderosae), and white pine blister rust (Cronartium ribicola) under current and future climates, across three diverse study areas.

Methods

We assessed changes in tree basal area as a measure of landscape response over a 300-year simulation period for the Crown of the Continent in north-central Montana, East Fork of the Bitterroot River in western Montana, and Yellowstone Central Plateau in western Wyoming, USA.

Results

Interacting disturbances reduced overall basal area via increased tree mortality of host species. Wildfire decreased basal area more than beetles or rust, and disturbance interactions modeled under future climate significantly altered landscape basal area as compared with no-disturbance and current climate scenarios. Responses varied among landscapes depending on species composition, sensitivity to fire, and pathogen and beetle suitability and susceptibility.

Conclusions

Understanding disturbance interactions is critical for managing landscapes because forest responses to wildfires, pathogens, and beetle attacks may offset or exacerbate climate influences, with consequences for wildlife, carbon, and biodiversity.

     

Can we face different types of storms under the same umbrella? Efficiency and consistency of connectivity umbrellas across different patchy landscape patterns

Context

The umbrella approach applied to landscape connectivity is based on the principle that the conservation or restoration of the dispersal habitats for some species also can facilitate the movement of others. Species traits alone do not seem to be enough to identify good connectivity umbrella species, showing the need to investigate the influence of additional factors on this property.

Objectives

We test whether the potential of a species as a connectivity umbrella can be influenced by landscape composition and configuration.

Methods

We simulated movement routes for eight hypothetical species in artificial patchy landscapes with different levels of fragmentation, habitat amount and matrix permeability. We determined the effectiveness of the connectivity umbrella of the virtual species using pairwise intersections of important habitats for their movements in all landscapes.

Results

The connectivity umbrella performance of all species was affected by the interaction of fragmentation level and habitat amount. In general, species performance increased with decreasing fragmentation and increasing habitat amount. In most landscapes and considering the same dispersal threshold, species able to move more easily through the matrix showed higher umbrella performance than those for which the matrix offered greater resistance.

Conclusions

The connectivity umbrella is not a static feature that depends only on the species traits, but rather a dynamic property that also varies according to the landscape attributes. Therefore, we do not recommend spatial transferability of the connectivity umbrella species identified in a landscape to others that have divergent levels of fragmentation and habitat quantity.

     

Spatial assessment of aesthetic services in a complex mountain region: combining visual landscape properties with crowdsourced geographic information

Context

Human and natural systems interact at multiple scales which are context specific in relation to ecosystem service supply. Scenic beauty is recognised as a cultural ecosystem service whose aesthetic value is perceived at a holistic landscape level.

Objectives

In this study we provide methodological advancements for assessing the relationship between landscape visual character and scenic beauty based on crowdsourced geographic information. The final aim is to demonstrate, through a case study application, an empirical method for mapping the scenic beauty of complex mountain landscapes from the perspective of observers which are realistically exposed to the environment being evaluated.

Methods

We propose a viewshed based approach which relies on visual indicators and the location of visitors retrieved by public image storage analysis. A cluster analysis was used to integrate visual characters of the landscape and visiting users’ preferences.

Results

Four different typologies of landscapes were finally characterized by distinct values of visual indicators. The spatial distribution of the landscape typologies presented a clustered pattern, allowing a regionalization of the landscape characters. The analysis of the visiting users’ provenance revealed that visual scale, naturalness and ephemera attract mainly foreign users, while imageability, complexity and historicity attract mostly domestic and local users.

Conclusions

The combination of crowdsourced images with visual indicators allows a systematic analysis of landscape scenic beauty properties. In all, by understanding how specific landscape characters contributes to aesthetic service provision we provide a tool for facilitating the visualization and interpretation of complex landscape characters.

     

Deciduous trees increase bat diversity at stand and landscape scales in mosaic pine plantations

Context

In heterogeneous landscapes, habitat complementation is a key process underlying the distribution of mobile species able to exploit non-substitutable resources over large home ranges. For instance, insectivorous bats need to forage in a diversity of habitat patches offering varied compositions and structures within forest landscape mosaics to fulfill their life cycle requirements.

Objectives

We aimed at analyzing the effects of forest structure and composition measured at the stand and landscape scales on bat species richness, abundance and community composition in pine plantation forests of south-western France.

Methods

We sampled bat communities at different periods of the summer season using automatic ultrasound recorders along a tree composition gradient from pine monocultures to pure oak stands. We analyzed bat species activity (as a proxy for bat abundance) and species richness with linear mixed models. Distance-based constrained ordinations were used to partition the spatio-temporal variation in bat communities.

Results

Deciduous tree cover increased bat activity and modified community composition at both stand and landscape scales. Changes in bat communities were mostly driven by landscape-scale variables while bat activity responded more to stand-scale predictors.

Conclusions

The maintenance of deciduous trees at both stand and landscape scales is likely critical for bat communities living in fast-growing conifer plantations, by increasing the availability and diversity of prey and roosting sites. Our study suggests that bats respond to forest composition at both stand and landscape scales in mosaic plantation landscapes, mainly through a resource complementation process.

     

The use of native vegetation as a proxy for habitat may overestimate habitat availability in fragmented landscapes

Context

Native vegetation is often used as a proxy for habitat to estimate habitat availability in landscapes. This approach may lead to incorrect estimates of the impacts of habitat loss and fragmentation on species, which have not been thoroughly quantified so far.

Objectives

We quantified to what extent the loss of native vegetation reflect actual habitat loss by native species in landscapes. We tested the hypothesis that habitat availability declines at greater rates than native vegetation and thus is overestimated when it is quantified on the basis of native vegetation.

Methods

Using simulations, we quantified how the loss of native vegetation in artificial and real landscapes affects habitat availability for species with different habitat requirements. We contrasted a generalist species, which uses all native vegetation, with 10 habitat-specialist species classified into three categories (interior, patchy and riparian species).

Results

Habitat availability generally declined at greater rates than native vegetation for all specialist species. This pattern was apparent for different specialist species in a broad range of landscape types. Interior species always lost habitat availability more rapidly than the generalist species. Most riparian species lost habitat availability more rapidly than the generalist species. Responses of patchy species were more complex, depending on their dispersal abilities and landscape structure.

Conclusions

Habitat availability is likely to be overestimated when native vegetation is used as proxy for habitat, because habitat availability will generally decline at greater rates than native vegetation. Therefore, a species-centered approach should be adopted when estimating habitat availability in landscapes.

     

Using topographic geodiversity to connect conservation lands in the Central Yukon,Alaska

Context

Alaskan landscapes are changing due to climate change impacts. Maintaining or restoring landscape connectivity is a widely suggested climate change adaptation strategy because species are shifting their distributions to align with emerging conditions. Natural resource managers in Alaska have an opportunity to proactively design connected landscapes as infrastructure networks and economic development continue to increase in the state.

Objectives

We provide an example of strategic, multijurisdictional planning to maintain landscape connectivity at a large spatial scale.

Methods

We use geodiversity to model climate-resilient landscape linkages between conservation lands within and adjacent to a 59-million-acre planning area.

Results

The resulting landscape linkage design consists of as little as 1% of the planning area, but can connect over 64 million acres of conservation land allowing the Bureau of Land Management to leverage the current land designations to maximize the conservation value of the entire landscape.

Conclusions

Maintaining landscape connectivity is above and beyond the mandates and responsibilities of a single organization or land owner. Bridging institutions and partnerships, such as the Northwest Boreal Landscape Conservation Cooperative, can facilitate the coordination needed for this type of multi-jurisdictional planning effort. The opportunity to manage proactively, rather than waiting for system degradation and then responding reactively, should not be undervalued. The implementation of this work will serve as a model for other relatively intact systems and moreover showcases the potential of twenty-first century models of conservation and sustainability.

     

Butterfly dispersal in farmland: a replicated landscape genetics study on the meadow brown butterfly (<Emphasis Type="Italic">Maniola jurtina</Emphasis>)

Context

Anthropogenic activities readily result in the fragmentation of habitats such that species persistence increasingly depends on their ability to disperse. However, landscape features that enhance or limit individual dispersal are often poorly understood. Landscape genetics has recently provided innovative solutions to evaluate landscape resistance to dispersal.

Objectives

We studied the dispersal of the common meadow brown butterfly, Maniola jurtina, in agricultural landscapes, using a replicated study design and rigorous statistical analyses. Based on existing behavioral and life history research, we hypothesized that the meadow brown would preferentially disperse through its preferred grassy habitats (meadows and road verges) and avoid dispersing through woodlands and the agricultural matrix.

Methods

Samples were collected in 18 study landscapes of 5 × 5 km in three contrasting agricultural French regions. Using circuit theory, least cost path and transect-based methods, we analyzed the effect of the landscape on gene flow separately for each sex.

Results

Analysis of 1681 samples with 6 microsatellites loci revealed that landscape features weakly influence meadow brown butterfly gene flow. Gene flow in both sexes appeared to be weakly limited by forests and arable lands, whereas grasslands and grassy linear elements (road verges) were more likely to enhance gene flow.

Conclusion

Our results are consistent with the hypothesis of greater dispersal through landscape elements that are most similar to suitable habitat. Our spatially replicated landscape genetics study allowed us to detect subtle landscape effects on butterfly gene flow, and these findings were reinforced by consistent results across analytical methods.

     

Implications of forest type and land tenure diversity for the sustainability of ecosystem services provided by northern Amazonia’s multiple-use tree species

Context

As global landscapes continue to change, the sustainability of the ecosystem services they support are increasingly coming into question. In the rapidly changing neotropics, multiple-use plants epitomize sources of ecosystem services. To sustain the relationship that exists between such plants and human populations, a sound understanding of their well-being is required.

Objectives

Density data on multiple-use plants were compared across forest types and land tenure classes to understand the implications of these two spatial frames of reference for landscape sustainability.

Methods

The density of an aggregate sample of seventeen multiple-use and a sub-sample of five species were examined relative to forest type and land tenure class across fourteen Rupununi, Southern Guyana, study sites. The examination of plant density based on the two sample sizes was used to make inferences on how the two frames of reference may impact landscape sustainability.

Results

The mean density of the aggregate sample was highest in three of six forest types, but showed no statistical difference across land tenure classes. When individual species were considered mean densities showed no statistical difference across land tenure classes, but differences were observed for three species across forest types. Mean densities were highest in forest types within which swidden agriculture occurs and in the protected area where logging is prohibited.

Conclusions

Our findings suggested that in changing tropical landscapes plant species distribution can be predicted by forest types, but land tenure classes may provide clearer signals as to where a species well-being and hence ecosystem services may be compromised.