Laboratory for
Climatology and Remote Sensing

Abstract:

Tropical forests are highly diverse at many spatial scales. In these forests, small-sized canopy organisms can form species-rich communities already within a few cm2. Understanding how species numbers increase when expanding the sampling along the tree and the forest is critical for evaluating the processes maintaining biodiversity. We therefore studied epiphytic bryophyte diversity in tree crowns and along trunks across spatial scales in a tropical lowland forest in Amazonian Ecuador, sampling bryophytes in 100-cm2 quadrats on 24 trees (15–22 quadrats each) using a spatially hierarchical design, analyzing alpha and beta diversity at different spatial grains and extents. At the smallest grain, tree crowns held more bryophyte species than trunks, but at the largest grain the trunks held most species (93 vs. 77), as beta diversity was higher among trunks than among crowns. However, except for trunks at the largest extent (all 24 trees), the highest beta diversity among quadrats was always found between crowns and trunks. Species turnover strongly dominated beta diversity at all spatial scales. This and the high species richness resulted in highly unpredictable species compositions, especially in trunk communities. These patterns suggest different controls of diversity in crowns than on trunks and an important role for chance processes in shaping these communities. The high beta diversity within trees, in combination with the large effort involved in climbing trees, implies that diversity sampling of small canopy organisms is most efficient using an intensive (many plots on few trees) rather than extensive (many trees across a large area) sampling.

Abstract:

Biodiversity and ecosystem functions are highly threatened by global change. It has been proposed that geodiversity can be used as an easy-to-measure surrogate of biodiversity to guide conservation management. However, so far, there is mixed evidence to what extent geodiversity can predict biodiversity and ecosystem functions at the regional scale relevant for conservation planning. Here, we analyse how geodiversity computed as a compound index is suited to predict the diversity of four taxa and associated ecosystem functions in a tropical mountain hotspot of biodiversity and compare the results with the predictive power of environmental conditions and resources (climate, habitat, soil). We show that combinations of these environmental variables better explain species diversity and ecosystem functions than a geodiversity index and identified climate variables as more important predictors than habitat and soil variables, although the best predictors differ between taxa and functions. We conclude that a compound geodiversity index cannot be used as a single surrogate predictor for species diversity and ecosystem functions in tropical mountain rain forest ecosystems and is thus little suited to facilitate conservation management at the regional scale. Instead, both the selection and the combination of environmental variables are essential to guide conservation efforts to safeguard biodiversity and ecosystem functions.

Abstract:

The montane and premontane rainforests of southern Ecuador constitute a hotspot of biodiversity (cf. Brehm et al. 2008; Barthlott et al. 2007, Neill 2007). The use of plant resources from these forest areas is a fundamental part of the portfolio of livelihood activities of the local population. Increasing human activity however results in biodiversity loss. The extension of pastures and fields, logging, mining and the construction of roads represent the main threats to biodiversity in southern Ecuador. In order to develop conservation strategies it is of utmost importance to understand the plant and forest-use patterns of the inhabitants of this region. In this way, it will be possible to develop alternatives that consider local claims while conserving biodiversity (cf. Pohle et al. 2010). In this study ethnoecological and agrogeographical research methods have been used to make a qualitative analysis of the ethnospecific plant knowledge and plant use of the three main ethnic groups of southern Ecuador, namely the Shuar, the Saraguros and the Mestizos. This is followed by a discussion of the feasibility in the study sites of four so-called instruments for biodiversity conservation: agroforestry, ecotourism, payments for environmental services, and bioprospecting.

Abstract:

Abstract Conversion of tropical forests is among the primary causes of global environmental change. The loss of their important environmental services has prompted calls to integrate ecosystem services (ES) in addition to socio-economic objectives in decision-making. To test the effect of accounting for both ES and socio-economic objectives in land-use decisions, we develop a new dynamic approach to model deforestation scenarios for tropical mountain forests. We integrate multi-objective optimization of land allocation with an innovative approach to consider uncertainty spaces for each objective. These uncertainty spaces account for potential variability among decision-makers, who may have different expectations about the future. When optimizing only socio-economic objectives, the model continues the past trend in deforestation (1975–2015) in the projected land-use allocation (2015–2070). Based on indicators for biomass production, carbon storage, climate and water regulation, and soil quality, we show that considering multiple ES in addition to the socio-economic objectives has heterogeneous effects on land-use allocation. It saves some natural forest if the natural forest share is below 38%, and can stop deforestation once the natural forest share drops below 10%. For landscapes with high shares of forest (38%–80% in our study), accounting for multiple ES under high uncertainty of their indicators may, however, accelerate deforestation. For such multifunctional landscapes, two main effects prevail: (a) accelerated expansion of diversified non-natural areas to elevate the levels of the indicators and (b) increased landscape diversification to maintain multiple ES, reducing the proportion of natural forest. Only when accounting for vascular plant species richness as an explicit objective in the optimization, deforestation was consistently reduced. Aiming for multifunctional landscapes may therefore conflict with the aim of reducing deforestation, which we can quantify here for the first time. Our findings are relevant for identifying types of landscapes where this conflict may arise and to better align respective policies.

Abstract:

Tropical montane forests, particularly Andean rainforest, are important ecosystems for regional carbon and water cycles as well as for biological diversity and speciation. Owing to their remoteness, however, ecological key-processes are less understood as in the tropical lowlands. Remote sensing allows modeling of variables related to spatial patterns of carbon stocks and fluxes (e.g., biomass) and ecosystem functioning (e.g., functional leaf traits). However, at a landscape scale most studies conducted so far are based on airborne remote sensing data which is often available only locally and for one time-point. In contrast, multispectral satellites at moderate spectral and spatial resolutions are able to provide spatially continuous and repeated observations. Here, we investigated the effectiveness of Landsat-8 imagery in modeling tropical montane forest biomass, its productivity and selected canopy traits. Topographical, spectral and textural metrics were derived as predictors. To train and validate the models, in-situ data was sampled in 54 permanent plots in forests of southern Ecuador distributed within three study sites at 1000?m, 2000?m and 3000?m a.s.l. We used partial least squares regressions to model and map all response variables. Along the whole elevation gradient biomass and productivity models explained 31%, 43%, 69% and 63% of variance in aboveground biomass, annual wood production, fine litter production and aboveground net primary production, respectively. Regression models of canopy traits measured as community weighted means explained 62%, 78%, 65% and 65% of variance in leaf toughness, specific leaf area, foliar N concentration, and foliar P concentration, respectively. Models at single study sites hardly explained variation in aboveground biomass and the annual wood production indicating that these measures are mainly determined by the change of forest types along with elevation. In contrast, the models of fine litter production and canopy traits explained between 8%–85% in variation depending on the study site. We found spectral metrics, in particular a vegetation index using the red and the green band to provide complementary information to topographical metrics. The model performances for estimating leaf toughness, biochemical canopy traits and related fine litter production all improved when adding spectral information. Our findings therefore revealed that differences in fine litter production and canopy traits in our study area are driven by local changes in vegetation edaphically induced by topography. We conclude that Landsat-derived metrics are useful in modeling fine litter production and biochemical canopy traits, in a topographically and ecologically complex tropical montane forest.

Abstract:

Phylogenetic niche conservatism (PNC) is the tendency of species within a clade to retain ancestral traits and to persist in their primary ecological niches on geological time scales. It links evolutionary and ecological processes and has been hypothesized to explain patterns of species richness and the composition of species assemblages. Decreasing patterns of species richness along latitudinal gradients were often explained by the combination of ancient tropical climates, trait retention of tropical lineages and environmental filtering. PNC also predicts decreasing phylodiversity and family age with decreasing tropicality and has been invoked to explain these patterns along climatic gradients across latitudinal as well as elevational gradients. However, recent studies on tree assemblages along latitudinal and elevational gradients in South America found patterns contradicting the PNC framework. Our study aims to shed light on these contradictions using three different metrics of the phylogenetic composition that form a gradient from recent evolutionary history to deep phylogenetic relationships. We analyzed the relationships between elevation and taxonomic species richness, phylodiversity and family age of tree assemblages in Andean rainforests in Ecuador. In contrast to predictions of the PNC we found no associations of elevation with species richness of trees and increasing clade level phylodiversity and family age of the tree assemblages with elevation. Interestingly, we found that patterns of phylodiversity across the studied elevation gradient depended especially on the deep nodes in the phylogeny. We therefore suggest that the dispersal of evolutionarily old plant lineages with extra-tropical origins influences the recent composition of tree assemblages in the Andes. Further studies spanning broader ecological gradients and using better resolved phylogenies to estimate family and species ages are needed to obtain a deeper mechanistic understanding of the processes that drive the assembly of tree communities along elevational gradients.

Abstract:

It is widely recognized that biodiversity and ecosystem services are globally threatened by environmental change and that the goal to halt the loss of species richness by 2010 has failed (Butchart et al., 2010). Despite the apparent interrelationships between biodiversity and abiotic (e.g. in case of climate change) and anthropogenic factors (e.g. in case of land use change), much remains to be understood about the causative mechanisms of biodiversity change and their interactions (Fischer et al., 2010 and Sala et al., 2000). This lack of understanding points to a clear need for more integrative biodiversity research that engages biologists and scientists from diverse disciplines, ranging from geosciences to socioeconomics. Such comprehensive research approaches are underpinned by the development of new monitoring systems of biodiversity and ecosystem services as indicated by the new international body IPBES (Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services; Marris, 2010). Knowledge of past biodiversity changes and accurate forecasts of future changes (c.f. La Sorte and Jetz, 2010; Pereira et al., 2010; Sala et al., 2000) depend upon diverse data and data types from innumerable sources over long time scales. Such data requirements are challenged by the scarcity of relevant biodiversity data from the last century due to the absence of comprehensive data stewardship practices and long-lived digital repositories, particularly for short-term research projects (see “fate of research data” in Easterbrook and Matthews, 1992; and “data entropy” in Michener et al., 1997). Although there is increasing awareness of the importance of data stewardship and preservation, the research community is now facing the challenge of exponentially growing data volumes in all disciplines that could contribute to more integrative biodiversity research (e.g. species data: Soberón and Peterson, 2009; genomic data: Kahn, 2011; climate data: Overpeck et al., 2011). Furthermore, globally available data are characterized by many problems including: incomplete taxonomic and spatial coverage, incompatibility among data sets, and inherent difficulties in integrating data across different scales (Pereira and Cooper, 2006). Most existing data repositories provide limited support for managing, integrating and visualizing relevant data (Guralnick et al., 2007 and Torres et al., 2006) and are not well positioned for dealing with upcoming biodiversity-related science challenges (Reichman et al., 2011). Some positive changes are underway. For instance, during the last decade of the preceding century, most data were managed by individuals in small, independent, institution-specific databases (Frawley et al., 1992). Increasingly, however, data are being deposited in community-based data repositories. As an example, the Directory of Open Access Repositories (OpenDOAR, http://www.opendoar.org/about.html, access: 5 Mar 2011) encompasses 1873 repositories, although just 2% are specifically focused on biodiversity and ecological data. To cope with the growing volume of taxonomic data, Bisby (2000) estimated a global demand for approximately 150 species databases, each covering 10,000 to 25,000 or more species. Arzberger et al. (2004) highlighted three actions that would lead to more open global data access. First, from the technical perspective, data and metadata standardization, data interoperability and user-friendly interfaces are priority needs. Second, sustainable technical, institutional and funding strategies are required. Third, technical and administrative solutions will largely be shaped through consideration of property rights and user behavior. These three principal challenges will be discussed in the current special issue by information technology experts from the biodiversity and environmental sciences. Some of the specific challenges addressed in this special issue are briefly introduced in the following sections.

Abstract:

The current study investigates existing infrastructure, its technical solutions and implemented standards for data repositories related to integrative biodiversity research. The storage and reuse of complex biodiversity data in central databases are becoming increasingly important, particularly in attempts to cope with the impacts of environmental change on biodiversity and ecosystems. From the data side, the main challenge of biodiversity repositories is to deal with the highly interdisciplinary and heterogeneous character of standardized and unstandardized data and metadata covering information from genes to ecosystems. Furthermore, the technical improvements in data acquisition techniques produce ever larger data volumes, which represent a challenge for database structure and proper data exchange. The current study is based on comprehensive in-depth interviews and an online survey addressing IT specialists involved in database development and operation. The results show that metadata are already well established, but that non-meta data still is largely unstandardized across various scientific communities. For example, only a third of all repositories in our investigation use internationally unified semantic standard checklists for taxonomy. The study also showed that database developers are mostly occupied with the implementation of state of the art technology and solving operational problems, leaving no time to implement user's requirements. One of the main reasons for this dissatisfying situation is the undersized and unreliable funding situation of most repositories, as reflected by the marginally small number of permanent IT staff members. We conclude that a sustainable data management system that fosters the future use and reuse of these valuable data resources requires the development of fewer, but more permanent data repositories using commonly accepted standards for their long-term data. This can only be accomplished through the consolidation of hitherto widely scattered small and non-permanent repositories.

Abstract:

Data sharing has become an important issue in modern biodiversity research to address large scale questions. Despite the steadily growing scientific demand, data are not easily accessed. Why is this the case? This study explores the reasons for the reluctance to share data on the one hand and the motivations for sharing on the other by summarising results from > 60 interviews and > 700 survey participants within the biodiversity science community. As result, there is a clear commitment to share biodiversity data, but also a reluctance to actually do so due to a mixture of social and technical impediments, such as loss of control over data and lack of professional reward for sharing. This exploratory study summarises the formal and technical requirements for data sharing and reuse, stated by voluntarily participating scientists worldwide. To ensure sustainable data use, user friendly data infrastructure have to be expanded or newly designed, data management plans for all scientific investigations have to be promoted, training for the users has to be provided and motivational aspects at all stages of data submission and re-use have to be considered.

Abstract:

Ecosystems worldwide are threatened by the increasing impact of land use and climate change. To protect their diversity and functionality, spatially explicit monitoring systems are needed. In remote areas, monitoring is difficult and recurrent field surveys are costly. By using Lidar or the more cost-effective and repetitive optical satellite data, remote sensing could provide proxies for habitat structure supporting measures for the conservation of biodiversity. Here we compared the explanatory power of both, airborne Lidar and optical satellite data in modeling the spatial distribution of biodiversity of birds across a complex tropical mountain forest ecosystem in southeastern Ecuador. Weused data fromfield surveys of birds and chose three measures as proxies for different aspects of diversity: (i) Shannon diversity as a measure of ?-diversity that also includes the relative abundance of species, (ii) phylodiversity as a first proxy for functional diversity, and (iii) community composition as a proxy for combined ?- and ?-diversity.We modeled these diversity estimates using partial least-square regression of Lidar and optical texturemetrics separately and compared themodels using a leave-one-out validated R2 and root mean square error. Bird community information was best predicted by both remote sensing datasets, followed by Shannon diversity and phylodiversity. Our findings reveal a high potential of optical texture metrics for predicting Shannon diversity and a measure of community composition, but not for modeling phylodiversity. Generalizing from the investigated tropical mountain ecosystem,we conclude that texture information retrieved from multispectral data of operational satellite systems could replace costly airborne laser-scanning for modeling certain aspects of biodiversity.