21-40 von 42 Publikationen

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      Multi-temporal RapidEye Tasselled Cap data for land cover classification 

      Raab, Christoph; Tonn, B.; Meißner, M.; Balkenhol, N.; Isselstein, J.
      European Journal of Remote Sensing 2019; 52(1) p.653-666
      Land cover mapping can be seen as a key element to understand the spatial distribution of habitats and thus to sustainable management of natural resources. Multi-temporal remote sensing data are a valuable data source for land cover mapping. However, the increased amount of data requires effective machine learning algorithms and data compression approaches. In this study, the Random Forest and C 5.0 classification algorithms were applied to (1) a multi-temporal Tasselled-Cap-transformed, (2) top of atmosphere and (3) surface reflectance RapidEye time-series. The overall accuracies ranged from 91.44% to 91.80%, with only minor differences between algorithms and datasets. The McNemar test showed, however, significant differences between the Tasselled-Cap-transformed and untransformed mapping results in most cases. The temporal profiles for the Tasselled-Cap-transformed RapidEye data indicated a good separability between considered classes. The phenological profiles of vegetated surfaces followed a typical green-up curve for the Greenness Tasselled-Cap-index. A permutation-based variable importance measure indicated that late autumn should be considered as most important phenological phase contributing to the classification model performance. The results suggested that the RapidEye Tasselled Cap Transformation, which was designed for agricultural applications, can be an effective data compression tool, suitable to map heterogeneous landscapes with no measurable negative impact on classification accuracy.
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      Changes in Nematode Communities and Functional Diversity With the Conversion of Rainforest Into Rubber and Oil Palm Plantations 

      Krashevska, Valentyna; Kudrin, Alexey A.; Widyastuti, Rahayu; Scheu, Stefan
      Frontiers in Ecology and Evolution 2019; 7: Art. 487
      Focusing on nematodes and their well-developed indices of community, ecosystem structure and function, we investigated the effects of the conversion of rainforest into rubber and oil palm plantations in Sumatra, Indonesia. Land use did not affect the total abundance of litter- and soil-dwelling nematodes, neither in riparian nor in well-drained sites. However, the rainforest nematode community differed from communities in plantations, with differences in litter being more pronounced compared to soil. In litter, fungivores and nematodes with short generation time (c-p2) increased in monoculture plantations, while that of bacterivores, herbivores, and nematodes with longer generation time and higher sensitivity to disturbances (c-p3) decreased. This indicates higher environmental pressure on nematodes in monoculture plantations than in rainforest. In soil of monoculture plantations, bacterivores, and c-p3 nematodes decreased while herbivores increased. This suggests that the damage of plants by nematodes in oil palm plantations exceeds that in rainforest. Overall, nematode functional diversity indices suggest that the stability of the decomposer community is higher in rainforest compared to monoculture plantations. Importantly, functional diversity indices were much more meaningful than nematode abundance. Further, changes with land use manifested more in litter than in soil, reflecting that nematode communities in soil are buffered against changes in land use and associated environmental conditions. Therefore, to fully assess changes in the structure and functioning of decomposer systems with changes in land use, the litter layer, which often receives little attention, requires more careful consideration.
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      Similar factors underlie tree abundance in forests in native and alien ranges 

      Sande, Masha T.; Bruelheide, Helge; Dawson, Wayne; Dengler, Jürgen; Essl, Franz; Field, Richard; Haider, Sylvia; Kleunen, Mark; Kreft, Holger; Pagel, Joern; et al.
      Pergl, JanPurschke, OliverPyšek, PetrWeigelt, PatrickWinter, MartenAttorre, FabioAubin, IsabelleBergmeier, ErwinChytrý, MilanDainese, MatteoDe Sanctis, MicheleFagundez, JaimeGolub, ValentinGuerin, Greg R.Gutiérrez, Alvaro G.Jandt, UteJansen, FlorianJiménez‐Alfaro, BorjaKattge, JensKearsley, ElizabethKlotz, StefanKramer, KoenMoretti, MarcoNiinemets, ÜloPeet, Robert K.Penuelas, JosepPetřík, PetrReich, Peter B.Sandel, BrodySchmidt, MarcoSibikova, MariaViolle, CyrilleWhitfeld, Timothy J. S.Wohlgemuth, ThomasKnight, Tiffany M.
      Global Ecology and Biogeography p.1-14
      Aim: Alien plant species can cause severe ecological and economic problems, and therefore attract a lot of research interest in biogeography and related fields. To identify potential future invasive species, we need to better understand the mechanisms underlying the abundances of invasive tree species in their new ranges, and whether these mechanisms differ between their native and alien ranges. Here, we test two hypotheses: that greater relative abundance is promoted by (a) functional difference from locally co-occurring trees, and (b) higher values than locally co-occurring trees for traits linked to competitive ability. Location: Global. Time period: Recent. Major taxa studied: Trees. Methods: We combined three global plant databases: sPlot vegetation-plot database, TRY plant trait database and Global Naturalized Alien Flora (GloNAF) database. We used a hierarchical Bayesian linear regression model to assess the factors associated with variation in local abundance, and how these relationships vary between native and alien ranges and depend on species’ traits. Results: In both ranges, species reach highest abundance if they are functionally similar to co-occurring species, yet are taller and have higher seed mass and wood density than co-occurring species.
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      Soil biota in vineyards are more influenced by plants and soil quality than by tillage intensity or the surrounding landscape 

      Buchholz, Jacob; Querner, Pascal; Paredes, Daniel; Bauer, Thomas; Strauss, Peter; Guernion, Muriel; Scimia, Jennifer; Cluzeau, Daniel; Burel, Françoise; Kratschmer, Sophie; et al.
      Winter, SilviaPotthoff, MartinZaller, Johann G.
      Scientific Reports 2017; 7(1)
      Tillage is known for its adverse effects on soil biota, at least in arable agroecosystems. However, in vineyards effects might differ as tillage is often performed during dry periods or only in every other inter-row allowing species to re-colonise disturbed areas. We examined the response of earthworms (lumbricids), springtails (collembola) and litter decomposition to periodically mechanically disturbed (PMD) and permanently green covered (PGC) vineyard inter-rows and assessed whether site effects are altered by the surrounding landscape. In commercial vineyards in Austria we sampled earthworms by handsorting, springtails by soil coring and pitfall trapping and installed litter decomposition bags. Earthworm species diversity increased with plant biomass under PMD but not under PGC; earthworm density was unaffected by tillage but increased with plant biomass mainly at high soil quality (soil fertility index). Springtail species diversity was unaffected by tillage; springtail densities (mainly larger species) were reduced under PGC. Litter decomposition was little affected by investigated parameters. Landscape heterogeneity affected the functional diversity of surface springtails, but did not influence soil-dwelling springtails, earthworms or litter decomposition. We conclude that effects on soil biota of periodical tillage in vineyards need not necessarily be detrimental and will be modified by plant biomass and soil quality.
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      Effects of forest‐use intensity on vascular epiphyte diversity along an elevational gradient 

      Guzmán‐Jacob, Valeria; Zotz, Gerhard; Craven, Dylan; Taylor, Amanda; Krömer, Thorsten; Monge‐González, María Leticia; Kreft, Holger
      Diversity and Distributions
      Aim: Understanding patterns of tropical plant diversity and their vulnerability to anthropogenic disturbance at different spatial scales remains a great challenge in ecology and conservation. Here, we study how the effects of forest‐use intensity on vascular epiphyte diversity vary along a tropical elevational gradient. Location: 3,500‐m elevational gradient along the eastern slopes of Cofre de Perote, Mexico. Methods: We studied the effects of forest‐use intensity on alpha, beta and gamma diversity of vascular epiphyte assemblages in old‐growth, degraded and secondary forests at eight study sites at 500‐m intervals along the elevational gradient. At each elevation and in each of the three forest‐use intensity levels, we established five 400‐m2 plots yielding a total of 120 plots. Results: Interactive effects of elevation and forest‐use intensity strongly impacted local‐scale patterns of vascular epiphyte diversity. Species diversity peaked at 500 as well as 1,500 m above sea level, which deviates from the previously reported humpshaped pattern. In most cases, alpha diversity did not differ significantly among forest‐ use intensity levels. However, gamma diversity was always lower in secondary forests compared to old‐growth forests across the entire elevational gradient. Within each elevational belt, beta diversity was dominated by species turnover along the forest‐use intensity gradient in the lowlands and declined with increasing elevation, where community composition became increasingly nested. Along the elevational gradient, the spatial turnover of vascular epiphyte community composition was similar among forest‐use intensity levels. Main conclusions: Our results reveal a strong interaction between forest‐use intensity and elevation, making it difficult to extrapolate findings from one elevational belt to another. Our findings highlight the value of old‐growth forest for epiphyte diversity, but also show that degraded and secondary forests—depending on the elevational belt—may maintain a high species diversity and thus play an important role in conservation planning.
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      The NLRX R package: A next‐generation framework for reproducible NetLogo model analyses 

      Salecker, Jan; Sciaini, Marco; Meyer, Katrin M.; Wiegand, Kerstin
      Methods in Ecology and Evolution
      1. Agent‐based models find wide application in all fields of science where large‐scale patterns emerge from properties of individuals. Due to increasing capacities of computing resources it was possible to improve the level of detail and structural realism of nextgeneration models in recent years. However, this is at the expense of increased model complexity, which requires more efficient tools for model exploration, analysis and documentation that enable reproducibility, repeatability and parallelization. NetLogo is a widely used environment for agent‐based model development, but it does not provide sufficient built‐in tools for extensive model exploration, such as sensitivity analyses. One tool for controlling NetLogo externally is the r‐package RNetLogo. However, this package is not suited for efficient, reproducible research as it has stability and resource allocation issues, is not straightforward to be setup and used on high performance computing clusters and does not provide utilities, such as storing and exchanging metadata, in an easy way. 2. We present the r‐package nlrx, which overcomes stability and resource allocation issues by running NetLogo simulations via dynamically created XML experiment files. Class objects make setting up experiments more convenient and helper functions provide many parameter exploration approaches, such as Latin Hypercube designs, Sobol sensitivity analyses or optimization approaches. Output is automatically collected in user‐friendly formats and can be post‐processed with provided utility functions. nlrx enables reproducibility by storing all relevant information and simulation output of experiments in one r object which can conveniently be archived and shared. 3. We provide a detailed description of the nlrx package functions and the overall workflow. We also present a use case scenario using a NetLogo model, for which we performed a sensitivity analysis and a genetic algorithm optimization. 4. The nlrx package is the first framework for documentation and application of reproducible NetLogo simulation model analysis.
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      EFForTS-LGraf: A landscape generator for creating smallholder-driven land-use mosaics 

      Salecker, Jan; Dislich, Claudia; Wiegand, Kerstin; Meyer, Katrin M.; Pe´er, Guy
      PLOS ONE 2019; 14(9): Art. e0222949
      Spatially-explicit simulation models are commonly used to study complex ecological and socio-economic research questions. Often these models depend on detailed input data, such as initial land-cover maps to set up model simulations. Here we present the landscape generator EFFortS-LGraf that provides artificially-generated land-use maps of agricultural landscapes shaped by small-scale farms. EFForTS-LGraf is a process-based landscape generator that explicitly incorporates the human dimension of land-use change. The model generates roads and villages that consist of smallholder farming households. These smallholders use different establishment strategies to create fields in their close vicinity. Crop types are distributed to these fields based on crop fractions and specialization levels. EFForTS-LGraf model parameters such as household area or field size frequency distributions can be derived from household surveys or geospatial data. This can be an advantage over the abstract parameters of neutral landscape generators. We tested the model using oil palm and rubber farming in Indonesia as a case study and validated the artificially-generated maps against classified satellite images. Our results show that EFForTS-LGraf is able to generate realistic land-cover maps with properties that lie within the boundaries of landscapes from classified satellite images. An applied simulation experiment on landscape-level effects of increasing household area and crop specialization revealed that larger households with higher specialization levels led to spatially more homogeneous and less scattered crop type distributions and reduced edge area proportion. Thus, EFForTS-LGraf can be applied both to generate maps as inputs for simulation modelling and as a stand-alone tool for specific landscape-scale analyses in the context of ecological-economic studies of smallholder farming systems.
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      Mortality of Different Populus Genotypes in Recently Established Mixed Short Rotation Coppice with Robinia pseudoacacia L. 

      Rebola-Lichtenberg, Jessica; Schall, Peter; Annighöfer, Peter; Ammer, Christian; Leinemann, Ludger; Polle, Andrea; Euring, Dejuan
      Forests 2019; 10(5): Art. 410
      Short rotation coppices play an increasing role in providing wooden biomass for energy. Mixing fast-growing tree species in short rotation coppices may result in complementary e ects and increased yield. The aim of this study was to analyze the e ect on mortality of eight di erent poplar genotypes (Populus sp.) in mixed short rotation coppices with three di erent provenances of the N-fixing tree species black locust (Robinia pseudoacacia L.). Pure and mixed stands were established at two sites of contrasting fertility. Survival of poplar was assessed for each tree two times a year, for a period of three years. In the first two years, high variation in mortality was observed between the genotypes, but no significant di erences between pure and mixed stands were identified. However, three years after planting, higher mortality rates were observed in the mixtures across all poplar genotypes in comparison to pure stands. The expected advantage on growth of combining an N-fixing tree with an N-demanding tree species, such as poplar, was overshadowed by the Robinia’s dominance and competitiveness.
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      Biodiversity data integration—the significance of data resolution and domain 

      König, Christian; Weigelt, Patrick; Schrader, Julian; Taylor, Amanda; Kattge, Jens; Kreft, Holger
      PLOS Biology 2019; 17(3): Art. e3000183
      ecent years have seen an explosion in the availability of biodiversity data describing the distribution, function, and evolutionary history of life on earth. Integrating these heterogeneous data remains a challenge due to large variations in observational scales, collection purposes, and terminologies. Here, we conceptualize widely used biodiversity data types according to their domain (what aspect of biodiversity is described?) and informational resolution (how specific is the description?). Applying this framework to major data providers in biodiversity research reveals a strong focus on the disaggregated end of the data spectrum, whereas aggregated data types remain largely underutilized. We discuss the implications of this imbalance for the scope and representativeness of current macroecological research and highlight the synergies arising from a tighter integration of biodiversity data across domains and resolutions. We lay out effective strategies for data collection, mobilization, imputation, and sharing and summarize existing frameworks for scalable and integrative biodiversity research. Finally, we use two case studies to demonstrate how the explicit consideration of data domain and resolution helps to identify biases and gaps in global data sets and achieve unprecedented taxonomic and geographical data coverage in macroecological analyses.
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      Collembola interact with mycorrhizal fungi in modifying oak morphology, C and N incorporation and transcriptomics 

      Graf, Marcel; Bönn, Markus; Feldhahn, Lasse; Kurth, Florence; Grams, Thorsten E. E.; Herrmann, Sylvie; Tarkka, Mika; Buscot, Francois; Scheu, Stefan
      Royal Society Open Science 2019; 6(3): Art. 181869
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      Protura are unique: first evidence of specialized feeding on ectomycorrhizal fungi in soil invertebrates 

      Bluhm, Sarah L; Potapov, Anton M; Shrubovych, Julia; Ammerschubert, Silke; Polle, Andrea; Scheu, Stefan
      BMC Ecology. 2019 Feb 22;19(1):10
      Abstract Background Ectomycorrhizal fungi (ECM) play a central role in nutrient cycling in boreal and temperate forests, but their role in the soil food web remains little understood. One of the groups assumed to live as specialised mycorrhizal feeders are Protura, but experimental and field evidence is lacking. We used a combination of three methods to test if Protura are specialized mycorrhizal feeders and compared their trophic niche with other soil invertebrates. Using pulse labelling of young beech and ash seedlings we analysed the incorporation of 13C and 15N into Acerentomon gallicum. In addition, individuals of Protura from temperate forests were collected for the analysis of neutral lipid fatty acids and natural variations in stable isotope ratios. Results Pulse labelling showed rapid incorporation of root-derived 13C, but no incorporation of root-derived 15N into A. gallicum. The transfer of 13C from lateral roots to ectomycorrhizal root tips was high, while it was low for 15N. Neutral lipid fatty acid (NLFA) analysis showed high amounts of bacterial marker (16:1ω7) and plant marker (16:0 and 18:1ω9) fatty acids but not of the fungal membrane lipid 18:2ω6,9 in A. gallicum. Natural variations in stable isotope ratios in Protura from a number of temperate forests were distinct from those of the great majority of other soil invertebrates, but remarkably similar to those of sporocarps of ECM fungi. Conclusions Using three in situ methods, stable isotope labelling, neutral lipid fatty acid analysis and natural variations of stable isotope ratios, we showed that Protura predominantly feed on mycorrhizal hyphae via sucking up hyphal cytoplasm. Predominant feeding on ectomycorrhizal mycelia by Protura is an exception; the limited consumption of ECM by other soil invertebrates may contribute to carbon sequestration in temperate and boreal forests.
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      Response of Collembola and Acari communities to summer flooding in a grassland plant diversity experiment 

      González-Macé, Odette; Scheu, Stefan
      2018; 13(8) p.1-18: Art. e0202862
      Flooding frequency is predicted to increase during the next decades in Europe. Therefore, it is important to understand how short-term disturbance events affect soil biota providing essential ecosystem functions and uncover factors modulating their response such as plant community composition. Here we report on the response of soil microarthropod communities (Collembola and Acari) to a severe summer flood in 2013, which affected major parts of central Europe. Collembola and Acari density and Collembola and Oribatida richness were strongly affected by the flood, but they recovered within three months. Effects of plant community composition on soil microarthropods disappeared after the flood, presumably due to homogenization of the field, but the effects of plant community were in a stage of being reasserted three months after the flood. Widespread, surface living and generalistic microarthropod species recolonized the field quickly. Prostigmata and Oribatida were more resilient or recovered to flooding than Astigmata and Gamasida. Long-term impacts, however, remain unknown and deserve further investigation.
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      Carbon costs and benefits of Indonesian rainforest conversion to plantations 

      Guillaume, Thomas; Kotowska, Martyna M.; Hertel, Dietrich; Knohl, Alexander; Krashevska, Valentyna; Murtilaksono, Kukuh; Scheu, Stefan; Kuzyakov, Yakov
      2018; 9(1)
      Land-use intensification in the tropics plays an important role in meeting global demand for agricultural commodities but generates high environmental costs. Here, we synthesize the impacts of rainforest conversion to tree plantations of increasing management intensity on carbon stocks and dynamics. Rainforests in Sumatra converted to jungle rubber, rubber, and oil palm monocultures lost 116 Mg C ha−1, 159 Mg C ha−1, and 174 Mg C ha−1, respectively. Up to 21% of these carbon losses originated from belowground pools, where soil organic matter still decreases a decade after conversion. Oil palm cultivation leads to the highest carbon losses but it is the most efficient land use, providing the lowest ratio between ecosystem carbon storage loss or net primary production (NPP) decrease and yield. The imbalanced sharing of NPP between short-term human needs and maintenance of long-term ecosystem functions could compromise the ability of plantations to provide ecosystem services regulating climate, soil fertility, water, and nutrient cycles.
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      The relevance of herders’ local ecological knowledge on coping with livestock losses during harsh winters in western Mongolia 

      Soma, Takuya; Schlecht, Eva
      2018; 8(1): Art. 3
      In many regions of the world, traditional and local ecological knowledge is still important today for coping with environmental challenges. This study explored the relevance of such knowledge for predicting and coping with harsh winter conditions (dzud) in a remote area of western Mongolia, where government support to disaster-affected herders is restricted by weak infrastructure. Structured face-to-face interviews were held in 50 households (HHs), addressing aspects of livestock possession and management as well as disaster prediction and mitigation. The responses disclosed that livestock losses during the 2009/10 dzud averaged 112.4 animals per HH, equaling nearly 80% of the interviewees’ total livestock possession in summer 2013. To reduce such high losses in the future, herders planned to improve their hay-making efforts and winter pen preparation. However, they also stated that the earliest signs for a dzud occur in September, when it is already too late for substantial hay-making. Therefore, some herders underlined the necessity of maintaining livestock productivity through segregated summer grazing of specific animal groups, controlled mating and early sale of weak livestock. Animals are then entering a harsh winter in good body condition. National and international organizations wishing to support livestock keepers in this and similar regions should therefore highlight the relevance of local strategies for disaster prevention and support community-based approaches that can compensate for the prevalent lack of family labour.
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      Author Correction: Soil biota in vineyards are more influenced by plants and soil quality than by tillage intensity or the surrounding landscape 

      Buchholz, Jacob; Querner, Pascal; Paredes, Daniel; Bauer, Thomas; Strauss, Peter; Guernion, Muriel; Scimia, Jennifer; Cluzeau, Daniel; Burel, Françoise; Kratschmer, Sophie; et al.
      Winter, SilviaPotthoff, MartinZaller, Johann G.
      Scientific Reports; 8
      2018
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      A new instrument for stable isotope measurements of C-13 and O-18 in CO2 - instrument performance and ecological application of the Delta Ray IRIS analyzer 

      Braden-Behrens, Jelka; Yan, Yuan; Knohl, Alexander
      Atmospheric Measurement Techniques 2017; 10(11) p.4537-4560
      We used the recently developed commercially available Delta Ray isotope ratio infrared spectrometer (IRIS) to continuously measure the CO2 concentration c and its isotopic composition δ13C and δ18O in a managed beech forest in central Germany. Our objectives are (a) to characterize the Delta Ray IRIS and evaluate its internal calibration procedure and (b) to quantify the seasonal variability of c, δ13C, δ18O and the isotopic composition of nighttime net ecosystem CO2 exchange (respiration) Reco13C and Reco18O derived from Keeling plot intercepts. The analyzer's minimal Allan deviation (as a measure of precision) was below 0.01 ppm for the CO2 concentration and below 0.03 ‰ for both δ values. The potential accuracy (defined as the 1σ deviation from the respective linear regression that was used for calibration) was approximately 0.45 ppm for c, 0.24 ‰ for 13C and 0.3 ‰ for 18O. For repeated measurements of a target gas in the field, the long-term standard deviation from the mean was 0.3 ppm for c and below 0.3 ‰ for both δ values. We used measurements of nine different inlet heights to evaluate the isotopic compositions of nighttime net ecosystem CO2 exchange Reco13C and Reco18O in a 3-month measurement campaign in a beech forest in autumn 2015. During this period, an early snow and frost event occurred, coinciding with a change in the observed characteristics of both Reco13C and Reco18O. Before the first snow, Reco13C correlated significantly (p  <  10−4) with time-lagged net radiation Rn, a driver of photosynthesis and photosynthetic discrimination against 13C. This correlation became insignificant (p  >  0.1) for the period after the first snow, indicating a decoupling of δ13C of respiration from recent assimilates. For 18O, we measured a decrease of 30 ‰ within 10 days in Reco18O after the snow event, potentially reflecting the influence of 18O depleted snow on soil moisture. This decrease was 10 times larger than the corresponding decrease in δ18O in ambient CO2 (below 3 ‰) and took 3 times longer to recover (3 weeks vs. 1 week). In summary, we conclude that (1) the new Delta Ray IRIS with its internal calibration procedure provides an opportunity to precisely and accurately measure c, δ13C and δ18O at field sites and (2) even short snow or frost events might have strong effects on the isotopic composition (in particular 18O) of CO2 exchange on an ecosystem scale.
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      Expansion of oil palm and other cash crops causes an increase of the land surface temperature in the Jambi province in Indonesia 

      Sabajo, Clifton R.; le Maire, Guerric; June, Tania; Meijide, Ana; Roupsard, Olivier; Knohl, Alexander
      Biogeosciences 2017; 14(20) p.4619-4635
      Indonesia is currently one of the regions with the highest transformation rate of land surface worldwide related to the expansion of oil palm plantations and other cash crops replacing forests on large scales. Land cover changes, which modify land surface properties, have a direct effect on the land surface temperature (LST), a key driver for many ecological functions. Despite the large historic land transformation in Indonesia toward oil palm and other cash crops and governmental plans for future expansion, this is the first study so far to quantify the impacts of land transformation on the LST in Indonesia. We analyze LST from the thermal band of a Landsat image and produce a highresolution surface temperature map (30 m) for the lowlands of the Jambi province in Sumatra (Indonesia), a region which suffered large land transformation towards oil palm and other cash crops over the past decades. The comparison of LST, albedo, normalized differenced vegetation index (NDVI) and evapotranspiration (ET) between seven different land cover types (forest, urban areas, clear-cut land, young and mature oil palm plantations, acacia and rubber plantations) shows that forests have lower surface temperatures than the other land cover types, indicating a local warming effect after forest conversion. LST differences were up to 10.1 2.6 C (mean SD) between forest and clear-cut land. The differences in surface temperatures are explained by an evaporative cooling effect, which offsets the albedo warming effect. Our analysis of the LST trend of the past 16 years based on MODIS data shows that the average daytime surface temperature in the Jambi province increased by 1.05 C, which followed the trend of observed land cover changes and exceeded the effects of climate warming. This study provides evidence that the expansion of oil palm plantations and other cash crops leads to changes in biophysical variables, warming the land surface and thus enhancing the increase of the air temperature because of climate change.
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      Land-use choices follow profitability at the expense of ecological functions in Indonesian smallholder landscapes 

      Clough, Yann; Krishna, Vijesh V.; Corre, Marife D.; Darras, Kevin; Denmead, Lisa H.; Meijide, Ana; Moser, Stefan; Musshoff, Oliver; Steinebach, Stefanie; Veldkamp, Edzo; et al.
      Allen, KaraBarnes, Andrew D.Breidenbach, NatalieBrose, UlrichBuchori, DamayantiDaniel, RolfFinkeldey, ReinerHarahap, IdhamHertel, DietrichHoltkamp, A. MareikeHörandl, ElviraIrawan, BambangJaya, I. Nengah SuratiJochum, MalteKlarner, BernhardKnohl, AlexanderKotowska, Martyna M.Krashevska, ValentynaKreft, HolgerKurniawan, SyahrulLeuschner, ChristophMaraun, MarkMelati, Dian NurainiOpfermann, NicolePérez-Cruzado, CésarPrabowo, Walesa EdhoRembold, KatjaRizali, AkhmadRubiana, RatnaSchneider, DominikTjitrosoedirdjo, Sri SudarmiyatiTjoa, AiyenTscharntke, TejaScheu, Stefan
      Nature Communications 2016; 7
      Smallholder-dominated agricultural mosaic landscapes are highlighted as model production systems that deliver both economic and ecological goods in tropical agricultural landscapes, but trade-offs underlying current land-use dynamics are poorly known. Here, using the most comprehensive quantification of land-use change and associated bundles of ecosystem functions, services and economic benefits to date, we show that Indonesian smallholders predominantly choose farm portfolios with high economic productivity but low ecological value. The more profitable oil palm and rubber monocultures replace forests and agroforests critical for maintaining above- and below-ground ecological functions and the diversity of most taxa. Between the monocultures, the higher economic performance of oil palm over rubber comes with the reliance on fertilizer inputs and with increased nutrient leaching losses. Strategies to achieve an ecological-economic balance and a sustainable management of tropical smallholder landscapes must be prioritized to avoid further environmental degradation.
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      Economic and ecological trade-offs of agricultural specialization at different spatial scales 

      Klasen, Stephan; Meyer, Katrin M.; Dislich, Claudia; Euler, Michael; Faust, Heiko; Gatto, Marcel; Hettig, Elisabeth; Melati, Dian N.; Jaya, I. Nengah Surati; Otten, Fenna; et al.
      Pérez-Cruzado, CésarSteinebach, StefanieTarigan, SuriaWiegand, Kerstin
      Ecological Economics 2016; 122 p.111-120
      Specialization in agricultural systems can lead to trade-offs between economic gains and ecosystem functions. We suggest and explore a conceptual framework in which economic gains can be maximized when production activities are specialized at increasingly broader scales (from the household to the village, region or above), particularly when markets for outputs and inputs function well. Conversely,more specialization likely reduces biodiversity and significantly limits ecosystem functions. When agricultural specialization increases and moves to broader scales as a result of improved infrastructure and markets or other drivers, ecosystem functions can also be endangered at broader spatial scales. Policies to improve agricultural incomes may influence the level of specialization at different scales and thus affect the severity of the trade-offs. This paper takes Jambi province in Indonesia, a current hotspot of rubber and oil palm monoculture, as a case study to illustrate these issues.We empirically show that the level of specialization differs across scales with higher specialization at household and village levels and higher diversification towards the province level. We discuss ways to resolve trade-offs between economic gains and ecological costs, including landscape design, targeted policies, and adoption of longterm perspectives.
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      Fast Growing Plantations for Wood Production – Integration of Ecological Effects and Economic Perspectives 

      Bredemeier, Michael; Busch, Gerald; Hartmann, Linda; Jansen, Martin; Richter, Falk; Lamersdorf, Norbert P.
      Frontiers in Bioengineering and Biotechnology 2015; 3 p.1-14: Art. 72
      Biomass crops are perceived as a feasible means to substitute sizeable amounts of fossil fuel in the future. A prospect of CO2 reduction (resp. CO2 neutrality) is credited to biomass fuels, and thus a potential contribution to mitigate climate change. Short rotation coppices (SRCs) with fast growing poplar and willow trees are an option for producing high yields of woody biomass, which is suitable for both energetic and material use. One negative effect that comes along with the establishment of SRC may be a decrease in groundwater recharge, because high rates of transpiration and interception are anticipated. Therefore, it is important to measure, analyze, and model the effects of SRC-planting on landscape water budgets. To analyze the effects on the water budget, a poplar SRC plot was studied by measuring hydrological parameters to be used in the hydrological model WaSim. Results reveal very low or even missing ground water recharge for SRC compared to agricultural land use or grassland, especially succeeding dry years. However, this strong effect on plot level is moderated on the larger spatial scale of catchment level, for which the modeling was also performed. In addition to water, nutrient fluxes and budgets were studied. Nitrogen is still a crucial issue in today’s agriculture. Intensive fertilization or increased applications of manure from concentrated livestock breeding are often leading to high loads of nitrate leaching, or enhanced N2O emissions to the atmosphere on arable crop fields. SRC or agroforestry systems on former crop land may offer an option to decrease such N losses, while simultaneously producing woody biomass. This is mainly due to the generally smaller N requirements of woody vegetation, which usually entail no need for any fertilization. The trees supply deep and permanent rooting systems, which can be regarded as a “safety net” to prevent nutrient leaching. Thus, SRC altogether can help to diminish N eutrophication. It is important to offer viable and attractive economic perspectives to farmers and other land managers besides of the potential ecological benefits of SRCs. For this reason, an integrated tool for scenario analysis was developed within the BEST project (“BEAST – Bio-Energy Allocation and Scenario Tool”). It combines ecological assessments with calculations of economic revenue as a basis for a participative regional dialog on sustainable land use and climate protection goals. Results show a substantial capacity for providing renewable energy from economically competitive arable SRC sites while generating ecological synergies.
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