Plant photosynthesis and biomass production are associated with the amount of intercepted light, especially the light distribution inside the canopy. Three virtual canopies (n = 80, 3.25 plants/m2) were constructed based on average leaf size of the digitized plant structures: ‘small leaf’ (98.1 cm2), ‘medium leaf’ (163.0 cm2) and ‘big leaf’ (241.6 cm2). The ratios of diffuse light were set in three gradients (27.8%, 48.7%, 89.6%). The simulations of light interception were conducted under different ratios of diffuse light, before and after the normalization of incident radiation. With 226.1% more diffuse light, the result of light interception could increase by 34.4%. However, the 56.8% of reduced radiation caused by the increased proportion of diffuse light inhibited the advantage of diffuse light in terms of a 26.8% reduction in light interception. The big-leaf canopy had more mutual shading effects, but its larger leaf area intercepted 56.2% more light than the small-leaf canopy under the same light conditions. The small-leaf canopy showed higher efficiency in light penetration and higher light interception per unit of leaf area. The study implied the 3D structural model, an effective tool for quantitative analysis of the interaction between light and plant canopy structure.
MULTIFILE
Peat swamp forests in Southeast Asia are under heavy pressure. Deforestation, forest degradation, wildfires, and drainage have damaged or destroyed substantial areas of the once extensive peat swamp forest formations. Several efforts are underway to rehabilitate degraded peat forests areas in order to restore some of the valuable ecosystem services these forested areas once provided. However, these efforts often result in (mixed)-plantations that only partly resemble the original peat forests. Information about these peat swamp forests' complex origin and ecology is needed to improve restoration outcomes further. Our paper analyses historical data from coastal peat swamp forests in Sarawak and Brunei and discusses the potential to use this as the reference value for intact peat forests. We describe the observed stand structure and species composition for pristine peat swamp forest, and we analyze the population structure of three dominant peat swamp forest species: Gonystylus bancanus (ramin), Dactylocladus stenostachys (jongkong) and Shorea albida (alan batu). We compare the historical data with data from recently measured, degraded peat swamp forests. We discuss our results in relation to processes of peat dome formation, nutrient availability and hydrology, and give recommendations for peat swamp forest management and restoration.
DOCUMENT
PowerPoint presentation used at the 6th International Conference of Indonesia Forestry Researchers - Stream 2 Managing Forest and Natural Resources, Meeting Sustainable and Friendly Use 7-8 September 2021, Bogor, Indonesia.
DOCUMENT
Sporen uit het verleden zijn het waard bewaard te wordenvoor volgende generaties!In het onderzoeksproject Energieke Restauratie (2011-2013)van het kenniscentrum NoorderRuimte istwee jaar onderzoek gedaan naar restauratie, energieconceptenen herontwikkeling van historische gebouwen. Dit project,gefinancierd door SIA-RAAK, werd uitgevoerd in samenwerkingmet vele bedrijven en instellingen in Noord-Nederland.Energieke Restauratie verwijst naar een integrale aanpak vanbehoud en vernieuwing in historische gebouwen, met eenhoge ambitie voor energiebesparing.Een ‘Energieke Restauratie’ begint met het herkennen vanwensen en randvoorwaarden in het vooronderzoek. Zo wordtbij het ontwerp rekening gehouden met historische waarden,energie, en gebruikerswensen. Uiteraard wordt er bij derestauratie van een historisch gebouw veel aandacht besteedaan effecten op de lange termijn, bijvoorbeeld voor hetvoorkomen van schade aan historische materialen, flexibiliteitvoor (toekomstig) gebruik, energielasten en gebruikscomfort.Op 19 september 2013 vond de afsluitende internationaleconferentie ERIC2013 plaats in Groningen. Met trots bieden wiju nu het magazine Energieke Restauratie aan, waarin u korteweergaves vindt van de presentaties op ERIC2013, voornamelijkin het Engels. Bovendien zijn de volledige artikelen van veledeelnemers aan de conferentie opgenomen.Verder vindt u een beknopt overzicht van alle uitgevoerde casestudies van Energieke Restauratie.Tot slot bedanken wij iedereen die heeft bijgedragen aan detotstandkoming van dit magazine: de schrijvers van de artikelen,de vormgever en uiteraard de sponsors die het drukken van ditmagazine mogelijk hebben gemaakt.
DOCUMENT
Predation risk is a major driver of the distribution of prey animals, which typically show strong responses to cues for predator presence. An unresolved question is whether naïve individuals respond to mimicked cues, and whether such cues can be used to deter prey. We investigated whether playback of wolf sounds induces fear responses in naïve ungulates in a human-dominated landscape from which wolves have been eradicated since 1879. We conducted a playback experiment in mixed-coniferous and broadleaved forest that harboured three cervid and one suid species. At 36 locations, we played wolf sounds, sounds of local sheep or no sounds, consecutively, in random order, and recorded visit rate and group size, using camera traps. Visit rates of cervids and wild boar showed a clear initial reduction to playback of both wolf and sheep sounds, but the type of response differed between sound, forest type and species. For naïve wild boar in particular, responses to predator cues depended on forest type. Effects on visit rate disappeared within 21 days. Group sizes in all the species were not affected by the sound treatment. Our findings suggest that the responses of naïve ungulates to wolf sound seem to be species specific, depend on forest type and wear off in time, indicating habituation. Before we can successfully deter ungulates using predator sound, we should further investigate how different forest types affect the perception of naïve ungulates to these sounds, as responses to predator sound may depend on habitat characteristics.
MULTIFILE
Recent research has indicated an increase in the likelihood and impact of tree failure. The potential for trees to fail relates to various biomechanical and physical factors. Strikingly, there seems to be an absence of tree risk assessment methods supported by observations, despite an increasing availability of variables and parameters measured by scientists, arborists and practitioners. Current urban tree risk assessments vary due to differences in experience, training, and personal opinions of assessors. This stresses the need for a more objective method to assess the hazardousness of urban trees. The aim of this study is to provide an overview of factors that influence tree failure including stem failure, root failure and branch failure. A systematic literature review according to the PRISMA guidelines has been performed in databases, supported by backward referencing: 161 articles were reviewed revealing 142 different factors which influenced tree failure. A meta-analysis of effect sizes and p-values was executed on those factors which were associated directly with any type of tree failure. Bayes Factor was calculated to assess the likelihood that the selected factors appear in case of tree failure. Publication bias was analysed visually by funnel plots and results by regression tests. The results provide evidence that the factors Height and Stem weight positively relate to stem failure, followed by Age, DBH, DBH squared times H, and Cubed DBH (DBH3) and Tree weight. Stem weight and Tree weight were found to relate positively to root failure. For branch failure no relating factors were found. We recommend that arborists collect further data on these factors. From this review it can further be concluded that there is no commonly shared understanding, model or function available that considers all factors which can explain the different types of tree failure. This complicates risk estimations that include the failure potential of urban trees.
MULTIFILE
Ghanaian farmers suffer from a decline in cocoa production partly due to damages and diseases from insect pests. To increase predation by bats on insects on the cocoa plantations we installed two different types of bat boxes on 15 plantations around the village of Buoyem. Bat activity, bat species composition (numbers of insectivorous and frugivorous bats) and insect abundance were measured before and after bat box installation. Insectivorous bats were present on all ofthe sampled plantations, namelyleaf-nosed bats (Hipposideros sp.), slit-faced bats (Nycteridae sp.), horseshoe bats (Rhinolophus sp.) and vesper bats (Vespertilionidae sp.). Furthermore, no correlation between insect abundance and bat activity could be detected. The bat boxes were not occupied yet during the research period since rainy season started in the second half of the measurements and bat activity decreases with increasing precipitation which is supported by our Un dings. Additionally, the available time period between in stallation and measuring of the effects of the boxes was very short when compared to similar researches. Bats alsohave different preferences per species for size and shape of bat boxes and the number of naturally available roosting sites also influences bat box occupancy. Our results suggest that bats are abundant above cocoa plantations in Buoyem and therefore bat boxes have the potential to be ahelpful tool in insect pest control.
DOCUMENT
This study presents an automated method for detecting and measuring the apex head thickness of tomato plants, a critical phenotypic trait associated with plant health, fruit development, and yield forecasting. Due to the apex's sensitivity to physical contact, non-invasive monitoring is essential. This paper addresses the demand for automated, contactless systems among Dutch growers. Our approach integrates deep learning models (YOLO and Faster RCNN) with RGB-D camera imaging to enable accurate, scalable, and non-invasive measurement in greenhouse environments. A dataset of 600 RGB-D images captured in a controlled greenhouse, was fully preprocessed, annotated, and augmented for optimal training. Experimental results show that YOLOv8n achieved superior performance with a precision of 91.2 %, recall of 86.7 %, and an Intersection over Union (IoU) score of 89.4 %. Other models, such as YOLOv9t, YOLOv10n, YOLOv11n, and Faster RCNN, demonstrated lower precision scores of 83.6 %, 74.6 %, 75.4 %, and 78 %, respectively. Their IoU scores were also lower, indicating less reliable detection. This research establishes a robust, real-time method for precision agriculture through automated apex head thickness measurement.
DOCUMENT
Most beginning food forests face the following challenge: how do we get the harvest to the consumer? At food forest 't Mortelke they had the same question. The following research presents the answer to the following question: 'What are potential outlets for the harvest of Voedselbos 't Mortelke and how can these collaborations be realized?' The research provides more clarity on the needs of the market regarding potential collaborations with Voedselbos 't Mortelke. Interviews with interested parties (restaurants, country stores, organic supermarkets, individuals) revealed that the most appropriate form of cooperation with the food forest lies with fine-dining restaurants in the Eindhoven area. To initiate these collaborations an experimental phase is needed in which the chefs can get to know the products of the food forest. As a result of this research, several collaborations with restaurants have been initiated! Due to privacy reasons, certain parts of the research have been removed from the publication version.
DOCUMENT
The sensitivity of tropical forest carbon to climate is a key uncertainty in predicting global climate change. Although short-term drying and warming are known to affect forests, it is unknown if such effects translate into long-term responses. Here, we analyze 590 permanent plots measured across the tropics to derive the equilibrium climate controls on forest carbon. Maximum temperature is the most important predictor of aboveground biomass (−9.1 megagrams of carbon per hectare per degree Celsius), primarily by reducing woody productivity, and has a greater impact per °C in the hottest forests (>32.2°C). Our results nevertheless reveal greater thermal resilience than observations of short-term variation imply. To realize the long-term climate adaptation potential of tropical forests requires both protecting them and stabilizing Earth’s climate.
DOCUMENT
