Mixed Species Research Articles

Evaluating the applicability of high-density UAV LiDAR data for monitoring tundra grassland vegetation

ABSTRACT Grasslands are one of the most widespread biomes on Earth. The interaction of UAV LiDAR with grasses and herbaceous plants is an infrequently covered area of research, apart from its utilisation for the estimation of above ground biomass. To evaluate the applicability of LiDAR for monitoring grassland vegetation, two model plots in the arctic-alpine tundra (Krkonoše Mountains, Czech Republic) were selected. Throughout the growing season, UAV LiDAR point clouds (800 points/m2) and multispectral imagery (9 cm) were acquired in monthly intervals, along with reference botanical and terrestrial LiDAR data. The study provides insight into the analysis of compact low-lying vegetation at the species level. A set of experiments was conducted focusing on the analysis of LiDAR information loss, vertical strata, and structural metrics computed over the grass species/communities. Random forest was used to determine the importance of metrics by out-of-bag permutation of predictors and to classify vegetation species using UAV LiDAR-based metrics, as well as image-based digital surface models alone and in fusion with multispectral data. The vertical distribution of the UAV LiDAR points varied significantly between species and throughout the growing season. Loss at the canopy bottoms was apparent, with the lowest points corresponding to dry grass matter rather than relief. Grasslands had the highest penetration capability at the start of the growing season. In terms of metrics, maximum canopy height was the most important. The multitemporal LiDAR-derived structural metrics were able to differentiate (F-1 score above 90%) all the shrubs/trees and dominant grass Calamagrostis villosa. Mixed and low-abundance species were indistinguishable. The overall accuracy scores in a 9 (27) cm grid reached 75.1% (78.1) and 63.5% (66.4) for Bílá louka meadow and Úpské rašeliniště bog, respectively. Fusing the LiDAR-derived features with multispectral imagery did not enhance the classification results apart from the delineation of shrubs and trees.

Short Communication: Humpback whales demonstrate group protection response to killer whale harassment in Brazil

Mixed species groups are usually associated with group protection to avoid predation. Reports of killer whale (Orcinus orca) occurrence and attacks are scarce in Brazilian waters. Here we report the first case of an attack by killer whales on a mixed group of humpbacks (Megaptera novaeangliae) and a southern right whale (Eubalaena australis). This is also the first report of humpback whales possibly interfering with killer whales harassing right whales. The recent increase in humpback and southern right whale populations in Brazil may be influencing the presence of killer whales, which are known to attack humpback whales.

Reduction of damage by the exotic invasive conifer seed bug Leptoglossus occidentalis in mixed pine-birch plantations: A case of biotic resistance

The number of invasive non-native pests is increasing rapidly in forests as a result of global change. It is therefore important to prevent their damage in order to preserve the integrity of forest ecosystems and the associated services. According to the biotic resistance hypothesis, species-rich communities are less likely to be invaded. The associational resistance hypothesis states that insect herbivores are more likely to colonise and exploit plants surrounded by conspecific neighbours than heterospecific, non-host plant species. More diverse forests would therefore be less damaged by non-native pests than tree monocultures. We tested these hypotheses by comparing the damage caused to seeds by the western conifer bug Leptoglossus occidentalis, an invasive insect native to North America, in plots of pure maritime pine and mixed plots of maritime pine and birch. These plots were in two tree diversity experiments in Europe. Mixed pine plots differed in terms of pine density (1250 versus 625 pines/ha), proportion of pine and birch (25 %, 50 %, 75 %) and spatial mixing pattern (aggregated versus dispersed). We sampled 635 cones in 37 plots. Overall, the proportion of seeds damaged by the invasive bug was significantly lower in mixed plots than in pure pine plots at both experimental sites. There was no significant effect of pine density or relative proportion in the mixtures on seed damage. Aggregated pines in the mixed plots were significantly more damaged than dispersed pines, suggesting that bugs may have done less damage when they had more difficulty locating their host trees. This is consistent with the hypothesis of lower plant apparency. These results support the view that forest plantations of mixed species, which are known to be less vulnerable to attack by native insects, may also be more resistant to infestation by exotic insects. Row-wise, intimate mixtures of two species represent a promising option for designing tree plantations that are more resistant and easier to manage.

Anti-biofilm activity of 445nm and 970nm diode laser on mixed species colonies of- aggregatibacter actinomycetemcomitans and porphyromonas gingivalis cultured on titanium discs -an in vitro study.

To assess and compare the anti-microbial efficacy of 445nm and 970nm diode laser on mixed species biofilm of Aggregatibacter actinomycetemcomitans [A.a] and Porphyromonas gingivalis [P.g] cultured on machined pure titanium discs. A total of 65 machined pure titanium discs with no surface modifications with a 10-mm diameter and a 2-mm height were sterilized by autoclaving at 121°C for 15min and incubated with the commercially available bacterial strains ATCC(American Type Culture Collection- P.g 33277 and A.a 29522)mixture of Aggregatibacter actinomycetemcomitans(A.a) and Porphyromonas gingivalis(P.g).After a 2-week incubation period with the mixture of bacteria to develop a mixed species biofilm, the discs were divided into three groups: (1) no treatment (control), (2) 445nm laser (test), (3) 970nm laser (test). For each laser wavelength (445 and 970nm), the discs were exposed to 1.0W and 2.0W in continuous wave mode for the times points of 15, 30, and 60s. The antimicrobial efficacy was assessed by qPCR. A significant reduction in the levels of both species of bacteria was observed between control and the laser intervention groups. A higher efficacy for the 445nm diode laser against Porphyromonas gingivalis and a similar efficacy against Aggregatibacter actinomycetemcomitans was observed as compared to the 970nm group. 445nm wavelength represents a potential and effective laser wavelength which can be used for the management of peri-implant infection. The present study findings also need to be further validated through clinical interventional trials.

First record of a mixed species association between Hatinh langur (Trachypithecus hatinhensis) and red-shanked douc (Pygathrix nemaeus).

In primates, mixed species associations are not common occurrences, and have been linked to both ecological and anthropogenic factors. We present camera-trapping records of a mixed association between two primates, the Hatinh langur (Trachypithecus hatinhensis) and red-shanked douc (Pygathrix nemaeus) and discuss possible hypotheses for this occurrence. To our knowledge, this is the first evidence of such an association in the wild of these two threatened primates, and thus contributes to our limited ecological knowledge of the species.

Gut microbiome and metabolome signatures in liver cirrhosis-related complications.

Shifts in the gut microbiota and metabolites are interrelated with liver cirrhosis progression and complications. However, causal relationships have not been evaluated comprehensively. Here, we identified complication-dependent gut microbiota and metabolic signatures in patients with liver cirrhosis. Microbiome taxonomic profiling was performed on 194 stool samples (52 controls and 142 cirrhosis patients) via V3-V4 16S rRNA sequencing. Next, 51 samples (17 controls and 34 cirrhosis patients) were selected for fecal metabolite profiling via gas chromatography mass spectrometry and liquid chromatography coupled to time-of-flight-mass spectrometry. Correlation analyses were performed targeting the gut- microbiota, metabolites, clinical parameters, and presence of complications (varices, ascites, peritonitis, encephalopathy, hepatorenal syndrome, hepatocellular carcinoma, and deceased). Veillonella bacteria, Ruminococcus gnavus, and Streptococcus pneumoniae are cirrhosis-related microbiotas compared with control group. Bacteroides ovatus, Clostridium symbiosum, Emergencia timonensis, Fusobacterium varium, and Hungatella_uc were associated with complications in the cirrhosis group. The areas under the receiver operating characteristic curve (AUROCs) for the diagnosis of cirrhosis, encephalopathy, hepatorenal syndrome, and deceased were 0.863, 0.733, 0.71, and 0.69, respectively. The AUROCs of mixed microbial species for the diagnosis of cirrhosis and complication were 0.808 and 0.847, respectively. According to the metabolic profile, 5 increased fecal metabolites in patients with cirrhosis were biomarkers (AUROC > 0.880) for the diagnosis of cirrhosis and complications. Clinical markers were significantly correlated with the gut microbiota and metabolites. Cirrhosis-dependent gut microbiota and metabolites present unique signatures that can be used as noninvasive biomarkers for the diagnosis of cirrhosis and its complications.

Neighbourhood benthic configuration reveals hidden co-occurrence social diversity.

Ecological interactions among benthic communities are crucial for shaping marine ecosystems. Understanding these interactions is essential for predicting how ecosystems will respond to environmental changes, invasive species, and conservation management. However, determining the prevalence of species interactions at the community scale is challenging. To overcome this challenge, we employ tools from social network analysis, specifically exponential random graph modelling (ERGM). Our approach explores the relationships among animal and plant organisms within their neighbourhoods. Inspired by companion planting in agriculture, we use spatiotemporal co-occurrence as a measure of mixed species interaction. In other words, the variety of community interactions based on co-occurrence defines what we call 'co-occurrence social diversity'. Our objective is to use ERGM to quantify the proportion of interactions at both the simple paired level and the more complex triangle level, enabling us to measure and compare co-occurrence social diversity. Applying our approach to the Spanish coastal zone across eight sites, five depths, and sunlit/shaded aspects, we discover that 80% of sessile communities, consisting of over a hundred species, exhibit co-occurrence social diversity, with 5% of species consistently forming associations with other species. These organism-level interactions probably have a significant impact on the overall character of the site. This article is part of the theme issue 'Connected interactions: enriching food web research by spatial and social interactions'.

Adaptive stacked species distribution modelling: Novel approaches to large scale quantification of blue carbon to support marine management

This study introduces a novel concept of ‘Adaptively Stacked’ Species Distribution Models (AS-SDMs) to predict blue carbon habitat distribution, abundance, carbon stocks, and carbon sequestration potential in Orkney. AS-SDMs are built from Weighted Boosted Regression Trees (WBRTs) that adaptively stack blue carbon sediment thickness, sediment carbon content, and sequestration potential to predicted abundance. A novel method to describe substrate types by relative inputs of mud, sand, and gravel is detailed that better characterises the determining factors of seagrass, maerl, and horse mussel abundance. This study also introduces a novel use of indexes to mitigate double counting issues of mixed species distribution models.Seagrass, maerl, horse mussel, and mixed seagrass and maerl (SGM) habitats are estimated to cover a maximum area of 657 km2 in Orkney, have a total sediment carbon stock of 16 Mt. C, and sequester 6000 t C yr−1. Applying a conservative threshold of 50 % abundance to habitat predictions, six key potential areas of blue carbon offset projects are identified. These areas cover just over 9 km2, have a total carbon stock of 330,000 t C, and sequester 330 t C yr−1. When applied to UK carbon credit value, assuming integration with voluntary markets and compliance with accreditation criteria, the habitats in these areas have a potential value of £24.5 million. If applied as annual values, these areas have carbon stocks with a potential value of £0.93 million yr−1 and a carbon sequestration potential value of £24,000 yr−1.

Close-range imaging for green roofs: Feature detection, band matching, and image registration for mixed plant communities

Green roofs offer ecological benefits but harsh rooftop environment stressors like heat, water scarcity, and wind can limit optimal plant growth. Monitoring plant health is crucial for optimizing green roof performance and remote sensing provides a non-destructive approach, yet challenges persist in tight, urban settings. This allows for close-range ground monitoring as a viable solution in these emerging environments. Recent studies explored automatic image registration techniques, showing promise in homogeneous settings, but faced uncertainties in mixed species systems or early plant growth stages. Feature detection techniques such as Speeded up Robust Features (SURF) using fixed and moving image spaces have been proposed for alignment. This study aimed to assess feature detection, matching, and image registration techniques in mixed species plant communities on green roofs throughout the growing season. This study developed a sophisticated monitoring system using close-range multispectral sensors for aligning bands in mixed species plant communities, contributing to enhanced green roof management and sustainability. The results of the study showed no significant differences in band alignment accuracy between growth stages for mixed species bush bean/sedum and single species sedum modules, but significant differences were found in single species bush bean systems. Additionally, mixed species modules showed better accuracy compared to single species bush bean modules, indicating that heterogenous systems provide better alignment accuracy due to more diverse feature extractions.

Assessment of the assimilation potential (by carbon) of urban green areas (on the example of the city of Penza)

The dependence of carbon assimilation in mixed plantings of the Penza city on the influence factors used in the ROBUL algorithm was studied. Specific carbon assimilation in the city by 99 % depends on the forest cover of the residential area, assimilation age rank and average conversion coefficient. The first factor has the greatest influence, while the conversion coefficient has the least one. The average carbon assimilation by the tree stand of the residential zone was 0.199 t/year/ha (43.6 kg/year/person). The highest indicators were in districts with forest park zones, the lowest ones were in districts with development not earlier than 2000. A positive carbon balance is observed relative to respiration of the population, but this balance is negative within the administrative borders of districts. A comparison of specific carbon assimilation at the Penza agglomeration sites calculated using the ROBUL algorithm and the obtained general regression assimilation model (RMA) showed no significant differences between them with a significant difference in the labor intensity of obtaining results in favor of the RMA model. The PMA model can be used to determine the temporal dynamics of carbon assimilation based on the planned area and composition of plantations. For the maximum possible share (42.6 %) of the green residential area of the Penza city, the potential carbon assimilation according to the RMA model for mixed species is 0.44 t/year/ha and is achieved in 40 years from tree planting, after which there is a decrease due to self-cutting.

Tolerance of plantain (Plantago lanceolata) to translocated herbicides wiped on flower stems

ABSTRACT Growing plantain (Plantago lanceolata) within pastures reduces nitrate leaching following grazing. Plantain is usually grown with grass and clover species, making selective weed control challenging. One strategy to selectively remove tall weeds in pastures with mixed species is to apply herbicides using weed wipers. However, for many months of the year, plantain has upright leafless flower stems that will intercept herbicide applied using wipers. To determine if this means plantain might be damaged by wipers used in such swards, two glasshouse experiments tested the tolerance of mature plantain plants to the application of herbicides suitable for use in weed wipers (glyphosate, clopyralid, aminopyralid, dicamba, metsulfuron, picloram and triclopyr) to the flower stems. Aminopyralid (0.075% ai solution) and a low rate of glyphosate (1.8% ai) caused the least decrease in plantain biomass and should be safe for weed wiping within swards containing plantain. A higher rate of glyphosate (7.2% ai) and a glyphosate/metsulfuron mix (0.9% + 0.01% ai, respectively) caused the most damage to plantain, particularly following simulated rainfall after application. Thus, applying some herbicides using wipers should be possible for selective weed control within plantain swards even if rain falls soon afterwards, though field trials are required to fine-tune recommendations.

Pollen foraging preferences in honey bees and the nutrient profiles of the pollen

Honey bees are important insect pollinators that provide critical pollination services to fruit and nut crops in the US. They face challenges likely due to pressures associated with agricultural intensification related habitat loss. To better understand this, pollen preferences of foraging bees and the nutritional profile of pollen brought into hives by foraging bees in crop fields and nut orchards can provide valuable information. We trained bees to forage on bee-collected pollen from hives placed for pollination services in almond orchards, sunflower fields, or mixed species from inter-row plantings. Using bees trained to a certain kind of hive pollen, we applied a binary scoring system, to test preferences of these preconditioned foragers. We also performed metabolomic analyses of the hive pollen used for training and testing to elucidate their nutritional content. Irrespective of preconditioning, bees collected all the available choice pollen types, predominantly choosing hive-collected mixed species pollen (MSP), followed by almond orchard pollen. The hive-collected MSP was chemically diverse, richest in cholesterol, vitamins, and phytochemicals quercetin, kaempferol, coumarin, and quinine, but was not consistently high for essential amino acids and polyunsaturated fatty acids. Although diversity in chemical profiles may not directly relate to plant species diversity, our results suggest that foragers collect a variety of pollen types when available reiterating the importance of diverse floral resources.

Streamer formation dynamics with mixed bacterial species: Effects of cultivation conditions, hydrodynamics, and species

Streamer formation dynamics with mixed bacterial species: Effects of cultivation conditions, hydrodynamics, and species

Scaling relationships between the total number of leaves and the total leaf area per culm of two dwarf bamboo species.

Total leaf area per plant is an important measure of the photosynthetic capacity of an individual plant that together with plant density drives the canopy leaf area index, that is, the total leaf area per unit ground area. Because the total number of leaves per plant (or per shoot) varies among conspecifics and among mixed species communities, this variation can affect the total leaf area per plant and per canopy but has been little studied. Previous studies have shown a strong linear relationship between the total leaf area per plant (or per shoot) (A T) and the total number of leaves per plant (or per shoot) (N T) on a log-log scale for several growth forms. However, little is known whether such a scaling relationship also holds true for bamboos, which are a group of Poaceae plants with great ecological and economic importance in tropical, subtropical, and warm temperate regions. To test whether the scaling relationship holds true in bamboos, two dwarf bamboo species (Shibataea chinensis Nakai and Sasaella kongosanensis 'Aureostriatus') with a limited but large number of leaves per culm were examined. For the two species, the leaves from 480 and 500 culms, respectively, were sampled and A T was calculated by summing the areas of individual leaves per culm. Linear regression and correlation analyses reconfirmed that there was a significant log-log linear relationship between A T and N T for each species. For S. chinensis, the exponent of the A T versus N T scaling relationship was greater than unity, whereas that of S. kongosanensis 'Aureostriatus' was smaller than unity. The coefficient of variation in individual leaf area increased with increasing N T for each species. The data reconfirm that there is a strong positive power-law relationship between A T and N T for each of the two species, which may reflect adaptations of plants in response to intra- and inter-specific competition for light.

The Impact of Artificial Afforestation on the Soil Microbial Community and Function in Desertified Areas of NW China

Afforestation is a widely used method of controlling desertification globally as it significantly impacts the soil quality, microbial community structure, and function. Investigating the effects of various artificial vegetation restoration models on soil microbial communities is crucial in understanding the mechanisms involved in combating desertification. However, research on this topic in arid, desertified regions is limited. In this study, we collected soil samples from two types of artificial forests (single species and mixed species) and bare desert soils in desertified areas of Northwest China to explore the impact of afforestation on soil nutrients, the microbial community composition, network relationships, and carbohydrate degradation abilities using metagenomic sequencing techniques. Our findings indicate that afforestation significantly enhances the soil moisture, total carbon, available phosphorus, and total nitrogen levels. The soil under mixed-species forests exhibited significantly higher levels of total carbon, total phosphorus, available phosphorus, and total nitrogen than that under single-species forests. Following afforestation, the populations of Pseudomonadota, Acidobacteriota, and Cyanobacteria increased significantly, whereas Actinomycetota decreased markedly. In single-species forests, Pseudomonadota and Bacillota were enriched, whereas Chloroflexota, Planctomycetota, and Acidobacteriota were more prevalent in mixed-species plantations. Afforestation increases the complexity and stability of microbial community networks. Afforestation enhances microbial metabolic activity, particularly increasing the abundance of carbon degradation functional genes in forest soils compared to bare desert soils. Mixed-species plantations outperform single-species forests in enhancing carbohydrate metabolism, amino acid metabolism, and the biodegradation and metabolism of xenobiotics. The abundance of functional genes associated with the degradation of starch, cellulose, hemicellulose, chitin, and pectin in mixed-species forests was significantly greater than in single-species plantations. Our study shows that mixed-species afforestation effectively improves the soil quality, enhances the stability of soil microbial communities, and bolsters the carbon cycle in arid regions prone to desertification. The reciprocal relationship between microorganisms and plants may serve as an intrinsic mechanism by which mixed-species afforestation more effectively controls desertification.

Effect of bicultural rearing of pikeperch (Sander lucioperca) and Russian sturgeon (Acipenser gueldenstaedtii) on growth and fish condition parameters in RAS

This study investigated the intensive rearing of pikeperch (Sander lucioperca) and Russian sturgeon (Acipenser gueldenstaedtii) in a recirculating aquaculture system for 84 days, with five different stocking ratios (with P as a percentage of pikeperch): P100, P90, P80, P70, and P0. The growth parameters, fish condition parameters, and blood biochemistry were measured. The P70 group showed the highest final total length, standard length, and body weight of pikeperch (82.95 ± 18.92 g), while the lowest values were found in Groups P100 (63.46 ± 18.49 g) and P90 (68.63 ± 13.79 g). The sturgeon did not show significant differences, except for Group P90, which had the lowest body weight (86.10 ± 33.95 g). Survival rates were high for pikeperch (96.098.6%) and no mortality in the sturgeon was evident in all groups. The feed conversion ratio (FCR) for pikeperch was similar between Group P100 (0.88 ± 0.02) and the two bicultural groups P90 (0.80 ± 0.04) and P80 (0.69 ± 0.05). For the sturgeon in Group P0, had a comparable FCR (0.71 ± 0.13). The lowest FCR for sturgeon was observed in the bicultural group P70 (0.66 ± 0.03). Tissue-somatic indices, hepatosomatic index (HSI), and fat-somatic index (FSI), supported significant differences only for pikeperch, with the highest values for the P80 and P70 groups. This study of pikeperch and Russian sturgeon rearing in various stocking ratios for 84 days demonstrates optimal growth and health parameters in the P70 group for pikeperch, with overall high survival rates and minimal health variations in sturgeon, suggesting the effectiveness of a mixed species approach in recirculating aquaculture systems.

Restoring a dry tropical forest through assisted natural regeneration: enhancing tree diversity, structure, and carbon stock

Deforestation is a key factor in global climate change, severely impacting ecosystem services. Effective implementation of reducing emissions from deforestation and forest degradation (REDD+) initiatives is essential for mitigating this change. Reforestation is a sustainable way to mitigate deforestation effects. We studied the impact of assisted natural regeneration (ANR) on restoring dry forest land, increasing biodiversity, structure, and carbon stock. Reforestation units were established at a multiple row planting system in a dry tropic region. We selected 63 plots, each 20 m × 20 m, categorized into multiple row–mixed plantation (MRMP) and multiple row–unmixed plantation (MRUP). We measured tree height and diameter at breast height (DBH) and evaluated biodiversity indices, including the Shannon–Weiner Index (SWI), species richness, evenness, and Important Value Index (IVI). Carbon stock was estimated using allometric equations. We identified 931 individual trees representing 27 species, 24 genera, and 14 families. MRMP showed significantly higher biodiversity, species richness, and evenness than MRUP. Terminalia arjuna was the most dominant species (IVI=124.45), followed by Khaya senegalensis (53.84). Survival rates exceeded 90 % for T. arjuna, K. senegalensis, Madhuca longifolia, and Pongamia pinnata (p<0.001). No significant differences were observed in tree DBH, tree height, tree density, basal area, and carbon stock among the plantation categories. The species Albizia saman exhibited a high diameter increment rate (4.07 ± 1.55 cm/year), followed by K. senegalensis (3.83 ± 0.43 cm/year). A mean value of 5.63 ± 1.13 MgC/ha of carbon stock was stored, while 20.66 ± 4.13 Mg/ha of atmospheric CO2 was sequestered. The results highlight that promoting mixed tree species in multiple rows to enhance biodiversity and optimize carbon regulation. This technique should be popularized to restore the dry forest landscape across the region.

Ecological Adaptation and Sustainable Cultivation of Citrus reticulata by Applying Mixed Design Principles under Changing Climate in China

Climate change is heavily altering plant distributions, posing significant challenges to conventional agricultural practices and ecological balance. Meanwhile, mixed species planting emerges as a potent strategy to enhance agricultural resilience, counteract climate change, preserve ecological balance, and provide a solution to economic instability. The MaxEnt model was used to predict the suitable area of Citrus reticulata under five climate scenarios and to explore affecting environmental factors. Litchi chinensis, Punica granatum, and Lycium chinense were selected as mixed species to analyze the spatial distribution and centroid migration trend of potentially suitable areas. The research results show the following: (1) The primary environmental factors impacting C. reticulata distribution are annual precipitation (1000–4000 mm), precipitation of driest quarter over 100 mm, and mean temperature of coldest quarter (12–28 °C). Crucially, the mixed species exhibited similar environmental sensitivities, indicating mutual mixing suitability. (2) Currently, the C. reticulata suitable area is of 240.21 × 104 km2, primarily in South, East, Central, and Southwest China, with potential for expansion to 265.41 × 104 km2 under the 2090s SSP1-2.6 scenario. (3) The geometric center of the moderately-to-highly suitable areas for C. reticulata is located in Hunan Province. Future scenarios show the C. reticulata’s centroid migrating northwest, with distances of less than 110 km. Mixed planting trends toward higher latitudes, fluctuating from 6 km to 210 km. (4) Mixed planting area planning: C. reticulata and L. chinensis are suitable for mixed planting in South China. C. reticulata and P. granatum, C. reticulata and L. chinense are suitable for mixed planting in most areas of Central, East, Southwest, and South China. This research presents a new perspective on using mixed design principles for ecological adaptation and the sustainable mixed planting of C. reticulata, in response to China’s changing climate. This approach is expected to help the economic fruit tree industry enhance ecological resilience and economic stability in the face of future climate change challenges.

Linking ex situ germination to in situ direct seeding for landscape scale restoration efforts in the semiarid Mallee region of Victoria, Australia

Direct seeding has high potential for arid revegetation, but success is limited by decreased germination and seedling emergence. Direct seeding success may be improved through developing an understanding of the germination biology and requirements of species used for these projects. This study looked into the germination temperature and moisture requirements of four semiarid species from Victoria's Mallee ecosystems to understand how their germination biology may advise strategies for future plantings. Temperature's effect on germination was analyzed by incubating the seeds under three different regimes: 30/20, 25/15, and 17/7°C. Moisture requirements were determined by germinating seeds along a water potential gradient created using polyethylene glycol 8000 solutions. Results showed three different strategies employed by the study species: (1) Acacia ligulata has a generalist approach, germinating well in all temperatures with a reasonable tolerance to water stress; (2) Eucalyptus calycongona and Melaleuca lanceolata germinate rapidly under higher germination temperatures and have generally higher water stress tolerance; while (3) Callitris gracilis germinates poorly in hot or dry conditions restricting germination to cooler and wetter conditions. Based on our results, A. ligulata would be the most widely applicable species for direct seeding work based on generalist germination habits. Callitris gracilis appears to do well if planted in cool, wet conditions where the species prefers to germinate but would be intolerant to warm‐weather planting. The ideal planting time for a mixed species planting based on germination requirements would be mid‐autumn, as that is when temperature and moisture levels would be optimal for germination.

Factors affecting crop damage by elephants in the buffer zone of Huai Kha Khaeng, a world heritage site

Context Human–elephant conflict is a growing global problem. To mitigate such conflict, understanding factors affecting elephant intrusions into human-dominated areas is crucial. These factors are, however, complex because they are site specific and context dependent. Aims This study aimed to identify factors associated with crop damage incidents from elephants in a buffer zone of a protected area in western Thailand. Methods Interviews were conducted with local people to quantify crop damage by elephants between November 2020 to April 2021. We used compositional analysis to determine whether different crop types received different damage from elephants, and logistic regression analysis to examine environmental factors associated with crop damage incidents. Key results Although it was previously thought that elephants focus on dominant palatable crops, we found that small patches of highly preferred crops can influence where elephants choose to feed. Distance from village was also a significant factor in crop foraging. Crop damage was not different between dry and wet seasons, probably because key crops were available year-round. Conclusions Crop damage occurred across multiple crop types but mainly those with higher sugar content. The damage mostly occurred in fields farther from villages, suggesting that presence of humans may alter elephant crop foraging. No specific seasonal period of crop damage was observed. Implications Changing crop types from species preferred by elephants to less preferred species and growing mixed species (multi-crop systems) instead of single species (mono-crops) may reduce elephant incursions. However, this needs field testing, including market-based assessments to evaluate the economic viability for farmers.