Cone Production Research Articles

CONE YIELD AND GROWTH CHARACTERISTICS IN A PLANTATION OF CUPRESSUS SEMPERVIRENS

Mediterranean cypress (Cupressus sempervirens L.) is an important secondary forest tree species in Turkish forestry because of its high adaptation ability and resistance to different ecological condition. However, limited studies were carried out in cypress. In this study, cone numbers, tree height, diameters at breast height and at base were surveyed from 75 individuals chosen randomly at eighteen years’ plantation in the species. Interaction between number of cones and growth characteristics was estimated together with fertility variation and linkage parameters (i.e. population size) to contribute management and practices of seed collection and gene conservation areas, and other forestry practices of the species. Mean cone number was 86/tree ranged from 36 to 174. Individual trees had large differences for the growth traits, while means of tree height, diameters of breast height and base were 6.1 m, 9.9 cm, and 12.6 cm, respectively. Fertility variation was 1.15 (87% of total trees, CV%=38.9), which close to typical population. Positive and significant (p≤0.05) relations were found between growth characteristics and cone production in Cupressus sempervirens. Tree height was better predictor in cone production than diameters.

Effect of Pine Cone Vinegar on The Survival of Listeria monocytogenes and Salmonella typhimurium and Some Physico-Chemical Properties in Raw Beef

Pine cones from pine (Pinus) trees contain various bioactive compounds with antibacterial and antioxidant activity. However, the use of pine cone products as functional foods or food additives is limited and there is a paucity of research in the literature. The objective of this study was the evaluation of pine cone vinegar as a marinade against Listeria monocytogenes and Salmonella typhimurium in raw beef. For this purpose, raw beef was marinated with pine cone vinegar at three different levels (25%, 50% and 75%) and three different marination times (2, 6 and 24 hours) and L. monocytogenes, S. typhimurium counts, pH and colour values (L*, a*, b*) were determined. Concentration*time interaction was significant for pH and the lowest pH value was found at 75% x 24 hours interaction. Although the marinating process had a significant effect on the colour values of the meat, the concentration x time interaction was not significant for the a* value (p>0.05). The number of S. typhimurium in pine cone vinegar decreased by 3.7 log10 in 2 hours and by 5.26 log10 in 6 hours (p

Spatial and Temporal Variation in the Antagonistic and Mutualistic Interactions among Seed Predator Arthropods, Seed-Dispersing Birds, and the Spanish Juniper.

Plants interact with both antagonistic and mutualistic animals during reproduction, with the outcomes of these interactions significantly influencing plant reproductive success, population dynamics, and the evolution of plant traits. Here, we investigated the spatial and temporal variations in the interactions between Juniperus thurifera, its seed-dispersing birds, and three specific arthropod species that attack the fleshy cones during the predispersal period. We assessed how plant traits affect levels of cone damage by arthropods and seed dispersal by birds, the occurrence of competition among arthropod species, and the impact of seed predators on the activity of frugivores. Plant traits, cone damage by arthropods, and seed dispersal by birds showed spatiotemporal variability. Fluctuation in cone abundance was the leading factor determining damage by arthropods and bird dispersal with a secondary role of cone traits. Large crops satiated predispersal seed predators, although the amount of frugivory did not increase significantly, suggesting a potential satiation of bird dispersers. Crop size and cone traits at individual trees determined preferences by seed predator species and the foraging activity of bird dispersers. Competition among arthropods increased during years of low cone production, and seed predators sometimes negatively affected bird frugivory. High supra-annual variations in cone production appear to be a key evolutionary mechanism enhancing J. thurifera reproductive success. This strategy reduces the impact of specialized seed predators during years of high seed production, despite the potential drawback of satiating seed dispersers.

How do intervals between fires influence canopy seed production and viability?

Abstract Canopy storage of seed (serotiny) is an important persistence strategy in fire‐prone environments. Serotinous populations can be threatened when fire intervals are shorter than the time needed to accumulate seed, or when longer than plant lifespans. Understanding how fire regimes influence canopy seedbanks requires study of the timing of plant maturity, seed output and germination traits. Research that spans plant functional types, such as resprouters or obligate seeders, helps to understand the mechanisms through which fire has influence. Using field data collected at 57 sites in a Mediterranean shrubland of southeastern Australia, we modelled how time since fire and mean fire interval influenced infructescence (hereby cone) production. Additionally, seed output, viability and germination speed were assessed in the laboratory. Reproductively mature resprouters were first observed 2 to 4 years post‐fire in the field, and reproductively mature obligate seeders 6 years post‐fire, depending on the species. Reproductively mature plants were not observed at short mean fire intervals: until 3 and 9 years for resprouters and nine and 18 years for obligate seeders, again, varying by species. When resprouter species reached maturity, we observed a decline in cone production as time since fire increased. This decline was not observed for obligate seeder species. Fire influenced the number of viable seeds produced within cones for one resprouter species, Allocasuarina paludosa, but we did not detect a relationship for other species. Germination speed was faster for species that produce few seeds per cone, and slower for species that produce many seeds, indicating a trade‐off between fire‐related seed traits. For example, Hakea rostrata, which holds two seeds per cone, germinated mostly within the first few weeks, while Callitris rhomboidea, which holds many seeds per cone, germinated asynchronously over 9 months. Short intervals between fires reduce canopy seed production for the serotinous species studied. Obligate seeders were more sensitive to frequent fire than resprouters. In the context of expected increases in wildfire frequency and droughts in Mediterranean ecosystems, our findings suggest that serotinous species' reproduction and recruitment will be differentially impacted depending on a suite of functional traits. Read the free Plain Language Summary for this article on the Journal blog.

A STUDY ON LABOUR WELFARE MEASURE TOWARDS MANO CONE PRODUCTS WITH REFERENCE TO MADURAI

A STUDY ON LABOUR WELFARE MEASURE TOWARDS MANO CONE PRODUCTS WITH REFERENCE TO MADURAI

Principles of Ice Cream Cone Production in an Islamic Economic Perspective in Pacitan Home Industries

Introduction/Main Objectives: This research aims to determine ice cream cones' production and production principles "Proceed Established" Pacitan home industry. Research Methods: The method used in this research is qualitative, data collection is by field research, including interviews, observation, and documentation with business owners and employees of the Pacitan "Proceed Established" ice cream cone production. Finding/Results: The results of this research 1) the production of "Maju Mapan" ice cream cones functions of labor, materials, capital, organization/management, and technology. 2) Based on the production principles applied, they are in understanding with Islamic production principles: creating quality ice cream cones, halal, and tayyib; implementing justice to all employees and meeting consumer demand and satisfaction; not committing acts of exploitation and exploration of existing natural resources; intertwine good relations or ties of friendship between business owners, workers and consumers; free in the use of materials and technology by paying attention to whether it is halal or not violate sharia, and freely manage business income and expenses; Responsible for all production activities which is conducted. Conclusion: Institutions are advised to arrange halal product certification and include production raw materials and expiry dates on the packaging.

Stochastic Optimization of the Management Schedule of Korean Pine Plantations

Korean pine is one of the most important tree species in northeastern China, where Korean pine plantations produce timber and edible seeds. Often, seeds create more income than timber. Predicting the timber and cone yields of alternative management schedules of the plantations involves uncertainty because the future climatic conditions for tree growth and cone production are unknown. This study developed a simulation model that generates stochastic variation around the predictions of tree growth and cone yield models, allowing the forest manager to seek cutting schedules that maximize the expected amounts of timber or cones, or the expected economic profit, under uncertain future states of nature. Stochastic analysis also facilitates management optimizations for different risk attitudes. The differential evolution algorithm and the developed stochastic simulation model were used to optimize the management of planted Korean pine. Timber and cone yields of a management schedule were calculated under 100 different scenarios for tree growth and cone production. When the growth and cone yield scenarios were stationary (no temporal trends), the optimal management schedules were similar to those of deterministic optimization. The benefits of stochastic optimization increased when it was assumed that the tree growth scenarios may contain climate-change-induced trends. Non-stationary growth variation led to shorter optimal rotation lengths than stationary growth variation. Increasing risk tolerance shortened optimal rotations.

Exploring interspecific hybridization dynamics in artificial forests of Pinus brutia and P. halepensis: Implications for sustainable afforestation.

Interspecific hybridization increases genetic diversity, which is essential for coping with changing environments. Hybrid zones, occurring naturally in overlapping habitats of closely related species, can be artificially established during afforestation. The resulting interspecific hybridization may promote sustainability in artificial forests, particularly in regions facing degradation due to climate change. Currently, there is limited evidence of hybridization during regeneration of artificial forests. Here, we studied the frequency of Pinus brutia Ten. × P. halepensis Mill. hybridization in five planted forests in Israel in three stages of forest regeneration: seeds before dispersal, emerged seedlings and recruited seedlings at the end of the dry season. We found hybrids on P. brutia, but not on P. halepensis trees due to asynchronous cone production phenology. Using 94 single-nucleotide polymorphism (SNP) markers, we found hybrids at all stages, most of which were hybrids of advanced generations. The hybrid proportions increased from 4.7 ± 2.1 to 8.2 ± 1.4 and 21.6 ± 6.4 per cent, from seeds to emerged seedlings and to recruited seedlings stages, respectively. The increased hybrid ratio implies an advantage of hybrids over P. brutia during forest regeneration. To test this hypothesis, we measured seedling growth rate and morphological traits under controlled conditions and found that the hybrid seedlings exhibited selected traits of the two parental species, which likely contributed to the fitness and survival of the hybrids during the dry season. This study highlights the potential contribution of hybrids to sustainable-planted forests and contributes to the understanding of genetic changes that occur during the regeneration of artificial forests.

Low-severity fires in the boreal region: reproductive implications for black spruce stands in between stand-replacing fire events.

Stand-replacing crown fires are the most prevalent type of fire regime in boreal forests in North America. However, a substantial proportion of low-severity fires are found within fire perimeters. Here we aimed to investigate the effects of low-severity fires on the reproductive potential and seedling recruitment in boreal forests stands in between stand-replacing fire events. We recorded site and tree characteristics from 149 trees within twelve sites dominated by mature black spruce [Picea mariana (Mill.) B.S.P.] trees in the Northwest Territories, Canada. The presence of fire-scarred trees supported classification of sites as unburned or affected by low-severity fires in recent history. We used non-parametric tests to evaluate differences in site conditions between unburned and low-severity sites, and mixed effect models to evaluate differences in tree age, size, and reproductive traits among unburned trees and trees from low-severity sites. Results showed significantly higher density of dead black spruce trees in low-severity sites, and marginally significant higher presence of permafrost. Trees from low-severity fire sites were significantly older, exhibited significantly lower tree growth, and showed a tendency towards a higher probability of cone presence and percentage of open cones compared to trees from unburned sites. Surviving fire-scarred trees affected by more recent low-severity fires showed a tendency towards higher probability of cone presence and cone production. Density of black spruce seedlings significantly increased with recent low-severity fires. Trees in low-severity sites appeared to have escaped mortality from up to three fires, as indicated by fire scar records and their older ages. Shallow permafrost at low-severity sites may cause lower flammability, allowing areas to act as fire refugia. Low-severity surface fires temporarily enhanced the reproductive capacity of surviving trees and the density of seedlings, likely as a stress response to the fire event.

Reproductive patterns in Araucaria araucana forests in the Andean range, Chile

BackgroundAraucaria araucana is a mast species that presents a high variability in annual cone production. Researchers have recorded synchronization events in cone production in different populations, which allows the seed production to be concentrated, reducing the percentage of seeds consumed by different animal species.MethodsWe sampled three populations located in the Andes Mountains, Araucanía Region, Chile. In 2004 we began the collection of data on cone production, for which we installed permanent plots (1200 m2 each) at each location. We identified and labeled each female tree in each plot to monitor its cone production. In 2012 we selected a total of 30 trees near the plots to evaluate the number of seeds per cone. In each February from 2012 to 2014 we selected two mature cones and covered them with a porous mesh for subsequent collection and storage in March. At the beginning of June, we counted and weighed the seeds, determining the average weight, the number of seeds per cone, the germination capacity (GC), and the germination speed (GS).ResultsCone production was synchronous across the three locations. We observed significant differences among the locations and years evaluated. The cones had fewer seeds in 2013 (high production) compared to those in 2012 (low production), but their weights were similar. In 2014 the cones produced smaller seeds in fewer quantities. The difference between the years 2013 and 2014 resulted from the high-energy expenditure in 2013. Regarding GC and GS, there were significant differences among the three locations (GC: F = 45.41, p < 0.01; GS: F = 96.08, p < 0.01), where the highest values were observed in 2013.ConclusionsBoth GC and GS are related to seed weight but not to the number of cones produced in a given year. These annual fluctuations in seed production are determining factors in the population dynamics of forest species. Our results allow a better understanding of the reproductive phenology of A. araucana and could help define sustainable use and conservation actions for this species.

Recommendations for increasing yield of the edible Pinus pinea L. pine nuts.

In Pinus pinea, cone to pine nut yield (total pine nut weight expressed as percentage of cone weight), an important crop trait, is decreasing worldwide. This phenomenon is of great concern, since the nuts of this species are highly demanded. Cone weight, seed and pine nut morphometry, and pine nut yield were monitored in a non-native area in Chile for 10 years. For this purpose, 560 cones, and the seeds and pine nuts contained in them, were counted, measured and weighed in a multi-environment study involving seven plantations. Seed and pine nut damage was evaluated. Two contrasting categories of cone weight (heavy/light) were defined. Cone to pine nut yield (PY) and other traits were calculated and compared between categories using a mixed linear model. Regression trees were used to explain PY variability. Cone weight was higher than in the species' native range (474 g vs 300 g on average). Pine nut number per cone and PY were significantly higher in the heavy cone category than in the light cone category (125 vs 89 units, and 4.05 vs 3.62%, respectively), The percentage of damaged seeds was lower in heavy than in light cones (9.0% vs 15.9%). Thus, PY depended on seed and pine nut morphometry as well as on seed health. Management practices, such as fertilization and irrigation, could be used to boost production of heavy cones and consequently increase PY.

Evaluating immaturity risk in young stands of the serotinous knobcone pine (Pinus attenuata)

AbstractAs wildfire becomes increasingly frequent, many serotinous plant populations risk local extirpation if fire recurs prior to sufficient seed accumulation in the canopy (i.e., “immaturity risk”). Following two 2018 wildfires in northwestern California, we studied seed viability, cone production, and postfire regeneration of a serotinous conifer, knobcone pine (Pinus attenuata), with stand ages (time since fire) ranging from 6 to 79 years. Cone density per tree was more strongly associated with tree diameter than age, and cone density was positively related to postfire seedling regeneration. Most of the postfire knobcone pine regeneration established during the first year with high survivorship in the following first postfire year. Adjusting for survivorship, the estimated minimum age for knobcone pine to promote self‐replacement (one recruit per tree) was 9.5 years (or 4.6‐cm dbh) and the probability of reburning at the modern fire rotation of 43 years was 19.8%. Based on our results, we found that immaturity risk was currently low for knobcone pine. Our approach provides a quantitative method to assess immaturity risk in knobcone pine and other serotinous conifer species that can be used to evaluate future risk under rapidly changing climate and fire conditions.

Diallel crosses in Picea abies VI. Genetic variation in early reproduction in three young Norway spruce progeny trials

Abstract Female flowering and cone production took place in three Norway spruce progeny tests at ages 17 and 20 years, each planted with full-sib families from a half diallel. The number of cones on individual trees were scored in five classes. More than 50 % of the trees produced cones, and a considerable variation was found among families for the ability to produce cones (precocity) and for the number of clones scored in classes (fruitfulness). Both traits were strongly related to tree heights and diameters at the individual and at the family level. In general, tall trees produced the highest number of cones. However, some families produced many cones even if their average heights were low. In two of the half diallels, estimates of GCA variance components for the number of cones produced had twice the value of the SCA component, indicating additive genetic inheritance of cone production. Heritability estimates of cone scores were 0.10, 0.17 and 0.23, and the genetic correlations between cone production and tree heights were 0.40, 0.50 and 0.35 in the tree half-diallels, respectively.

High stand density improves seed production in seed orchards of the masting species Picea abies

Reproduction in masting species is characterised by long intervals between good cone and seed production years, and only sparse reproduction between mast years. The physiological mechanisms behind masting, and how these are linked to internal resource status and external weather factors, is still a subject of scientific exploration and debate, as is the effect of climate change on masting. This study investigates cone production in one operational seed orchard in Sweden which was established with two different spacings and has since been subject to three tree thinning experiments. The spacings before thinning varied between 800 and 400 stems ha–1, and then thinning reduced the stand density in all trials to half, i.e. between 400 and 200 stems ha–1. In all three experiments cone production per tree was equal in un-thinned and thinned treatments, both in mast years and in non-mast years. Thus, the cone production per unit area was twice as high in the un-thinned areas. The conclusion from these experiments is that the establishment of Picea abies (L.) H. Karst. seed orchards with wide tree spacing is both a misuse of good orchard locations and bad economics.

Quantification of heritable variation in multiple lodgepole pine chemical and physical traits that contribute to defense against mountain pine beetle (Dendroctonus ponderosae)

Bark beetles are major causes of conifer mortality worldwide. We quantified genetic contributions to key chemical and physical traits in lodgepole pine that contribute to defense against mountain pine beetle, a native tree-killing herbivore. Assays were conducted with mature trees in replicated provenance trials. Among chemical defenses, monoterpene composition (relative proportions of various compounds) had higher genetic variability than monoterpene concentration (absolute quantities). Additionally, constitutive concentrations had higher genetic variabilities than induced concentrations elicited by simulated attack. Resin flow elicited by mechanical wounding likewise showed very low genetic variability. In previous studies with this and related systems, induced monoterpene concentration and resin flow are the two best predictors respectively of which trees will survive outbreaks under natural conditions. This means that expression of the most efficacious defense traits is strongly influenced by environmental factors. These low heritabilities despite their survival values likely arise from specific life history and ecological aspects of this system, such as the lengthy period between when lodgepole pines begin cone production and become large enough for brood development, the extended viability of serotinous cones post-mortem, the high heterogeneity of both resources and stressors that trees experience across landscapes, and a strong proximate-neighbor effect on tree mortality arising from beetle aggregation pheromones. However, low heritability values do not preclude long-term evolvability and coadaptation of defenses, for which there is extensive mechanistic and associational evidence in this system. Among other traits we evaluated, sesquiterpenes had higher genetic variability than monoterpenes. Sesquiterpenes are not known to influence conifer-bark beetle interactions but have anti-herbivore properties in some other plant-insect systems. The lengths of lesions formed in response to simulated attack showed no heritable component and likewise do not predict tree survival in nature. Bark texture was highly heritable and is known to influence beetle post-landing orientation and colonization patterns, but whether it influences survival patterns at the whole-tree level is unknown. Relationships between tree defenses and growth were generally positive, suggesting that environmental heterogeneity in resource quality among trees supersedes potential underlying substrate allocation processes within trees. Similarly, relationships between various defense traits were generally positive rather than showing trade-offs, suggesting conifer resistance to native bark beetles entails coordinated defense syndromes. Implications to tree breeding, forest management, and coevolution between long-lived plants and rapidly reproducing herbivores are discussed. The extent to which these trends may apply to other bark beetle systems is evaluated, along with specific priorities for future research.

Clark's nutcracker forest community visitation: Whitebark pine maintains a keystone seed disperser.

Clark's nutcrackers (Nucifraga columbiana) are obligate seed dispersers for whitebark pine (Pinus albicaulis), but they frequently use other conifer seed resources because of annual variability in cone production or geographic variation in whitebark pine availability. Whitebark pine is declining from several threats including white pine blister rust, leading to potential population declines in the nutcracker and the pine. We hypothesize that where there are few additional seed resources, whitebark pine becomes the key and limiting resource supporting nutcracker populations. We investigated how nutcrackers use coniferous forest community types within Yellowstone National Park to determine potential seed resources and the importance of whitebark pine. We established sites representing five forest community types, including whitebark pine, lodgepole pine (P. contorta), Engelmann spruce (Picea engelmannii), limber pine (P. flexilis), and Douglas-fir (Pseudotsuga menziesii). Each transect annually generated nutcracker point counts, conifer cone production indices, community composition data, and seed resource use observations. We compared hierarchical distance sampling models, estimating nutcracker density and its relationship to forest community type, seed harvesting time-period, year, study site, and cone seed energy. We found cone production varied across years indicating annual variability in energy availability. Nutcracker density was best predicted by forest community type and survey time-period and was highest in whitebark pine stands during the mid-harvesting season. Nutcracker density was comparatively low for all other forest community types. This finding underscores the importance of whitebark pine as a key seed resource for Clark's nutcracker in Yellowstone National Park. The decline of whitebark pine potentially leads to a downward spiral in nutcrackers and whitebark pine, arguing for continued monitoring of nutcrackers and implementation of restoration treatments for whitebark pine.

Tropical cyclone winds and precipitation stimulate cone production in the masting species longleaf pine (Pinus palustris).

Many trees exhibit masting - where reproduction is temporally variable and synchronous over large areas. Several dominant masting species occur in tropical cyclone (TC)-prone regions, but it is unknown whether TCs correlate with mast seeding. We analyzed long-term data (1958-2022) to test the hypothesis that TCs influence cone production in longleaf pine (Pinus palustris). We integrate field observations, weather data, satellite imagery, and hurricane models to test whether TCs influence cone production via: increased precipitation; canopy density reduction; and/or mechanical stress from wind. Cone production was 31% higher 1 yr after hurricanes and 71% higher after 2 yr, before returning to baseline levels. Cyclone-associated precipitation was correlated with increased cone production in wet years and cone production increased after low-intensity winds (≤ 25 m s-1 ) but not with high-intensity winds (> 25 m s-1 ). Tropical cyclones may stimulate cone production via precipitation addition, but high-intensity winds may offset any gains. Our study is the first to support the direct influence of TCs on reproduction, suggesting a previously unknown environmental correlate of masting, which may occur in hurricane-prone forests world-wide.

Efficacy of 3D screens for sustainable mosquito control: a semi-field experimental hut evaluation in northeastern Tanzania

BackgroundA three-dimensional window screen (3D-Screen) has been developed to create a window double-screen trap (3D-WDST), effectively capturing and preventing the escape of mosquitoes. A 2015 laboratory study demonstrated the 3D-Screen's efficacy, capturing 92% of mosquitoes in a double-screen setup during wind tunnel assays. To further evaluate its effectiveness, phase II experimental hut trials were conducted in Muheza, Tanzania.MethodsThree experimental hut trials were carried out between 2016 and 2017. Trial I tested two versions of the 3D-WDST in huts with open or closed eaves, with one version using a single 3D-Screen and the other using two 3D-Screens. Trial II examined the 3D-WDST with two 3D-Screens in huts with or without baffles, while Trial III compared handmade and machine-made 3D structures. Mosquito capturing efficacy of the 3D-WDST was measured by comparing the number of mosquitoes collected in the test hut to a control hut with standard exit traps.ResultsTrial I showed that the 3D-WDST with two 3D-Screens used in huts with open eaves achieved the highest mosquito-capturing efficacy. This treatment captured 33.11% (CI 7.40–58.81) of female anophelines relative to the total collected in this hut (3D-WDST and room collections) and 27.27% (CI 4.23–50.31) of female anophelines relative to the total collected in the control hut (exit traps, room, and verandahs collections). In Trial II, the two 3D-Screens version of the 3D-WDST captured 70.32% (CI 56.87–83.77) and 51.07% (CI 21.72–80.41) of female anophelines in huts with and without baffles, respectively. Compared to the control hut, the capturing efficacy for female anophelines was 138.6% (37.23–239.9) and 42.41% (14.77–70.05) for huts with and without baffles, respectively. Trial III demonstrated similar performance between hand- and machine-made 3D structures.ConclusionsThe 3D-WDST proved effective in capturing malaria vectors under semi-field experimental hut conditions. Using 3D-Screens on both sides of the window openings was more effective than using a single-sided 3D-Screen. Additionally, both hand- and machine-made 3D structures exhibited equally effective performance, supporting the production of durable cones on an industrial scale for future large-scale studies evaluating the 3D-WDST at the community level.Graphical

Patterns of Water Consumption in Longleaf Pine Restoration Areas and the Relationship with Cone Production

Monitoring water consumption dynamics across the geographic range of an ecosystem may indicate the possible variation and stress in a biome. Here, model output data based on remote sensing (1979–2022) were used to examine the water consumption dynamics and effects on cone production in three geographic margins in the longleaf pine’s range (i.e., Bladen Lake State Forest, Escambia Experimental Forest, and Kisatchie National Forest) under varying climatic conditions. Results indicated that the mean annual transpiration at Escambia was approximately 431 mm and that at Bladen and Kisatchie was 500 mm. Mean monthly transpiration peaked twice (June and October) at Escambia but only once (August) at Bladen and Kisatchie. The mean annual evapotranspiration ranged from approximately 900 mm at Kisatchie to about 791 mm at Escambia and Bladen. The mean annual transpiration/evapotranspiration ratio was about 0.65 at Bladen and 0.55 at Escambia and Kisatchie. A significant correlation existed between evapotranspiration and specific humidity across the sites on a monthly scale but not on a yearly scale. Significant negative relationships existed between precipitation and the ratios of transpiration/precipitation and evapotranspiration/precipitation on the yearly scale across the sites. Negative power relationships were observed between precipitation and the specific humidity/precipitation ratio on monthly and yearly scales. Cone production was generally highest in years with moderate water consumption. These results provide baseline information on how hydrological and ecological processes of longleaf pine forests interact with climate across broad spatial and temporal scales.

Impact of poaching on the population structure and insect associates of the Endangered Encephalartos eugene-maraisii from South Africa

Background: South Africa is an important centre of cycad diversity in Africa, however, the country’s cycads face extinction. Among the primary causes is the poaching of plants from the wild, even within protected areas. Objectives: This study examined poaching patterns in a local population of the Endangered Encephalartos eugene-maraisii I.Verd. and how it might affect the population structure, sex ratios, as well as interactions with associated insects. Methods: The population was surveyed in 2008 and 40% of this population was resurveyed between 2021 and 2022. We mapped missing cycads and generated heatmaps. Lastly, we investigated whether the proportion of stems from different size classes, sex ratios and abundance of insect associates varied between areas with a high and low poaching incidence. Results: Poaching, defined as the illegal removal of individuals from the wild, occurred 1.5 times more frequently along the border fence line than areas further away. Medium-sized stems (21–80 cm) are primarily targeted (likely as they can be carried more easily) and low proportions of these stems remain in areas with a high poaching incidence. While E. eugene-maraisii exhibits some resilience against poaching through basal suckering, it takes several decades for suckers to mature and replace harvested stems. No effect on sex ratios were recorded in areas with a high poaching incidence, suggesting poachers have not deliberately selected female or male cycads at this site. No pollinating insects were detected on E. eugene-maraisii, and no seedlings were observed. Conclusion: Cone production may be too rare in diminished populations to support pollinators that utilise cones as brood sites. The presence of insects that use other plant parts, including leaves, dried leaf stalks and cycad trunks, in the larger population suggests that they are more resilient to diminishing host populations. However, these insects were absent in smaller populations, and their abundances were lower in low-density sites and smaller clump sizes of their host in the larger population. This suggests these insects may be vulnerable to the decline of their host populations due to poaching.