Annual Fruit Production Research Articles

Relatives reproduce in synchrony: kinship and individual condition shape intraspecific variation in masting phenotype.

Masting (synchronous and interannually variable seed production) is frequently called a reproductive strategy; yet it is unclear whether the reproductive behaviour of individuals has a heritable component. To address this, we used 22 years of annual fruit production data from 110 Sorbus aucuparia L. trees to examine the contributions of genetic factors to the reproductive phenotype of individuals, while controlling for environmental variation. Trees sharing close genetic relationships and experiencing similar habitat conditions exhibited similar levels of reproductive synchrony. Trees of comparable sizes displayed similar levels of year-to-year variation in fruiting, with relatedness contributing to this variation. External factors, such as shading, influenced the time intervals between years with abundant fruit production. The effects of genetic relatedness on the synchrony of reproduction among trees and on interannual variation provide long-awaited evidence that the masting phenotype is heritable, and can respond to natural selection.

The potential for sustainable harvest of Common Persimmon (Diospyros virginiana L.) fruits at Pea Ridge National Military Park

Background: The large, sweet fruits of the Common Persimmon (Diospyros virginiana L.) have a long history as a wild-harvested food in the eastern United States, by both Indigenous people and European settlers. However, little is known about the sustainability of persimmon fruit harvest. Persimmon fruits are a culturally important food for the Osage Nation. Pea Ridge National Military Park (hereafter PERI) is within the Osage ancestral territory Methods: We examine the sustainability of persimmon fruit harvest through field surveys of fruit production and the application of the United Plant Savers “At-Risk Assessment Tool”, which assesses the risk of overharvesting wild plants. Our field work to determine persimmon fruit yield was conducted at PERI in response to a National Park Service’s (NPS) 2016 rule which provides a pathway for Native American tribes, the Osage Nation in our case, to collect culturally important plants from NPS land if harvest is sustainable. Results: Combining our field surveys of fruit production with NPS data on persimmon tree density and potential persimmon habitat at PERI, we estimate annual fruit production of about 143,000 persimmon fruits, or about 1,990 kg (4100 lbs.) at PERI. Persimmon fruit harvest has a low risk of overharvest, with an At-Risk score of 19 on a scale with a max score of 96 (highest risk). Conclusions: An annual harvest of 9-15 kgs (~20-30 lbs.) of persimmon fruit by the Osage at PERI (< 1% of total estimated yield), would be sustainable and help promote traditional Osage practices of collecting, preserving, and eating persimmons. Keywords: persimmon, sustainable harvest, At-Risk assessment, Pea Ridge, ethnobotany

Sustainability indicators of the Brazil nut tree management

Brazil nut tree (Bertholletia excelsa Bonpl) management, is a traditional activity that plays a key role in the economy of forestbased Amazon communities and in the conservation of forests. Nevertheless, some threats and critical points related to sustainability indicate to the need for establishment of monitoring procedures that can assist in the management of this natural resource. The overall aim of the research was to evaluate the MESMIS method as a tool to support the participatory definition of sustainability indicators to monitor Brazil nut management, and the viability of Brazil nut harvest over time. For that, we carried out a case study in the Porvir Community, RESEX Chico Mendes, Acre State (Brazil), aiming to integrate the perceptions of Brazil nut harvesters, researchers, managers, and technicians to define the indicators. The result was the generation of 18 strategic indicators to assess sustainability in the environmental, technical-economic and social dimensions. Assessment parameters, representing conditions that must be achieved for system sustainability, were collectively defined for each indicator. The main critical values attributed in the evaluation of the indicators are related to Brazil nut commercialization to intermediaries and oscillation in the annual fruit production. The use of the MESMIS method was considered appropriate to the studied context and can be recommended to similar non-timber forest product management systems.

Strong El Niño reduces fruit production of Brazil-nut trees in the eastern Amazon

ABSTRACT The Brazil-nut tree (Bertholletia excelsa) is native to the Amazon rainforest, and its fruit production varies naturally with climatic conditions. Our aim was to evaluate the temporal variation in Brazil-nut production associated with climatic variables, including the strong El Niño of 2015/2016. The study was carried out in two 9-ha permanent plots in the northeastern Brazilian Amazon from 2007 to 2018: one in forest (12-year monitoring) and the other in savannah/forest transition (eight years). Overall, we monitored fruit production of 205 trees with diameter at breast height ≥ 50 cm. Annual fruit production was related to temporal series (2005-2018) of climatic data (the Oceanic Niño Index; and precipitation and air temperature from two local meteorological stations). Average fruit production per tree in 2017 was eight times lower than in 2015 and two times lower than the general average for both sites, and was significantly associated to the El Niño of 2015/2016, that increased average maximum monthly temperature and reduced the precipitation in the region, extending the dry season from three to six months. Years with higher and lower fruit production per tree coincided in both sites. Annual fruit production was significantly and negatively correlated with thermal anomalies that occurred in the third semester prior to harvest monitoring. Years with higher production were related with predominance of neutrality or the La Niña phenomenon at the global scale, and higher rainfall at the local scale. The relationship of fruit production with climate was independent of the local habitat.

Long-term persistence of experimental populations beyond a species' natural range.

Ecological experiments usually infer long-term processes from short-term data, and the analysis of geographic range limits is a good example. Species' geographic ranges may be limited by low fitness due to niche constraints, a hypothesis most directly tested by comparing the fitness of populations transplanted within and beyond the range. Such studies often fail to find beyond-range fitness declines strong enough to conclude that geographic range limits are solely imposed by niche limits. However, almost all studies only follow transplants for a single generation, which will underestimate the importance of niche limitation because critical but infrequent range-limiting events may be missed and methodological issues may artificially boost the fitness of beyond-range transplants. Here, we present the first multi-generation beyond-range transplant experiment that involves adequate replication and proper experimental controls. In 2005, experimental populations of the coastal dune plant Camissoniopsis cheiranthifolia were planted at four sites within and one site beyond the northern limit. Fitness of initial transplants was high beyond the limit, suggesting that the range was limited by dispersal and not niche constraints. To better address the niche-limitation hypothesis, we quantified density and fitness of descendant C. cheiranthifolia populations 12-14 yr (˜10 generations) after transplant. Average annual fruit production and density of reproductive individuals were as high beyond the range as at four comparable experimental populations and eight natural populations within the range, and the beyond-range population had more than tripled in size since it was planted. This provides unprecedented support for the conclusion that northern range limit of C. cheiranthifolia results from something other than niche limitation, likely involving constraints on local dispersal.

First Report of Pseudomonas oryzihabitans Causing Stem and Leaf Rot on Muskmelon in China.

Muskmelon (Cucumis melo L.) is an important economic crop in China, which is planted on more than 376, 000 hectares with over 13 million tons of annual fruit production. In February 2020, a serious bacterial stem and leaf rot disease on muskmelon plants was observed in greenhouses in Liguo Town, Ledong County, Hainan Province, China (18.54° N, 108.87° E), with disease incidences being approximately 10 to 12%. Initially, soft rot symptoms appeared on petioles and stems, showing yellow bacterial ooze signs, which was different from the milky white ooze produced by Erwinia tracheiphila infection. The infected tissues of petioles, stems, and leaves eventually developed into browning and withering symptoms. To isolate and identify the causal agent, the lesion tissues were sterilized by immersion in 75% ethanol for 30 s, washed three times with sterile water, and then cut and soaked in 1 ml of distilled water for 10 min. The suspension was serially diluted and spread on Luria-Bertani agar (LB) medium. After incubation at 28°C for 24 to 36 h, the resulted bacterial colonies were tiny and were streaked on LB plate for further culture. After purification, the colonies were yellow, circular, smooth-margined, and two independent representative isolates CM-11 and CM-12 were used for further validation experiments. The electron microscope analysis showed that the pathogen was rod-shaped, with a length of 1.34 ± 0.22 μm and a width of 0.54 ± 0.06 μm (N=50), and had a single terminal flagellum. The gram staining of the two isolates was negative. Moreover, the tested strains were positive for catalase but negative for oxidase and were able to utilize D-glucose, L-arabinose, and D-mannitol. Morphological, physiological, and biochemical characteristics of both isolates were consistent with those of Pseudomonas spp. To verify the species identity of the bacterial pathogens, genomic DNA of isolates CM-11 and CM-12 was extracted and several conserved genes were amplified and sequenced, including the 16S rRNA gene with primers 27F/1492R (GenBank MW187499 and MW187500), rpoB gene with primers V4/LAPS27 (MW201910 and MW446819), and gyrB gene with primers gyrBBAUP2/APrU (MW187501 and MW187502) (Mulet et al. 2010). In the BLAST analysis, the 16S rRNA sequences showed a 99% similarity to that of Pseudomonas oryzihabitans strains TH19 (LC026009), AA21 (MG571765). The rpoB and gyrB sequences showed high similarity (> 98%) to P. oryzihabitans strains FDAARGOS_657. The phylogenetic tree analysis of rpoB and gyrB genes further verified that the two isolates CM-11 and CM-12 were most closely related to P. oryzihabitans species. Consequently, the two pathogenic isolates CM-11 and CM-12 were identified as P. oryzihabitans. Both strains of CM-11 and CM-12 were tested to accomplish Koch's postulates. Young branches of muskmelons (cultivar Yugu, 10 days after pollination) were chosen as the material for inoculation. Ten healthy detached branches were placed in 15 ml tubes by submerging the cutting wound in 5 ml of the bacterial suspension (108 CFU/ml). Ten additional branches were implemented with sterilized distilled water as a negative control. The inoculated branches were placed in a plastic box containing moistened paper at 28°C. Rotting symptoms appeared within 5 days after infection, while the control samples remained healthy. Bacteria were re-isolated from diseased tissues, and the 16S rRNA gene sequences of the isolates showed the same as those from the original pathogen. Panicle blight and grain discoloration disease caused by P. oryzihabitans on rice has been described in China (Hou et al. 2020). It's also recently found that P. oryzihabitans caused center blackening disease on muskmelon fruit in Korea (Choi et al. 2019). This study indicated that it was a causative agent of stem and leaf rot disease during the field growth period. To the best of our knowledge, this is the first report of P. oryzihabitans causing muskmelon stem rot in China.

Yield, fruit quality, and survival of 'Pêra' sweet orange on eight rootstocks in tropical cohesive soils

Abstract: The objective of this work was to determine the influence of eight rootstocks on the yield, fruit quality, and survival of 'Pêra CNPMF D6' sweet orange (Citrus sinensis) trees grown under rainfed conditions in a cohesive soil of the Brazilian Northeast. In 2014-2018, the yield, fruits, and survival of trees planted in 1997 were evaluated in a randomized complete block design. Yield was assessed using annual fruit production, yield efficiency, and the alternate bearing index. Tree survival was considered the percentage of plants that remained alive until 2018. Fruit quality was evaluated by physicochemical attributes. 'Cravo' confirmed its good yield performance. Despite the lower number of trees, the 'Mazoe' rough lemon rootstock induced the highest fruit yield. The 'Cravo' x 'Cleópatra' hybrid and 'Volkameriano' lemon favored the highest trees survival, whereas 'Indio' citrandarin and 'Cravo' lime resulted in intermediate levels. The 'San Diego' and 'Riverside' citrandarins induced shorter tree with a high yield efficiency and a higher alternate bearing index, respectively. Fruits with less juice and mass were induced, respectively, by 'Riverside' citrandarin and 'Volkameriano' lemon. It can be concluded that the 'Mazoe' rootstock induces a higher fruit yield and 'Cravo' x 'Cleópatra' and 'Volkameriano', a greater survival. In addition, all rootstocks, except 'Riverside' and 'Volkameriano', induce fruit that meet the minimum quality requirements.

Organic Amendments for Pathogen and Nematode Control.

The loss of methyl bromide as a soil fumigant and minimal advances in the development and registration of new chemical fumigants has resulted in a resurgence of interest in the application of organic amendments (OAs) for soilborne plant pathogen and plant-parasitic nematode management. Significant progress has been made in the characterization of OAs, application of strategies for their use, and elucidation of mechanisms by which they suppress soilborne pests. Nonetheless, their utility is limited by the variability of disease control, expense, and the logistics of introducing them into crop production systems. Recent advances in molecular techniques have led to significant progress in the elucidation of the role of bacteria and fungi and their metabolic products on disease suppression with the addition of OAs. Biosolarization and anaerobic soil disinfestation, developed to manipulate systems and favor beneficial microorganisms to maximize their impact on plant pathogens, are built on a strong historical research foundation in OAs and the physical, chemical, and biological characteristics of disease-suppressive soils. This review focuses on recent applications of OAs and their potential for the management of soilborne plant pathogens and plant-parasitic nematodes, with emphasis primarily on annual fruit and vegetable production systems.

Production and morphological traits of Lophira lanceolata fruits in natural stands

ABSTRACT Lophira lanceolata is an important indigenous oil tree species with high socio-economic potential in Africa. This study aimed to assess the fruit production of the species, the impact of infestation on production, and the variability of fruit morphological traits. Thirty mature trees were sampled from each of the two sites in western Burkina Faso. For each tree, all the fruits were collected, counted, dried, and weighed. One hundred fruits were randomly sampled per tree to estimate the infestation rate. 300 fruits collected on 30 trees were sampled to measure their morphological traits. Analysis of variance and regression analyses were performed to test for relationships between fruit production and stem diameter of trees. Results showed that the mean annual fruit production per tree varied significantly among diameter classes, from 0.47 to 8.01 kg dry mass. The infestation rate varied between 3% and 18% of the total fruit production. The prediction model showed a great predictive ability for fruit production (pR2 = 62%) with stem diameter and crown area of trees as explanatory variables. Three shape-groups of fruits were distinguished: spindle-shape (30%), orbicular-shape (19%), and elliptic-shape (51%). Lophira lanceolata has a high fruit production potential with spindle-shaped fruits as the most interesting for exploitation.

Consumption of Euterpe edulis fruit by wildlife: implications for conservation and management of the Southern Brazilian Atlantic Forest.

This study aimed to measure the wildlife consumption of Euterpe edulis fruit and use this data to discuss management possibilities. To estimate infructescence fruit volume consumed, collectors were installed in fruit-bearing palms. To characterize consumption from the ground, samples were placed next to fruiting palms. To identify wildlife and their activities, camera traps were installed in infructescences and on the ground. The results suggested that there was a small fruit surplus (1.8 %), and this finding indicated the possibility of a harvest to reduce food for the wildlife. However, recurrent variations in the annual fruit production (21.4 %) were also noted, and suggested that wildlife could tolerate some fruit harvesting. Thus, a harvest could be restricted to fruit volume that exceeds the annual average (94 kg/ha/year). Turdus flavipes, a migratory bird, was the most active species in the dispersal of seeds; this finding indicates the need for broader conservation strategies. Wildlife composition also changed along with the fruiting, and this alteration suggests that dependence on the fruit is variable among different species. Seed germination and seedling mortality were high, results that indicate that local conditions may have a predominant effect on seed volume in natural regeneration density.

Variability and estimating in fruiting of shea tree (Vitellaria paradoxa C.F. Gaertn) associated to climatic conditions in West Africa: implications for sustainable management and development

ABSTRACT Shea tree (Vitellaria paradoxa) is one of the main native oil plants with high economic value in Africa. Its fruits are used for food, medicinal, cultural and exportation purposes. However, the lack of efficient tools to assess annual fruit production of the species limits the sustainable management of its resources. Therefore, production statistics are useful to organize the activities of the shea sector. This study aimed to (i) assess the interannual variation in fruit production along a climatic gradient in Burkina Faso, (ii) examine fruit production patterns according to climatic zones and tree size, (iii) assess the contribution of high-yielding trees in the annual potential production and (iv) develop allometric equations for estimating fruit yields of the species. The yield of 212 trees distributed across three climatic zones was monitored over four successive years. Within each climatic zone, fruit production was significantly different among years. Fruit production was positively and significantly correlated with tree size. The interannual variation in fruit production at tree individual level was higher in drier climatic conditions. The mean interindividual synchrony was less than 50% in each zone, suggesting a large range in fruit production patterns of the species. Annually, more than 55% of the total fruit production was supported by high-yielding trees. The best regression models for estimating fruit yields had R 2 values of 69–73% with prediction errors ranging from −7% to 4%. Our findings are useful tools for the planning of rational exploitation of shea tree’s resources and its sustainable management.

Brazilian fruit processing, wastes as a source of lipase and other biotechnological products: a review.

The global food loss and waste is the most urgent research area in food science to attend the current demand for more sustainable and profitable processes. Along the productive chain about 1/3 of the food is lost or wasted, this number reaches 1/2 for fruit and vegetable production in developing countries. Brazil has been investing in researches aiming to turn its wastes into byproducts, as biomolecules of high value such as lipases. These enzymes are found in a high diversity of plant sources and their researches are covered by promising market growth expectations due to the current demand for biofuels and bio-transformed food. Thus, the aim of the present study is to discuss the potential of wastes generated by the Brazilian fruit processing to become a source of lipases, by the analysis of the most recent studies on fruit lipases, as well as the inclusion of this process in the biorefinery concept. According to this concept, different products can be obtained from the same raw material. Considering the confirmation of the presence of lipases on fruit wastes, the annual fruit production and the percentage of residues, the assessed data showed that wastes from the processing of orange, mango, papaya and palmare promising for lipase obtainment.

EFFECT OF FIRE ON FLOWERING AND FRUITING OF ANACARDIUM HUMILE (ANACARDIACEAE) IN CERRADO STRICTO SENSU

ABSTRACT Knowledge about the effects of fire on sexual reproduction of Cerrado woody species is fundamental for elaborating public policies and management plans for its conservation. The present study evaluated the effect of a controlled burning on flowering and fruiting of Anacardium humile in an Cerrado stricto sensu environment, in Cavalcante, GO. An area with no fire records for five years was submitted to controlled burning in May 2016, used as the experimental area and its adjacent areas protected from fire as control area. In each area, 16 reproductive individuals were selected and their production of floral buds, flowers and fruits, followed up for 17 months. In 2016 the production of reproductive structures was higher in the control area, since the majority of individuals of the burned area invested in the recovery of vegetative structures (branches) damaged by fire. Only three individuals flowered in the burned area in 2016 and presented greater effort in the production of buds and flowers per panicle than the individuals in the control area, however, the fruit set was equal between the areas. One year after fire, the production of reproductive structures became equal between areas. The control area presented higher fruit production in 2017 in comparison to 2016, indicating a variable pattern in annual fruit production. The impact of fire on the reproductive structures of A. humile is greater in the same year of fire and its reproductive potential can be normalized in the subsequent year.

Cornelian cherry (Cornus masL.) fruit as a non-timber forest product of Arasbaran biosphere reserve forests in Northwest of Iran

AbstractThe present research aimed to quantitatively and economically evaluate Cornelian cherry (Cornus masL.) fruit as a non-timber forest product for a resident rural community across three consecutive years. A forest stand of 50 hectares in Kalaleh village, Northwest of Iran (Arasbaran biosphere reserve), was selected. After estimating the number of stems per hectare, the rate of fruit production rate was determined. Forty five individuals were then selected and assessed for their vegetative characteristics, including total height (m), crown height (m), crown diameter (m), diameter at breast height (mm), number of coppice shoots and annual fruit production (kg). Relationships between the vegetative characteristics and fruit production were then determined using multiple regression analysis to estimate the total fruit production per ha (estimated number of stems per hectare x mean fruit production per stem). Questionnaires and interviews were conducted to determine the number of stakeholders, quantity of fruit harvested and their harvesting methods; in addition to the costs and revenues of the harvest. Our results indicated that in 2012, 2013 and 2014, the annual total fruit production and local harvesting rates were: (i) 17 500, 10 705 and 8 169 kg and (ii) 4 900, 6 540 and 6 700 kg respectively. The revenue from selling the fruit contributed from 3.6% to 7.3% to household livelihoods. Mean economic rent of Cornelian cherry utilization and the average expected value of the forest were US$ 52.9 and US$ 17.6 respectively, while the average marketing margin of utilization was 65.5%. We believe that the inflated harvest rate recorded in 2014, which was above the allowable quota, might be a crucial threat to viability and also the sustainability of the forest stand. In conclusion, launching and implementing non-timber forest products projects including tree domestication is required to help conserving biodiversity in one hand and to sustainably manage natural resources in the other hand.

Response of Perlka (Calcium cynamide) on Plant Growth and Production of Kinnow Mandarin(C.nobilis XC.deliciosa)in Sub Montane Low Hill Zone of Himachal Pradesh

Perlka, a multifunctional fertilizer was tested in kinnow mandarin as a soil application at four different doses, 500 g, 1000 g, 1500 g and 2000 g per tree and its effect on plant growth and production was compared against the soil application of CAN (800 g and 1600 g/tree). Perlka and CAN were applied during the month of February & May in two equal splits. Effect of Perlka application on annual shoot extension, fruit production and fruit quality was recorded. Annual shoot extension in kinnow mandarin was observed significantly more with the Perlka treatment 1000 g per tree when compared to other Perlka treatment (500 g, 1500 g and 2000 g) and as well as the CAN application. Significant improvement in response to soil application of Perlka (1000 g) when compared to other Perlka treatments including the application of CAN was observed for fruit size, fruit weight and fruit volume. Biochemical analysis of fruits showed variable results for total soluble content of kinnow fruits in response to different treatment. Maximum TSS (10.3° B) was observed with the treatment of 800 g CAN and 2000 g Perlka individually. Maximum fruit yield (32.18 Kg) per tree was obtained with 1000 g Perlka application followed by 1600 g CAN. Perlka application at 1000 g per tree resulted in significant improvement in annual shoot growth and tree health particularly by exhibiting resistance against collar rot and root rot fungi caused by Phtopthora citrophora, Phtopthora nicotiane in all of the trees receiving perlka in comparison to CAN treatments, fruit yield and other fruit quality parameters of the fruits in kinnow mandarin. The highest BC ratio of 3.5 was obtained in trees of kinnow mandarin treated with 1000g of perlka per tree.

Size-based fruit selection by a keystone avian frugivore and effects on seed viability

ABSTRACTThe non-random selection of fruits by frugivores can affect plant demography by changing the probability of seedling recruitment. We investigated whether the New Zealand pigeon (Hemiphaga novaeseelandiae) exhibits size-based preference of fruit in two indigenous tree species, Vitex lucens and Prumnopitys ferruginea, that have large fleshy diaspores containing single seeds. We also assessed if there was an advantage for seeds that were actively dispersed since birds may select fruits that have viable seeds (although the cue for such selection remains unclear) and whether a combined scarification–deinhibition advantage was conferred on germination due to seed passage through the gut. Using seed length as a proxy for fruit size, we compared the length of passively dispersed fruits in traps with the estimated fruit length of actively dispersed seeds in six trees of each species across three areas in one fruiting season. For both species, actively dispersed seeds were significantly longer than seeds from passively dispersed fruit, suggesting frugivore preference for larger fruit. Seeds from passively dispersed P. ferruginea fruit had significantly higher viability than actively dispersed seeds and there was no measurable scarification–deinhibition effect. For V. lucens, there was no significant difference in viability between actively and passively dispersed seeds and there was a total lack of seed germination in our trial. Our results show a significant preference by H. novaeseelandiae for larger fruit in both tree species, which was possibly associated with annual fruit production since P. ferruginea trees that had more fruit produced larger fruit on average. That H. novaeseelandiae selected longer fruit in our study is consistent with the prediction that birds will prefer larger fruit when beak gape limitation is absent. However, active dispersal of larger seeds may not always be advantageous since passively dispersed intact fruit germinated equally well and may even have had a viability advantage.

Muster und treibende Kräfte der Samenproduktion bei Waldbäumen

Patterns and driving forces for seed production in forest tree species Why is the annual fruit production in forest tree species not constant, and which factors cause massive fruit production (seed mast year)? These and other related questions were already posed more than 100 years ago when tree breeding was economically beneficial. The questions have not been fully answered, yet. Rather, the same questions are studied again today as the climate is changing and the uncertainty about the continuation of forests at their current locations is growing. A 25 year long observation series on the variation of fruit production in Switzerland revealed a mean frequency of three years for mast seeding (full and medium mast) at low elevation on the Central Plateau in European beech (Fagus sylvatica), oak (Quercus petraea, Q. robur) and silver fir (Abies alba). In contrast, mast seed years of Norway spruce (Picea abies) occurred, on average, every sixth year. In 1992 and 2011, all four species synchronously showed mast seeding. The results are discussed in the light of different theories and new research findings. From the state of the current know ledge, we derive the need for long-term and fine-scale baseline data and present the new reporting and information webpage «mast web.ch». Here, volunteers can report observations on the fruit production of main tree species following a few simple criteria (citizen science approach). With this data, distribution maps on mass fructification levels will be made available and will serve for spatio-temporal fine-scale studies on mast seeding phenomena.

Use of columnar cacti in the Tehuacán Valley, Mexico: perspectives for sustainable management of non-timber forest products.

BackgroundTEK, ecological and economic aspects of columnar cacti were studied in the Tehuacán Valley, Mexico to design sustainable regimes of fruit harvest. We analysed the amounts of edible fruit, seeds and flowers produced per hectare of cardonal, jiotillal and tetechera forests, their economic value and actual extraction rates, hypothesizing that the economic benefits of these NTFP would potentially be comparable to maize agriculture, which involves forest removal.MethodsOur study comprised the whole territory of the community of Quiotepec, Oaxaca. Sustainable gathering rates were analysed through population dynamics models and simulations of harvesting regimes (10%, 25%, and 50% of fruit gathered) per hectare of forest type. We used estimations on economic benefit and ecological impact of these scenarios to evaluate their relative sustainability, compared with maize agroforestry systems harbouring 2-47% of vegetation cover.ResultsFor the whole territory, the total annual fruit production is 509.3 ton of Pachycereus weberi, 267.4 ton of Neobuxbaumia tetetzo, 99.5 ton of Escontria chiotilla, and 8.1 ton of Myrtillocactus geometrizans. The total economic value of fruits per hectare was $315.00 U.S. dollars for cardonal, $244.60 for jiotillal, and $113.80 for tetechera, whereas rainfed agriculture of maize was on average $945.52. Demographic models for E. chiotilla and N. tetetzo indicate that 70% and 95% of fruit harvesting, respectively maintain λ > 1, but these harvest rates cannot be recommendable since the models do not consider the high inter-annual environmental variations and the non-estimated amount of fruit consumed by natural frugivorous. Extracting 25% of fruit is ecologically more sustainable, but with low economic benefits. Agroforestry systems maintaining the higher vegetation cover provide economic benefits from agriculture and forest resources.ConclusionsCombining forest extraction and agroforestry systems are ideal scenarios to sustainable fruit harvest programmes. In addition, fair commerce of transformed products would substantially favour goals of sustainable management.

Masting in a temperate tree: Evidence for environmental prediction?

AbstractMany plant species produce large fruit crops in some years and then produce few or no fruits in others. Synchronous, inter‐annual variation in plant reproduction is known as ‘masting’ and its adaptive significance has yet to be fully resolved. For 8 consecutive years, I quantified every fruit produced by 22 females of a New Zealand tree species (Dysoxylum spectabile), which has an unusual habit of taking a full calendar year to mature fruits after flowering. Fruit production varied strongly among years and was tightly synchronized among trees. Annual variability in fruit production declined with total reproductive output, indicating trees with lower fecundity exhibited a stronger tendency to mast. Although unrelated to temperature, annual fruit production was positively related to precipitation during annual periods of fruit development, and negatively related to fruit production in the previous year. Seedlings had higher rates of survivorship in a wet, high‐seed year than in a dry, low‐seed year, suggesting that seedlings might be drought sensitive. Therefore, D. spectabile produced large fruit crops during periods of high rainfall prior to fruit maturation, which may enhance survivorship of drought‐intolerant seeds. Results were inconsistent with several hypotheses that are widely believed to be the most likely explanations for masting. Instead, results were consistent with the environmental prediction hypothesis, suggesting that this hypothesis may be more important than previously appreciated.

Reproductive potential and seed fate of Sclerocarya birrea subsp. caffra (marula) in the low altitude savannas of South Africa

Even though Sclerocarya birrea subsp. caffra (marula) is a well-studied, keystone tree species with high ecological, commercial and cultural value, significant gaps in our understanding of its reproductive biology exist, particularly the factors limiting fruit and seed production, seed fate and the persistence of the seed bank. Therefore, a detailed quantitative assessment of these factors was conducted at five sites in the low altitude savannas of South Africa. Sites varied with respect to fire regime, large mammals, geology and rainfall. Most sites showed male-biased secondary sex ratios and the minimum fruiting stem diameter ranged between 7.1 and 15.7 cm across sites. Sites with higher levels of disturbance (fire and large browsers) had trees producing fruit at larger minimum stem diameters than sites with lower levels of disturbance. Fruit production was highly variable between individuals, within and between sites, and from year to year. Variability in fruit production across years at one site was greater than the variability across sites in one year, indicating that drivers such as weather, insect herbivory, fire and predator numbers, which vary annually, play a greater role than more constant drivers such as mammalian herbivory, soil types or long-term rainfall. No significant relationship was found between environmental variables (rainfall and temperature) and annual fruit production, indicating a trade-off between vegetative growth and reproduction between years. Since marula fruits are large and heavy, the species relies primarily on mammalian dispersal agents such as the African elephant, which have also been shown to increase the germination rate. However, rodents also appear to play a significant role in seed dispersal. Seed predation rates tend to be highest in areas of low disturbance (no fire and no large browsers). While marula has a small persistent seed bank, recruitment appears to be reliant on the current season's fruit crop. This study provides a detailed quantitative assessment of important reproductive and seed fate vital rates for future population modelling.