Early growth performance and water use of planted West African provenances of Vitellaria paradoxa C.F. Gaertn (karité) in Gonsé, Burkina Faso

A participatory selection trial of five provenances from Burkina Faso (3), Mali (1) and Senegal (1) was established in Burkina Faso in 1997 with the aim of addressing issues of the long juvenile phase and the large variability in annual fruit yields of Vitellaria paradoxa C.F. Gaertn in West Africa. The objectives of the present study were to evaluate survival rate and the growth performance of the five provenances, characterize the wetting profile under which the trees of these provenances are growing and quantify the variation in their seasonal transpiration. The design was a randomized complete block design (RCBD) with single tree as the experimental unit which was replicated 70 times. The results showed a mean survival rate of 50% for all provenances. Passoré (Burkina Faso), Djonon-Karaba (Mali) and Botou-Fada (Burkina Faso) provenances showed the highest height and collar diameter whereas the provenance of Gonsé (Burkina Faso) performed poorly. Djonon-Karaba provenance displayed the highest water use (2.70 l day⁻¹ tree⁻¹ in 2004 and 2.85 l day⁻¹ tree⁻¹ in 2005). Soil water content under Passoré provenance was the lowest (9.38%) whereas its content under Gonsé provenance (11%) was the highest with no clear pattern according to the distance from tree trunk. Samecouta and Djonon-Karaba provenances showed the highest transpiration values per sapwood unit area in 2004 (0.079 l cm⁻² day⁻¹) and in 2005 (0.069 l m⁻² day⁻¹), respectively. Based on growth performance and water use, it can be recommended at this early stage the selection of Djonon-Karaba and Passoré provenances as the most suitable for semi-arid regions of West Africa. However, there is a need for further data to model the long term effects of these provenances on soil water balance and their fruit production before reliable recommendations can be made to farmers.     

Provenance variation in growth and wood properties of juvenile Cyclocarya paliurus

Cyclocarya paliurus is a highly valued and multiple function tree species. There has been increasing interest in planting and managing C. paliurus for timber production and medical use owing to loss of harvestable acreage. Seed from six provenances was collected from the main natural range of this species. Significant variation in growth and wood properties was measured among the six provenances at age 7 years. Provenance mean height and DBH varied significantly from 730–991 and 6.7–10.0 cm, whereas provenance means of wood basic density and crystallinity ranged from 463–554 kg m^?3 and 51.4–74.1 %, respectively. Mean provenance microfibril angle (MFA) at breast height ranged from 18.1° to 23.2°, while MFA at breast height varied from 11.0° to 34.5° among growth rings which showed a consistent pith-to-bark trend of declining angles. There was no significant relationship of growth rate with latitude or longitude of seed sources, however, provenances from low latitude and longitude grew faster at the trial site. Wood quality was significantly related to latitude of seed sources, showing a positive correlation for both wood basic density and wood crystallinity, but a highly negative association with MFA. Significant correlations between wood properties measured indicated that there exists a great opportunity to improve wood quality of C. paliurus through selection of juvenile trees with low MFA.     

Soil amelioration and root symbioses ofParkia biglobosa (Jacq.) Benth. in West Africa

Parkia biglobosa is an important multipurpose tree from the savanna zone of West Africa. It has been reported to increase soil fertility and crop yields beneath its crown. However, no work has been conducted to determine the role of root symbioses in soil amelioration by this species. The existing reports of nodulation inParkia biglobosa are contradictory and the presence of mycorrhizae is not documented in the literature.Fieldwork was conducted at six sites in Burkina Faso and Nigeria, to investigate the amelioratory effect ofParkia biglobosa on soil fertility and to ascertain the occurence of root symbioses. Soil samples were collected from points close to the trunk, the mid-crown, crown edge and the open areas away from individual trees. The samples were analysed chemically to assess pH, organic matter, nitrogen, phosphorus and potassium content. Root samples were also collected from the field and examined for nodules and for evidence of mycorrhizal infection.The results of the soil analysis showed a significant amelioration for total nitrogen and available potassium with proximity to the tree, but organic matter, available phosphorus and soil pH showed no significant trend. This pattern was similar for all sites. The results also indicated that amelioration of nitrogen and potassium with proximity to the tree increased with tree size.Root nodules were absent from the roots of trees examined in the field, both in Burkina Faso and Nigeria. A pot experiment was set up using the soil collected from beneath the trees and a laboratory grown cowpea miscellany culture as rhizobial inoculum forParkia biglobosa seedlings. The roots of these seedlings also showed no evidence of nodulation. Ectomycorrhizae were not present in roots collected from the field, but endomycorrhizal infection was prolific.A study of root distribution in Burkina Faso suggested that one mechanism for increased soil fertility beneathParkia biglobosa is the widespread lateral root system, which redistributes nutrients from an extensive radius to a concentrated area beneath the crown. The root system is aided in the efficient uptake of nutrients by endomycorrhizae. Other possible mechanisms include interception of dust by the crown and deposition by throughfall and stemflow, defacation by animals beneath the tree and decomposition of leaf litter.     

Inter- and intra-provenances variations in seed size and seedling characteristics of Khaya senegalensis A. Juss in Burkina Faso

Within- and between-provenance variations in seed and seedling traits of Khaya senegalensis A. Juss were studied at INERA in Burkina Faso. Nursery grown seedlings from four provenances in Burkina Faso were used for the study. The studies revealed significant variability in all traits evaluated. Seed length and weight significantly varied among provenances and families within provenances, where Bopiel and Koyenga had the highest mean values. Height and root collar diameter of 1 year old seedlings significantly varied among families within provenances. Except leaf biomass ratio and carbon isotope ratio which varied significantly among provenances but not among families within provenances, all other seedling biomass traits—total plant biomass, stem biomass ratio, leaf biomass ratio, root biomass ratio, root shoot ratio, specific leaf area, and leaf area ratio were significantly affected by provenances and families within provenances. The magnitude of variation due to family effect ranged from 65 to 93 % for seed size traits, and from 4.5 to 17.8 % for seedling characters. Estimates of family heritability were moderate to high (0.67–0.95) for seed traits, but low to moderate (0.19–0.59) for seedling characters, indicating that much of the total variation in seed traits is due to the genetic effect. The two most prominent provenances, Koyenga and Bopiel, with higher seed size and greater seedling growth could be considered for an eventual K. senegalensis improvement program in Burkina Faso.     

Variation in spring and autumn frost tolerance among provenances of Russian larches (Larix Mill.)

Abstract

Spring and autumn frost tolerance was measured using material from a range-wide (50–67° N, 38–158° E) provenance trial of four Russian larch species (Larix sukaczewii Dyl., L. sibirica Ledeb., L. gmelinii Rupr. and L. cajanderi Mayr.) growing in northern Sweden. Shoots were collected in early May and late September and frozen at ?8, ?12, ?16 and ?20°C. Cambial damage was assessed visually after development under ideal conditions for 2 weeks. Differences in frost damage among provenances were highly significant in both spring and autumn. Autumn frost damage was significantly correlated with provenance latitude and longitude and spring frost damage was significantly correlated with provenance longitude but not latitude. Frost damage was not correlated with provenance elevation. North-western provenances showed the least damage and far-eastern provenances the greatest damage in both spring and autumn. A possible explanation for less spring frost damage to north-western provenances is adaptation to maritime conditions in proximity to the Barents Sea, which is often ice free in late winter. This would counteract early loss of frost tolerance and bud flushing if warm spells occurred in late winter. North-eastern Siberian provenances did not show similar adaptation and may exhibit increased spring frost damage if global warming eventually results in the Arctic Ocean north of Siberia becoming ice free in late winter.     

Testing the shade tolerance of selected crops under Parkia biglobosa (Jacq.) Benth. in an agroforestry parkland in Burkina Faso, West Africa

In Western Africa, interactions between trees and agricultural crops are a key element in determining parkland management in an agricultural environment that is rapidly changing. Eggplant (Solanum melongena), chilli pepper (Capsicum annuum), taro (Colocasia esculenta) and pearl millet (Pennisetum glaucum) were tested for their shade tolerance under Parkia biglobosa trees in south-central Burkina Faso using a split-plot design. Soil characteristics, chlorophyll fluorescence and crop growth and yield were measured to quantify the effect of P. biglobosa on the crops and their environment. The experiment ran during 2?years. P. biglobosa suppressed the vegetative growth and yield of pearl millet in both years. Eggplant and chilli pepper were severely injured by the rains and produced fruits only during the first year. Eggplant yields were suppressed by trees to between one third and one tenth of the yield in the control plots. However, chilli pepper yields increased by up to 150% when grown under the tree canopy compared to the control. In both years, the vegetative growth and yield of taro was higher when grown in the shade than outside the tree canopy.     

云杉种和种源生长性状早期评价

[目的]通过对引种的云杉种和种源试验林的适应性和生长变异研究,选育出最适合当地栽培的优良种和种源。[方法]以甘肃省小陇山沙坝试验基地引种的欧洲云杉、黑云杉、白云杉、蓝云杉、红皮云杉和青海云杉6个树种20个种源为研究对象,分别对6、7、9 a幼林龄的生长性状(树高、地径、新梢和冠幅)进行方差分析和相关性分析,以早期评价云杉种和种源。[结果]6、7、9 a生长期内不同云杉种间和种源间的差异多数达到极显著,表明不同种间和种源间存在较大的遗传变异。利用树高兼地径为主要指标筛选出7个优良种源,分别为欧洲云杉加拿大AB01、AB03种源、白云杉加拿大GL01种源;黑云杉加拿大MA05、MA07、MA08和MA10种源,树高、地径现实增益均超过11%。欧洲云杉、白云杉种源树高与经纬度呈极显著的正相关,与海拔呈极显著的负相关;黑云杉种源树高也与经纬度呈极显著的正相关,但与海拔相关不显著。[结论]在原产地纬度49°16'～58°38'N,经度68°13'～118°24'W区域范围内引进欧洲云杉、白云杉、黑云杉种源,是适宜在甘肃小陇山栽培的云杉树种。     

Variability of Baobab (Adansonia digitata L.) fruits’ physical characteristics and nutrient content in the West African Sahel

The present study was carried out to evaluate variability in fruit characteristics and nutritional quality of Baobab fruits with the aim of providing the background to select trees bearing fruit with desirable characteristics for further utilisation. Vitamin C, total sugar and ash contents were assessed in 178 Baobab fruit samples from 11 sites in Burkina Faso, Mali and Niger. Furthermore the following tree and fruit physical characteristics were recorded: tree height, bark colour, fruit size, pulp weight, seed weight, seed size and pulp colour. The content (mean?±?SD) of vitamin C was 4.78?±?1.02?g?kg^?1, sugar 514?±?72?g?kg^?1 and fruit weight 293?±?96?g. There was a significant correlation between annual precipitation of the tree population site and vitamin C content but not with sugar content. For sugar, there were significant positive correlations with latitude and longitude. Negative correlations were found between fruit size and both longitude and latitude with smaller fruits generally being found to the north/east. No relation was found between pulp or bark colour and the sugar or vitamin C content. The contents of protein, lipid, carbohydrates, ash and moisture in the seeds ranged from 156 to 159, 143 to 150, 641 to 652, 44 to 49 and 50 to 55.7?g?kg^?1 respectively. The variation for vitamin C and sugar found within populations is a first indication that valuable gains could be made by selection of superior trees.     

Variation in the date of budburst in <Emphasis Type="Italic">Quercus robur</Emphasis> and <Emphasis Type="Italic">Q. petraea</Emphasis> across a range of provenances grown in Southern England

The widely observed advance in spring budburst across a range of temperate forest species due to climatic warming has received considerable attention. This change in forest phenology has important implications for the choice of species and provenances currently being planted, which need to be suited to both current and future climatic conditions. Using a provenance trial in the south of England, this study assessed variation in the timing of budburst across 23 different European provenances of oak (Quercus robur L. and Q. petraea (Matt.) Liebl.) over 8 years of observations. The order in which the different provenances reached budburst was related to provenance source latitude: the southern provenances were always earlier than those from more northerly latitudes. The statistical technique partial least squares regression was used to identify critical periods of both chilling and warming. A General Linear Model and three-dimensional temperature response surfaces were used to analyse the temporal trends in budburst. There was a negative correlation between the date of budburst and mean daily air temperature in both the chilling and warming periods for all provenances, which was statistically significant for a majority. Spring warming had a larger effect on budburst than winter chilling with a mean spring temperature-driven advance of 3.61 days/°C (standard error = 0.17 days/°C) and mean winter period temperature-driven advance of 0.99 days/°C (standard error = 0.17 days/°C). Surprisingly, there was no statistically significant interaction between mean air temperatures during the chilling and warming phases on the date of budburst.     

Genetic variation in wood density and correlations with tree growth in Prosopis africana from Burkina Faso and Niger

? Variation in wood basic density and its correlation with tree growth were investigated at 13 years in a provenance/progeny test of Prosopis africana in Niger. The test included progeny from 256 trees sampled from 24 provenances in the Sahelian ecozone of Burkina Faso and Niger.

? Variation in wood density was significant due to provenances and families within provenances. Individual tree heritability was higher for wood density than for growth traits. Provenance means for wood density increased from the more humid to the drier parts of the sample region. Phenotypic correlations indicated that larger trees tended to have denser wood.

? Clines suggest that natural populations of P. africana from the drier parts of the sample region have the genetic capacity to produce denser wood, compared with populations from the more humid parts of the region. Correlations and heritability estimates suggest that selection of faster-growing trees may produce a small gain in wood volume but little (if any) gain in density in the subsequent generation. Multi-location provenance/tests are needed to confirm this tentative conclusion.

     

Variation in seed traits and seedling vigour of <Emphasis Type="Italic">Cordia africana</Emphasis> Lam. provenances in Ethiopia

Cordia africana is a very important indigenous tree species for timber and other products and services in Ethiopia. Seed traits and seedling vigour of seeds from 12 provenances of the species were compared. Mean seed mass for each provenance was assessed for 1000 seeds in 10 replications, and seed length and width were measured for 100 seeds in four replications per provenance. Germination was assessed in a glasshouse taking 400 seeds from each provenance. Root collar diameter and height of 440 seedlings grown in a nursery for 290 days in Addis Ababa were measured. Seed length, seed width, seed mass, and shoot height and root collar diameter of seedlings showed significant differences (P < 0.001) among provenances. Correlation analysis between seed and seedling traits and environmental variables revealed significant positive correlations between seed width and germination percentage, seed width and altitude, seed width and longitude and seed length and latitude. Negative correlations were obtained between seed width and temperature, seed width and rainfall, seed mass and temperature, and germination and temperature of the seed source. As expected, differences in seed trait did not explain the variability in seedling vigour. Determining quantitative variations in seed traits and seedling vigour among provenances and the patterns along environmental gradients are essential for informing decisions on the tree improvement programme of the species.     

Geographic variation and genetic performance of Picea koraiensis in growth and wood characteristics

Eight provenances of 19-year-oldPicea koraiensis Nakai from the provenance trials of Maoershan (45°20′N, 127°30′E), Liangshui (47°10′N, 128°53′E) and Jiagedaqi (50°24′N, 124°07′E) in Northeast China were investigated to analyze the genetic variation in growth characteristics (tree height and diameter) and wood characteristics (tracheid length, tracheid diameter, tracheid wall thickness, annual ring width as well as wood density). Great variation in height growth and breast height diameter growth was observed among the provenances, and along with the increase of tree age, these provenances presented different geographic adaptability. The growth characteristics ofPicea koraiensis stand at age of 10 in Maoershan and Liangshui provenance trials had a positive correlation with longitude, and with increase of tree age to 15 and 19, the tree growth of the provenances displayed a significant positive correlation with latitude as well as altitude. For wood characteristics, great variation was also found among the provenances. There exists a close relation between growth characteristics and wood properties of the provenance. The height and breast height diameter growth of the provenance had a positive correlation with tracheid diameter and annual ring width, and a negative correlation with tracheid wall thickness and wood density. Genetic performance of the provenance in all above characteristics was also investigated in order to provide more useful information for comprehensive selection of this species for pulpwood and plywood production. Foundation item: The paper was supported by National Key Project of The State Forestry Administration. (96-011-01-06) Biography: WANG Qiu-yu (1957-), female, professor in College of Life Sciences, Northeast Forestry University, Harbin 150040, P. R. China. Responsible editor: Song Funan     

Growth and survival of Prosopis africana provenances tested in Niger and related to rainfall gradients in the West African Sahel

Prosopis africana (Guill., Perrott. and Rich.) Taub. is important for farming and pastoralist communities in the West African Sahel. It provides a range of essential products (wood, fuel, food, fodder and medicines) and services (soil fertility improvement), and is one of many native tree species maintained in the traditional agroforesty system, known as the parkland. However, this and other valuable species are disappearing in many parts of the region due to over-exploitation and, perhaps, due to increasingly drier conditions in the region. A provenance/progeny test (275 families from 28 provenances in Burkina Faso and Niger) was established at one location in Niger to investigate geographic variation in the species. Mean annual rainfall decreases from south to north and from west to east in the seed collection area. Given these gradients, one would expect clinal variation in growth and survival of P. africana and other tree species that occur naturally in the region. Tree growth (height, number of primary branches, stem diameter at 20 cm and 1.3 m) and survival were analyzed at 11 years. Variation due to provenances was significant for growth variables and almost significant for survival. Variation due to families within provenances was not significant for any variable. Provenance means for growth and survival increased from the more humid to the drier parts of the sample region. The clines in growth and survival with regional rainfall patterns suggest that tree improvement and conservation programs should collect seeds from populations in the drier zones for planting and conservation in the West African Sahel. This may be particularly important when one considers the trend in global warming.     

林芝云杉不同地理种源苗期性状变异

正林芝云杉(Picea likiangensis var.linzhiensis Cheng et L.K.Fu)是松科(Pinaceae)云杉属(Picea Dietr.)常绿高大乔木,为西藏高原亚高山暗针叶林主要、特有的建群树种之一[1-2]。主要分布在西藏东南的林芝、米林、波密等地,并向西分布至朗县、错那、洛扎、隆子、工布江达。林芝云杉是云杉属中木材品质系数最高的树种[3],生长迅速,寿命持久,在水热条件优越的地区能长成罕见的巨树,胸径可达2.5 m,最大树高可达73 m,单株立木材积达到50     

Advances in domestication of indigenous fruit trees in the West African Sahel

Fruit trees play an important nutritional role for livelihoods of rural people in the West African Sahel through provision of energy and nutrients such as vitamins, minerals, and proteins. Research on the domestication of local fruit trees has started recently through projects concentrating on some of the most important indigenous species of dry West Africa, i.e. Adansonia digitata, Parkia biglobosa, Tamarindus indica, Vitellaria paradoxa and Ziziphus mauritiana. We present a status of finalised and ongoing domestication research with the aim of defining research gaps that would need to be covered by future research activities to obtain higher yields and better quality fruits. Germplasm collection in central West Africa has been intense compared to elsewhere in the species?? distribution areas, but conservation status of the material is poor since it is only planted in few trials. Knowledge of genetic parameters, especially for fruit traits, is almost absent, but characterisation of genotypes is underway for some of the species. Mating systems and patterns are still unknown for many species. Efficient vegetative propagation based on simple techniques was shown to be possible for all species except P. biglobosa. In order to secure immediate as well as long term gains, we recommend combining clonal propagation of selected plus individuals with recombination and breeding of selected genotypes. We discuss whether local institutions in the Sahel have the financial capacity to carry out long term breeding programmes, and suggest that efforts should be made to find new ways of disseminating improved germplasm.     

Germplasm collections of endangered agroforestry tree species: the case of Prosopis africana in the semi-arid lowlands of West Africa

The International Centre for Research in Agroforestry (ICRAF) coordinates a research network in the Semi-arid Lowlands of West Africa (SALWA) in four countries: Burkina Faso, Niger, Mali and Senegal. Prosopis africana, an important agroforestry tree species is seriously threatened in this eco-region. ICRAF organized seed collections of this species for long-term conservation and subsequent utilization by small-scale farmers in the West African Sahel. Prior to the collection, ICRAF, the International Plant Genetic Resources Institute (IPGRI) and International Crops Research Institute for the Semi-Arid Tropics (ICRISAT) organized a planning workshop with collaborating national research institutes. Out of this workshop came a consensus on the strategy, logistics and choice of collection sites. To collect as much genetic diversity of P. africana in the SALWA region as possible, 34 collection sites were selected: 15 in Niger, eight in Mali, seven in Burkina Faso and four in Senegal. The main aim of the collection was to capture the genetic diversity within P. africana before the valuable genetic resources are lost. This paper reviews the methodology and results of the germplasm collection. This revised version was published online in August 2006 with corrections to the Cover Date.     

巨桉种源早期生长对比及综合评价

对7个巨桉(Eucalyptus grandis)种源4a生时的生长性状进行测定分析,利用主成分分析结合模糊聚类法对各种源进行综合评价.结果显示:(1)7个种源间存在分化和差异,其中15508号种源平均树高及单株材积最大,分别为10.48 m、0.022 8 m3;13019号种源平均胸径和保存率表现最优,为8.09 cm和79％;种源16500号干形生长表现最优.(2)树高、胸径与单株材积三者与干形、保存率及海拔间均存在负相关;保存率与南纬、东经呈现显著正相关(P＜0.05),与海拔呈现负相关;干形与南纬、东经呈现负相关,与海拔间呈正相关.(3)基于主成分分析确定巨桉种源树高、胸径、单株材积、干形及保存率指标所占权重分别为:0.267 5,0.262 9,0.266 8,0.163 5和0.039 3.(4)根据综合评分及模糊聚类,第Ⅰ类种源(种源13019、15508、15875和16500)生长表现最优,适宜在引种地种植,其余种源可通过进一步测定选择优良个体作为世代育种材料.     

Different reactions of central and marginal provenances of Fagus sylvatica to experimental drought

Climate extremes are expected to increase in frequency and magnitude as a consequence of global warming, threatening the functioning, services and goods of forest ecosystems. Across Europe, the ecologically and economically important tree species Fagus sylvatica is expected to suffer particularly under such conditions. The regional introduction of provenances from drier and warmer climates is one option to adapt beech forest ecosystems to these adverse effects of climate change. Marginal populations from the drought-prone southern and north-eastern edges of the species’ distribution come into focus in search of suitable candidates for Central European deciduous forests. Here, we test three marginal provenances (Spain, Bulgaria and Poland) and three provenances from the centre of the distribution range (Germany) for their response to drought in two different soil types (sand, loam) in a full factorial common garden experiment in Landau, Germany. Drought impacted all growth parameters negatively (leaf damage +22 % (percentage points), height ?40 % and diameter increment ?41 %), and the sandy substrate exacerbated this effect. However, provenances differed in their response to drought and soil type. Evidence for a local adaptation to summer drought was detected, especially in terms of mortality rates. The Bulgarian and Spanish provenance showed a stable performance under drought conditions (BG ?27 % in diameter increment; ES ?32 %), compared to the Polish (?48 %) or the most sensitive German provenances (?57 %), yet for Bulgaria on a low level of total increment. This may indicate a trade-off between drought tolerance and growth. Therefore, a sole focus on drought-resistant marginal provenances seems to not be conducive, as they might be less adapted to other climatic factors, e.g. frost, as well. However, intermixed with local Central European provenances, these may act as functional insurance in future drought-prone forest stands.     

Site index variation with latitude and altitude in IUFRO Pinus contorta provenance experiments in western Canada and northern Sweden

Site index was calculated for 66 experimental plantations in western Canada and northern Sweden, containing a wide range of Pinus contorta provenances drawn from seed lots belonging to the IUFRO international provenance testing program. Growth data from recommended provenances were used to calculate the site index. Site index was defined as predicted average height of the 100 largest trees by diameter ha^‐1 at age 50.

Latitude and altitude explained 56% of site index variation by fitting the function:

Site Index (m) = 99.8 ‐ 1.226 ? Latitude (°N) ‐ 0.01205 ? Altitude (m).

The site index pattern indicated that forest productivity of the sites investigated decreased approximately by 0.8 m³ ha^‐1 yr^‐1 per one‐degree latitude northwards and per 100 m increase in altitude.     

Human impact on population structure and fruit production of the socio-economically important tree Lannea microcarpa in Burkina Faso

Non-timber forest products (NTFPs) are of high socio-economic value for rural people in West Africa. Main factors determining the status of the populations of socio-economically important tree species providing those NTFPs are human activities. This study assesses the impact of human population density, land use, and NTFP-harvesting (pruning and debarking) on population structure and fruit production of the socio-economically important tree Lannea microcarpa that is normally conserved by farmers on fields. We compared L. microcarpa stands of protected sites with those of their surrounding communal sites in two differently populated areas in Burkina Faso. Our results reveal an opposed land use impact on the population structure of L. microcarpa in the two areas. In the highly populated area, the species population was more stable in the protected site than in the communal site, while the opposite was observed for the less populated area. Trees of the communal sites bore more fruits than trees of the protected sites. Debarking and pruning had a negative impact on fruit production of the species. We conclude that low intensity of human impact is beneficial for the species and that indirect human impact facilitates fruit production of L. microcarpa. In contrast, in the densely populated area, human impact has reached an intensity that negatively affects the populations of L. microcarpa. While the extent of protecting L. microcarpa on fields still seems to be enough to guarantee the persistence of this important species in the less populated area, it is no longer sufficient in the densely populated area.