Water Availability Conditions Research Articles

Drought impacts on vegetation in the pre- and post-fire events over Iberian Peninsula

Abstract. The present work aims to study the combined effect of drought and large wildfires in the Iberian Peninsula relying on remotely sensed data of vegetation dynamics and leaf moisture content, in particular monthly NDVI, NDWI and NDDI time series from 1999–2009, derived from VEGETATION dataset. The impact of the exceptional 2004/2005 drought on vegetation was assessed for vegetation recovering from the extraordinary fire season of 2003 and on the conditions that contributed to the onsetting of the fire season of 2005. Drought severity was estimated by the cumulative negative effect on photosynthetic activity (NDVI) and vegetation dryness (NDDI), with about 2/3 of Iberian Peninsula presenting vegetative stress and low water availability conditions, in spring and early summer of 2005. Furthermore, NDDI has shown to be very useful to assess drought, since it combines information on vegetation and water conditions. Moreover, we show that besides looking at the inter-annual variability of NDVI and NDDI, it is useful to evaluate intra-annual changes (δNDVI and δNDDI), as indicators of change in vegetation greenness, allowing a detailed picture of the ability of the different land-cover types to resist to short-term dry conditions. In order to assess drought impact on post-fire regeneration, recovery times were evaluated by a mono-parametric model based on NDVI data and values corresponding to drought months were set to no value. Drought has shown to delay recovery times for several months in all the selected scars from 2003. The analysis of vegetation dynamics and fire selectivity in 2005 suggests that fires tended to occur in pixels presenting lower vegetative and water stress conditions during spring and early summer months. Additionally, pre-fire vegetation dynamics, in particular vegetation density and water availability during spring and early summer, has shown to influence significantly the levels of fire damage. These results stress the role of fuel availability in fire occurrence and impact on the Iberian Peninsula.

Studies of Physcomitrella patens reveal that ethylene‐mediated submergence responses arose relatively early in land‐plant evolution

Colonization of the land by multicellular green plants was a fundamental step in the evolution of life on earth. Land plants evolved from fresh-water aquatic algae, and the transition to a terrestrial environment required the acquisition of developmental plasticity appropriate to the conditions of water availability, ranging from drought to flood. Here we show that extant bryophytes exhibit submergence-induced developmental plasticity, suggesting that submergence responses evolved relatively early in the evolution of land plants. We also show that a major component of the bryophyte submergence response is controlled by the phytohormone ethylene, using a perception mechanism that has subsequently been conserved throughout the evolution of land plants. Thus a plant environmental response mechanism with major ecological and agricultural importance probably had its origins in the very earliest stages of the colonization of the land.

Seed germination, hydrothermal time models and the effects of global warming on a threatened high Andean tree species

AbstractSeed germination is a crucial event in a plant's life cycle. Because temperature and water availability are important regulators of seed germination, this process will likely be influenced by global warming. Insight into the germination process under global warming is thus crucial, and requires the study of a wide range of water availability and temperature conditions. As hydrothermal time (HTT) models evaluate seed germination for any combination of water potential and temperature, they can be suitable to predict global warming effects on seed germination. We studied the germination characteristics of the high Andean endemic tree speciesPolylepis besseri(Rosaceae), using HTT models. We were especially interested in the potential effects of global warming on seed germination. Assembly of HTT models forP. besseriwas fairly straightforward due to the lack of a seed dormancy mechanism. The models allowed prediction ofPolylepisgermination under constant and alternating temperatures. Initially, a global warming induced increase in the field minimum and mean temperature will increaseP. besserigermination, but as maximum temperatures rise above the optimum temperature for the species, seed germination will become jeopardized. Effects of global warming on seed germination are currently considerably underexplored. HTT models prove to be useful tools to study a plant species' general germination characteristics, and how they may become affected under global warming. For the endemic mountain tree speciesP. besseri, we predict an increase, followed by a decrease of seed germination under global warming.

Water regime and water consumption of spring soft wheat varieties of different ecological groups under contrasting water availability conditions

The characteristics of the water regime of spring soft wheat varieties of different ecological groups depending on water availability conditions are revealed. It is established that, under arid conditions, varieties of the Volga steppe and West Siberian forest-steppe ecotypes have more stable dynamics of total water content of plant tissues, less depression of transpiration, high water-retaining capacity, and comparatively low water consumption coefficients. The results of the investigations can be used when selecting parent forms for breeding spring wheat under the forest-steppe conditions of the Orenburg Cis-Ural region.

Leaf gas exchange and competitive ability of Zea mays and Sorghum halepense as affected by water competition

In an environment involving water deficit and competition, weed species may show inefficient water use. The aim was to determine the water consumption strategy of Zea mays and Sorghum halepense and the effects of these strategies on crop and weed competitive ability.Under two soil water availability conditions, the soil and leaf water potential (Ψl), relative water content (RWC) and leaf gas exchange parameters were measured during the critical period of crop competition in pot experiments where Z. mays and S. halepense were grown alone or in competition. In addition, the relative yield total and aggressivity index of both species were calculated.S. halepense showed continuous absorption of water, reaching a lower Ψl than the Z. mays hybrids. S. halepense maintained a RWC of above 90%, which only decreased to 70% in the case of competition for low water supplies. In Z. mays, RWC declined to values of 70% at both water levels. S. halepense exhibited active leaf gas exchange. Z. mays hybrids had lower competitive ability than S. halepense at both competition levels due to their conservative water use strategy. Sustained water use by the weed could be the cause of the increased aggressivity of S. halepense under water deficit conditions.

Development of a soil-plant-atmosphere continuum model (HDS-SPAC) based on hybrid dual-source approach and its verification in wheat field

HDS-SPAC, a new soil-plant-atmosphere continuum (SPAC) model, is developed for simulating water and heat transfer in SPAC. The model adopts a recently proposed hybrid dual source approach for soil evaporation and plant transpiration partitioning. For the above-ground part, a layer approach is used to partition available energy and calculate aerodynamic resistances, while a patch approach is used to derive sensible heat and latent heat fluxes from the two sources (soil and vegetation). For the below-ground part, soil water and heat dynamics are described by the mixed form of Richards equation, and the soil heat conductivity equation, respectively. These two parts are coupled through ground heat flux for energy transfer, root-zone water potential-dependent stomatal resistance, and surface soil water potential-dependent evaporation for water transfer. Evaporation is calculated from the water potential gradient at soil-atmosphere interface and aerodynamic resistance, and transpiration is determined using a Jarvis-type function linking soil water availability and atmospheric conditions. Some other processes, such as canopy interception and deep percolation, are also considered in the HDS-SPAC model. The hybrid dual-source approach allows HDS-SPAC to simulate heat and water transfer in an ecosystem with a large range of vegetation cover change temporally or spatially. The model was tested with observations at a wheat field in North China Plain over a time of three months covering both wet and dry conditions. The fractional crop covers change from 30% to over 90%. The results indicated that the HDS-SPAC model can estimate actual evaporation and transpiration partitioning and soil water content and temperature over the whole range of tested vegetation coverage.

Assemblage of a Semi-Arid Annual Plant Community: Abiotic and Biotic Filters Act Hierarchically

The study of species coexistence and community assembly has been a hot topic in ecology for decades. Disentangling the hierarchical role of abiotic and biotic filters is crucial to understand community assembly processes. The most critical environmental factor in semi-arid environments is known to be water availability, and perennials are usually described as nurses that create milder local conditions and expand the niche range of several species. We aimed to broaden this view by jointly evaluating how biological soil crusts (BSCs), water availability, perennial species (presence/absence of Stipa tenacissima) and plant-plant interactions shape a semi-arid annual plant community. The presence and cover of annual species was monitored during three years of contrasting climate. Water stress acted as the primary filter determining the species pool available for plant community assembly. Stipa and BSCs acted as secondary filters by modulating the effects of water availability. At extremely harsh environmental conditions, Stipa exerted a negative effect on the annual plant community, while at more benign conditions it increased annual community richness. Biological soil crusts exerted a contradictory effect depending on climate and on the presence of Stipa, favoring annuals in the most adverse conditions but showing repulsion at higher water availability conditions. Finally, interactions among co-occurring annuals shaped species richness and diversity of the final annual plant assembly. This study sheds light on the processes determining the assembly of annual communities and highlights the importance of Biological Soil Crusts and of interactions among annual plants on the final outcome of the species assembly.

Sunflower–Soybean Intercrop Productivity under Different Water Conditions and Sowing Managements

The sunflower (Helianthus annus L.)–soybean [Glycine max (L.) Merr.] intercrop has emerged as an option that increases land productivity in the southern Pampas of Argentina, compared with sole crops, because of complementary use of resources between species. A common management practice for this intercrop consists of delay soybean sowing, although delayed planting reduces the capacity of soybean to capture resources. Simultaneous sowing could improve total intercrop productivity because of an increase in soybean grain yield with no or little detrimental effects on sunflower grain yield. The objectives of this study were to analyze the response of the sunflower–soybean intercrop and of their component species under different sowing management (i.e., relay or simultaneous sowing) and water availability conditions. Three experiments were conducted at Balcarce, Argentina. Four cropping systems were evaluated: (i) sunflower–soybean intercrop with simultaneous sowing management (I00), (ii) sunflower–soybean intercrop with 30 d of delay between sunflower and soybean sowing (I30), (iii) sunflower sole crop (SUN), and (iv) soybean sole crop (SOY). Sunflower–soybean intercrop grain yield tend to be higher than that for sole crops of the component species. This yield advantage for intercrop increased with water availability and was associated with an increase in intercropped soybean productivity. Intercrop sowing management had no effect on total intercrop grain yield. However, simultaneous sowing increased soybean contribution to intercrop yield. Finally, our results indicate that agronomic practices that promote intercropped soybean performance increase intercrop productivity relative to the sole crops of their component species.

Forage yield and nitrogen nutrition dynamics of warm-season native forage genotypes under two shading levels and in full sunlight

The successful achievement of a highly productive understorey pasture in silvopastoral systems depends on the use of well-adapted forage genotypes, showing good agronomic performance and persistence under shading and grazing. In this study, the herbage dry matter yield (DMY) and nitrogen nutrition dynamics were determined in three native warm-season grasses (Paspalum regnellii, Paspalum dilatatum and Paspalum notatum) and a forage legume (Arachis pintoi) under two shading levels compared with full sun. The experiment was conducted in the Campanha region, Bagé, state of Rio Grande do Sul, Brazil, during two evaluation cycles (2008/2009 and 2009/2010). Three shade cloth levels (0%, 50% and 80% of light restriction) were applied to the forage genotypes in a split plot design, in which shading levels were the main plot and forage genotypes were the subplots, with three replications. P. regnellii showed the highest accumulated DMY (1500 and 1700 g m-2, respectively, for the first and second evaluation cycles) at all shading levels and showed no DMY decreased under the heavy shade (80%). Average DMY over the four genotypes under the 50% shade level was higher or equal compared with full sun. Influence of rainfall was observed on the DMY performance of all genotypes: the positive effect of moderate shading (50%) on P. dilatatum and P. notatum DMY was associated to a low soil water availability status. Increased shading level resulted in high nitrogen nutrition index values on grasses, in comparison with full sun. All genotypes performed well under the moderate shading level, but the DMY of both P. regnellii and P. dilatatum and the herbage N content in P. notatum and A. pintoi of all genotypes stood out, showing that those main genotypes are promising to grow in silvopastoral systems at the Campanha region in southern Brazil.

Dynamics of phreatophyte root growth relative to a seasonally fluctuating water table in a Mediterranean-type environment

While seasonal redistribution of fine root biomass in response to fluctuations in groundwater level is often inferred in phreatophytic plants, few studies have observed the in situ growth dynamics of deep roots relative to those near the surface. We investigated the root growth dynamics of two Banksia species accessing a seasonally dynamic water table and hypothesized that root growth phenology varied with depth, i.e. root growth closest to the water table would be influenced by water table dynamics rather than surface micro-climate. Root in-growth bags were used to observe the dynamics of root growth at different soil depths and above-ground growth was also assessed to identify whole-plant growth phenology. Root growth at shallow depths was found to be in synchrony with above-ground growth phenophases, following increases in ambient temperature and soil water content. In contrast, root growth at depth was either constant or suppressed by saturation. Root growth above the water table and within the capillary fringe occurred in all seasons, corresponding with consistent water availability and aerobic conditions. However, at the water table, a seasonal cycle of root elongation with drawdown in summer followed by trimming in response to water table rise and saturation in winter, was observed. The ability to grow roots year-round at the capillary fringe and redistribute fine root biomass in response to groundwater drawdown is considered critical in allowing phreatophytes, in seasonally water-limited environments, to maintain access to groundwater throughout the year.

TOMATO STEM AND FRUIT DIAMETER DYNAMICS IN RESPONSE TO CHANGING WATER AVAILABILITY

ISHS International Symposium on Advanced Technologies and Management Towards Sustainable Greenhouse Ecosystems: Greensys2011 TOMATO STEM AND FRUIT DIAMETER DYNAMICS IN RESPONSE TO CHANGING WATER AVAILABILITY

Daily evapotranspiration assessment by means of residual surface energy balance modeling: A critical analysis under a wide range of water availability

An operational use of the actual evapotranspiration assessed by remote sensing approaches requires the integration of instantaneous fluxes to daily values. This is commonly achieved under the hypotheses of daytime self-preservation of evaporative fraction and negligible daily ground heat flux. The aim of this study is to evaluate the effect of these assumptions on estimate daily evapotranspiration over a full phenological cycle, including phases characterized by significant changes both in net radiation and vegetation cover. To assess the reliability of these hypotheses, the observations made by a flux tower, installed within a homogeneous field of cereal located in the valley part of the Imera Meridionale basin, were analyzed. Additionally, the widely-known SEBAL (Surface Energy Balance Algorithm for Land) model was applied on the same study area by means of four MODIS (MODerate-resolution Imaging Spectroradiometer) images selected across a three-rainfall events period in March–April 2007 with the aim to analyze the consistency of its estimates in an operational study case under different conditions of water availability. The analysis of in situ data highlights errors on 24-h evapotranspiration characterized by an average value of 20% due to daily soil heat flux neglecting; whereas, the hypothesis of evaporative fraction self-preservation causes an average error equal to −16%. Moreover, the analysis of the observations suggests that a compensation effect of the errors related to each hypothesis occurs in most cases (56%), and this makes suitable the approach for practical daily integration purposes. The application of the SEBAL model at basin scale shows a good capability to detect the increase of the actual 24-h evapotranspiration under the tested hypotheses, also in the case of instantaneous evaporative fraction and daily net radiation not derived form in situ observations.

Seasonal variations of photosynthesis, gas exchange, quantum efficiency of photosystem II and biochemical responses of Jatropha curcas L. grown in semi-humid and semi-arid areas subject to water stress

This study aimed to compare the physiological adaptations of Jatropha curcas in two regions with different climates, the Agreste (a semi-arid tropical climate) and the Florest zone (a semi-humid tropical climate) subject to water stress. Measurements of gas exchange and photochemical and biochemical efficiency were performed in two seasons, the dry season (September to February) and the rainy season (April and August), between 2006 and 2007. During the dry season in the Florest zone, the J. curcas plants presented better photosynthetic performance, with smaller decreases in the rates of photosynthesis, stomatal conductance and transpiration because the conditions of water availability in the soil were slightly higher than in the semi-arid region. A greater vapor pressure deficit was observed during the dry season of the semi-arid region, showing a negative correlation with the stomatal opening of the leaves, which contributed to a reduction in the values of the net photosynthetic rate. During the dry season in the semi-arid region, dynamic photoinhibition occurred in the leaves of J. curcas around mid-day, with a rapid recovery during the afternoon. However, chronic photoinhibition may have occurred in some plants with a severe water deficit. A reduction in the effective quantum efficiency was also observed during the driest months. The increase of catalase activity and the accumulation of proline, total soluble sugars and amino acids during periods of low water availability in the soil suggest that J. curcas presents an efficient protection mechanism that allows the plant to survive under drought conditions.

Windows of opportunity for Prosopis velutina seedling establishment and encroachment in a semiarid grassland

Abstract Large increases in the density of woody plants in former grasslands have been documented globally over the past two centuries. Prosopis velutina (velvet mesquite) has recently expanded on over 38 million ha in the grasslands of the American southwest. Mesquite establishment and expansion is potentially influenced by competitive interactions with grasses, particle size distribution (texture) of soil and changes in the amount and/or seasonality of precipitation, amongst other factors. To investigate the relative importance of precipitation seasonality, grass competition, and soil texture on mesquite seedling and establishment, we experimentally manipulated seasonality of precipitation across 72 1.5 m × 1.7 m plots that we planted with two grasses from contrasting functional groups (or left unvegetated) across two highly contrasting soil textures within a semi-desert grassland in Arizona, USA, wherein we followed the demography of 8640 planted mesquite seeds between 2002 and 2006. Up to 70% of the variance in seedling emergence was explained by soil water content, and seedling mortality was more dependent on summer than on winter precipitation. Mortality of less drought tolerant grasses after drought in coarse textured soils created conditions most favorable for seedling establishment, whereas lower rates of seedling establishment were observed in finer textured soils or in plots dominated by more drought tolerant grasses. We conclude that mesquite encroachment is episodic, based on discontinuous patterns of seedling establishment, favored on coarse textured soils and associated with unique conditions of high summer water availability when precipitation is not limiting and when competition from grasses is lowered.

PENGARUH FREKUENSI IRIGASI TERHADAP PERTUMBUHAN DAN PRODUKSI LIMA GALUR PADI SAWAH

The research was conducted in February-July 2010 in the greenhouse University Farm, Cikabayan, Dramaga, Bogor. This study aims to determine the effect of irrigation frequency on growth and production of five strains of lowland rice, to determine critical point of soil water potential for drought tolerant screening. This study used a randomized block design which consists of two factors and three replications for each combination of treatments. The results of this study indicate that the frequency of irrigation effect on plant height at 8 and 12 weeks after planting (WAP), the number of tillering at 8 and 12 WAP, leaf length, ratio length / width of leaves, flowering age, number of productive tillers, panicle length, panicle number, number of grain per panicle, the percentage amount of grain fill, the weight of dry grain harvest, canopy dry weight, dry weight of milled grain, and the percentage decrease in production. Drought stress decreased production by 32.44%, 41.52% and 48.87% respectively at irrigation frequency of 8, 12, and 16 days. At optimum conditions of water availability, rice strains that produce the highest production is strain 1, 2, and 5. In drought conditions, all strains tested decreased production. Critical point of soil water potential were -35.9, -25.8 and 0.3 kPa respectively on the vegetative phase, reproductive phase, and ripening phase.

Arbuscular mycorrhizal fungi enhance photosynthesis, water use efficiency, and growth of frankincense seedlings under pulsed water availability conditions

Under drought conditions, arbuscular mycorrhizal (AM) fungi alter water relationships of plants and improve their resistance to drought. In a factorial greenhouse experiment, we tested the effects of the AM symbiosis and precipitation regime on the performance (growth, gas exchange, nutrient status and mycorrhizal responsiveness) of Boswellia papyrifera seedlings. A continuous precipitation regime was imitated by continuous watering of plants to field capacity every other day during 4 months, and irregular precipitation by pulsed watering of plants where watering was switched every 15 days during these 4 months, with 15 days of watering followed by 15 days without watering. There were significantly higher levels of AM colonization under irregular precipitation regime than under continuous precipitation. Mycorrhizal seedlings had higher biomass than control seedlings. Stomatal conductance and phosphorus mass fraction in shoot and root were also significantly higher for mycorrhizal seedlings. Mycorrhizal seedlings under irregular watering had the highest biomass. Both a larger leaf area and higher assimilation rates contributed to higher biomass. Under irregular watering, the water use efficiency increased in non-mycorrhizal seedlings through a reduction in transpiration, while in mycorrhizal seedlings irregular watering increased transpiration. Because assimilation rates increased even more, mycorrhizal seedlings achieved an even higher water use efficiency. Boswellia seedlings allocated almost all carbon to the storage root. Boswellia seedlings had higher mass fractions of N, P, and K in roots than in shoots. Irregular precipitation conditions apparently benefit Boswellia seedlings when they are mycorrhizal.Electronic supplementary materialThe online version of this article (doi:10.1007/s00442-012-2258-3) contains supplementary material, which is available to authorized users.

Modelling Visible Foliar Injury Effects on Canopy Photosynthesis and Potential Crop Yield Losses Resulting from Fluoride Exposure

Crop production models are highly developed to account for different nitrogen, light, temperature and water availability conditions and, in some species, disease or air pollutant effects. There is very limited knowledge on responses of many tropical crops, such as oil palm (Elaeis guineensis), to air pollutants although predictions of these effects are essential for industrial planning in several countries. In the absence of limitations due to water supply, the effects of leaf area loss due to necrosis and chlorosis are much more important to canopy photosynthesis than are changes in the physiological attributes that influence the efficiency of light use. Therefore, potential losses of crop production due to air pollutants such as fluoride can be inferred usefully from the extent of visible injury to foliage that may be associated with different levels of pollutant exposure.

Heritable Effect of Plant Water Availability Conditions on Restoration of Male Fertility in the “9E” CMS-Inducing Cytoplasm of Sorghum

Heritable changes of phenotype arising in plant ontogenesis by the influence of environmental factors belong to the most intriguing genetic phenomena. An unusual inheritance pattern was detected during examination of male fertility restoration in the CMS-inducing “9E” type cytoplasm of sorghum: Rf-genes were functional in self-pollinated progeny of F1 hybrids yet were either not expressed or poorly expressed in backcrosses of these hybrids to CMS-lines with the same cytoplasm type. In experiments on parallel growing of the same F1 hybrid combinations in the “dry plot” and in the “irrigated plot,” it was found that high level of plant water availability during panicle and pollen developmental stages significantly increased male fertility of F1 and test-cross hybrid populations, in which fertility-restoring genes were in heterozygote state, whereas in F2 populations the influences of water availability conditions cause less pronounce effects. Similarly, male-sterile F1 plants, being transferred from the “dry plot” to greenhouse, produced male-fertile panicles. In addition, male-sterile plants from F2 families, which segregated-out as recessives, being transferred to greenhouse also produced male-fertile panicles. In the progenies of these revertants that were grown in field conditions and in the “dry plot,” stable inheritance of male fertility for three cycles of self-pollination was observed, and a number of stable fertile lines in the “9E” cytoplasm were obtained. However, in test-crosses of these fertile lines to CMS-lines with the “9E” cytoplasm restoration of male fertility was not observed, except the progeny of one revertant that behaved as fertility-restorer line. These data suggest that the functional state of fertility-restoring genes for the “9E” sorghum cytoplasm is epigenetically regulated trait established by the influence of environmental factors and is transmitted to sexual generations.

Identificação e quantificação do efeito de fatores ambientais na produtividade da cultura do milho na região de janaúba, mg

In semiarid region of Minas Gerais State, Brazil, there is a large deficit on maize supply, even for family livelihood. Understanding factors that affect maize yield is crucial to develop appropriate crop management strategies. The study aimed at to identifying climatic factors that affect maize yield in Janauba, MG, Brazil, and quantify the degree of influence of climate elements by using crop yield data simulated with CSM-CERES-Maize model. The model was used to simulate maize yield sowed weekly throughout the year, under irrigated and rainfed conditions, from 1977 to 2008. Statistical analysis performed on simulated yield data indicated that the factors sowing date, year and irrigation (rainfed and irrigated) and their double interactions were significant at a 5% level. The water availability accounted for the greatest amount of total maize yield variation in the study region (61.9%), followed by sowing date and its second order interactions (26.2%). Under optimal water availability conditions (irrigated), the factors that most influence the yield of maize are, basically, the air temperature and solar radiation variations. This fact was evidenced by low productivity values found in years that the incident solar radiation was below the observed average.

TRANSPIRATION, GROWTH AND LATEX PRODUCTION OF A HEVEA BRASILIENSIS STAND FACING DROUGHT IN NORTHEAST THAILAND: THE USE OF THE WaNuLCAS MODEL AS AN EXPLORATORY TOOL

SUMMARYIn order to get the benefit of the growing world demand for natural rubber, Hevea brasiliensis is increasingly planted in drought-prone areas, such as in the southern part of northeast Thailand. Modelling can be a useful approach in identifying key points of improvement for rubber tree cultivation in such water-limited areas. The first objective of this study was to test the possibility of using the Water Nutrients and Light Capture in Agroforestry Systems (WaNuLCAS) model as an exploratory tool to simulate water use, growth and latex production in a pure stand on a daily basis. The second was to evaluate the relative accuracy of predictions with the current model version. Finally, the third aim of this study was to identify particular parameterisations that may be adapted to improve overall prediction quality. Model outputs were compared to measurements recorded in a mature rubber tree stand of RRIM 600 clones growing in the water-limited area of northeast Thailand. The period of analysis concerned seven months of full foliation, from May to November, including a severe drought spell. Whole-tree transpiration was estimated by xylem sap flow measurement from 11 trees. The results show that the model was able to simulate daily and seasonal change of soil water content, tree transpiration, girth increment and latex production within plausible ranges. However, under detailed scrutiny, the predictions show large inaccuracies compared to the observations: soil water content (determination coefficient (R2) = 0.461, relative root mean square error (RMSErel) = 35%), tree transpiration (R2 = 0.104, RMSErel = 94%), tree girth increment (R2 = 0.916, RMSErel = 208%) and latex production (R2 = 0.423, RMSErel = 169%). As soil water content was overestimated during the driest periods, no water stress was predicted and transpiration, growth and latex production were logically overestimated during such periods. However, tree transpiration was also largely overestimated in conditions of non-limiting soil water availability with high evaporative demand. Hence, two key points of parameterisation and improvement are identified for better simulation in our conditions: the soil water balance and particularly the ratio between water infiltration and run-off, and the regulation of transpiration under high evaporative demand. In conclusion, the WaNuLCAS model is usable as an exploratory model to simulate water use, growth and production for a pure rubber tree stand. However, in our conditions of much degraded soil and high evaporative demand, the modules of soil water balance and tree transpiration require particular parameterisations and improvement.