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Seeds are a source of organic (carbon, C) and mineral (nitrogen, N and phosphorus, P) nutrients for the growing seedling. There is much information on seed mass and N and P contents, and the relationship between these and seedling mass. Within the world’s temperate regions, these collectively show that N and P concentrations remain constant or rise with increase in seed mass and that seeds are larger and more nutrient-enriched in poorer soils. Seed N and P were more important than seed C in accounting for seedling mass in 85% of studies we assessed. In nutrient- and water-limited environments that are not light-limited, large seeds routinely provision the seedling with N and P that enhance C-fixation and thus general growth in the first wet season. This system is so efficient that growth response to soil nutrients may be negligible in first-year seedlings arising from seeds > 15 mg mass, N content > 5 mg and P content > 1.6 mg. The elongating taproot system absorbs nutrients and maintains water uptake as soil water retreats, enhancing the chances of survival in the first dry season. We outline an interpretative scenario for the special role of large seeds (>15 mg) in nutrient- and water-limited environments that recognizes the critical role of N and P for photosynthesis in ensuring sufficient C-supply to the rapidly descending roots for effective drought-avoidance by the young plant.

Reproductive allocation (RA) is a measure of how resources (biomass, nutrients) are partitioned between reproductive structures and the rest of the plant. For plants that resprout after fire, the percentage of resources allocated to reproduction may vary depending on their resprouting ability. Our study examines the percentage RA (biomass, N, P, K) and nutrient content of current season’s growth in southern (Swan Coastal Plain) epicormic and northern (Eneabba Plain) lignotuberous resprouter populations of Banksia menziesii (Proteaceae), a species endemic to nutrient-impoverished sandplains of southwestern Australia. Within each population, plants along road edges were compared with plants not associated with road edges. There was no difference in total nutrient content of current year’s growth between both resprouting types, except that total K in the shoots of lignotuberous populations was >2 times that in the epicormic populations. Non-road lignotuberous plants allocated twice the biomass, N and P, and 13.5 times the K, to reproduction as non-road epicormic plants. Lignotuberous populations had the highest RA (17–34% of biomass, N, P, K), with non-road epicormic populations the lowest RA (3–15%). This can be viewed as an adaptive (ultimate) response to the poorer postfire survival and recruitment conditions where the lignotuberous populations occur.Total biomass and nutrient content of road-edge plants was 2–3 times that of non-edge plants. Lignotuberous populations in both road positions allocated the same fraction of biomass, N and P to reproduction, whereas road-edge populations allocated 10% less K than non-road. Road-edge epicormic populations allocated 5–10% more biomass, N, P and K to reproduction than non-road populations. This can be viewed as an ecophysiological (proximate) response to the better growing conditions created by the roadways that may also ultimately have an adaptive explanation.

Hakea (Proteaceae) has winged seeds that rely on wind movement for dispersal, with seed dispersal being most effective in a post-fire environment. Seeds from 14 southwestern Australian species (8 fire-killed, 6 resprouters) had their seed mass, wing loading, and terminal falling velocity recorded to determine if a) overall relationships existed between seed properties and seed aerodynamics, and b) if seed dispersal was inherently different between the two post-fire persistence strategies. An increase in seed wing loading, calculated as the mass divided by area of the winged seed, resulted in an increase in seed terminal velocity. Using terminal velocity data to estimated initial seed dispersal distance, Hakea seeds have the potential to be dispersed up to 5 m from a parent plant, assuming seeds dispersed from less than 1.5 m above ground, and prevailing wind speeds of no more than 5 m s -1. However, under field conditions Hakea seeds are dispersed up to 20 m from the nearest adult. Secondary dispersal, the movement of seeds across the ground, is therefore more important in explaining Hakea post-fire dispersal patterns, and is a function of seed mass, prevailing surface wind conditions and the occurrence of litter microsites. Despite detecting no significant difference in wing loading or terminal velocity between fire-killed and resprouting in this study, field observations suggest that seeds of resprouter Hakea species tend to disperse their seeds further away from the parent plants.

In many parts of the world, access to groundwater is needed for domestic, agricultural and industrial uses, and global groundwater exploitation continues to increase. The significance of groundwater in maintaining the health of rivers, streams, wetlands and associated vegetation is often underestimated or ignored, resulting in a lack of scrutiny of groundwater policy and management. It is essential that management of groundwater resources considers the needs of natural ecosystems, including subterranean. We review the limited Australian literature on the ecological impacts of groundwater overdraft and place Australian information within an international context, focusing on lentic, lotic, stygobitic and hyporheic communities as well as riparian and phreatophytic vegetation, and some coastal marine ecosystems. Groundwater overdraft, defined as abstracting groundwater at a rate which prejudices ecosystem or anthropocentric values, can substantially impact natural communities which depend, exclusively or seasonally, on groundwater. Overdraft damage is often underestimated, is sometimes irreversible, and may occur over time scales at variance to those used by water management agencies in modelling, planning and regulation. Given the dangers of groundwater overdraft, we discuss policy implications in the light of the precautionary principle, and make recommendations aimed at promoting the conservation of groundwater-dependent ecosystems within a sustainable use context.

The family Proteaceae dominates the nutrient-poor, Mediterranean-climate floristic regions of southwestern Australia (SWA) and the Cape of South Africa. It is well-recognised that mediterranean Proteaceae have comparatively large seeds that are enriched with phosphorus (P), stored mainly as salts of phytic acid in protein globoids. Seed P can contribute up to 48% of the total aboveground P, with the fraction allocated depending on the species fire response. For SWA species, 70–80% of P allocated to fruiting structures is invested in seeds, compared with 30–75% for Cape species, with SWA species storing on average 4.7 times more P per seed at twice the concentration. When soil P is less limiting for growth, seed P reserves may be less important for seedling establishment, and hence plants there tend to produce smaller seeds with less P. For Australian Hakea and Grevillea species the translocation of P from the fruit wall to the seed occurs in the days/ weeks before final fruit dry mass is reached, and accounts for 4–36% of seed P. Seed P content increases with the level of serotiny, though it decreases marginally as a fraction of the total reproductive structure. The greater occurrence of serotiny and higher seed P content within the Proteaceae in SWA supports the notion that SWA soils are more P-impoverished than those of the Cape.

Mediterranean southwestern Australia experienced two successive days of extreme (>45 deg C) maximum temperatures and hot winds during the summer of 1991, resulting in adult mortality and extensive crown damage in a sclerophyllous mallee-heathland. To investigate the relationship between leaf attributes, plant environment, and heat tolerance in sclerophylls, measurements of plant height, leaf clustering, leaf morphology (thickness, dry density, area, perimeter/area ratio), percentage crown damage, and percentage mortality, and categories of exposure to wind, shade, and bare soils were recorded for 40 heat-damaged and 14 undamaged co-occurring species. Analyzing the entire dataset by principal components analysis showed that undamaged species had thicker leaves (on average 61% thicker) than species with damaged leave and were more exposed to wind, sun, and bare soil. Thicker leaves are a common respone to hot, dry, and more exposed environments and are more heat tolerant than thinner leaves. A separate analysis of the Proteaceae (25 damaged and six undamaged species) showed a similar trend to the overall dataset. An analysis of the Myrtaceae (10 damaged and three undamaged species) showed that wind exposure and level of shading were the most important variables influencing the degree of leaf damage. Percentage leaf damage was significantly correlated with percentage adult mortality, but not with the ability of a species to regrow (percentage of plants producing new shoots). Differences between undamaged and damaged species may be a result of preconditioning, whereby species growing in more exposed habitats were pre-adapted to tolerate periods of heat stress. It is unlikely that the study species were able to reduce leaf temperatures via transpirational cooling during the hottest part of the 2-d heatwave. The ability of a species to tolerate extreme temperature events will be determined by the interaction between leaf heat loads, leaf heat-storing capacity, and the deg

Hakea erinacea and H. trifurcata are related taxa that release their annual seed crop within a year of fruit maturity (weak serotiny). Both species produce similar-sized woody fruits (follicles) that protect two winged seeds. Fruit and seed development was completed 180 days (H. erinacea) and 215 days (H. trifurcata) after anthesis, with the fruits of both species reaching their maximum fresh mass during their ‘green’, non-woody state. This was associated with the commencement of wood formation in their fruit walls and the redistribution of certain nutrients (particularly phosphorus) from the fruit to developing seeds. Both H. erinacea and H. trifurcata retain chlorophyll in the walls of developing fruit, with H. trifurcata retaining chlorophyll in the mature fruit. This may have antiherbivore properties whereby the developing green fruits are cryptically disguised within a background of similarly green leaves.

Bringing together leaf trait data spanning 2,548 species and 175 sites we describe, for the first time at global scale, a universal spectrum of leaf economics consisting of key chemical, structural and physiological properties. The spectrum runs from quick to slow return on investments of nutrients and dry mass in leaves, and operates largely independently of growth form, plant functional type or biome. Categories along the spectrum would, in general, describe leaf economic variation at the global scale better than plant functional types, because functional types overlap substantially in their leaf traits. Overall, modulation of leaf traits and trait relationships by climate is surprisingly modest, although some striking and significant patterns can be seen. Reliable quantification of the leaf economics spectrum and its interaction with climate will prove valuable for modelling nutrient fluxes and vegetation boundaries under changing land-use and climate.

Leaf trait data were compiled for 258 Australian plant species from several habitat types dominated by woody perennials. Specific leaf area (SLA), photosynthetic capacity, dark respiration rate and leaf nitrogen (N) and phosphorus (P) concentrations were positively correlated with one another and negatively correlated with average leaf lifespan. These trait relationships were consistent with previous results from global datasets. Together, these traits form a spectrum of variation running from species with cheap but frequently replaced leaves to those with strategies more attuned to a nutrient-conserving lifestyle. Australian species tended to have SLAs at the lower end of the spectrum, as expected in a dataset dominated by sclerophyllous species from low fertility or low rainfall sites. The existence of broad-scale, 'global' relationships does not imply that the same trait relationships will always be observed in small datasets. In particular, the probability of observing concordant patterns depends on the range of trait variation in a dataset, which, itself, may vary with sample size or species-sampling properties such as the range of growth forms, plant functional 'types', or taxa included in a particular study. The considerable scatter seen in these broad-scale trait relationships may be associated with climate, physiology and phylogeny.

Banksia littoralis (Proteaceae) inhabits winter-wet locations and wetland fringes that are prone to seasonal flooding events on the Swan Coastal Plain. To survive in these locations, B. littoralis seedlings must be able to tolerate periods of flooding or complete submergence if establishment is to be successful. Flood tolerance was assessed in seedlings of B. littoralis subjected to 104 days of continual soil waterlogging by comparing changes in seedling growth and leaf ecophysiology with those of well-watered plants. Flood tolerance was also assessed in seedlings of Banksia prionotes, a species that grows in drier locations on the Swan Coastal Plain. As expected, B. prionotes was unable to survive long periods of soil waterlogging or submergence (97% mortality after 72 days of flooding). Both species responded to flooding by closing their stomates and reducing photosynthetic capacity, although B. littoralis was able to recover lost photosynthetic potential when flooded conditions subsided. After 72 days of flooding, there was a substantial decrease in relative growth rate in flooded B. prionotes seedlings, compared to that of well-watered plants, although this was not associated with significant differences in biomass allocation. Flood-affected B. littoralis seedlings were significantly smaller than well-watered seedlings after 72 days of flooding, but were the same size after 104 days. Flood tolerance enables B. littoralis seedlings to survive exceptionally wet winter-spring months when flooding events are more likely to occur, although surviving the annual summer drought may be more important to sustain seedling establishment.

Seasonal water relations and water source (δH analysis) data were examined for four Myrtaceae shrub species inhabiting a winter-wet depression (dampland) and surrounding landscape on Perth’s coastal sandplain. Data were collected during an exceptionally dry spring-autumn periodin 2000/2001. The two species occurring within the dampland, Astartea fascicularis and Pericalymma ellipticum, were probably accessing shallow soil moisture or groundwater (at a depth of 0.35 m) during October 2000 (spring), but were not accessing groundwater (at a depth of 1.45 m) duringthe summer drought (March 2001). Species occurring on the dampland embankment (Hypocalymma angustifolium, Eremaea pauciflora) and at a site further upslope (E. pauciflora only) had a significant reduction in predawn xylem water potential and morning stomatal conductance in response to the summer drought, with neither species accessing groundwater during summer. The dampland species were able to maintain summer morning stomatal conductances similar or greater than the conductance measured during the previous spring, implying that shallow soil moisture (gravimetric content of 10–20%) was sufficient to sustain their summer water-use requirements. δH data suggests that P. ellipticum may have been utilising groundwater in early winter (July 2001), implying that the minimum accessible groundwater depth for this species at the study dampland is approximately 1.4 m.

•Hakea species dominate shrubby vegetation on seasonally dry, nutrient impoverished soils in Australia. We hypothesized that the exposed cotyledons control growth of the young seedling by providing it with mineral nutrients rather than C-based compounds. • Two representative species with differing seed masses were tested. Cotyledon removal caused large reductions in plant mass and dimensions, but little effect on specific leaf area. Cotyledons expanded markedly on germination although their chlorophyll content was much lower than the first leaves. Shading the cotyledons or applying a C-storage compound (inositol) to the soil had no consistent effect on seedling properties. • Cotyledon removal greatly reduced seedling P (especially), N, K, Ca, Mg and Cu, but not Fe or Mn, whereas shading the cotyledons had no effect. Transfer of mineral nutrients from the embryos to the seedlings in their natural soils varied from 90 to 2% (for P and Ca, respectively), and accounted for 79% of total content (P) to negligible (K, Ca, Fe) at 3 months. Cotyledons indirectly increased soil nutrient uptake. Addition of P, N or P + N after cotyledon removal had no benefit but addition of P + N + K + Mg + S restored morphology and nutrient content. • In nutrient and water-limited habitats with abundant light, cotyledons in Hakea spp. might serve to maximize supply of mineral nutrients to the shoots, which then maximize C-supply to the rapidly elongating roots.

Long-term changes in vigour and distribution of the dominant Banksia (5 species) and Melaleuca (1 species) overstorey species were examined within four vegetation transects overlying the Gnangara Groundwater Mound, a superficial unconfined shallow aquifer on the northern Swan Coastal Plain, Western Australia. All transects were positioned along topographical gradients and monitored over a 20-30 year period. The two co-dominant overstorey species (Banksia attenuata and B. menziesii) inhabited a range of topographical positions within the landscape, from dune crest to low lying areas, with only B. attenuata increasing its distribution (moving further downslope) within the transects over time. Both species displayed a reduction in vigour, as indicated by foliage condition, during the monitored period. Species commonly inhabiting low-lying winter-wet areas (e.g. Banksia littoralis, Melaleuca preissiana) showed the greatest loss of tree vigour in response to declining groundwater levels, with B. littoralis replaced by the more drought tolerant B. prionotes. M. preissiana populations were overall more resilient to altered groundwater regimes, responding over a much greater time period (many decades) than B. littoralis (<10 years). Overall, changes in species distribution and vigour were primarily caused by long-term declines in groundwater levels resulting from the cumulative effects of abstraction and below average annual rainfall (low groundwater recharge). Long-term distribution trends and overall observed reductions in population vigour within the transects may be a function of the species’ dependency on groundwater to fulfil its water requirements. This may explain declining vigour and tree numbers of B. ilicifolia on the Gnangara Groundwater Mound, as this species is considered an important indicator of significant long- and short-term reductions in groundwater levels.

Analysis of four vegetation transects that were established on the Bassendean Dune System, northern Swan Coastal Plain classified 42 native plant species into four ‘habitat’ groups based on their preferred soil moisture regimes (Havel 1968). Using adult abundance and distribution data from three of these transects and an additional transect established in 1976, we investigated the various ecological responses of myrtaceous shrub species representing the four habitat groups to long-term (20-30 yr) decreasing groundwater and soil moisture levels. Myrtaceous shrubs were chosen for analysis because of their widespread occurrence and diversity on the Swan Coastal Plain, and because Myrtaceae is the only plant family to be represented in all four of Havel’s habitat categories. Myrtaceous species ‘tolerant of excessive wetness’ (Astartea fascicularis, Hypocalymma angustifolium, Pericalymma ellipticum, Regelia ciliata) are all shallow rooted (rooting depth < 1m), occur in winter-wet depressions, and displayed the greatest reduction in population size in response to decreasing groundwater levels. Species cateogorised as displaying ‘maximum development on dry sites’ (Eremaea pauciflora, Melaleuca scabra, Scholtzia involucrata) commonly occurred on the upper and mid-slopes of the transects, are deeper-rooted and varied in their population response to long-term declines in water availability. All three species probably rely to some extent on accessing soil moisture at depth (2-6 m) during summer drought. The scenario was similar for species ‘optimum on moist sites’ (M. seriata) and for species ‘without clear-cut site preferences’ (Calytrix flavescens). In the context of Havel’s four habitat categories, whether a particular habitat preference is ‘wet’ or ‘dry’ refers to availability of soil moisture, although to what soil depth and moisture levels are uncertain. Habitat preferences, based on soil moisture availability, may have no relevance to a species preferred groundwater reg

The Gnangara Groundwater Mound, centred 38 km north of Perth, Western Australia, is a large, shallow unconfined aquifer that is currently under abstraction as part of the public metropolitan water supply. To investigate the impact of lowering groundwater levels on a Banksia woodland on the Mound, vegetation monitoring near a groundwater abstraction bore (known as P50) began 1 year before becoming operational. In February 1991, 2 years after abstraction commenced, extensive death of the Banksia overstorey was observed within close proximity of the bore, following a short period of high summer temperatures. The site was subsequently revisited and the understorey floristic composition, abundance and vigour of overstorey species resurveyed, and compared with data collected from a site under longterm monitoring and not currently influenced by abstraction. A lowering of groundwater level by 2.2 m at P50 between the summers of 1990 and 1991, resulting from the cumulative effects of abstraction and below average annual rainfall (low groundwater recharge), coincided with a loss of between 20 and 80% of adults of overstorey species and up to 64% of adults of understorey species within 200 m of the bore. Over a similar time period no significant decreases in the abundance of overstorey or understorey species were recorded in the monitored site not influenced by groundwater abstraction. Of the overstorey species, Holly-leaf Banksia (Banksia ilicifolia) displayed the greatest susceptibility and lowest net recovery following the abstraction event at P50. The negative impact of groundwater drawdown on Hollyleaf Banksia populations makes this overstorey species an important indicator of decreasing groundwater levels on the Gnangara Groundwater Mound. Water stress may have been the primary cause of vegetation death in close proximity to the P50 bore, although this would have been exacerbated by extreme summer temperatures (> 45°C) recorded during February 1991. The P50 scenario repr

When describing the sclerophyllous nature of leaves, two indices are most commonly cited: fibre:protein ratio (FPR), better known as the Loveless sclerophylly index; and leaf mass per unit area (LMA), or its inverse, specific leaf area (SLA). Here, we assess the relative importance of these two indices in accounting for changes in leaf structure, the primary basis for variations in sclerophylly. FPR compares structural (i. e., lignin and cellulose [crude fibre]) to non-structural (i.e., protein = protoplasm) leaf material, on the basis that increasing sclerophylly is associated with a greater contribution of crude fibre and smaller contribution of protein to total dry weight. However, raising the crude fibre content is just one way of increasing sclerophylly, and a decrease in the nitrogen content (i. e., protein) does not contribute directly to the impression of leaf hardness. While FPR lacks a clear anatomical basis, it may provide a biochemical interpretation of sclerophylly. In contrast, LMA is the cross product of leaf thickness and leaf density, two (often independent) attributes that are linked to different components of a leaf’s anatomical/structural attributes. We show that FPR and LMA are often poorly correlated and conclude that LMA is a more useful measure of sclerophylly, especially when thickness and density are known.

Up to thirteen demographic, four morphological and four ecophysiological attributes were assessed in each of three studies of postfire recruitment patterns in mediterranean southwestern Australia. Three to seven of the most prominent, congeneric shrub species in each of five communities were monitored following a total of six fires, and numbers of individuals prefire were compared with those over two to four winters postfire. The proportion of individuals in each species only sometimes reflected the proportion at an earlier time. At least one species differed from the rest for twenty-six of a total of twenty- seven demographic steps assessed. Initial seedlings/ parent, which was largely a function of seeds available, and, to a lesser extent, level of germination, were the most important attributes in accounting for the recruitment patterns. There was a trend for the faster growing, drought avoiding species to increase at the expense of the others. In the most comprehensive study, life form (four nonsprouting Hcikea spp. i. four resprouting Hcakea spp.) was the best predictor of the recovery pattern. This was through its association with seed availability and level of germination and, to a lesser extent, drought survival (all higher for nonsprouters). Leaf type, as an indicator of drought tolerance, had inconsistent predictive power between studies. The least summer stressed species, in terms of survival and water relations, tended to have the largest seedlings derived from the largest seeds, but there were notable exceptions. Within each life form category, species behaviour varied widely, making most predictions of postfire community dynamics based on relative prefire numbers little more than conjectural. However, in only one of the three studies were the trends sufficiently clear to show that postfire densities would never mirror those prefire.

Within the Proteaceae, 353 species confined to 7 genera in the Grevilleoideae have woody fruits. The majority (> 70%) occur in fire-prone vegetation on nutrient-poor, summer-dry soils of south-western Australia. These species are characterised by large, winged seeds contained within serotinous follicles. Seed release is mediated by desiccation of the follicle walls resulting from fruit death, although wet–dry cycles are required in some genera. After release, germination must take place by the next wet season, as the seeds are not long-lived. Seeds are particularly high in protein (40–60%), P (1–2%) and Fe (10–60‰) compared with other Proteaceae. Seeds are favoured food for pre- and post-dispersal granivores (insects, birds, rodents) and young seedlings are favoured by herbivores (insects, marsupials), with the more serotinous fruits providing extra protection for their seeds. Successful establishment is facilitated by the protective and water retentive role of the testa during germination, and the remobilisation of N and P from the cotyledons to the seedling within 10 weeks of emergence. Drought stress reduces seedling establishment in otherwise favourable postfire microsites and prevents it (assisted by herbivores) in mature vegetation. Typically, < 10% of seeds released after fire become seedlings, and < 50% of these survive the first summer. Among fire-killed species, species that produce few seeds are more likely to have drought-resistant seedlings, often associated with larger seeds and/or needle-shaped leaves. Species that resprout after fire produce a few large viable seeds per plant, whereas fire-killed species produce many smaller seeds. Of all the Proteaceae, the ecology of woody-fruited species is best known, providing great scope for comparative biology studies.

Hakea Schrader (Proteaceae) species possess one of two contrasting leaf morphologies—broad or terete. Terete leaves are either simple (needle-like) or two- or three-pronged, and are further characterised by their greater thickness (> 1 mm), smaller projected area and mass, higher mass per unit area (a measure of sclerophylly) and lower density than broad leaves. Broad leaves are much more variable in their morphology, ranging from narrow-linear to fan-shaped or ovoid-elliptic, and may be flat, undulate, shell-shaped or spiralled. The greater thickness and sclerophylly of terete leaves can be partially attributed to the presence of a prominent, thick-walled parenchyma core and increased palisade thickness. The core contains a compact conduit of fibre-capped vascular bundles. The sclerophyllous nature of broad leaves is due to their high density, attributable to their thin palisade and large fibre caps surrounding the main vascular bundles. Both leaf types have a thick cuticle (> 20 μm) in mature plants, and sunken stomates, with terete leaves possessing a greater stomatal density than broad leaves. Both leaf types are isolateral and hence amphistomatous. Within a species, adult and seedling leaves having a similar leaf type differ morphologically rather than anatomically, with an overall increase in leaf thickness and higher levels of sclerophylly in adult leaves. Some species produce broad seedling leaves that are eventually replaced by terete adult leaves.

Successful seedling recruitment is vital for the persistence of fire-killed species in a community. Maximising seed and seedling production (fecundity) and the ability of adults and seedlings to survive summer drought are crucial in taking advantage of post-fire recruitment opportunities. In this study, the fecundity (seed and seedling production), mortality and water relations of fire-killed Hakea species with contrasting leaf morphologies (broad and terete) were examined over 2 consecutive years of exceptionally low rainfall at two sites, to investigate possible trade-offs between drought susceptibility (as influenced by leaf morphology) and fecundity of a species. Adult mortality was high in the broad-leaved species (H. smilacifolia Meissn. and H. undulata R.Br.) and low in terete-leaved species (H. erinacea Meissn., H. circumalata Meissn. and H. polyanthema Diels) with high transpiration rates (broad-leaved species) associated with greater plant death. Only H. smilacifolia had proportionally greater fecundity to compensate for high adult mortality. Seedling mortality increased proportionally with higher initial seedling : parent ratios (adult fecundity). Lowest mortality was for the terete-leaved species, apparently achieved by means of a combination of drought avoidance and tolerance mechanisms. Hakea undulata seedlings had the highest mean leaf area, but mortality was highest in H. smilacifolia. Thus, for seedlings, leaf morphology was not as strongly related to drought susceptibility as it was for adults.