Re-establishing the mid-storey tree <Emphasis Type="Italic">Persoonia longifolia</Emphasis> (Proteaceae) in restored forest following bauxite mining in southern Western Australia

Persoonia longifolia is a common mid-storey species that is difficult to return to post-mining environments. This study aimed to quantify in situ emergence of P. longifolia seeds on restored areas, investigate seed cueing prior to use in restoration and assess different tree guards for increasing seedling survival and health. Initial investigations found that <1 % of seeds buried or scattered on restored areas produced seedlings. However, if seeds were cued through burial in surrounding forest, retrieved and sown on restored areas, seedling emergence increased to 24 %. Significantly more seeds emerged as seedlings when buried (14.6 %) compared to those scattered on the soil surface (2.7 %). There was no significant difference in survival between seedlings planted at 2-3 weeks of age compared with those planted at 12 months of age after 20 months in situ growth. Additionally, those seedlings planted when younger were significantly taller (29.0 ± 2.9 cm) than those that were planted at 12 months of age (4.7 ± 0.3 cm). Use of “onion bag” guards improved survival from 58.1 ± 4.0 % (no guard) to 70.8 ± 3.4 % with an onion bag guard. The use of shade cloth guards did not significantly improve survival, however plant height did increase substantially after 32 months growth (22 cm compared with 7.2 cm for no guard). These data demonstrate that consideration needs to be given to specific species requirements to improve seedling emergence and survival when attempting to return difficult to germinate species to the post-mining environment.     

Tree guards and weed mats in a dry shrubland restoration in New Zealand

Associated with restoration of 150 ha of native plant communities within a highly exposed low rainfall landscape, we evaluated whether the benefits of tree guards and weed mats justified a doubling of planting costs. One‐year‐old nursery‐grown specimens of Kānuka (Kunzea serotina) and Pomaderris (Pomaderris amoena) were planted with and without polythene and rigid plastic tree guards, and weed mats, then monitored for 12 months. Herbivory was reduced with both types of tree guard by 10–35%, but mortality was largely caused by desiccation. Polythene tree guards provided the best protection, buffering extremes of ambient and soil temperature in summer but with no effect on soil temperature in winter. Weed mat addition reduced soil temperature fluctuation further in winter; a moss turf mat was best. Both mulch and moss weed mats reduced soil temperature in summer and raised soil moisture in winter. We showed that tree guards could save at least NZ$ 70 k/ha, but this is likely to vary with plant species traits and site conditions.     

Effects of Tree Guards and Weed Mats on the Establishment of Native Tree Seedlings: Implications for Forest Restoration in Hong Kong, China

The effects of tree guards and weed mats on establishment and growth of native tree seedlings, Thick‐leaved oak (Cyclobalanopsis edithiae (Skan) Schott., Fagaceae), planted in an exposed hillside grassland in Hong Kong, were investigated. The natural regeneration of C. edithiae is poor due to a lack of seed dispersal agents and high seed predation, and therefore, this species is often targeted for forest restoration. The experiment lasted for 3.5 years during which the height, basal diameter, and crown diameter of individual seedlings were measured and survivorship recorded. The use of weed mats alone did not have a significant effect, but a combination of tree guards and weed mats led to a significant improvement in establishment, survivorship, and growth of the seedlings during the experimental period. Initially, the guards promoted rapid height growth of the seedlings, although lateral growth and secondary stem thickening were compromised. After the seedlings grew over the tree guards, the basal diameter and crown diameter increased at a notably faster rate. The combined effect of the tree guard and weed mat on the seedling growth pattern was found to be beneficial and contributed to the high survivorship of the seedlings. Comparing the survivorship data and the costs of various treatments, the use of tree guards in combination with the weed mats was demonstrated to be more cost‐effective than planting the seedlings without tree guards or weed mats. The potential for applying the technique in afforestation programs with native tree species for forest restoration in Hong Kong and other tropical regions is discussed.     

Photosynthetic response of seedlings of the sub-tropical tree Schima superba with exposure to elevated carbon dioxide and temperature

Seedlings of Schima superba were exposed to both ambient (375 ppm) and 720 ppm levels of CO₂ in combination with two incubation temperatures (25/20, 30/25°C, day/night) for a six-month period. Net height growth of seedlings was enhanced in the early period of exposure to high levels of CO₂. However, when seedlings were exposed for a longer period of time to this high concentration, net height growth was inhibited. Decreased photosynthetic rate with elevated CO₂ was observed when measured in the ambient CO₂ over a long-term exposure of 6 months. In contrast, a significant increase in photosynthesis was noted for seedlings exposed to higher incubation temperature in either ambient or 720 ppm CO₂ concentrations. The response of CO₂ assimilation to internal Ci was indicated by the lower sensitivity in seedlings grown in elevated CO₂ concentration. Though this response could also be found in a higher sensitivity in seedlings grown at higher temperature, the seedlings grown in normal conditions (ambient CO₂ and temperature) were still more sensitive to CO₂ assimilation response to internal Ci. This experiment suggests that: (1) exposure of seedlings to higher CO₂ levels for longer periods may lead to a decrease in seedling height growth and photosynthetic rate, as well as decreasing sensitivity to changing internal CO₂ concentrations; (2) the optimum temperature for photosynthesis of seedlings grown in an elevated CO₂ concentration was higher than that for seedlings grown in ambient concentration.     

Altitudinal variations in seedling and sapling density and age structure of timberline tree species in the Sergyemla Mountains, southeast Tibet

The growth situation of seedlings of treeline species can be used as an indicator for the upper or lower shift of treeline under global climate change, since any advance of a treeline would require seedling survival above the current treeline elevation. We investigated seedling and sapling density of two dominant conifers Abies georgei var. smithii and Sabina saltuaria at lower, middle and upper altitude of two contrasting slopes in Sergyemla Mountain, southeast Tibet. Seedling and sapling age structure of A. georgei var. smithii was analyzed further. Seedling density of both species, as well as sapling density of S. saltuaria, showed a declining trend as elevation increased. Sapling density of A. georgei var. smithii was somewhat higher at middle altitude than other positions. The frequency of old-aged A. georgei var. smithii seedlings/saplings (age >10 year) was the lowest at the highest altitude and tended to increase with the declining elevation. The results indicate that the higher density of seedling and sapling in high-altitude might be attributed to better soil moisture availability and solar insolation than in the mid- and low-altitudes during the growth season. Yet confined by other environmental factors, A. georgei var. smithii seedlings in high-altitude suffer from lower survival rate and lower possibility to grow tall compared with those in mid- and low-altitudes.     

Altitudinal variations in seedling and sapling density and age structure of timberline tree species in the Sergyemla Mountains, southeast Tibet

The growth situation of seedlings of treeline species can be used as an indicator for the upper or lower shift of treeline under global climate change, since any advance of a treeline would require seedling survival above the current treeline elevation. We investigated seedling and sapling density of two dominant conifers Abies georgei var. smithii and Sabina saltuaria at lower, middle and upper altitude of two contrasting slopes in Sergyemla Mountain, southeast Tibet. Seedling and sapling age structure of A. georgei var. smithii was analyzed further. Seedling density of both species, as well as sapling density of S. saltuaria, showed a declining trend as elevation increased. Sapling density of A. georgei var. smithii was somewhat higher at middle altitude than other positions. The frequency of old-aged A. georgei var. smithii seedlings/saplings (age >10 year) was the lowest at the highest altitude and tended to increase with the declining elevation. The results indicate that the higher density of seedling and sapling in high-altitude might be attributed to better soil moisture availability and solar insolation than in the mid- and low-altitudes during the growth season. Yet confined by other environmental factors, A. georgei var. smithii seedlings in high-altitude suffer from lower survival rate and lower possibility to grow tall compared with those in mid- and low-altitudes.     

Seed germination and seedling growth of Zostera marina L. (eelgrass) in the chesapeake bay

Seed germination and seedling growth of Zostera marina L. were monitored in the Chesapeake Bay in 1979 and 1980. Harvested seeds were placed in small acrylic tubes at several sites representing the salinity range of Z. marina distribution. Seed germination was observed first in late September and continued through May, with peaks in the fall and spring. The majority of seeds that germinated (66%) did so between December and March when water temperatures ranged from 0–10°C. There was no correlation between sites (different salinity regimes) and frequency of germination rates, indicating that salinity was not a major factor in the germination process in this study. Additional information on seed germination was available for seeds collected in 1977 and 1980 and subsequently monitored for germination at only one site. These data were similar to germination frequency recorded in 1979–1980.Seedling growth was measured from individuals collected from an existing Zostera marina bed. Seedlings were collected from November through May, at which time we could no longer distinguish seedlings from existing vegetative stock. Growth was characterized by the increased length of the primary shoot, number of leaves per shoot and numbers of shoots per plant. Seedling growth was slow during the winter months (water temperature ? 10°C) but rapidly increased in the spring (temperatures > 10°C). The size range of the harvested seedlings indicated that seed germination in the field probably occurred from October through April, corroborating evidence from the seed germination experiments.     

Ecophysiology of Species with Distinct Leaf Morphologies: Effects of Plastic and Shadecloth Tree Guards

Ecological restoration using seedling tubestock is challenging under a Mediterranean-type climate of hot, dry summers. We investigated the ecophysiological effects of plastic tree guards and shadecloth tree guards during seedling establishment of four co-occurring tree species that differ in leaf morphology. Average temperature was 6.7°C higher in plastic guards than controls over a summer, with a maximum of 53.5°C compared to 47.9°C in controls. Light levels were 2-fold lower in both tree guard treatments relative to control. In spring, photosynthesis and specific leaf area were significantly elevated in shadecloth tree guards relative to other treatments. In summer, photosynthetic rate was significantly lower, and midday photochemical efficiency was significantly higher, in both tree guard treatments relative to controls. The effect of elevated temperature in plastic tree guards may partially explain our results of higher mortality of seedling in plastic tree guards. The relatively elevated spring photosynthesis of seedlings in shadecloth tree guards may partially explain the result of reduced mortality and increased growth in this treatment. We conclude that shadecloth tree guards create a microclimate more favorable for seedling establishment in a Mediterranean-type environment than plastic tree guards and control treatments. Our results may have wide applicability to the range of restoration settings where seedling tubestock is planted, except in environments where low temperature is limiting to plant growth.     

长白山不同演替阶段温带森林林下草本植物对乔木幼苗的影响

为了解次生针阔混交林和阔叶红松林林下草本植物对幼苗生长和存活的影响,基于长白山次生针阔混交林样地(Ⅰ)和阔叶红松林样地(Ⅱ),以246个1 m×1 m幼苗样方中乔木幼苗为研究对象,通过去除草本植物的对照试验探究草本植物对乔木幼苗高度生长和存活率的影响。结果表明,(1)群落水平上,草本植物去除有助于林下乔木幼苗的高度生长。次生针阔混交林和阔叶红松林中幼苗高度生长量在除草后较对照组均有显著提高,且阔叶红松林中幼苗高度增长在对照组和处理组中均高于次生针阔混交林。(2)去除草本植物对不同年龄级水平乔木幼苗高度生长影响不同。次生针阔混交林中,去除草本显著促进四年生及以上幼苗高度生长,对一至三年生幼苗影响不显著;阔叶红松中去除草本显著促进一至三年生幼苗高度生长,对四年生及以上幼苗影响不显著。(3)除草处理后,水曲柳幼苗高度生长量在两处样地均显著增加,假色槭幼苗高度增长量只在次生针阔混交林中显著增加,而其他幼苗高度增长量只在阔叶红松林中显著增加。(4)次生针阔混交林中,幼苗存活率与草本多度和物种数呈正相关关系,与草本盖度无相关关系;阔叶红松林中幼苗存活率与草本物种数呈正相关关系,与草本多度和盖度无相...     

Restoring Tree Islands in the Everglades: Experimental Studies of Tree Seedling Survival and Growth

In May 2004, 400 tree seedlings of seven different species found on tree islands in the Florida Everglades were planted at different elevations along five transects on eight newly constructed tree islands, four with and four without limestone cores. Seedlings suffered between 40 and 85% mortality during the first 120 days, the period with the lowest water levels. Ilex cassine L., Salix caroliniana Michx., Chrysobalanus icaco L., and Annona glabra had the highest number of surviving seedlings, whereas Magnolia virginiana L., Myrica cerifera L., and Acer rubrum L. had the fewest. During the remainder of the study, water levels were mostly higher and sometimes covered the entire islands for months at a time. After 220 days, nearly all seedlings of M. virginiana and My. cerifera had died. At the end of the study, seedlings of I. cassine and A. glabra had the highest survivorship rates. Seedling biomass of C. icaco and I. cassine was greatest at the highest elevations, whereas seedlings of A. glabra had similar biomass at all elevations. Seedling survivorship was not statistically different between islands with and without limestone cores; however, when seedlings of all species were combined, island core type was significantly different for aboveground biomass, seedling height, and canopy width. Because of the higher survivorship under both low and high water conditions, A. glabra , I. cassine , and S. caroliniana are the most suitable species for establishing tree species on restored tree islands in the Everglades.     

BALDCYPRESS SEEDLING GROWTH IN THERMALLY ALTERED HABITATS

Thermal discharges from nuclear production reactors killed large areas of baldcypress-water tupelo (Taxodium distichum-Nyssa aquatica) forests along streams on the Savannah River Plant in South Carolina. Recolonization by baldcypress has been slow in areas where present stream temperatures do not exceed ambient by more than 10 C and has not occurred at all at higher temperatures. Since it has been previously shown that cypress germination and establishment are not inhibited at stream temperature below 42 C, the growth of 1-yr-old baldcypress seedlings introduced into ambient (T_max = 32 C) and ambient + 10 C (T_max = 42 C) stream temperatures was examined during a 16-month period to determine the response of this growth stage. Growth in height, diameter and biomass of these seedlings was enhanced in a stream habitat with maximum water temperatures of 42 C. Allocation of dry weight into root and shoot tissues was modified by stream temperature, with a lower root/shoot ratio in plants at the 42 C location. In thermally altered (-42 C) areas, neither establishment nor growth of established cypress seedlings is limited by stream temperature. Thus, slow reinvasion of these sites by baldcypress is thought to be due to a lack of a seed source and/or competitive exclusion.     

新疆野核桃自然保护区不同坡向野核桃幼苗种群年龄结构及生长特征

为了解国家Ⅱ级渐危植物新疆野核桃不同年龄幼苗的数量组成及生长特性,在野核桃自然保护区不同坡向上设置4个2-hm²样地,应用相邻格子样方法对野核桃幼苗进行逐株调查,分析了野核桃幼苗种群的数量组成、基径和株高的生长特征及各性状间的生长关系.结果表明: 阳坡、半阳坡、阴坡和半阴坡野核桃1龄幼苗均较丰富,1～3龄幼苗数量均占绝对优势,不同坡向野核桃幼苗种群均呈增长型年龄结构.各坡向野核桃1龄幼苗平均5.7%可存活到4龄,平均1.7%可以存活到7龄.3龄是野核桃幼苗数量的一个转折点,幼苗种群在生活史中采用的是r对策.野核桃幼苗的基径和株高在3龄前生长缓慢,3龄后加快生长;基径平均生长速率为3.6 mm·a^-1,按阴坡、阳坡、半阴坡、半阳坡顺序减小;株高平均生长速率为9.0 cm·a^-1,按阳坡、半阳坡、半阴坡、阴坡顺序减小.不同坡向野核桃幼苗的基径与株高均随年龄的增加呈指数函数生长,株高与基径呈幂函数异速生长,幼苗各性状间的生长快慢可通过函数的性质和参数反映出来.     

Survival and growth of tree seedlings in anthropogenically disturbed Mexican montane rain forests

Abstract. The montane rain forest in Chiapas, Mexico has been subject to continuous human disturbance, mainly by wood extraction, cattle grazing and fire. To address the effect of this kind of disturbance regime on regeneration, survival and growth of naturally established tree seedlings were evaluated during a 3‐yr period in three forest stands which varied in frequency and intensity of human disturbance. Frequency of cattle browsing on transplanted seedlings of Cornus disciflora, Liquidambar styraciflua and Oreopanax xalapensis planted on different facing slopes was evaluated over an 18‐mo period, their survival and growth was also determined. The density of seedlings, number of species and survival of naturally recruited tree seedlings decreased with increased intensity of disturbance. Only seedlings of Pinus and Quercus species were recorded in heavily disturbed conditions. Seedlings grew more vigorously under moderately disturbed than in undisturbed or heavily disturbed conditions. More extreme microclimatic variation (air temperature, relative humidity and solar radiation) was recorded in heavily vs moderately disturbed forest. Survival and growth of transplanted tree seedlings differed with species. Grazing damage varied among seedlings located on different facing slopes. Plants located on NE facing slopes survived better than those on other slope positions. The mean proportion of surviving individuals of L. styraciflua (80%) and C. disciflora (78%) was higher than those for O. xalapensis (60%). A higher number of C. disciflora and O. xalapensis seedlings were grazed than L. styraciflua in any slope orientation treatment. The results suggest that human disturbance negatively affects natural recruitment, reduces richness of tree seedlings and favours a small number of tree species.     

Planting Seedlings in Tree Islands Versus Plantations as a Large‐Scale Tropical Forest Restoration Strategy

Planting tree seedlings in small patches (islands) has been proposed as a method to facilitate forest recovery that is less expensive than planting large areas and better simulates the nucleation process of recovery. We planted seedlings of four tree species at 12 formerly agricultural sites in southern Costa Rica in two designs: plantation (entire 50 × 50 m area planted) and island (six patches of three sizes). We monitored seedling survival, height, and canopy area over 3 years. To elucidate mechanisms influencing survival and growth, we measured soil and foliar nutrients, soil compaction, and photosynthesis. Survival of all species was similar in the two planting designs. Seedling height and canopy area were greater in plantations than islands at most sites, and more seedlings in islands decreased in height due to damage incurred during plot maintenance. Survival, height, and canopy area were both site‐ and species‐specific with the two N‐fixing species (Inga edulis and Erythrina poeppigiana) greater than the other species (Terminalia amazonia and Vochysia guatemalensis). Foliar N was higher in Terminalia and Vochysia in sites where Inga growth was greater. Soil nutrients, however, explained a small amount of the large differences in growth across sites. Leaf mass per area was higher in islands, and P use efficiency was higher in plantations. Our results show advantages (good seedling survival, cheaper) and disadvantages (more seedling damage, slightly lower growth) to the island planting design. Our study highlights the importance of replicating restoration strategies at several sites to make widespread management recommendations.     

High ambient temperatures induce aggregations of chimney swifts Chaetura pelagica inside a roost

One proposed advantage of communal roosting in birds is a reduction in the costs of thermoregulation. As thermoregulatory benefits are directly linked to the distance between roosting birds, we examined whether temperature is related to inter‐bird spacing in roosting chimney swifts Chaetura pelagica. To test the hypothesis that huddling is used to reduce the costs of thermoregulation, we predicted that swifts would cluster more at colder temperatures. We mounted an all‐weather camera atop a 61 m tall industrial masonry chimney, one of the largest swift roosts in the study region. We deployed temperature loggers inside the chimney and obtained ambient air temperature from a nearby weather station. From 16 May–24 July 2013, we captured hourly images of the positions of roosting swifts at night. We used image analysis software to mark the angular positions of all roosting swifts, and calculated mean angles of orientation (preferred direction) inside the roost and the circular variance (i.e. the concentration of swifts around the mean angle). We used a Gamma regression to relate temperature inside and outside the roost to the clustering of swifts around the mean angle for 3 time periods (pre‐nesting, nesting, and post‐nesting). Converse to our prediction, swifts were closer together when ambient air temperatures were warmer in all periods (pre‐nesting (p < 0.001, n = 168), nesting (p < 0.001, n = 224), and post‐nesting (p < 0.001, n = 135)). Our findings suggest that swifts do not increase clustering intensity in response to colder temperatures, but instead they increase clustering intensity in response to the warmest ambient temperatures. This likely a metabolic response to reduced prey availability at higher temperatures and/or an attempt to reduce evaporative water loss. We suggest clustering may be used by chimney swifts as an energy saving mechanism during periods of lowered food availability.     

鼎湖山南亚热带常绿阔叶林20公顷样地幼苗的分布

为了解鼎湖山常绿阔叶林树木幼苗的组成、分布及高度结构,在鼎湖山20 ha动态监测样地(简称DHS)内布置了149个种子雨收集器,并在周围设置了幼苗小样方.2008年31月完成了幼苗调查,共调查到2,632株.采用多元线性回归方法分析了9个树种幼苗多度与6个变鼍之间的关系.这6个变量包括种子雨收集器10 m内DBH≥1 cm同种个体的个体数、胸高断面积之和,以及地形的凹凸度、坡度、坡向和海拔.结果表明影响幼苗多度的因素随树种不同而不同.其中3个树种的幼苗多度只与地形变量有关,4个树种幼陌多度同时受到地形和同种个体多度的影响,1个树种的幼苗多度只与同种个体有关,1个树种幼苗多度与所有变量的关系都不显著.除谷木(Memecylon ligustrifolium)外,10 m范围内同种个体的多度和胸高断面积的偏回归系数一旦显著皆为正值,即幼苗多度随同种个体数或同种胸高断面积增大而增大.本研究为扩散限制和生态位理论提供了间接的证据.     

Eastern deciduous tree seedlings advance spring phenology in response to experimental warming,but not wetting,treatments

Changing global climate, particularly rising temperatures, has been linked through observations with advanced spring phenology in temperate regions. We experimentally tested if regional climate change predictions of increased temperature and precipitation alter the spring phenology of eastern US tree seedlings. This study reports the results of a 3-year-field experiment designed to study the responses of eastern deciduous tree species planted in a post-harvest environment to a 2 °C increase in temperature and a 20 % increase in precipitation. Species were monitored for timing of germination and leaf out in four treatment combinations (ambient, warmed, irrigated, and warmed + irrigated) on 16 plots located in a recently harvested central Pennsylvania forest. The 2 °C warming advanced day of seed germination by an average of 2 weeks and seedling leaf out by 10 days among all species (both p < 0.001). However, increased precipitation did not result in a significant change in spring phenology. Species responded uniquely to treatments, with germination advancing in three of five species in response to warming and leaf out advancing in six of six species. Southern species projected to expand northward into the study region with rising temperatures did not show responses to warming treatments that would provide them an advantage over current resident species. Timing of germination and leaf out varied among years of the experiment, most likely driven by year-to-year variability in spring temperatures. The climate change experiment highlighted the potential of a moderate 2 °C temperature increase to advance spring phenology of deciduous tree seedlings by up to 2 weeks, with a lack of a phenological response to a 20 % increase in precipitation.     

Morphotype community structure of ectomycorrhizas on Douglas fir (Pseudotsuga menziesii Mirb. Franco) seedlings grown under elevated atmospheric CO2 and temperature

Mycorrhizas alter the acquisition of carbon and nutrients, thereby affecting numerous plant and ecosystem processes. It is important, therefore, to determine how mycorrhizal populations will change under possible future climate conditions. Individual and interactive effects of elevated atmospheric CO₂ concentration and atmospheric temperature were assessed in a 2×2 factorial design [ambient and elevated (200 ppm above ambient) CO₂ concentrations, and ambient and elevated (4°C above ambient) temperatures]. In June 1993, 2-year-old Douglas fir (Pseudotsuga menziesii Mirb. Franco) seedlings were planted in 12 environment-tracking chambers (n=3) containing reconstructed, low-nitrogen, native forest soil. Climate treatments were imposed shortly thereafter, and the seedlings grew until June 1997. Soil cores were taken twice per year during the exposure period. We present findings on changes in the community structure of ectomycorrhizal (ECM) root tips, categorized into morphotypes using gross morphological traits. A diverse and stable community of morphotypes (a total of 40) was encountered; no more than 30 of which were seen at any sampling time. In the first sample, there were only 15 morphotypes found in the 12 chambers. Morphotype numbers increased during the first half of the experiment, remaining fairly constant thereafter. Near the end of the exposure, elevated-temperature treatments maintained more morphotypes than ambient treatments. However, overall, absolute measures (number of ECM tips) were affected primarily by CO₂ treatment, whereas proportional measures (e.g., Simpson’s index) were affected primarily by temperature. While some morphotypes were negatively affected seasonally by higher temperatures (putative Rhizopogon group), others (Cenococcum) seemed to thrive. Underlying the dominant patterns of change in diversity, driven by the Rhizopogon group, subdominant populations responded slightly differently. Community diversity through time tended to increase at a greater rate for all subdominant populations compared with the rate when dominant populations were included. Received: 16 August 1999 / Accepted: 2 March 2000     

Differences in situation efficacy indicators at the elite basketball players that play on different positions in the team

The aim of our study was to determine the differences in situational efficacy for basketball players, in relation to their team positions: between guards and forwards/centres, and between the players on the four major positions in the team. The final sample of subjects (74 basketball players) is selected from the initial sample of 107 subjects, selected from nine men's senior basketball teams that played in A-1 Croatian men's basketball league championship in 2006/2007. Results confirmed the hypothesis that there is a significant difference between different groups of players: point/shooting guards, comparing with forwards/centres; players that play on four positions: point guard, shooting guard, small forward, power forward/centre. Guards have shown greater efficiency and utilization of the three-point shots, while centres are better in two-point shots. Guards have a greater number of assists, successful and unsuccessful three-point shots, while centres are better in the offensive and defensive rebounds, as same as in successful and unsuccessful two-point shots. No statistically significant differences were found among the players on the guard positions (point guard and shooting guard), while only one statistically significant difference is found among the players on the position forward/centre (small forward and power forward/centre).     

Survival and growth responses of eight Everglades tree species along an experimental hydrological gradient on two tree island types

Questions: How are the early survival and growth of seedlings of Everglades tree species planted in an experimental setting on artificial tree islands affected by hydrology and substrate type? What are the implications of these responses for broader tree island restoration efforts? Location: Loxahatchee Impoundment Landscape Assessment (LILA), Boynton Beach, Florida, USA. Methods: An experiment was designed to test hydrological and substrate effects on seedling growth and survivorship. Two islands – a peat and a limestone‐core island representing two major types found in the Everglades – were constructed in four macrocosms. A mixture of eight tree species was planted on each island in March of 2006 and 2007. Survival and height growth of seedlings planted in 2006 were assessed periodically during the next two and a half years. Results: Survival and growth improved with increasing elevation on both tree island substrate types. Seedlings' survival and growth responses along a moisture gradient matched species distributions along natural hydrological gradients in the Everglades. The effect of substrate on seedling performance showed higher survival of most species on the limestone tree islands, and faster growth on their peat‐based counterparts. Conclusions: The present results could have profound implications for restoration of forests on existing landforms and artificial creation of tree islands. Knowledge of species tolerance to flooding and responses to different edaphic conditions present in wetlands is important in selecting suitable species to plant on restored tree islands