Tree Growth Patterns Research Articles

Demographic traits of understory trees and population dynamics of a Picea‐Abies forest in Taisetsuzan National Park, northern Japan

AbstractThe size structure transition matrices of Picea jezoensis, Picea glehnii and Abies sachalinensis of a sub‐boreal forest in Hokkaido, northern Japan were constructed based on the demography of each species (Picea jezoensis and Picea glehnii were dealt with together as Picea) during a 4‐year period. Two types of matrices, density‐independent and density‐dependent population dynamics models, were investigated for evaluating the ‘waiting pattern’ between Picea spp. and A. sachalinensis. For the density‐dependent model, it was assumed that the demographic traits of understory trees, the recruitment rate, the understory mortality rate and the transition probability from the understory to canopy stages, were regulated by the one‐sided competitive effect of canopy trees. The observed size structure of Picea was almost consistent with the stationary size structure obtained in both the density‐independent and the density‐dependent models, whereas the observed size structure of A. sachalinensis was not realized in the two models. The effects of both the transition probability from the understory to canopy stages and the recruitment rate on the dynamics of canopy trees were investigated. For Picea, two parameters—recruitment rate (ei) and transition probability from the understory to canopy stages‐exponentially affected the dynamics of canopy trees. In contrast, for Abies sachalinensis, the two parameters affected linearly the dynamics of canopy trees. In conclusion, the population dynamics of Picea and A. sachalinensis was determined by the parameters of the recruitment rate and the transition probability from the understory to canopy stages, relating to waiting patterns of understory trees for future gap formation. In Picea, the demographic parameters of understory trees intensively regulated the dynamics of canopy trees if compared with A. sachalinensis, suggesting that the performance of understory trees plays a key role in the population dynamics of Picea. This reflects the growth pattern of understory trees in the regeneration of the two species.

An individual-tree basal area growth model for loblolly pine stands

Tree basal area growth has been modeled as a combination of a potential growth function and a modifier function, in which the potential function is fitted separately from open-grown tree data or a subset of the data and the modifier function includes stand and site variables. We propose a modification of this by simultaneously fitting both a growth component and a modifier component. The growth component can be any function that approximates tree growth patterns, and the logistic function is chosen as the modifier component. This approach can be adapted to a variety of stand conditions, and its application is demonstrated using data from an uneven-aged loblolly pine (Pinustaeda L.) study located in Arkansas and Louisiana.

Growth patterns of early versus late successional multipurpose trees of the western Himalaya

In the mid-western Himalaya (altitude 1350 m, rainfall 1100 mm), multipurpose trees found as escapees in agricultural fields or naturally growing in the forests, play an important role in providing fuel, fooder and small timber to the farmers. Shoot elogation, and tree architecture of 4 year old trees of Grewia optiva, Robinia pseudoacacia and Celtis australis (early successionals), and Quercus leucotrichophora, Q. glauca and Ilex odorata (late successionals), were analyzed. All the late successional species showed a proleptic type of bud and branch production, while the early successional trees made growth through syllepsis. The shoot elongation differed significantly (P <0.05) with the crown position, and ranged from 11 to 30 cm in different species. Early successional species tended to maintain a comparatively narrow crown and showed a significantly (P <0.05) higher ramification ratio, and multilayered canopy. The late successionals, in contrast, showed a wide crown with monolayered canopy, adapted to the weak light intensity. There was only one flush of leaves in Q. leucotrichophora and Q. glauca while in the rest of the species there were two distinct flush periods. The results are important for the management of agroforestry trees.

Tectonic influences on tree growth in northern Patagonia, Argentina: the roles of substrate stability and climatic variation

In northern Patagonia, Argentina, we examined the influences of climatic variation and inter-site variation in substrate stability on the dendroecological effects of earthquakes. In association with the great earthquake in 1960 centered off the coast of nearby Valdivia, Chile, extensive tree mortality occurred in northern Patagonia in Nothofagusdombeyi–Austrocedruschilensis stands on unstable debris fans. To examine the effects of the 1960 and earlier earthquakes on tree growth, we developed tree-ring chronologies from samples of the surviving A. chilensis on unstable debris fan sites and at adjacent nonfan sites of more stable substrates. For controlling the effects of regional climatic variation, we also produced a tree-ring chronology from this species in a more distant and undisturbed stand. Strong variations in tree-growth patterns on fan sites were associated with the historically documented major seismic events of south central Chile that occurred in 1737, 1751, 1837, and 1960. Tree-ring chronologies from nonfan sites (i.e., sites of greater substrate stability) showed much less response to these earthquakes. On the fan sites, strong growth suppressions were associated with the former three earthquakes, whereas strong releases followed the 1960 earthquake. The difference in response is explained by the occurrence of the 1960 earthquake during a period of drought, which in combination with the violent shaking of the ground, resulted in extensive tree mortality followed by growth releases of the survivors. However, severe droughts in the absence of earthquakes also can produce tree mortality and subsequent release of the survivors. Consequently, the synergistic effects of climatic variation and earthquake events must be carefully considered in developing records of both climatic variation and earthquakes.

Effects of disturbance and size structure on the regeneration process in a sub‐boreal coniferous forest, northern Japan

AbstractThe stand structure and disturbance history in a sub‐boreal coniferous forest dominated by Picea jezoensis, Picea glehnii and Abies sachalinensis were investigated in four study plots set up in Taisetsuzan National Park, Japan. The effect of stand characteristics on the growth and mortality rates of understory trees was examined. Although all the stands showed inverse J‐shape d.b.h. (diameter at breast height) distributions, the age structure and disturbance history differed amongst the stands. The stands with wide d.b.h. distribution (i.e. large CV and skewness) were more uneven‐aged than those with narrow d.b.h. distribution (i.e. small CV and skewness). The disturbance‐return interval based on the model of Hett and Loucks was 31 to 65 years. The gap ratio in the canopy was also different among the stands. These suggest that the variations in stand structure represent different occurrences of natural disturbances. Furthermore, the structural features such as size structure, canopy gap ratio and density of canopy trees also affected the growth dynamics of understory trees (≥2 m in height and &lt;10 cm in diameter at breast height). The growth and mortality rates of understory trees changed with the canopy gap ratio and canopy tree density. The understory trees of stands with wide canopy d.b.h. distribution had higher growth and canopy recruitment rates than those of stands with narrow canopy d.b.h. distribution, contributing to the maintenance of continuous stand stratification. The understory trees of stands with narrow canopy d.b.h. distribution showed lower growth and higher mortality rates than those of stands with narrow canopy d.b.h. distribution, leading to the formation of a single‐canopy structure. It is suggested that natural disturbance governs the regeneration process in the future by affecting the growth and mortality patterns of understory trees through the stand structure (size and age structure, canopy tree density, canopy gap ratio).

Note on the Relation Between Ring Widths and Basal Area Increments

Abstract A primary aim of tree-ring analysis is to reconstruct the annual growth patterns of individual trees or groups of trees, and then derive growth models which allow for prediction of wood production. Tree growth is mostly measured as a series of annual ring widths. In practice, however, one is interested in annual basal area increments (BAIs). The calculation of BAIs is quite involved. One needs extra information in addition to ring widths: diameters measured at the thickest and thinnest sides of the tree and an estimate of bark width. In this note a summary of the relevant formulas is presented. For. Sci. 41(2):297-304.

Growth Response of Baldcypress [Taxodium distichum (L.) Rich.] to an Altered Hydrologic Regime

-Altering the hydrologic regime of a wetland forest may result in changes in tree growth, as hydrology is a primary factor influencing the growth of wetland trees. Road construction, a common cause of altered hydrologic regimes, modified the hydrology of a permanently flooded southeastern backwater swamp and resulted in significantly higher water levels upstream of the road. Following construction, upstream water levels averaged 85 cm, whereas downstream water levels were believed to be relatively unchanged at 22 cm. Study areas were selected upstream and downstream of the road. Increment cores were taken from canopy baldcypress trees Taxodium distichum (L.) Rich., to determine if the change in hydrologic regime was reflected in the annual growth rings. Before road construction, annual growth patterns were similar at the two sites. Following construction, annual growth patterns in trees below the road were unchanged; however, growth of trees in the upstream area was accelerated for several years followed by a long-term decline.

Interface Effects on Tree Growth of Cross-linked Polyethylene

It is well known that treeing is one of the main causes of breakdown of CV cables. It has been also considered that the interface exists between two solid insulation materials become a weak point on the electrical strength of CV cables. Therefore, it is important to reseach on the tree growing properties when there exists an interface. For evaluating the interface effect on the AC tree growth, an experimental investigation has been carried out by preparing an interface between two cross-linked polyethylene(XLPE) blocks. This paper describes the experimental results under various interface conditions. It was found that the interface had a great influence on the tree growth. The time to breakdown was reduced by the interface in the present test conditions. Painting the silicone oil on the interface, not only reduced the time to breakdown but also prevented the breakdown through the surface of spec imen(B). And the pressure applied on the interface had a slight effect on the time to breakdown but on the tree growth pattern. With the increasing of applied voltage, phenomena above mentioned were more significant It is proposed that the discharge column activities and the gas pressure reduction in the tree channels play important roles in the present situation.

Stand structure and growth patterns of understorey trees in a coniferous forest, Taisetsuzan National Park, northern Japan

AbstractStand structure was studied with special reference to growth and mortality patterns of sapling and understorey trees in a coniferous Picea jezoensis and Abies sachalinensis forest in Taisetsuzan National Park, Hokkaido, northern Japan. Picea jezoensis was dominant in the basal area, while A. sachalinensis was abundant in large numbers in the canopy. Estimated mortalities increased significantly with diameter at breast height (DBH) for both P. jezoensis and A. sachalinensis in the canopy, but the tendency was different between the two species. Picea jezoensis had a lower mortality rate than A. sachalinensis, especially at small DBH classes. The spatial distribution of understorey individuals of A. sachalinensis did not show any significant correlation with the spatial distribution of canopy gaps, but that of P. jezoensis showed a significant correlation. Abies sachalinensis can grow higher than P. jezoensis under suppressed conditions; while P. jezoensis requires canopy gaps for steady height growth. This growth pattern leads to a different waiting height in the understorey (≥2 m in height and 10 cm in diameter at breast height). Abies sachalinensis waited for an improvement in light conditions at higher strata (max. 7 m), while P. jezoensis waited at lower strata (max. 3 m). The estimated mortality of understorey A. sachalinensis increased with size, while that of understorey P. jezoensis decreased. Therefore, P. jezoensis gives priority to survival while A. sachalinensis gives priority to understorey growth. The difference in the ‘waiting pattern’ between the two species in the understorey was considered a significant feature for the canopy recruitment process of P. jezoensis and A. sachalinensis.

Study of structure and dynamics of Korean pine forest in the Xiaoxing’an Mountains

The thesis for the Doctorate consist of two parts. The first is to study on structure, dynamics and tree growth of natural Korean pine forest. The second is to research for tree architecture, growth and stand structure of artificial Korean pine (Pinus koraiensis) forests.The thesis compares the stand structure, process of regeneration, and various tree growth patterns between natural forests and artificial forests. Its purpose is to give a basis for forest management and silviculture. The study was carried out in Liangshui Experimental Forest Farm, which is located in the southern Xiaoxing’an Mountains.

Geostatistically modeling stem size and increment in an old-growth forest

Geostatistics provides tools to model, estimate, map, and eventually predict spatial patterns of tree size and growth. Variogram models and kriged maps were used to study spatial dependence of stem diameter (DBH), basal area (BA), and 10-year periodic basal area increment (BAI) in an old-growth forest stand. Temporal variation of spatial patterns was evaluated by fitting spatial stochastic models at 10-year intervals, from 1920 to 1990. The study area was a naturally seeded stand of southwestern ponderosa pine (Pinusponderosa Dougl. ex Laws. var. scopulorum) where total BA and tree density have steadily increased over the last decades. Our objective was to determine if increased stand density simply reduced individual growth rates or if it also altered spatial interactions among trees. Despite increased crowding, stem size maintained the same type of spatial dependence from 1920 to 1990. An isotropic Gaussian variogram was the model of choice to represent spatial dependence at all times. Stem size was spatially autocorrelated over distances no greater than 30 m, a measure of average patch diameter in this forest ecosystem. Because patch diameter remained constant through time, tree density increased by increasing the number of pine groups, not their horizontal dimension. Spatial dependence of stem size (DBH and BA) was always much greater and decreased less through time than that of stem increment (BAI). Spatial dependence of BAI was close to zero in the most recent decade, indicating that growth rates in 1980–1990 varied regardless of mutual tree position. Increased tree crowding corresponded not only to lower average and variance of individual growth rates, but also to reduced spatial dependence of BAI. Because growth variation was less affected by intertree distance with greater local crowding, prediction of individual growth rates benefits from information on horizontal stand structure only if tree density does not exceed threshold values. Simulation models and area estimates of tree performance in old-growth forests may be improved by including geostatistical components to summarize ecological spatial dependence.

Manual recording of minirhizotron data and its application to study the effect of herbicide and nitrogen fertiliser on tree and pasture root growth in a silvopastoral system

The use of a simple counting method using a borescope and minirhizotron system to study the interaction of roots of wild cherry trees (Prunus avium L) and pasture in an upland silvopastoral system is described. Operator variation was greatest when distinguishing different tree root categories (e.g. white, brown, woody) but was not significant in relation to total tree or grass root counts or species differences. Analysis of covariance was used to take these differences into account in a field trial using several operators. The seasonal patterns of tree and pasture root growth were different. Tree roots peaked in May before maximal shoot growth. The peak in pasture roots occurred two weeks earlier. Tree height growth was increased by the use of herbicides to control grass growth but this effect was only apparent during August when the soil was dry and when pasture root counts were reduced.

Response of tree growth to climatic variation in the mixed conifer and deciduous forests of the upper Great Lakes region

Tree-ring data were used to define regional tree-growth anomalies (i.e., recurring spatial patterns of growth that differ from long-term averages) for 11 species growing in a network of sites spanning the deciduous and mixed hardwood–conifer forest boundary in the upper Great Lakes region. Tree-ring samples were collected at 11 sites that are classified as mesic to dry–mesic based on species composition. At each stand at least 20 trees were sampled of each species dominant in the canopy, resulting in one to five species collections per stand and 31 chronologies in total. Principal component analysis was used to define the common variance among the chronologies. Three components explain 57.4% of the variation among the chronologies, indicating that common patterns of tree growth exist within the multispecies network. Component loadings indicate that (i) species to species variation is more important than site to site variation and (ii) species can be segregated into distinct groups based on their common patterns of growth through time. Correlations between the three-component-score time series and climatic data indicate that growth anomaly patterns are weakly, but significantly, correlated with growing-season temperature and precipitation variables. Extreme climatic events (i.e., greater than 1 SD above or below the mean) are very important in generating differential growth rates among the species sampled.

Using a simulation model to evaluate the effects of water and nutrients onthe growth and carbon partitioning of Pinus radiata

The model BIOMASS calculates the water and carbon balances of tree stands. Parameters for the model were estimated using data from an experiment in which a wide range of water and nutritional conditions were imposed on plots in a stand of Pinus radiata. The treatments caused considerable differences in the growth of trees. Net Primary Production (NPP) was estimated from total CO 2 uptake by the stand, minus the respiration rates of the component parts of the trees. CO 2 uptake was calculated from intercepted radiation and the photosynthetic properties of the foliage. Because of the close similarities between the processes involved in transpiration and CO 2 uptake, excellent correspondence ( r 2 = 0.92−0.94) between calculated and measured daily soil water balances over 4 years, gave confidence in the total CO 2 uptake calculations. There were differences in the relationships between NPP and above-ground production in the irrigated trees, where internal nutrient levels fell significantly, compared with trees in the other treatments. NPP was partitioned to foliage stems and roots using these relationships to estimate the partitioning coefficients. Above-ground production was 60–80% of NPP, stem growth was about 40% and root growth varied from 20 to 40% of NPP, with the higher value in the irrigated (low nutrient) treatment. The correspondence between observed and simulated growth patterns of trees — particularly those of stem and foliage — was excellent, indicating that BIOMASS can reproduce differences in growth caused by water and fertility.

The Biology of Forest Growth experiment: linking water and nitrogen availability to the growth of Pinus radiata

The Biology of Forest Growth (BFG) study in a 10- to 14-year-old Pinus radiata stand comprised detailed investigations of stand growth, water balance, soil and tree N cycling, canopy dynamics and stand growth modelling The BFG study: (a) developed a method for measuring soil mineral N dynamics in situ: (b) developed the water stress integral, an index of temporally integrated water stress: (c) identified annual average needle litter N concentration as a useful measure of N uptake by and N status of P. radiata stands; (d) demonstrated a marked positive interactive effect of water and N availability on the rate of canopy development, stand foliage carrying capacity, light-use efficiency and above-ground net primary productivity; (e) identified a water stress threshold at a soil water content of 40% of ‘plant-available water’ below which the level of tree water stress is controlled by oil water content and above which the degree of water stress is determined by N status and soil temperature; (f) demonstrated that the leaf area index (LAI) of P. radiata stands varies markedly both within and between years, and that variations in LAI can be monitored indirectly using light transmision techniques provided that account is taken of the surface area of other stand components (dead foliage, branches, boles); (g) quantified the water use of irrigated plantations and its dependence on LAI; (h) quantified the effects of water and N availability on N retranslocation in foliage, and demonstrated the importance of retained foliage for the provision of N for new growth; (i) elucidated mechanisms resulting in prolonged (greater than 8 year) growth responses to N fertilisation, including long-term increases in soil N mineralisation rates; (j) constructed and evaluated a biological model (BIOMASS) of forest stand growth. The BIOMASS model estimates total CO 2 uptake by a forest stand from intercepted radiation and photosynthetic properties of the foliage. Net Primary Production is obtained by subtracting respiration rates of the component parts of trees. BIOMASS simulated well the observed growth patterns of trees, especially stem and foliage components. Close similarities between the processes involved in transpiration and CO 2 uptake, and good correspondence between calculated and measured soil water balances over a 4 year period, increased confidence in the total CO 2 uptake predictions of the model. Research needed to improve tree growth models is briefly discussed. It is argued that long-term multidisciplinary research, such as the BFG study is necessary for advancing understanding of the links between site conditions and forest productivity.

Disturbance and forest dynamics along a transect from Andean rain forest to Patagonian shrubland

Abstract. At ca. 40° S in northern Patagonia, Andean rain forests are replaced eastwards by woodlands and shrublands and eventually by steppe. Along this gradient we examined stand dynamics by analyzing tree population age structures and tree growth patterns. We also examined spatial and temporal characteristics of disturbance regimes by dating disturbances and mapping stands of differing disturbance history. From west to east, the ecological importance of earthquake‐related disturbance decreases, whereas that of fire, logging, and livestock increases. Abrupt changes in rates of tree growth correspond with earthquakes in 1837, 1939 and 1960. In the mesic western forests earthquakes can result in massive new tree establishment on landslide‐affected sites and increased rates of treefall.Fire, however, is the more pervasive disturbance over most of the gradient and creates extensive even‐aged patches dominated by the regionally dominant trees, Nothofagus and Austrocedrus. Although some lightning‐ignited and aboriginal‐set fires occurred in these forests prior to European settlement, much of the present forest structure may be attributed to the massive burning associated with European settlement of this area near the turn of the present century. In contrast to the settlement‐related increase in fire frequency in the western forested district, at the woodland/steppe ecotone the demise of the native American population resulted in a decrease in fire frequency. Heavy browsing and grazing following fire can seriously impede post‐fire tree regeneration. These preliminary results document the important influences of varying disturbance regimes along a major environmental gradient in creating landscape‐scale vegetation patterns.

Diameter Growth of Taxodium distichum (L.) Rich. and Nyssa aquatica L. From 1979-1985 in Four Louisiana Swamp Stands

-Annual diameter growth of baldcypress and water tupelo trees in four swamp stands in S central Louisiana were measured from 1979 to 1985. Seasonal patterns of growth were also monitored during 1979 and 1980 using vernier tree bands. Most growth occurred from late April to early July for both species, with baldcypress exhibiting the greatest growth in all sites. Trees of both species on the site with the least hydrological alteration, had the lowest growth rate. Trees in the crayfish pond (water level managed by pumping) and the impounded area (permanently flooded) had much higher growth rates than the control area. Annual defoliation by the forest tent caterpillar probably accounted for the low water tupelo growth rates compared to baldcypress. It is becoming more difficult to relate annual growth differences to hydroperiod alone in S Louisiana because of changes in tree growth and successional patterns due to increased waterlogging as a result of eustatic sea level rise and subsidence combined with insect herbivory and human manipulation of the environment.

Disturbance and Stand Development of a Colorado Subalpine Forest

Stand development patterns were examined in an Engelmann spruce (Picea engelmannii [Parry] Engelm.), subalpine fir (Abies lasiocarpa [Hook.] Nutt), and lodgepole pine (Pinus contorta [Dougl.] var. latifolia Engelm.) forest in Rocky Mountain National Park in the northern Colorado Rocky Mountains. Two old-growth stands and one c. 260-year-old post-fire stand were sampled for tree sizes, ages, tree growth patterns, and replacement patterns in windthrow gaps. Growth patterns were analysed both by visual assessment of the frequency of growth releases on increment cores and by dendrochronological techniques. In the 260-year-old post-fire stand, initial colonization was by spruce and lodgepole pine but subalpine fir has become increasingly abundant over the past c. 100 years of stand development. Canopy dominance is gradually shifting from lodgepole pine towards spruce and fir. In the oldgrowth stands, tree growth pattems indicate that they too were initiated by a stand-devastating fire. However, they have entered a phase of development in which fine-scale windthrows dominate their dynamics. In the old-growth stands, fir is the more common gap occupant but its greater rate of treefall and the greater longevity of spruce imply that the two species will continue to codominate these stands. Substantially different species' responses to fire result in a relatively predictable pattern of post-fire stand development whereas canopy disturbance by wind does not differentially favour spruce or fir.

Managing Dense, Seed-Origin Loblolly Stands to Utilize the Favorable Juvenile Wood Core for Sawlog Production: A Case Study

Abstract Approximately two-thirds of the loblolly pine forests in the South are regenerated by natural or direct seeding. Many of these stands are overstocked, challenged by hardwood and herbaceous competition, or lacking in fertility. Due to minimal management inputs, the initial diameter growth rates for stems in these stands are slow in many instances. Consequently, the juvenile wood cores in the boles of these trees are small relative to those of faster grown plantation stems. Thinning of such a stand at age 21 and application of fertilizer at age 23 dramatically increased diameter growth at breast height for all crown classes. The proportion of earlywood to latewood and the specific gravity of annual rings were not affected by either treatment, and they were highly favorable for quality sawn lumber. Earlier treatment of the study stand to coincide with the transition phase from juvenile to mature wood formation at age 15 would likely have optimized the future production of quality sawlogs. Timing of these treatments could best be gauged by the ring growth pattern of codominant trees in the stand and the stabilization of the annual earlywood to latewood ratio. South. J. Appl. For. 15(1):5-9.

Disturbance regime of a cold temperate forest as deduced from tree-ring patterns: the Tantaré Ecological Reserve, Quebec

The recent history and disturbance regime of an old-growth sugar maple – yellow birch forest located in the Tantaré Ecological Reserve, Québec, were determined using tree-ring growth patterns of individual trees that had undergone suppression and release. Within a sampling quadrat (0.25 ha) where all living and dead trees were mapped, the age, size, and spatial pattern of gaps formed since the mid-19th century were inferred from tree-ring signatures of standing trees. From 1860 onwards, more than 30 gaps of various form and size occurred, most gaps being &lt; 200 m2 and covering a total area of 3775 m2. During the 1930–1985 period, the tree-fall frequency was 0.45 per year, the tree fall free interval was 3.2 years, and the tree-fall rotation period (turnover rate) was estimated to be 45 years. The rather short life-span of most trees (&lt;125 years) may be attributed to the cool and humid conditions prevailing at the site, which stimulated self-pruning of mature trees. The spatiotemporal development of the sugar maple forest has been active during the past 2 centuries through small-scale disturbances associated with successve, often overlapping, single and multiple tree falls. This situation explains the uneven age distribution of sugar maple and yellow birch populations subjected to differential survival conditions caused by gap dynamics. It is concluded that tree-ring patterns corresponding to periods of suppression and release will likely give a finer resolution record of gap dynamics than other methods of determining natural disturbance regime and reconstruction of recent stand history.