Managed Pine Forests Research Articles

Cost–Benefit Analysis of Monitoring Insect Pests and Aerial Spraying of Insecticides: The Case of Protecting Pine Forests against Dendrolimus pini in Brandenburg (Germany)

Monitoring of insect pests and aerial spraying of insecticides have proven to be effective in protecting forests against needle-feeding insect pests. However, the literature on the economic viability of insect monitoring and aerial spraying of insecticides is scant. This research conducts a cost–benefit analysis of monitoring insect pests and use of insecticides for 5600 ha of managed pine forests. The case studied is the mass outbreak of the pine tree lappet moth (Dendrolimus pini L.) in Brandenburg (Germany) in 2014. Costs were estimated based on information from standardized questionnaires and semi-structured expert interviews. Benefits were analyzed by comparing the loss of revenue due to D. pini with the costs of insect monitoring and insecticide spraying in two scenarios of pine production (with protection vs. without protection). The results show that monitoring D. pini and aerial spraying of insecticides are economically beneficial to forest owners. The total net present value (NPV) of protection was about EUR 1965 ha−1 at a discount rate of 0% and the benefit–cost ratio (BCR) was about 22.14. NPVs and BCRs per hectare were highest for protecting stands with high site index and stands in the age class of 20–39 years. Sensitivity analyses revealed that NPV results are more sensitive to changes in timber prices than to changes in protection costs. The authors conclude that monitoring insect pests and aerial spraying of insecticides are economically viable options to protect forests against needle-feeding insect pests.

The Composite Physiological Response of Hydraulic and Photosynthetic Traits and Nonstructural Carbon in Masson Pine Seedlings to Drought Associated with High Temperature

Masson pine (Pinus massoniana Lamb.) is a dominant coniferous species in southern China, known for its rapid growth, abundant yield, and extensive utilization. Despite the robust adaptability of Masson pine and the rich annual precipitation in its distribution areas, this species still faces the mortality risk caused by the recurrent high temperatures in summer and low precipitation in subtropical regions. The mortality risk of Masson pine may increase in the future when facing a more frequent or intensive drought threat due to climate change. In this study, we conducted a manipulated drought experiment accompanying high temperature (~32.3 ± 0.7 °C in daytime and 28 °C in nighttime) to simulate a flash drought, aiming to explore the composite physiological response (hydraulic, gas exchange, and nonstructural carbon (NSC) characteristics) of Masson pine seedlings to extreme drought characterized by a high intensity and long duration. We found that, as the drought developed, the leaf water potential and gas exchange traits (net photosynthesis rate, stomatal conductance, and transpiration) significantly decreased while the percentage loss of hydraulic conductivity (PLC) significantly increased. In contrast, NSC remained a more constant trend before it was significantly reduced on day 30 after the beginning of the drought. Except for NSC, all the other traits had significant correlations between them. Additionally, hydraulic dysfunction indicated by the increasing PLC preceded the NSC depletion, which may indicate a more significant role for hydraulic failure than carbon starvation in drought-induced mortality. Conclusively, hydraulic and gas exchange traits showed a coupling response to drought, but NSC displayed an independent dynamic. The findings may improve our understanding of drought-coping strategies of Masson pine and provide some theoretical basis for Masson pine forest management.

Base-age invariant models for predicting individual tree accumulated annual resin yield using two tapping methods in maritime pine (Pinus pinaster Ait.) forests in north-western Spain

In southern Europe, especially in Spain and Portugal, maritime pine resin is one of the main non-timber forest products. After suffering a crisis at the end of the 20th century, it is currently a growing sector. In Spain, depending on the area, the management of pine forests is one of the pillars of the national bioeconomy. In addition to timber production, these forests may be oriented towards resin production only, or resin production as a complementary activity to timber production. In both cases, as in any sector, it is essential to have tools to manage and anticipate production, especially in the new context of the bioeconomy. For this reason, the aim of this study is to develop a dynamic model to estimate the accumulated resin yield during the resin production season. For this study, 180 trees from three plots located in the northwest of the Iberian Peninsula were resin tapped using two extraction methods (non-mechanized and mechanized circular notching) and stimulant pastes. Four base models were used from which eight equations were derived using ADA and GADA techniques. The most efficient equations, both for modelling with the train data and for prediction with the test data, were those derived from the Bertalanffy-Richards model. The RRMSE was 23% for the non-mechanised method and 29% for the mechanised circular method. The results of this study make it possible to add the cumulative annual resin yield of maritime pine to the processes that the Bertalanffy-Richards equation is capable of modelling. Furthermore, the great versatility of these models will be of great use to the forest manager in optimising the annual harvesting season as well as for the scientific community.

Soil Burn Severities Evaluation Using Micromorphology and Morphometry Traits After a Prescribed Burn in a Managed Forest

Prescribed burn is a tool that must imply low soil burn severity (SBS) levels; however, a wide range of soil impacts have been demonstrated because of the influence of very variable factors. The effects on biological, physical, and chemical soil properties are well reported in numerous studies; nonetheless, there are still questions about the effect of prescribed burns on soils at the micro-scale. As a result, an analysis of the link between micromorphological features and SBS does not currently exist. Thus, the main aim of the present study is to perform a micro-scale evaluation for complementing the SBS visual examination after prescribed burning in a managed pine forest in western Mexico. Morphometry and micromorphology analyses of mineral soil revealed that at low SBS levels, only the soil structure in the first centimeter is affected by prescribed burns. While at high SBS, the prescribed burn affected the first 2 cm, showing soil structure disturbance, ash filling porous, and soil aggregates getting reddish. Therefore, immediate actions have to be made by land managers after applying prescribed burns before the first rain to prevent post-fire surface soil erosion, particularly in bare soil patches where the burned aggregates are more susceptible to rain splash and runoff.

Survey Study Reveals High Prevalence of Heterobasidion Root Rot Infection in Scots Pine (Pinus sylvestris) Stands Established on Seemingly Low-Risk Sites

Heterobasidion spp. are among the most destructive root rot pathogens, causing severe economic losses to conifer forestry. High infection frequency has been observed in Scots pine stands growing on dry sandy soils with low organic matter or former agricultural soils. In this study, we investigated the incidence of Heterobasidion spp. infection in Scots pine forests established on low-risk sites where the trees looked healthy and unlikely to be infected. In total, 135 healthy-looking pine trees from nine different stands were examined for Heterobasidion spp. presence. Heterobasidion spp. was detected in six stands and infection frequency was 13%–33%. There was a significant correlation between site index and infection frequency, which was higher in pine stands established on more fertile soils. There was no correlation between disease incidence and defoliation level, diameter of tree at breast height, root diameter, tree volume, or stand age. Overall, our results showed that, regardless of the soil type, Scots pine can be intensively infected by Heterobasidion pathogens while showing no outward signs. Therefore, the risk of Heterobasidion disease should be taken into consideration in management of pine forests growing on both low- and high-risk sites for more productive and sustainable forests.

Characteristics of Dieback of Pinus densiflora and Risk Assessment in the Wangpicheon Ecosystem and Landscape Conservation Area in Uljin, South Korea

The correlation between climate change and pine tree dieback must be understood to implement a proactive forest management system. In this study, an ensemble model combining random forest, the generalized boosting model, and the generalized linear model was used to analyze the topographical and environmental characteristics of pine trees suffering from dieback in the Wangpicheon Ecosystem and Landscape Conservation Area, and the areas in which pine trees are at risk of dieback were evaluated to promote efficient pine forest management. The results showed that pine trees suffering from dieback in the conservation area were mainly located on ridges, were age class 6 or older, or were in areas with a low topographic wetness index south of the conservation area. An evaluation of the risk of dieback among pine trees was performed based on the results of two ensemble models. An area of 365 ha accounting for 6.8% of the total area was identified as requiring “caution” with respect to the risk of dieback of coniferous forests and mixed forests. The developed methodology is expected to provide valuable information for the implementation of an appropriate management system for the protection of pine and mixed forests from the negative effects of climate change.

Silviculture in the function of sustainable development

Silviculture in the function of sustainable development

Effects of management intensity, soil properties and region on the nematode communities in temperate forests in Germany

A key to forest productivity is structure and function of the biotic microbiome in the soil, which determines nutrient mineralisation and consequently tree growth and fitness. Soil nematodes are a dominant part of these assemblages, with an important role in the associated micro-food web. However, nothing is known about how forest management and soil properties affect soil nematodes. This study investigated the nematode communities in the organic layer and mineral soil of 150 forests located in three different German regions. Fifty forest stands each were studied in Schwäbische Alb (ALB), Hainch-Dün (HAI) and Schorfheide-Chorin (SCH). The effect of forest management (forest management index – ForMI, silvicultural management intensity indicator – SMI), soil properties (total C, N, S, P, organic C, inorganic C, pH, water content) and microbial food source (phospholipid fatty acids - PLFA) on nematode density, community and ecological indices were assessed.The nematode density in the organic layer of the forests was with a mean of 290 individuals g−1 DW comparable across all three regions, while in the mineral soil nematode density was significant lower in SCH. Here, dry sandy soils are frequently stocked with intensively managed pine forests, and the associated fungal-based decomposition is reflected in a greater proportion of fungal-feeding nematodes and a higher Channel Index. Effects of region and soil layer were mirrored by the structure of the nematode community. Organic layer and mineral soil differed distinctly, while in the latter SCH separated from ALB and HAI. The nematode community was predominantly affected by region, soil properties and resources, with microbial diet as driving factor in the organic layer, whereas soil parameters were more important in mineral soil. In comparison, the influence of forest management was low, with ForMI and SIM together explaining 8% (organic layer) and 4% (mineral soil) of the overall variation. Most remarkable, the nematode community in HAI, a region dominated by broad-leaf forests, was resilient to management intensity in the organic layer. On the other hand, management practice had family-specific impact: In the organic layer of ALB, the density of the bacterial-feeding Teratocephalidae and the fungal-feeding Aphelenchoididae increased with higher Inonat (indicates non-natural tree species) and higher SMIr (addresses stand age and species selection related to the risk of stand loss). In sum, the structure and function of nematode communities were driven by both, biotic factors such food source (i.e. the soil layer inhabited) and abiotic factors such as soil type and climate (i.e. region). Furthermore, forest management can affect nematode communities, mainly by the selected tree species, but also by stand age and density.

Economic analysis of uneven-aged forest management in the southeastern United States

We determine the economic revenues and optimal forest management of uneven-aged loblolly pine, longleaf pine, and slash pine forests considering timber and carbon benefits in the southeastern United States. Our results show that uneven-aged management of southern pines generates positive total revenues, with the exception of those stands managed with high residual basal areas and long cutting cycles. The uneven-aged management of pine forests is economically more attractive with loblolly pine stands than with longleaf pine or slash pine for all cutting cycles and residual basal areas; on average, loblolly pine returns $1389.60·ha−1 more than slash pine and $1500.70·ha−1 more than longleaf pine for all cutting cycles. For uneven-aged loblolly pine forests, our results suggest that landowners should experience highest profits with the shortest viable cutting cycle (10 years) and a medium-high residual basal area (11.5 m2·ha−1). For uneven-aged longleaf pine forests, landowners would be economically better off with a longer cutting cycle (20 years) and a lower residual basal area (6.9 m2·ha−1). Notably, uneven-aged management of longleaf pine and slash pine for timber production becomes unprofitable with low-medium or high residual basal areas (9.2–11.5 m2·ha−1).

Effects of retained dead wood on predation pressure on herbivores in young pine forests.

Retention of logging residue as dead wood could be a method to simultaneously increase biodiversity and predation rates of pest insects, in managed forests. Managed forests are generally low in diversity, and dead wood has been demonstrated to increase species diversity. Moreover, managed forests are predicted to suffer from higher frequency of insect outbreaks in the future, particularly in the northern hemisphere. In this study, we explore the effect of dead wood removal and addition in managed pine forest stands in Sweden on arthropod diversity and abundance and predation rates. We performed a controlled field experiment, focusing on logging residue type of dead wood. We used pitfall traps and sticky traps to measure arthropod diversity and abundance and plasticine larvae to assess predation rates. We specifically targeted generalist arthropods (i.e. non-wood living species), and predation rate on tree-dwelling larvae (corresponding to defoliating outbreak pests). We found no effect of dead wood addition on arthropod abundance or diversity, neither did we find an effect on predation rate. Despite the lack of effects in our study, we argue that dead wood can be an important component for both biodiversity of generalist arthropod and for pest control, but the effect may depend on both the specific arthropod group targeted and the specific life stage of the pest insect as well as on inherent components of the dead wood, such as age.

Effects of Pine Forest Management Practices on Bat Functional Traits in a Subtropical Region

Changes in landscape environmental characteristics may influence habitat use by bat species as well as species composition and community functional structure. Landscape features may drive the functional role variability of bat species on the ecosystems. Consequently, landscapes may change the degree of functional differentiation between species. We have evaluated the effect of pine forest monoculture and their environmental characteristics on the distribution and functional attributes of bat species. We sampled bat communities in areas with high (three sites) and low (three sites) forest land use management practices including six mist-netting locations in order to sample for bats at each site. In addition, we have also measured temperature, humidity, percentage of land use coverage (managed forest, agriculture, and native forest), and percentage of canopy openness at each site. We captured 87 bats belonging to eight species representing two families: Phyllostomidae and Vespertilionidae. For the functional analysis, we used three functional attributes to describe wing morphology: wing loading, aspect ratio, and forearm length. No significant effect of any environmental variable was observed on bat species composition. However, bat species distribution was driven by the ability associated with their functional attributes to occupy the space. Moreover, forearm length was positively correlated with forest cover, canopy openness, and humidity. Species with similar wing morphology have responded in a similar way to environmental variables in the studied areas. Functional dispersion was high in the native forest. The monoculture of exotic species may increase the functional attributes related with vulnerability as described by bat wing morphology. Therefore, the native forest conversion to pine forest monoculture may increase the loss of functional attributes in the bat community.

Pine Forest Management and Disturbance in Northern Poland: Combining High-Resolution 100-Year-Old Paleoecological and Remote Sensing Data

Global warming has compelled to strengthen the resilience of European forests. Due to repeated droughts and heatwaves, weakened trees become vulnerable to insect outbreaks, pathogen invasions, and strong winds. This study combines high-resolution analysis of a 100-year-old high-resolution peat archive synthesized from the Martwe peatland in Poland with remote sensing data. We present the first REVEALS based vegetation reconstruction in a tornado-hit area from Poland on the background of previous forest management in monocultural even-aged stands – Tuchola Pinewoods. During the 20th century, the pine monocultures surrounding the peatland were affected by clear-cutting and insect outbreaks. In 2012, a tornado, destroyed ca. 550 ha of pine forest around the peatland. The palynological record reflects these major events of the past 100 years as well as changes in forest practices. Our study showed the strong relationships between the decrease of Pinus sylvestris (Scots pine) in palynological record as well as planting patterns after the tornado. Moreover, past forestry practices [such as domination of Pinus sylvestris, the collapse of Picea abies (Norway spruce), low share of Betula spec. (birch) due to Pinus sylvestris promotion and probable also to a lesser by removal of Betula as a “forest weed,” and low plant coverage of tree species due to clear-cutting and cutting after insect outbreaks] were well identified in the proxy record. In monocultures managed over decades, the reconstruction of vegetation may be challenging due to changes in the age composition of the Pinus sylvestris stands. We found that through historical, remote sensing, and paleoecological data, the dynamics of disturbances such as insect outbreaks and tornadoes, as well as the changing perceptions of local society about forests, can be determined.

Increased growth rates of stream salamanders following forest harvesting.

Timber harvesting can influence headwater streams by altering stream productivity, with cascading effects on the food web and predators within, including stream salamanders. Although studies have examined shifts in salamander occupancy or abundance following timber harvest, few examine sublethal effects such as changes in growth and demography. To examine the effect of upland harvesting on growth of the stream‐associated Ouachita dusky salamander (Desmognathus brimleyorum), we used capture–mark–recapture over three years at three headwater streams embedded in intensely managed pine forests in west‐central Arkansas. The pine stands surrounding two of the streams were harvested, with retention of a 14‐ and 21‐m‐wide forested stream buffer on each side of the stream, whereas the third stream was an unharvested control. At the two treatment sites, measurements of newly metamorphosed salamanders were on average 4.0 and 5.7 mm larger post‐harvest compared with pre‐harvest. We next assessed the influence of timber harvest on growth of post‐metamorphic salamanders with a hierarchical von Bertalanffy growth model that included an effect of harvest on growth rate. Using measurements from 839 individual D. brimleyorum recaptured between 1 and 6 times (total captures, n = 1229), we found growth rates to be 40% higher post‐harvest. Our study is among the first to examine responses of individual stream salamanders to timber harvesting, and we discuss mechanisms that may be responsible for observed shifts in growth. Our results suggest timber harvest that includes retention of a riparian buffer (i.e., streamside management zone) may have short‐term positive effects on juvenile stream salamander growth, potentially offsetting negative sublethal effects associated with harvest.

Management of pine forests by assessment of insect pests and nematodes

Management of pine forests by assessment of insect pests and nematodes

The impact of pine forest management on the surrounding community in Malang Forest Management Unit

Pine forest used by the community surrounding forest to improve the community’s economy through Community Forest Management Program established by Perum Perhutani with division of arable land and plantation of species vegetation. This study aims to: (1) determine the diversity of plants in pine forest; (2) to analyze socioeconomic of the land user farmers, and (3) to recognize the optimization of land use and the diversity of cultivated vegetables. The research was conducted at the Junggo Forest Resort Production, Forest Management Unit Malang, East Java, Indonesia. The survey method was carried out through a plant inventory with total of 23 plots. Farmers were interviewed from 30 respondents through a structured questionnaire and the data were analyzed descriptively qualitatively. There were five species of stands found at tree canopy level namely Eucalyptus alba, Albizia sp, Toona sureni, Persea americana, and Pinus merkussi species with the highest. Various vegetables that combined in 2-3 species, implementing an agroforestry system. The average of land user’s income is IDR 4,500,000 - IDR 6,000,000 per 4 months of the harvest season. The implementation of Community Forest Management Program under pine stands would provide benefits for improving welfare of communities around the forest.

Influence of insect abundance and vegetation structure on site-occupancy of bats in managed pine forests

Site-occupancy of bats in forested landscapes has been linked to vegetation clutter, but clutter alone may not sufficiently explain observed site-occupancy. Abundance of prey likely has a strong influence on habitat use in forest landscapes as well. Therefore, we simultaneously examined influence of insect abundance and vegetation characteristics on bat site-occupancy across 3 pine (Pinus spp.)-dominated landscapes within the southeastern U.S. Coastal Plain. We conducted acoustic surveys and used Akaike’s Information Criterion to evaluate plausibility of occupancy and detection models that incorporated vegetation- and insect-related factors. Results indicate that bat site-occupancy was better explained by a combination of vegetation characteristics and insect abundance than either separately, and vegetation structure has a stronger influence than prey abundance. Additionally, our data generally suggest insect taxon is more influential in predicting occupancy than insect size. Management activities on pine-dominated landscapes that simultaneously reduce vegetation clutter and increase insect abundance are likely to benefit resident bat species.

Response of Nutrients and Sediment to Hydrologic Variables in Switchgrass Intercropped Pine Forest Ecosystems on Poorly Drained Soil

In the present study, we examined the relationships between (1) N, P, total organic carbon (TOC), and total suspended sediment (TSS) each and stream flow and water table elevation, individually (2) N, P, and TOC, each and TSS, and (3) stream water C/N ratios and stream flow in managed pine forests with various switchgrass treatments implemented on four watersheds in coastal North Carolina plain. The treatments included a young pine forest–natural understorey (27.5 ha), a young pine forest with switchgrass intercropped between pine rows replacing natural understorey (IC) (26.3 ha), a mature thinned pine forest (25.9 ha), and pure switchgrass (27.1 ha). Precipitation, flow, water table elevation, N, phosphate, TOC, and TSS concentrations were measured from November 2009 to June 2014 (switchgrass growth from May 2012 after site preparation (SP) that ended in April 2012). Relationships (α = 0.05) among water quality and hydrologic variables were examined using a Spearman rank correlation coefficient and the principal component analysis (PCA). Nitrogen concentrations on IC were positively correlated with flow during SP. The export of nutrients and sediment from this drained pine plantation forest intercropped with switchgrass was affected by changes in hydrological and biochemical processes regulating the formation and transport of different water quality constituents during both site preparation and pine and switch growth periods. The PCA showed strong interaction between the hydrological and biochemical processes.

Bat community response to intensification of biomass production for bioenergy across the southeastern United States.

Human demand for food, fiber, and space is accelerating the rate of change of land cover and land use. Much of the world now consists of a matrix of natural forests, managed forests, agricultural cropland, and urbanized plots. Expansion of domestic energy production efforts in the United States is one driver predicted to influence future land-use and land management practices across large spatial scales. Favorable growing conditions make the southeastern United States an ideal location for producing a large portion of the country's renewable bioenergy. We investigated patterns of bat occurrence in two bioenergy feedstocks commonly grown in this region (corn, Zea mays, and pine, Pinus taeda and P. elliottii). We also evaluated potential impacts of the three major pathways of woody biomass extraction (residue removal following clearcut harvest, short-rotation energy plantations, and mid-rotation forest thinning) to bat occurrence through a priori land-use contrasts. We acoustically sampled bat vocalizations at 84 sites in the Southeastern Plains and Southern Coastal Plains of the southeastern United States across three years. We found that mid-rotation thinning resulted in positive effects on bat occurrence, and potential conversion of unmanaged (reference) forest to managed forest for timber and/or bioenergy harvest resulted in negative effects on bat occurrence when effects were averaged across all species. The effects of short-rotation energy plantations, removal of logging residues from plantation clearcuts, and corn were equivocal for all bat species examined. Our results suggest that accelerated production of biomass for energy production through either corn or intensively managed pine forests is not likely to have an adverse effect on bat communities, so long as existing older unmanaged forests are not converted to managed bioenergy or timber plantations. Beyond bioenergy crop production, mid-rotation thinning of even-aged pine stands intended for timber production, increases to the duration of plantation rotations to promote older forest stands, arranging forest stands and crop fields to maximize edge habitat, and maintaining unmanaged forests could benefit bat communities by augmenting roosting and foraging opportunities.

Effect of scots pine forest management on soil properties and carabid beetle occurrence under post-fire environmental conditions - a case study from Central Europe

BackgroundFires have a fundamental impact on phytocoenoses and, depending on the size of the fire, can have a positive or negative effect. The role of fires in the formation of the species composition of plants, restoration of stands and changes in soil properties is well studied. However, the long-term relationship between forest management methods, soil properties and epigeic entomofauna assemblages in post-fire areas is still not clear. The effects of Scots pine stand management methods on biochemical soil properties and ground beetle assemblages in the largest post-fire area in Central Europe after the second World were investigated. The study was conducted in the Rudy Raciborskie Forest district in southern Poland. The soil properties and epigeic beetle community structure were analysed. The research covered areas with natural and artificial pine regeneration, which were subjected to various care treatments.ResultsThe tendency for higher accumulations of organic matter in the soil of stands that underwent natural regeneration was proven. The stimulating role of soil organic carbon on the activity of dehydrogenases in the soil of naturally renewed areas with silvicultural treatment (NRAT) was noted. Regardless of the manner of stand regeneration, the activity of β-glucosidase was higher in the areas in which breeding treatments were practised. Furthermore, managed forest stands presented a higher abundance of carabid beetles than stands without treatment practices. Thirteen epigeic beetle species from the families Geotrupidae, Carabidae, Curculionidae, Cerambycidae and Silphidae were captured, with beetles from the first two families being the most numerous. Rare epigeal carabid species in the fauna of Poland and Europe, such as Carabus glabratus (Paykull) and Carabus auronitens Fabr., found appropriate habitat conditions for survival in the post-fire areas. Compared with the other areas, in the NRAT area, there were better stand and soil properties and more features conducive to epigeic entomofaunal occurrences. The highest post-fire content of polycyclic aromatic hydrocarbons was recorded in the soils of the sites that underwent artificial regeneration. The results suggest that preparing the soil before the introduction of new vegetation affects the amount of aromatic hydrocarbons (PAHs).ConclusionsThe better performance of the NRAT stand draws attention to the positive aspects of the use of natural regeneration, both from ecological and economic perspectives. The effects of forest management on the amount of soil organic matter after fires have been proven. The natural regeneration of stands was conducive to the accumulation of organic matter. The enzymatic activity of soils is influenced by the renewal method and forest management strategy. The NRAT area was characterized by the highest number of carabid species.

Spring Moisture Availability is the Major Limitation for Pine Forest Productivity in Southwest China

Forests in low-latitude (0° N–30° N) regions are important for greenhouse gas sequestration. They harbor around 25% of vegetation carbon stocks. The productivity of these forests is expected to change as the global climate changes. They may absorb less greenhouse gasses, with negative effects on the global climate. However, little is known about how exactly these forests will respond to climate change. Here, we focus on the largest pine forests in low-latitude forests areas in southwest China. These forests have experienced rapid climate warming over the past 60 years. We collected tree-ring cores from two naturally occurring key afforestation pine tree species: Pinus yunnanensis Franch. and Pinus armandii Franch. in Baoshan and Lijiang of Yunnan. We used basal area increment (BAI) to examine the productivity trends of these two species over long-time scales, and Partial Least Squares regression analysis together with Pearson correlation analysis to identify the critical climate periods for the growth of these two species. We found that: (1) regional pine tree productivity began to decline at the beginning of this century. (2) The radial growth of both species had the strongest positive correlation with the spring Palmer Drought Severity Index (PDSI) and precipitation and the strongest negative correlation with spring temperatures. (3) Climate responses differ by species with higher positive correlations between tree-ring width, PDSI, and precipitation in P. armandii than in P. yunnanensis at similar locations. (4) Climate responses differ by location with higher positive correlations between tree-ring width and PDSI in Lijiang than in Baoshan for P. yunnanensis. Our results suggest that spring moisture availability is the main limiting factor for pine tree growth, especially for P. yunnanensis in Lijiang and P. armandii in Baoshan. Future regional warming and warm-induced drought conditions may have negative effects on the growth of pine trees. These results provide reference data for the sustainable management of pine forests in low-latitude regions of southwest China and may be useful in assessing the sustainable carbon sink ability of pine forests in this region under climate change.