Potentials for win-win alliances among animal agriculture and forest products industries: Application of the principles of industrial ecology and sustainable development

Commercial forests in many parts of the world are deficient in nitrogen and phosphorus. These nutrient-deficient forests often exist in close proximity to large animal feeding operations, meat processing and other food, textile, or other biomass-processing plants, and municipal waste treatment facilities. Many of these facilities produce large surpluses of nitrogen,phosphorus, and organic matter as gaseous ammonia, urea, uric acid, phosphorus compounds,bacterial sludges, and partially treated municipal wastewaters. These co-existing and substantial nutrient deficiencies and surpluses offer ready-made opportunities for discovery, demonstration,and commercial development of science-based, technology-facilitated, environmentally sound,economically viable, and socially acceptable "win-win alliances" among these major industries based on the principles of industrial ecology and sustainable development. The major challenge is to discover practical means to capture the surplus nutrients and put them to work in forest stands from which value-added products can be produced and sold at a profit.     

Potentials for win-win alliances among animal agriculture and forest products industries: Application of the principles of industrial ecology and sustainable development

Commercial forests in many parts of the world are deficient in nitrogen and phosphorus. These nutrient-deficient forests often exist in close proximity to large animal feeding operations, meat processing and other food, textile, or other biomass-processing plants, and municipal waste treatment facilities. Many of these facilities produce large surpluses of nitrogen, phosphorus, and organic matter as gaseous ammonia, urea, uric acid, phosphorus compounds, bacterial sludges, and partially treated municipal wastewaters. These co-existing and substantial nutrient deficiencies and surpluses offer ready-made opportunities for discovery, demonstration, and commercial development of science-based, technology-facilitated, environmentally sound, economically viable, and socially acceptable “win-win alliances” among these major industries based on the principles of industrial ecology and sustainable development. The major challenge is to discover practical means to capture the surplus nutrients and put them to work in forest stands from which value-added products can be produced and sold at a profit.     

Aspects of the nitrogen cycle in peatland and plantation forest ecosystems in western Ireland

Extensive plantation forests cover large areas of blanket peatland in western Ireland. Sites are characterised by the ombrotrophic nature of the peat and the often extreme maritime conditions prevailing. The study area is located close to two coastlines and in consequence, ions of marine origin are dominant in the bulk precipitation. Mean annual nitrogen deposition is 2.26 kg ha^-1. Forestry development in the region dates from the early 1950s. Deficiency of phosphorus is universally encountered, sometimes accompanied by a shortage of nitrogen. A fertilizer experiment in the study area was maintained for 16 years. The principal response was to applied phosphorus and although nitrogen had a positive influence on growth in the early years, it was of little consequence in the longer term.Over 900 kg N ha^-1 was accumulated in the forest floor. In a mineralisation study of peat collected from plots fertilized 14 years previously, differences in total mineral nitrogen production between treatments were small, but in nitrogen-treated plots a higher proportion of the mineral nitrogen was as nitrate than in those which had not received fertilizer nitrogen. Throughfall measurements in pole-stage crops of Sitka spruce and lodgepole pine which had received no fertilizer nitrogen, showed significantly greater quantities of nitrogen than bulk precipitation.     

Nitrogen stable isotopic composition of leaves and soil: Tropical versus temperate forests

Several lines of evidence suggest that nitrogen in most tropical forests is relatively more available than N in most temperate forests, and even that it may function as an excess nutrient in many tropical forests. If this is correct, tropical forests should have more open N cycles than temperate forests, with both inputs and outputs of N large relative to N cycling within systems. Consequent differences in both the magnitude and the pathways of N loss imply that tropical forests should in general be more¹⁵N enriched than are most temperate forests. In order to test this hypothesis, we compared the nitrogen stable isotopic composition of tree leaves and soils from a variety of tropical and temperate forests. Foliar ¹⁵N values from tropical forests averaged 6.5 higher than from temperate forests. Within the tropics, ecosystems with relatively low N availability (montane forests, forests on sandy soils) were significantly more depleted in¹⁵N than other tropical forests. The average ¹⁵N values for tropical forest soils, either for surface or for depth samples, were almost 8 higher than temperate forest soils. These results provide another line of evidence that N is relatively abundant in many tropical forest ecosystems.     

Nutrient limitations to plant growth during primary succession in Hawaii Volcanoes National Park

We determined the effects of nutrient amendments on plant growth in three tropical montane rainforest sites representing a sequence of soil ages (< 30, 200, and 2000 y). Factorial fertilization with nitrogen, phosphorus, and all other essential nutrients (combined) was applied to the two younger sites; only nitrogen was applied to the oldest one. Nitrogen supply represented the most important limitation to plant growth in the two younger sites; additions of nitrogen caused significant increases in tree diameter increment, height growth, litterfall, and most other growth-related parameters. In contrast, nitrogen additions had no significant effect on plant growth in the oldest site. Phosphorus additions increased extractable soil phosphorus and plant tissue phosphorus, but did not increase plant growth at the young sites. The results are consistent with Walker & Syers' (1976) model for the control of nutrient limitation during soil development.     

Herbivory makes major contributions to ecosystem carbon and nutrient cycling in tropical forests

The functional role of herbivores in tropical rainforests remains poorly understood. We quantified the magnitude of, and underlying controls on, carbon, nitrogen and phosphorus cycled by invertebrate herbivory along a 2800 m elevational gradient in the tropical Andes spanning 12°C mean annual temperature. We find, firstly, that leaf area loss is greater at warmer sites with lower foliar phosphorus, and secondly, that the estimated herbivore‐mediated flux of foliar nitrogen and phosphorus from plants to soil via leaf area loss is similar to, or greater than, other major sources of these nutrients in tropical forests. Finally, we estimate that herbivores consume a significant portion of plant carbon, potentially causing major shifts in the pattern of plant and soil carbon cycling. We conclude that future shifts in herbivore abundance and activity as a result of environmental change could have major impacts on soil fertility and ecosystem carbon sequestration in tropical forests.     

Phosphorus Fertilization Increases the Abundance and Nitrogenase Activity of the Cyanolichen Pseudocyphellaria crocata in Hawaiian Montane Forests

Nitrogen-fixing epiphytes (especially lichens with a cyanobacterial symbiont—cyanolichens) have the potential to contribute significant amounts of nitrogen (N) to montane tropical forests, which are typically low in N—but the factors controlling the abundance and distribution of epiphytic cyanolichens are poorly understood. In long-term fertilization experiments in montane forests on a 4.l million-yr-old Oxisol on the island of Kauà'i and on a 152-yr-old lava flow on the island of Hawai'i, the epiphytic cyanolichen Pseudocyphellaria crocata increased significantly in abundance in canopies of host trees fertilized with phosphorus (P). There was no response to fertilization with N or other essential elements. Nitrogen-fixation rates were also elevated in lichens in P-fertilized plots at both sites. Phosphorus supply to host trees may be an important factor controlling N inputs to montane tropical forests by N-fixing epiphytes.     

Nutrient transport within and between habitats through seed dispersal processes by woolly monkeys in north‐western Amazonia

The contribution of vertebrate animals to nutrient cycling has proven to be important in various ecosystems. However, the role of large bodied primates in nutrient transport in neotropical forests is not well documented. Here, we assess the role of a population of woolly monkeys (Lagothrix lagothricha lugens) as vectors of nutrient movement through seed dispersal. We estimated total seed biomass transported by the population within and between two habitats (terra firme and flooded forests) at Tinigua Park, Colombia, and quantified potassium (K), phosphorus (P) and nitrogen (N) content in seeds of 20 plant species from both forests. Overall, the population transported an estimated minimum of 11.5 (±1.2 SD) g of potassium, 13.2 (±0.7) g of phosphorus and 34.3 (±0.1) g nitrogen, within 22.4 (±2.0) kg of seeds ha^?1 y^?1. Approximately 84% of all nutrients were deposited in the terra firme forest mostly through recycling processes, and also through translocation from the flooded forest. This type of translocation represents an important and high‐quality route of transport since abiotic mechanisms do not usually move nutrients upwards, and since chemical tests show that seeds from flooded forests have comparatively higher nutrient contents. The overall contribution to nutrient movement by the population of woolly monkeys is significant because of the large amount of biomass transported, and the high phosphorus content of seeds. As a result, the phosphorus input generated by these monkeys is of the same order of magnitude as other abiotic mechanisms of nutrient transport such as atmospheric deposition and some weathering processes. Our results suggest that via seed dispersal processes, woolly monkey populations can contribute to nutrient movement in tropical forests, and may act as important nutrient input vectors in terra firme forests. Am. J. Primatol. 72:992–1003, 2010. © 2010 Wiley‐Liss, Inc.     

Nutrient Addition Differentially Affects Soil Carbon Sequestration in Secondary Tropical Dry Forests: Early‐ versus Late‐Succession Stages

There is considerable interest in the potential use of soils to sequester carbon for climate change mitigation. As such, there is a need to evaluate the potential for carbon accumulation in tropical regions. We compared the effects of three annual additions of nitrogen and/or phosphorus on soil carbon and nitrogen contents and pools (bulk soil, macro‐, meso‐, and microaggregates) of two regenerating secondary tropical dry forest differing in nutrient status and succession stage (10‐year‐old early‐succession stage and approximately 60‐year‐old late‐succession stage). The selected forest sites were located on a shallow calcareous soil in the Yucatán Peninsula (Mexico). The primary production is limited by nitrogen and phosphorus in early‐succession stage and by phosphorus in late‐succession stage. In each forest site, four independent plots (12 × 12 m²) were established, the treatments being: controls and plots fertilized during three consecutive years with nitrogen, phosphorus, or nitrogen plus phosphorus. In both forests, soil carbon and nitrogen contents were consistently high, with soil carbon:nitrogen ratios generally greater than 10. Results indicate that usually there are no significant increases of soil carbon stock associated to late succession but can be increased to 3.7 Mg·ha^?1·yr^?1 with adoption of fertilizer practices. The potential soil carbon sequestration in early‐succession forest was estimated to be 2.7 Mg·ha^?1·yr^?1, and there is no indication that fertilization improves carbon sequestration. In short, results suggest that the soil potential for carbon sequestration in these ecosystems is high and depends on the specific nutrient status of the site.     

Phosphatase activity and nitrogen fixation reflect species differences,not nutrient trading or nutrient balance,across tropical rainforest trees

A fundamental biogeochemical paradox is that nitrogen‐rich tropical forests contain abundant nitrogen‐fixing trees, which support a globally significant tropical carbon sink. One explanation for this pattern holds that nitrogen‐fixing trees can overcome phosphorus limitation in tropical forests by synthesizing phosphatase enzymes to acquire soil organic phosphorus, but empirical evidence remains scarce. We evaluated whether nitrogen fixation and phosphatase activity are linked across 97 trees from seven species, and tested two hypotheses for explaining investment in nutrient strategies: trading nitrogen‐for‐phosphorus or balancing nutrient demand. Both strategies varied across species but were not explained by nitrogen‐for‐phosphorus trading or nutrient balance. This indicates that (1) studies of these nutrient strategies require broad sampling within and across species, (2) factors other than nutrient trading must be invoked to resolve the paradox of tropical nitrogen fixation, and (3) nitrogen‐fixing trees cannot provide a positive nitrogen‐phosphorus‐carbon feedback to alleviate nutrient limitation of the tropical carbon sink.     

Transferring soils from high- to low-elevation forests increases nitrogen cycling rates: climate change implications

It is well recognized that photosynthesis of C3 plants is highly responsive to CO₂ concentration. However, in natural ecosystems, plants are subject to a range of feed-back effects that can interact with increased photosynthetic carbon gain in different ways so that it is not clear to what extent increased photosynthesis will translate into increased growth. To assess the probable growth response of nutrient-limited forests to increasing CO₂ concentration, we use a previously developed modelling framework and apply it under conditions where the supply of nutrients is affected by a range of different factors. Our analysis indicates that forest growth is likely to be highly stimulated by increasing CO₂ concentration in forests with high fertility, in forests with nitrogen fixing plants, in those subject to fire or where nitrogen in wood is effectively removed from the biologically active cycle either through physical removal of stems in harvesting or through continued stem growth over long time periods. Forest growth is likely to be stimulated by CO₂ concentration in both phosphorus- and sulphur-limited forests provided nutrients in heartwood of trees are removed from the active nutrient cycle. Without this removal from the cycling system, however, sulphur-limited forests should show little response to increasing CO₂. In phosphorus-limited forests without phosphorus removal, the response to increasing CO₂ depends further on the equilibration state of the large pool of unavailable secondary phosphorus. Considered over periods of centuries during which the secondary pool has equilibrated, growth of phosphorus-limited forests is likely to be only weakly stimulated by increasing CO₂ concentration. However, over shorter periods, increasing CO₂ concentration should lead to a substantial increase in productivity. In general, it can be concluded that systems that are more open with respect to nutrient gains and losses are likely to be more responsive to increasing CO₂ concentration than systems where the amount of available nutrients is less variable. In more open systems, operation at a lower internal nutrient concentration as a result of increasing atmospheric CO₂ concentration can lead to reduced nutrient losses per unit carbon gain. Our analysis shows that the effect of increasing CO₂ on forest growth can differ substantially between forests due to interactions with a range of factors that affect nutrient supply. The response of a particular forest to increasing CO₂ concentration can only be predicted if the main factors controlling nutrient supply and growth in that forest are understood and incorporated into an assessment.     

城市生活废水用于产油微藻培养

将废水与产油微藻培养结合起来,可以实现废水的无害化处理,还可为微藻的培养提供营养组分和大量水源。利用高产油栅藻,以城市生活废水为水源,在气泡柱式光反应器中,考察了添加不同营养组分对栅藻细胞的生长、生物质产量、总脂含量以及氮磷的去除情况的影响。结果表明：生活废水非常适合于产油微藻的培养,利用生活废水进行微藻培养中,仅需补充添加无机氮、无机磷、柠檬酸铁铵以及微量元素。但这些营养组分的加入量对藻细胞的生长、生物量和油脂积累有重要影响。在优化的废水培养基中微藻细胞浓度可达8.0 g/L左右,远高于标准BG11培养基5.0 g/L的水平。微藻细胞对于无机氮与磷有着高的吸收能力,在废水中加入185.25 mg/L以下无机氮,16.1 mg/L以下无机磷的条件下培养3~4 d后,培养液水体中未检测到有氮磷残留。由此表明利用城市生活废水培养含油微藻可以在获得微藻油脂产品的同时实现水体的无害化处理。     

Dipterocarp Biology as a Window to the Understanding of Tropical Forest Structure: Where are we Looking Now?

The dipterocarps are dominant trees across a large part of lowland Southeast Asia. These forests provide a valuable timber resource, are rich in biodiversity, and are among the most important terrestrial carbon sinks in the world. Yet, these forests are fast disappearing, often unsustainably managed and are rapidly being replaced by agricultural crops such as oil palm and other commercial plantations. Here, we provide a brief overview to this family, outline its significance, and introduce the articles of this Special Section which provides a collection of the recent advances in our understanding of the biology of this important family of tropical trees.     

中亚热带森林转换对土壤磷积累的影响

磷是植物生长的必需元素之一,是维持亚热带森林生态系统生产力的关键因子。研究森林转换后土壤因素对磷素的影响,对生态系统的稳定和森林经营具有重要意义。选取由亚热带常绿阔叶林转换而成的米槠次生林(SF)、米槠人促林(AR)和杉木人工林(CF)为研究对象,测定了土壤理化性质、铁铝氧化物、各形态磷含量以及酸性磷酸酶活性,旨在探究土壤磷对森林转换的响应和驱动土壤磷变化的影响因子。结果显示:米槠人促林土壤的全磷、有机磷和微生物生物量磷显著高于米槠次生林和杉木人工林;冗余分析(RDA)发现,土壤含水量、总氮和无定型铁是影响淋溶层土壤磷的主要因子,而在淀积层,则是酸性磷酸酶、游离型铁和总氮起主要作用;土壤生物化学属性和微生物特性都会影响着不同形态土壤P的积累,其中土壤中的水分和酸性磷酸酶活性是调控土壤磷的关键因子。研究表明,中亚热带地区天然林转换为人促更新林更有利于森林土壤磷的储存和供应,有助于维持本区域森林生态系统的稳定。     

Physical and biogeochemical controls over terrestrial ecosystem responses to nitrogen deposition

Anthropogenic perturbations to the global nitrogen (N) cycle nowexceed those to any other major biogeochemical cycle on Earth, yet ourability to predict how ecosystems will respond to the rapidly changing Ncycle is still poor. While northern temperate forest ecosystems haveseen the greatest changes in N inputs from the atmosphere, other biomes,notably semi-arid and tropical regions of the globe, are nowexperiencing increases in N deposition. These systems are even less wellunderstood than temperate forests, and are likely to respond to excess Nin markedly different ways. Here, we present a new integratedterrestrial biophysics-biogeochemical process model, TerraFlux, and usethis model to test the relative importance of factors that may stronglyinfluence the productivity response of both humid tropical and semi-aridsystems to anthropogenic N deposition. These include hydrological lossesof dissolved inorganic and organic N, as well as multiple nutrientinteractions with deposited inorganic N along the hydrological pathway.Our results suggest that N-rich tropical forests may have reducedproductivity following excess N deposition. Our simulations of semi-aridsystems show increases in productivity following N inputs if wateravailability is sufficient and water losses are moderate. The mostimportant model controls over the carbon cycle response in eachsimulation were interactions that are not represented in the most commonterrestrial ecosystem models. These include parameters that control soilsolute transport and nutrient resorption by plants. Rather than attemptprognostic simulations, we use TerraFlux to highlight a variety ofecological and biogeochemical processes that are poorly understood butwhich appear central to understanding ecosystem response to excessN.     

Soil phosphorus heterogeneity promotes tree species diversity and phylogenetic clustering in a tropical seasonal rainforest

The niche theory predicts that environmental heterogeneity and species diversity are positively correlated in tropical forests, whereas the neutral theory suggests that stochastic processes are more important in determining species diversity. This study sought to investigate the effects of soil nutrient (nitrogen and phosphorus) heterogeneity on tree species diversity in the Xishuangbanna tropical seasonal rainforest in southwestern China. Thirty‐nine plots of 400 m² (20 × 20 m) were randomly located in the Xishuangbanna tropical seasonal rainforest. Within each plot, soil nutrient (nitrogen and phosphorus) availability and heterogeneity, tree species diversity, and community phylogenetic structure were measured. Soil phosphorus heterogeneity and tree species diversity in each plot were positively correlated, while phosphorus availability and tree species diversity were not. The trees in plots with low soil phosphorus heterogeneity were phylogenetically overdispersed, while the phylogenetic structure of trees within the plots became clustered as heterogeneity increased. Neither nitrogen availability nor its heterogeneity was correlated to tree species diversity or the phylogenetic structure of trees within the plots. The interspecific competition in the forest plots with low soil phosphorus heterogeneity could lead to an overdispersed community. However, as heterogeneity increase, more closely related species may be able to coexist together and lead to a clustered community. Our results indicate that soil phosphorus heterogeneity significantly affects tree diversity in the Xishuangbanna tropical seasonal rainforest, suggesting that deterministic processes are dominant in this tropical forest assembly.     

Understanding the Influences of Spatial Patterns on N Availability Within the Brazilian Amazon Forest

Nitrogen variations at different spatial scales and integrated across functional groups were addressed for lowland tropical forests in the Brazilian Amazon as follows: (1) how does N availability vary across the region over different spatial scales (regional × landscape scale); (2) how are these variations in N availability integrated across plant functional groups (legume × non-legume trees). Leaf N, P, and Ca concentrations as well the leaf N isotope ratios (δ¹⁵N) from a large set of legume and non-legume tree species were measured. Legumes had higher foliar N/Ca ratios than non-legumes, consistent with the high energetic costs in plant growth associated with higher foliar P/Ca ratios found in legumes than in non-legumes. At the regional level, foliar δ¹⁵N decreased with increasing rainfall. At the landscape level, N availability was higher in the forests on clayey soils on the plateau than in forests on sandier soils. The isotope as well as the non-isotope data relationships here documented, explain to a large extent the variation in δ¹⁵N signatures across gradients of rainfall and soil. Although at the regional level, the precipitation regime is a major determinant of differences in N availability, at the landscape level, under the same precipitation regime, soil type seems to be a major factor influencing the availability of N in the Brazilian Amazon forest.     

Mangroves as filters of shrimp pond effluent: predictions and biogeochemical research needs

Preliminary estimates of the ratio of mangrove forest: shrimp pond area necessary to remove nutrients from shrimp pond effluent are made using budgets of nitrogen and phosphorus output for semi-intensive and intensive shrimp ponds combined with estimates of total net primary production in Rhizophora-dominated mangrove forests in tropical coastal areas. If effluent is delivered directly to mangrove forest plots, it is estimated that, depending on shrimp pond management, between 2 and 22 hectares of forest are required to filter the nitrogen and phosphorus loads from effluent produced by a 1 hectare pond. While such ratios may apply to small scale, integrated shrimp aquaculture — mangrove forestry farming systems, the variability in mangrove hydrodynamics makes it difficult to apply such ratios at a regional scale. Before mangroves can be used to strip shrimp pond effluent more research is required on the effects that high ammonia and particulate organic matter loads in pond effluent have on nutrient transformations in mangrove sediments and on forest growth.     

Do Forests Receive Occult Inputs of Nitrogen?

The nitrogen (N) cycle of forest ecosystems is understood relatively well, and few scientists expect that major revisions will be necessary; most current work on N cycling focuses on improving the precision estimates of pools and fluxes, or measuring the magnitudes of well-known pools in response to management or disturbances. However, in the past few decades more than a dozen articles in refereed journals have claimed very high rates of N input, far beyond the rates expected for known sources of N. In this review, we summarize the literature on N accretion rates in forests that lack substantial contributions from symbiotic N-fixing plants. We critique each study for the strength of the experimental design behind the estimate of N accretion and consider whether unexpectedly large inputs of N really occur in forests. Only 6 of 24 estimates of N accretion had strong experimental designs, and only 2 of these 6 yielded estimates of >5 kgN ha^-1 y^-1. The high accretion estimates with a strong experimental design come from repeated sampling at the Walker Branch watersheds in Tennessee, where N accretion rates ranged from 50 to 80 kg N ha^-1 y^-1 over 15 years after harvesting. At the same location, an unharvested stand showed no significant change. We conclude that there is no widespread evidence of high rates of occult N input in forests. Too few studies have carefully tested for balanced N budgets in forests (inputs minus outputs plus change in storage), and we recommend that at least a few of these studies be undertaken on soils that permit high precision sampling. Received 14 December 1999; accepted 22 March 2000.     

Remarks on the effects of nitrogen deposition to forest ecosystems

The effects of increased deposition of nitrogen compounds on forest sites are discussed based on literature data and own results from both earlier fertilization experiments and the ARINUS study area in the Black Forest. The influence on mycorrhiza is stated suppressive as well as stimulating so that no general conclusion can be drawn. The nitrogen nutrition status of coniferous forests is still sub-optimal over wide areas with a yearly deposition of 10–20 kg N ha^-1. Under considerable higher input rates the insufficient supply of other nutrients and imbalances in the nutritional status of trees are possible. When discussing nitrogen saturation of ecosystems, the nitrogen storage capacity of soils has to be considered as a decisive factor which varies from site to site. Any actual input/output balance is strongly influenced by the internal turnover processes resulting from former land use.