Annual litterfall dynamics and nutrient deposition depending on elevation and land use at Mt. Kilimanjaro

Abstract. Litterfall is one of the major pathways connecting above- and below-ground processes. The effects of climate and land-use change on carbon (C) and nutrient inputs by litterfall are poorly known. We quantified and analyzed annual patterns of C and nutrient deposition via litterfall in natural forests and agroforestry systems along the unique elevation gradient of Mt. Kilimanjaro. Tree litter in three natural (lower montane, Ocotea and Podocarpus forests), two sustainably used (homegardens) and one intensively managed (shaded coffee plantation) ecosystems was collected on a biweekly basis from May 2012 to July 2013. Leaves, branches and remaining residues were separated and analyzed for C and nutrient contents. The annual pattern of litterfall was closely related to rainfall seasonality, exhibiting a large peak towards the end of the dry season (August–October). This peak decreased at higher elevations with decreasing rainfall seasonality. Macronutrients (N, P, K) in leaf litter increased at mid elevation (2100 m a.s.l.) and with land-use intensity. Carbon content and micronutrients (Al, Fe, Mn, Na) however, were unaffected or decreased with land-use intensity. While leaf litterfall decreased with elevation, total annual input was independent of climate. Compared to natural forests, the nutrient cycles in agroforestry ecosystems were accelerated by fertilization and the associated changes in dominant tree species.

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Annual litterfall dynamics and nutrient deposition depending on elevation and land use at Mt. Kilimanjaro

Biogeosciences Discussions ◽

10.5194/bgd-12-10031-2015 ◽

2015 ◽

Vol 12 (13) ◽

pp. 10031-10057 ◽

Cited By ~ 4

Author(s):

J. Becker ◽

H. Pabst ◽

J. Mnyonga ◽

Y. Kuzyakov

Keyword(s):

Land Use ◽

Elevation Gradient ◽

Agroforestry Systems ◽

Climatic Conditions ◽

Land Use Intensity ◽

Natural Forests ◽

Nutrient Inputs ◽

Nutrient Deposition ◽

Rainfall Seasonality ◽

Intensively Managed

Abstract. Litterfall is one of the major pathways connecting above- and belowground processes. The effects of climate and land-use change on carbon (C) and nutrient inputs by litterfall are poorly known. We quantified and analyzed annual patterns of C and nutrient deposition via litterfall in natural forests and agroforestry systems along the unique elevation gradient of Mt. Kilimanjaro. Tree litter in three natural (lower montane, Ocotea and Podocarpus forests), two sustainably used (homegardens) and one intensively managed (shaded coffee plantation) was collected on a biweekly basis from May 2012 to July 2013. Leaves, branches and remaining residues were separated and analyzed for C and nutrient contents. The annual pattern of litterfall was closely related to rainfall seasonality, exhibiting a large peak towards the end of the dry season (August–October). This peak decreased at higher elevations with decreasing rainfall seasonality. Macronutrients (N, P, K) in leaf litter increased at mid elevation (2100 m a.s.l.) and with land-use intensity. Carbon content and micronutrients (Al, Fe, Mn, Na) however, were unaffected or decreased with land-use intensity. On the southern slope of Mt. Kilimanjaro, the annual pattern of litterfall depends on seasonal climatic conditions. While leaf litterfall decreased with elevation, total annual input was independent of climate. Compared to natural forests, the nutrient cycles in agroforestry ecosystems were accelerated by fertilization and the associated changes in dominant tree species.

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Species richness of lichen functional groups in relation to land use intensity

The Lichenologist ◽

10.1017/s0024282906006207 ◽

2006 ◽

Vol 38 (4) ◽

pp. 331-353 ◽

Cited By ~ 58

Author(s):

Silvia STOFER ◽

Ariel BERGAMINI ◽

Gregorio ARAGÓN ◽

Palmira CARVALHO ◽

Brian J. COPPINS ◽

...

Keyword(s):

Land Use ◽

Species Richness ◽

Functional Groups ◽

Agricultural Landscape ◽

Land Use Intensity ◽

Natural Forests ◽

Lichen Diversity ◽

Relative Species Richness ◽

Intensively Managed ◽

Managed Landscapes

Changing land use has a major impact on lichen diversity. This study attempts to identify patterns or trends of lichen functional groups along a land use gradient, ranging from natural forests to open agricultural landscape. In eight countries, covering six main European biogeographic regions, lichen vegetation was assessed according to a standardized scheme. Data on reproductive, vegetative and ecological traits was compiled and relative species richness for all classes of all traits calculated. Relationships between the land use gradient and relative species richness of trait classes were analysed. Open and intensively managed landscapes harbour more fertile species while sterile species are relatively more important in forests. This finding is also supported by analyses of different classes of dispersal propagules. The importance of species with the principal photobiont Trebouxia s.l. increases linearly with intensification of land use. A converse pattern is revealed by species with Trentepohlia. Concerning substratum specialization only generalists show an effect along the land use intensity gradient. Their relative species richness decreases from landscapes dominated by forests to open agricultural landscape. A considerable decline in the rare lichen species richness as a result of land intensification is predicted.

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Effects of Land-Use Intensity in Tropical Agroforestry Systems on Coffee Flower-Visiting and Trap-Nesting Bees and Wasps

Conservation Biology ◽

10.1046/j.1523-1739.2002.00499.x ◽

2002 ◽

Vol 16 (4) ◽

pp. 1003-1014 ◽

Cited By ~ 183

Author(s):

Alexandra-Maria Klein ◽

Ingolf Steffan-Dewenter ◽

Damayanti Buchori ◽

Teja Tscharntke

Keyword(s):

Land Use ◽

Agroforestry Systems ◽

Land Use Intensity ◽

Flower Visiting ◽

Effects Of Land Use

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Aboveground Deadwood Biomass and Composition Along Elevation and Land-Use Gradients at Mount Kilimanjaro

Frontiers in Ecology and Evolution ◽

10.3389/fevo.2021.732092 ◽

2022 ◽

Vol 9 ◽

Author(s):

Armin Komposch ◽

Andreas Ensslin ◽

Markus Fischer ◽

Andreas Hemp

Keyword(s):

Land Use ◽

Aboveground Biomass ◽

Environmental Gradients ◽

Woody Debris ◽

Elevation Gradient ◽

Selective Logging ◽

Natural Forests ◽

Temperature And Precipitation ◽

Mount Kilimanjaro ◽

C Cycle

Deadwood is an important structural and functional component of forest ecosystems and biodiversity. As deadwood can make up large portions of the total aboveground biomass, it plays an important role in the terrestrial carbon (C) cycle. Nevertheless, in tropical ecosystems and especially in Africa, quantitative studies on this topic remain scarce. We conducted an aboveground deadwood inventory along two environmental gradients—elevation and land use— at Mt. Kilimanjaro, Tanzania. We used a huge elevation gradient (3690 m) along the southern slope of the mountain to investigate how deadwood is accumulated across different climate and vegetation zones. We also compared habitats that differed from natural forsts in land-use intensity and disturbance history to assess anthropogenic influence on deadwood accumulation. In our inventory we distinguished coarse woody debris (CWD) from fine woody debris (FWD). Furthermore, we calculated the C and nitrogen (N) content of deadwood and how the C/N ratio varied with decomposition stages and elevation. Total amounts of aboveground deadwood ranged from 0.07 ± 0.04 to 73.78 ± 36.26 Mg ha–1 (Mean ± 1 SE). Across the elevation gradient, total deadwood accumulation was highest at mid-elevations and reached a near-zero minimum at very low and very high altitudes. This unimodal pattern was mainly driven by the corresponding amount of live aboveground biomass and the combined effects of decomposer communities and climate. Land-use conversion from natural forests into traditional homegardens and commercial plantations, in addition to frequent burning, significantly reduced deadwood biomass, but not past selective logging after 30 years of recovery time. Furthermore, we found that deadwood C content increased with altitude. Our study shows that environmental gradients, especially temperature and precipitation, as well as different anthropogenic disturbances can have considerable effects on both the quantity and composition of deadwood in tropical forests.

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River water quality changes in New Zealand over 26 years: response to land use intensity

Hydrology and Earth System Sciences ◽

10.5194/hess-21-1149-2017 ◽

2017 ◽

Vol 21 (2) ◽

pp. 1149-1171 ◽

Cited By ~ 26

Author(s):

Jason P. Julian ◽

Kirsten M. de Beurs ◽

Braden Owsley ◽

Robert J. Davies-Colley ◽

Anne-Gaelle E. Ausseil

Keyword(s):

Water Quality ◽

Land Use ◽

New Zealand ◽

River Water ◽

River Water Quality ◽

Land Use Intensity ◽

Land Disturbance ◽

Areal Coverage ◽

Legacy Nutrients ◽

Intensively Managed

Abstract. Relationships between land use and water quality are complex with interdependencies, feedbacks, and legacy effects. Most river water quality studies have assessed catchment land use as areal coverage, but here, we hypothesize and test whether land use intensity – the inputs (fertilizer, livestock) and activities (vegetation removal) of land use – is a better predictor of environmental impact. We use New Zealand (NZ) as a case study because it has had one of the highest rates of agricultural land intensification globally over recent decades. We interpreted water quality state and trends for the 26 years from 1989 to 2014 in the National Rivers Water Quality Network (NRWQN) – consisting of 77 sites on 35 mostly large river systems. To characterize land use intensity, we analyzed spatial and temporal changes in livestock density and land disturbance (i.e., bare soil resulting from vegetation loss by either grazing or forest harvesting) at the catchment scale, as well as fertilizer inputs at the national scale. Using simple multivariate statistical analyses across the 77 catchments, we found that median visual water clarity was best predicted inversely by areal coverage of intensively managed pastures. The primary predictor for all four nutrient variables (TN, NOx, TP, DRP), however, was cattle density, with plantation forest coverage as the secondary predictor variable. While land disturbance was not itself a strong predictor of water quality, it did help explain outliers of land use–water quality relationships. From 1990 to 2014, visual clarity significantly improved in 35 out of 77 (34∕77) catchments, which we attribute mainly to increased dairy cattle exclusion from rivers (despite dairy expansion) and the considerable decrease in sheep numbers across the NZ landscape, from 58 million sheep in 1990 to 31 million in 2012. Nutrient concentrations increased in many of NZ's rivers with dissolved oxidized nitrogen significantly increasing in 27∕77 catchments, which we largely attribute to increased cattle density and legacy nutrients that have built up on intensively managed grasslands and plantation forests since the 1950s and are slowly leaking to the rivers. Despite recent improvements in water quality for some NZ rivers, these legacy nutrients and continued agricultural intensification are expected to pose broad-scale environmental problems for decades to come.

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Agroforestry Systems of the Tehuacán-Cuicatlán Valley: Land Use for Biocultural Diversity Conservation

Land ◽

10.3390/land8020024 ◽

2019 ◽

Vol 8 (2) ◽

pp. 24

Author(s):

Mariana Vallejo ◽

M. Isabel Ramírez ◽

Alejandro Reyes-González ◽

Jairo López-Sánchez ◽

Alejandro Casas

Keyword(s):

Land Use ◽

Agricultural Land ◽

Agroforestry Systems ◽

World Heritage Site ◽

Biocultural Diversity ◽

Semiarid Region ◽

Agricultural Land Use ◽

Visual Interpretation ◽

Natural Ecosystems ◽

Human Settlements

The Tehuacán-Cuicatlán Valley, Mexico, is the semiarid region with the richest biodiversity of North America and was recently recognized as a UNESCO's World Heritage site. Original agricultural practices remain to this day in agroforestry systems (AFS), which are expressions of high biocultural diversity. However, local people and researchers perceive a progressive decline both in natural ecosystems and AFS. To assess changes in location and extent of agricultural land use, we carried out a visual interpretation of very-high resolution imagery and field work, through which we identified AFS and conventional agricultural systems (CAS) from 1995 to 2003 and 2012. We analyzed five communities, representative of three main ecological and agricultural zones of the region. We assessed agricultural land use changes in relation to conspicuous landscape features (relief, rivers, roads, and human settlements). We found that natural ecosystems cover more than 85% of the territory in each community, and AFS represent 51% of all agricultural land. Establishment and permanence of agricultural lands were strongly influenced by gentle slopes and the existence of roads. Contrary to what we expected, we recorded agricultural areas being abandoned, thus favoring the regeneration of natural ecosystems, as well as a 9% increase of AFS over CAS. Agriculture is concentrated near human settlements. Most of the studied territories are meant to preserve natural ecosystems, and traditional AFS practices are being recovered for biocultural conservation.

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Enriching plant diversity in grasslands by large-scale experimental sward disturbance and seed addition along gradients of land-use intensity

Journal of Plant Ecology ◽

10.1093/jpe/rtw062 ◽

2016 ◽

pp. rtw062 ◽

Cited By ~ 3

Author(s):

Valentin H. Klaus ◽

Deborah Schäfer ◽

Till Kleinebecker ◽

Markus Fischer ◽

Daniel Prati ◽

...

Keyword(s):

Land Use ◽

Plant Diversity ◽

Large Scale ◽

Land Use Intensity ◽

Seed Addition

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Variation in regrowth ability in relation to land-use intensity in three common grassland herbs

Journal of Plant Ecology ◽

10.1093/jpe/rtab001 ◽

2021 ◽

Author(s):

Anna Kirschbaum ◽

Oliver Bossdorf ◽

J F Scheepens

Keyword(s):

Land Use ◽

Phenotypic Plasticity ◽

Temporal Variation ◽

Temporal Stability ◽

Common Garden ◽

Grassland Management ◽

Land Use Intensity ◽

Evolutionary Changes ◽

Biomass Removal ◽

Reproductive Biomass

Abstract Aims Plant populations in managed grasslands are subject to strong selection exerted by grazing, mowing and fertilization. Many previous studies showed that this can cause evolutionary changes in mean trait values, but little is known about the evolution of phenotypic plasticity in response to land use. In this study, we aimed to elucidate the relationships between phenotypic plasticity – specifically, regrowth ability after biomass removal – and the intensity of grassland management and levels of temporal variation therein. Methods We conducted an outdoor common garden experiment to test if plants from more intensively mown and grazed sites showed an increased ability to regrow after biomass removal. We used three common plant species from temperate European grasslands, with seed material from 58 – 68 populations along gradients of land-use intensity, ranging from extensive (only light grazing) to very intensive management (up to four cuts per year). Important findings In two out of three species, we found significant population differentiation in regrowth ability after clipping. While variation in regrowth ability was unrelated to the mean land-use intensity of populations of origin, we found a relationship with its temporal variation in P. lanceolata, where plants experiencing less variable environmental conditions over the last 11 years showed stronger regrowth in reproductive biomass after clipping. Therefore, while mean grazing and mowing intensity may not select for regrowth ability, the temporal stability of the environmental heterogeneity created by land use may have caused its evolution in some species.

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