Environments with reciprocal patchiness of resources, in which the availability of two resources such as light and soil nutrients are patchily distributed in horizontal space and negatively correlated in each patch, a...Environments with reciprocal patchiness of resources, in which the availability of two resources such as light and soil nutrients are patchily distributed in horizontal space and negatively correlated in each patch, are common in many ecosystems. The strategies by which clonal plants adapt to this type of heterogeneous environment were examined in three stoloniferous herbs,Potentilla reptans L. var. sericophylla Franch., P. anserina L. and Halerpestes ruthenica (Jacq.) Qvcz., commonly inhabiting forest understories, grasslands and low saline meadows, respectively. As pairs of connected ramets were subjected to reciprocal patchiness of light and nutrients, stolon connection between the two ramets significantly enhanced biomass of both ramet growing in low light intensity but high soil nutrient condition (LH ramet) and ramet growing in high light intensity but low soil nutrient condition (HL ramet) as well as whole ramet pairs (consisting of LH ramets and HL ramets). Additionally, stolon connection greatly increased root/shoot ratio of LH ramet while significantly decreased that of HL ramet. The results indicate that a reciprocal transportation of resources between interconnected ramets and a functional specialization of ramets in uptake of abundant resources occurred. By resource sharing and functional specialization, clonal plants can efficiently acquire locally abundant resources and buffer the stress caused by reciprocal patchiness of resources.展开更多
Sustainable forage production is one of the most important factors in livestock production system. Smallholder livestock production system is a part of agricultural practice in Indonesia. Limited land owned by farmers...Sustainable forage production is one of the most important factors in livestock production system. Smallholder livestock production system is a part of agricultural practice in Indonesia. Limited land owned by farmers was dominantly cultivated for food crops, and very small part of it used for cultivating forage plants. This leads to restriction of smallholder livestock development, because no more land available for forage production. Integrated forage production system by planting forage plants and food crops or trees in the same area becomes a considerable cropping system that widely practiced by the farmers in Indonesia. Some grasses and legumes have morphological advantages overcoming growth condition under shading. These growth characteristics are benefit in designing compatible system components for enhanced productivity in tree-pasture systems. Four potential shade-tolerant creeping forages that were combined with 2 levels of nitrogen application were tested using factorial completely randomized design 3 replicates. The first factor was species of creeping forages （stoloniferous）： BH = Brachiaria humidicola, PN = Paspalum notatum, AC - Axonopus compressus and, AP = Arachis pintoi. The second factor was nitrogen （urea） fertilizer： A = without N fertilizer and B = with N fertilizer （300 kg Urea/ha）. The observations included the growth rates of plant length, plant length, number of leaves, herbages yield （shoot）, root dry weight, senescence, total N-shoot, N-soil and N-uptake. The results showed that growth characteristics and productivity of creeping forage plants was significantly differed by the species. Most species showed an increase in growth trend, except P. notatum. A. compressus significantly showed as the best performance species compared to other, in terms of growth rates, plant length, number of leaves, herbage yield （shoot） and root dry weight, N-uptake and N-shoot. This was lbllowed by B. humidicola, P. notatum, and A. pintoi. Based on previous study, A. compressus found as one of the native species in most tree system. It indicated its superior growth compared to other species tested. However, it is needed further research to observe the compatibility of each species in tree-pasture systems.展开更多
Plant invasion is one of the most serious threats to ecosystems worldwide.When invasive plants with the ability of clonal growth invading or colonizing in new habitat,their interconnected ramets may suffer from hetero...Plant invasion is one of the most serious threats to ecosystems worldwide.When invasive plants with the ability of clonal growth invading or colonizing in new habitat,their interconnected ramets may suffer from heterogeneous light.Effects of clonal integration on allelopathy of invasive plants are poorly understood under heterogeneous light conditions.To investigate the effects of clonal integration on allelopathy of invasive plant Wedelia trilobata under heterogeneous light conditions,a pot experiment was conducted by using its clonal fragments with two successive ramets.The older ramets were exposed to full light,whereas the younger ones were subjected to 20%full light.The younger ramets of each clonal fragment were adjacently grown with a target plant(one tomato seedling)in a pot.Stolon between two successive ramets was either severed or retained intact.In addition,two tomato seedlings(one as target plant)were adjacently grown in a pot as contrast.Compared with severing stolon,biomass accumulation,foliar chlorophyll and nitrogen contents,chlorophyll fluorescence parameters and net photosynthetic rates of the target plants as well as their root length and activity,were significantly decreased when stolon between interconnected ramets of W.trilobata retained intact.Under heterogeneous light conditions,transportation or sharing of carbohydrate between two successive ramets enhanced allelopathy of the young ramets subjected to 20%full light treatment.It is suggested that clonal integration may be important for invasion or colonization of invasive plants with ability of clonal growth under heterogeneous light conditions.展开更多
Phenotypic plasticity enables plants to buffer against environmental stresses and match their phenotypes to local conditions.However,consistent conclusive evidence for adaptive plasticity has only been obtained for a ...Phenotypic plasticity enables plants to buffer against environmental stresses and match their phenotypes to local conditions.However,consistent conclusive evidence for adaptive plasticity has only been obtained for a few traits.More studies on a wider variety of plant functional traits and environmental factors are still needed to further understand the adaptive significance of plasticity.We grew 21 genotypes of the stoloniferous clonal plant Duchesnea indica under different light and nutrient conditions,and used selection gradient analyses to test the adaptive value(benefits)of morphological and physiological plasticity responding to variation in light and nutrient availability.Plants grown in shade exhibited lower values for fitness measures(fruit number,ramet number and biomass),shortened thinner internode length and decreased adult leaf chlorophyll content,but higher petiole length,specific leaf area and old leaf chlorophyll content,than plants grown without shade.Plants grown in the low nutrient condition had shorter petiole length,thicker and smaller leaf area,lower chlorophyll content,but higher fruit number and root:shoot ratio than plants grown under the high nutrient condition.Selection gradient analyses revealed that plasticity of petiole length and old leaf chlorophyll content in response to light variation was adaptive,and plasticity of old and adult leaf chlorophyll content in response to nutrient variation was adaptive.Therefore,the adaptive value of plasticity in different traits depends on the specific ecological context.Our findings contribute to understanding the adaptive significance of phenotypic plasticity of clonal plants in response to environmental variation.展开更多
文摘Environments with reciprocal patchiness of resources, in which the availability of two resources such as light and soil nutrients are patchily distributed in horizontal space and negatively correlated in each patch, are common in many ecosystems. The strategies by which clonal plants adapt to this type of heterogeneous environment were examined in three stoloniferous herbs,Potentilla reptans L. var. sericophylla Franch., P. anserina L. and Halerpestes ruthenica (Jacq.) Qvcz., commonly inhabiting forest understories, grasslands and low saline meadows, respectively. As pairs of connected ramets were subjected to reciprocal patchiness of light and nutrients, stolon connection between the two ramets significantly enhanced biomass of both ramet growing in low light intensity but high soil nutrient condition (LH ramet) and ramet growing in high light intensity but low soil nutrient condition (HL ramet) as well as whole ramet pairs (consisting of LH ramets and HL ramets). Additionally, stolon connection greatly increased root/shoot ratio of LH ramet while significantly decreased that of HL ramet. The results indicate that a reciprocal transportation of resources between interconnected ramets and a functional specialization of ramets in uptake of abundant resources occurred. By resource sharing and functional specialization, clonal plants can efficiently acquire locally abundant resources and buffer the stress caused by reciprocal patchiness of resources.
文摘Sustainable forage production is one of the most important factors in livestock production system. Smallholder livestock production system is a part of agricultural practice in Indonesia. Limited land owned by farmers was dominantly cultivated for food crops, and very small part of it used for cultivating forage plants. This leads to restriction of smallholder livestock development, because no more land available for forage production. Integrated forage production system by planting forage plants and food crops or trees in the same area becomes a considerable cropping system that widely practiced by the farmers in Indonesia. Some grasses and legumes have morphological advantages overcoming growth condition under shading. These growth characteristics are benefit in designing compatible system components for enhanced productivity in tree-pasture systems. Four potential shade-tolerant creeping forages that were combined with 2 levels of nitrogen application were tested using factorial completely randomized design 3 replicates. The first factor was species of creeping forages （stoloniferous）： BH = Brachiaria humidicola, PN = Paspalum notatum, AC - Axonopus compressus and, AP = Arachis pintoi. The second factor was nitrogen （urea） fertilizer： A = without N fertilizer and B = with N fertilizer （300 kg Urea/ha）. The observations included the growth rates of plant length, plant length, number of leaves, herbages yield （shoot）, root dry weight, senescence, total N-shoot, N-soil and N-uptake. The results showed that growth characteristics and productivity of creeping forage plants was significantly differed by the species. Most species showed an increase in growth trend, except P. notatum. A. compressus significantly showed as the best performance species compared to other, in terms of growth rates, plant length, number of leaves, herbage yield （shoot） and root dry weight, N-uptake and N-shoot. This was lbllowed by B. humidicola, P. notatum, and A. pintoi. Based on previous study, A. compressus found as one of the native species in most tree system. It indicated its superior growth compared to other species tested. However, it is needed further research to observe the compatibility of each species in tree-pasture systems.
基金supported by the Key Research and Development Program of Sichuan Province(19ZDYF).
文摘Plant invasion is one of the most serious threats to ecosystems worldwide.When invasive plants with the ability of clonal growth invading or colonizing in new habitat,their interconnected ramets may suffer from heterogeneous light.Effects of clonal integration on allelopathy of invasive plants are poorly understood under heterogeneous light conditions.To investigate the effects of clonal integration on allelopathy of invasive plant Wedelia trilobata under heterogeneous light conditions,a pot experiment was conducted by using its clonal fragments with two successive ramets.The older ramets were exposed to full light,whereas the younger ones were subjected to 20%full light.The younger ramets of each clonal fragment were adjacently grown with a target plant(one tomato seedling)in a pot.Stolon between two successive ramets was either severed or retained intact.In addition,two tomato seedlings(one as target plant)were adjacently grown in a pot as contrast.Compared with severing stolon,biomass accumulation,foliar chlorophyll and nitrogen contents,chlorophyll fluorescence parameters and net photosynthetic rates of the target plants as well as their root length and activity,were significantly decreased when stolon between interconnected ramets of W.trilobata retained intact.Under heterogeneous light conditions,transportation or sharing of carbohydrate between two successive ramets enhanced allelopathy of the young ramets subjected to 20%full light treatment.It is suggested that clonal integration may be important for invasion or colonization of invasive plants with ability of clonal growth under heterogeneous light conditions.
基金supported by the National Natural Science Foundation of China(31870610,32071527,31761123001)the Ten Thousand Talent Program of Zhejiang Province(2018R52016)the Joint Fund of Zhejiang Provincial Natural Science Foundation(LTZ20C030001).
文摘Phenotypic plasticity enables plants to buffer against environmental stresses and match their phenotypes to local conditions.However,consistent conclusive evidence for adaptive plasticity has only been obtained for a few traits.More studies on a wider variety of plant functional traits and environmental factors are still needed to further understand the adaptive significance of plasticity.We grew 21 genotypes of the stoloniferous clonal plant Duchesnea indica under different light and nutrient conditions,and used selection gradient analyses to test the adaptive value(benefits)of morphological and physiological plasticity responding to variation in light and nutrient availability.Plants grown in shade exhibited lower values for fitness measures(fruit number,ramet number and biomass),shortened thinner internode length and decreased adult leaf chlorophyll content,but higher petiole length,specific leaf area and old leaf chlorophyll content,than plants grown without shade.Plants grown in the low nutrient condition had shorter petiole length,thicker and smaller leaf area,lower chlorophyll content,but higher fruit number and root:shoot ratio than plants grown under the high nutrient condition.Selection gradient analyses revealed that plasticity of petiole length and old leaf chlorophyll content in response to light variation was adaptive,and plasticity of old and adult leaf chlorophyll content in response to nutrient variation was adaptive.Therefore,the adaptive value of plasticity in different traits depends on the specific ecological context.Our findings contribute to understanding the adaptive significance of phenotypic plasticity of clonal plants in response to environmental variation.
